<?xml version='1.0' encoding='utf-8'?>
<rfc xmlns:xi="http://www.w3.org/2001/XInclude" version="3" category="exp" docName="draft-ietf-pce-pcep-extension-native-ip-40" number="9757" consensus="true" ipr="trust200902" sortRefs="true" submissionType="IETF" symRefs="true" tocInclude="true" obsoletes="" updates="" xml:lang="en" tocDepth="3" prepTime="2025-03-14T16:06:49" indexInclude="true" scripts="Common,Latin">
  <link href="https://datatracker.ietf.org/doc/draft-ietf-pce-pcep-extension-native-ip-40" rel="prev"/>
  <link href="https://dx.doi.org/10.17487/rfc9757" rel="alternate"/>
  <link href="urn:issn:2070-1721" rel="alternate"/>
  <front>
    <title abbrev="PCEP for Native IP">Path Computation Element Communication Protocol (PCEP) Extensions for Native IP Networks</title>
    <seriesInfo name="RFC" value="9757" stream="IETF"/>
    <author fullname="Aijun Wang" initials="A" surname="Wang">
      <organization showOnFrontPage="true">China Telecom</organization>
      <address>
        <postal>
          <street>Beiqijia Town, Changping District</street>
          <city>Beijing</city>
          <code>102209</code>
          <country>China</country>
        </postal>
        <email>wangaijun@tsinghua.org.cn</email>
      </address>
    </author>
    <author fullname="Boris Khasanov" initials="B" surname="Khasanov">
      <organization abbrev="" showOnFrontPage="true">MTS Web Services (MWS)</organization>
      <address>
        <postal>
          <street>Andropova av., 18/9</street>
          <city>Moscow</city>
          <code>115432</code>
          <country>Russian Federation</country>
        </postal>
        <email>bhassanov@yahoo.com</email>
      </address>
    </author>
    <author fullname="Sheng Fang" initials="S" surname="Fang">
      <organization abbrev="" showOnFrontPage="true">Huawei Technologies</organization>
      <address>
        <postal>
          <street>Huawei Bld., No.156 Beiqing Rd.</street>
          <city>Beijing</city>
          <country>China</country>
        </postal>
        <email>fsheng@huawei.com</email>
      </address>
    </author>
    <author fullname="Chun Zhu" initials="C" surname="Zhu">
      <organization showOnFrontPage="true">ZTE Corporation</organization>
      <address>
        <postal>
          <street>50 Software Avenue, Yuhua District</street>
          <city>Nanjing</city>
          <region>Jiangsu</region>
          <code>210012</code>
          <country>China</country>
        </postal>
        <email>zhu.chun1@zte.com.cn</email>
      </address>
    </author>
    <date month="03" year="2025"/>
    <area>RTG</area>
    <workgroup>pce</workgroup>
    <keyword>CCDR</keyword>
    <keyword>PCECC</keyword>
    <abstract pn="section-abstract">
      <t indent="0" pn="section-abstract-1">This document introduces extensions to the Path Computation Element Communication Protocol
      (PCEP) to support path computation in Native IP networks through a
      PCE-based central control mechanism known as Centralized Control Dynamic
      Routing (CCDR). These extensions empower a PCE to calculate and manage
      paths specifically for Native IP networks, thereby expanding PCEP's
      capabilities beyond its past use in MPLS and GMPLS networks. By
      implementing these extensions, IP network resources can be utilized more
      efficiently, facilitating the deployment of traffic engineering in
      Native IP environments.</t>
    </abstract>
    <boilerplate>
      <section anchor="status-of-memo" numbered="false" removeInRFC="false" toc="exclude" pn="section-boilerplate.1">
        <name slugifiedName="name-status-of-this-memo">Status of This Memo</name>
        <t indent="0" pn="section-boilerplate.1-1">
            This document is not an Internet Standards Track specification; it is
            published for examination, experimental implementation, and
            evaluation.
        </t>
        <t indent="0" pn="section-boilerplate.1-2">
            This document defines an Experimental Protocol for the Internet
            community.  This document is a product of the Internet Engineering
            Task Force (IETF).  It represents the consensus of the IETF community.
            It has received public review and has been approved for publication
            by the Internet Engineering Steering Group (IESG).  Not all documents
            approved by the IESG are candidates for any level of Internet
            Standard; see Section 2 of RFC 7841. 
        </t>
        <t indent="0" pn="section-boilerplate.1-3">
            Information about the current status of this document, any
            errata, and how to provide feedback on it may be obtained at
            <eref target="https://www.rfc-editor.org/info/rfc9757" brackets="none"/>.
        </t>
      </section>
      <section anchor="copyright" numbered="false" removeInRFC="false" toc="exclude" pn="section-boilerplate.2">
        <name slugifiedName="name-copyright-notice">Copyright Notice</name>
        <t indent="0" pn="section-boilerplate.2-1">
            Copyright (c) 2025 IETF Trust and the persons identified as the
            document authors. All rights reserved.
        </t>
        <t indent="0" pn="section-boilerplate.2-2">
            This document is subject to BCP 78 and the IETF Trust's Legal
            Provisions Relating to IETF Documents
            (<eref target="https://trustee.ietf.org/license-info" brackets="none"/>) in effect on the date of
            publication of this document. Please review these documents
            carefully, as they describe your rights and restrictions with
            respect to this document. Code Components extracted from this
            document must include Revised BSD License text as described in
            Section 4.e of the Trust Legal Provisions and are provided without
            warranty as described in the Revised BSD License.
        </t>
      </section>
    </boilerplate>
    <toc>
      <section anchor="toc" numbered="false" removeInRFC="false" toc="exclude" pn="section-toc.1">
        <name slugifiedName="name-table-of-contents">Table of Contents</name>
        <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1">
          <li pn="section-toc.1-1.1">
            <t indent="0" keepWithNext="true" pn="section-toc.1-1.1.1"><xref derivedContent="1" format="counter" sectionFormat="of" target="section-1"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-introduction">Introduction</xref></t>
          </li>
          <li pn="section-toc.1-1.2">
            <t indent="0" pn="section-toc.1-1.2.1"><xref derivedContent="2" format="counter" sectionFormat="of" target="section-2"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-conventions-used-in-this-do">Conventions Used in This Document</xref></t>
            <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.2.2">
              <li pn="section-toc.1-1.2.2.1">
                <t indent="0" keepWithNext="true" pn="section-toc.1-1.2.2.1.1"><xref derivedContent="2.1" format="counter" sectionFormat="of" target="section-2.1"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-use-of-rbnf">Use of RBNF</xref></t>
              </li>
              <li pn="section-toc.1-1.2.2.2">
                <t indent="0" keepWithNext="true" pn="section-toc.1-1.2.2.2.1"><xref derivedContent="2.2" format="counter" sectionFormat="of" target="section-2.2"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-experimental-status-conside">Experimental Status Consideration</xref></t>
              </li>
            </ul>
          </li>
          <li pn="section-toc.1-1.3">
            <t indent="0" pn="section-toc.1-1.3.1"><xref derivedContent="3" format="counter" sectionFormat="of" target="section-3"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-terminology">Terminology</xref></t>
          </li>
          <li pn="section-toc.1-1.4">
            <t indent="0" pn="section-toc.1-1.4.1"><xref derivedContent="4" format="counter" sectionFormat="of" target="section-4"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-capability-advertisement">Capability Advertisement</xref></t>
            <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.4.2">
              <li pn="section-toc.1-1.4.2.1">
                <t indent="0" pn="section-toc.1-1.4.2.1.1"><xref derivedContent="4.1" format="counter" sectionFormat="of" target="section-4.1"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-open-message">Open Message</xref></t>
              </li>
            </ul>
          </li>
          <li pn="section-toc.1-1.5">
            <t indent="0" pn="section-toc.1-1.5.1"><xref derivedContent="5" format="counter" sectionFormat="of" target="section-5"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-pcep-messages">PCEP Messages</xref></t>
            <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.5.2">
              <li pn="section-toc.1-1.5.2.1">
                <t indent="0" pn="section-toc.1-1.5.2.1.1"><xref derivedContent="5.1" format="counter" sectionFormat="of" target="section-5.1"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-the-pcinitiate-message">The PCInitiate Message</xref></t>
              </li>
              <li pn="section-toc.1-1.5.2.2">
                <t indent="0" pn="section-toc.1-1.5.2.2.1"><xref derivedContent="5.2" format="counter" sectionFormat="of" target="section-5.2"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-the-pcrpt-message">The PCRpt Message</xref></t>
              </li>
            </ul>
          </li>
          <li pn="section-toc.1-1.6">
            <t indent="0" pn="section-toc.1-1.6.1"><xref derivedContent="6" format="counter" sectionFormat="of" target="section-6"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-pcecc-native-ip-te-procedur">PCECC Native IP TE Procedures</xref></t>
            <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.6.2">
              <li pn="section-toc.1-1.6.2.1">
                <t indent="0" pn="section-toc.1-1.6.2.1.1"><xref derivedContent="6.1" format="counter" sectionFormat="of" target="section-6.1"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-bgp-session-establishment-p">BGP Session Establishment Procedures</xref></t>
              </li>
              <li pn="section-toc.1-1.6.2.2">
                <t indent="0" pn="section-toc.1-1.6.2.2.1"><xref derivedContent="6.2" format="counter" sectionFormat="of" target="section-6.2"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-explicit-route-establishmen">Explicit Route Establishment Procedures</xref></t>
              </li>
              <li pn="section-toc.1-1.6.2.3">
                <t indent="0" pn="section-toc.1-1.6.2.3.1"><xref derivedContent="6.3" format="counter" sectionFormat="of" target="section-6.3"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-bgp-prefix-advertisement-pr">BGP Prefix Advertisement Procedures</xref></t>
              </li>
              <li pn="section-toc.1-1.6.2.4">
                <t indent="0" pn="section-toc.1-1.6.2.4.1"><xref derivedContent="6.4" format="counter" sectionFormat="of" target="section-6.4"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-selection-of-the-raw-mode-a">Selection of the Raw Mode and Tunnel Mode Forwarding Strategy</xref></t>
              </li>
              <li pn="section-toc.1-1.6.2.5">
                <t indent="0" pn="section-toc.1-1.6.2.5.1"><xref derivedContent="6.5" format="counter" sectionFormat="of" target="section-6.5"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-cleanup">Cleanup</xref></t>
              </li>
              <li pn="section-toc.1-1.6.2.6">
                <t indent="0" pn="section-toc.1-1.6.2.6.1"><xref derivedContent="6.6" format="counter" sectionFormat="of" target="section-6.6"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-other-procedures">Other Procedures</xref></t>
              </li>
            </ul>
          </li>
          <li pn="section-toc.1-1.7">
            <t indent="0" pn="section-toc.1-1.7.1"><xref derivedContent="7" format="counter" sectionFormat="of" target="section-7"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-new-pcep-objects">New PCEP Objects</xref></t>
            <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.7.2">
              <li pn="section-toc.1-1.7.2.1">
                <t indent="0" pn="section-toc.1-1.7.2.1.1"><xref derivedContent="7.1" format="counter" sectionFormat="of" target="section-7.1"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-cci-object">CCI Object</xref></t>
              </li>
              <li pn="section-toc.1-1.7.2.2">
                <t indent="0" pn="section-toc.1-1.7.2.2.1"><xref derivedContent="7.2" format="counter" sectionFormat="of" target="section-7.2"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-bgp-peer-info-object">BGP Peer Info Object</xref></t>
              </li>
              <li pn="section-toc.1-1.7.2.3">
                <t indent="0" pn="section-toc.1-1.7.2.3.1"><xref derivedContent="7.3" format="counter" sectionFormat="of" target="section-7.3"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-explicit-peer-route-object">Explicit Peer Route Object</xref></t>
              </li>
              <li pn="section-toc.1-1.7.2.4">
                <t indent="0" pn="section-toc.1-1.7.2.4.1"><xref derivedContent="7.4" format="counter" sectionFormat="of" target="section-7.4"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-peer-prefix-advertisement-o">Peer Prefix Advertisement Object</xref></t>
              </li>
            </ul>
          </li>
          <li pn="section-toc.1-1.8">
            <t indent="0" pn="section-toc.1-1.8.1"><xref derivedContent="8" format="counter" sectionFormat="of" target="section-8"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-new-error-type-and-error-va">New Error-Type and Error-Values Defined</xref></t>
          </li>
          <li pn="section-toc.1-1.9">
            <t indent="0" pn="section-toc.1-1.9.1"><xref derivedContent="9" format="counter" sectionFormat="of" target="section-9"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-bgp-considerations">BGP Considerations</xref></t>
          </li>
          <li pn="section-toc.1-1.10">
            <t indent="0" pn="section-toc.1-1.10.1"><xref derivedContent="10" format="counter" sectionFormat="of" target="section-10"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-deployment-considerations">Deployment Considerations</xref></t>
          </li>
          <li pn="section-toc.1-1.11">
            <t indent="0" pn="section-toc.1-1.11.1"><xref derivedContent="11" format="counter" sectionFormat="of" target="section-11"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-manageability-consideration">Manageability Considerations</xref></t>
            <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.11.2">
              <li pn="section-toc.1-1.11.2.1">
                <t indent="0" pn="section-toc.1-1.11.2.1.1"><xref derivedContent="11.1" format="counter" sectionFormat="of" target="section-11.1"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-control-of-function-and-pol">Control of Function and Policy</xref></t>
              </li>
              <li pn="section-toc.1-1.11.2.2">
                <t indent="0" pn="section-toc.1-1.11.2.2.1"><xref derivedContent="11.2" format="counter" sectionFormat="of" target="section-11.2"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-information-and-data-models">Information and Data Models</xref></t>
              </li>
              <li pn="section-toc.1-1.11.2.3">
                <t indent="0" pn="section-toc.1-1.11.2.3.1"><xref derivedContent="11.3" format="counter" sectionFormat="of" target="section-11.3"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-liveness-detection-and-moni">Liveness Detection and Monitoring</xref></t>
              </li>
              <li pn="section-toc.1-1.11.2.4">
                <t indent="0" pn="section-toc.1-1.11.2.4.1"><xref derivedContent="11.4" format="counter" sectionFormat="of" target="section-11.4"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-verify-correct-operations">Verify Correct Operations</xref></t>
              </li>
              <li pn="section-toc.1-1.11.2.5">
                <t indent="0" pn="section-toc.1-1.11.2.5.1"><xref derivedContent="11.5" format="counter" sectionFormat="of" target="section-11.5"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-requirements-on-other-proto">Requirements on Other Protocols</xref></t>
              </li>
              <li pn="section-toc.1-1.11.2.6">
                <t indent="0" pn="section-toc.1-1.11.2.6.1"><xref derivedContent="11.6" format="counter" sectionFormat="of" target="section-11.6"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-impact-on-network-operation">Impact on Network Operations</xref></t>
              </li>
            </ul>
          </li>
          <li pn="section-toc.1-1.12">
            <t indent="0" pn="section-toc.1-1.12.1"><xref derivedContent="12" format="counter" sectionFormat="of" target="section-12"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-security-considerations">Security Considerations</xref></t>
          </li>
          <li pn="section-toc.1-1.13">
            <t indent="0" pn="section-toc.1-1.13.1"><xref derivedContent="13" format="counter" sectionFormat="of" target="section-13"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-iana-considerations">IANA Considerations</xref></t>
            <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.13.2">
              <li pn="section-toc.1-1.13.2.1">
                <t indent="0" pn="section-toc.1-1.13.2.1.1"><xref derivedContent="13.1" format="counter" sectionFormat="of" target="section-13.1"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-pcep-path-setup-types">PCEP Path Setup Types</xref></t>
              </li>
              <li pn="section-toc.1-1.13.2.2">
                <t indent="0" pn="section-toc.1-1.13.2.2.1"><xref derivedContent="13.2" format="counter" sectionFormat="of" target="section-13.2"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-pcecc-capability-sub-tlv-fl">PCECC-CAPABILITY Sub-TLV Flag Field</xref></t>
              </li>
              <li pn="section-toc.1-1.13.2.3">
                <t indent="0" pn="section-toc.1-1.13.2.3.1"><xref derivedContent="13.3" format="counter" sectionFormat="of" target="section-13.3"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-pcep-objects">PCEP Objects</xref></t>
              </li>
              <li pn="section-toc.1-1.13.2.4">
                <t indent="0" pn="section-toc.1-1.13.2.4.1"><xref derivedContent="13.4" format="counter" sectionFormat="of" target="section-13.4"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-pcep-error-objects">PCEP-Error Objects</xref></t>
              </li>
              <li pn="section-toc.1-1.13.2.5">
                <t indent="0" pn="section-toc.1-1.13.2.5.1"><xref derivedContent="13.5" format="counter" sectionFormat="of" target="section-13.5"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-cci-object-flag-field">CCI Object Flag Field</xref></t>
              </li>
              <li pn="section-toc.1-1.13.2.6">
                <t indent="0" pn="section-toc.1-1.13.2.6.1"><xref derivedContent="13.6" format="counter" sectionFormat="of" target="section-13.6"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-bpi-object-status-codes">BPI Object Status Codes</xref></t>
              </li>
              <li pn="section-toc.1-1.13.2.7">
                <t indent="0" pn="section-toc.1-1.13.2.7.1"><xref derivedContent="13.7" format="counter" sectionFormat="of" target="section-13.7"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-bpi-object-error-codes">BPI Object Error Codes</xref></t>
              </li>
              <li pn="section-toc.1-1.13.2.8">
                <t indent="0" pn="section-toc.1-1.13.2.8.1"><xref derivedContent="13.8" format="counter" sectionFormat="of" target="section-13.8"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-bpi-object-flag-field">BPI Object Flag Field</xref></t>
              </li>
            </ul>
          </li>
          <li pn="section-toc.1-1.14">
            <t indent="0" pn="section-toc.1-1.14.1"><xref derivedContent="14" format="counter" sectionFormat="of" target="section-14"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-references">References</xref></t>
            <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.14.2">
              <li pn="section-toc.1-1.14.2.1">
                <t indent="0" pn="section-toc.1-1.14.2.1.1"><xref derivedContent="14.1" format="counter" sectionFormat="of" target="section-14.1"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-normative-references">Normative References</xref></t>
              </li>
              <li pn="section-toc.1-1.14.2.2">
                <t indent="0" pn="section-toc.1-1.14.2.2.1"><xref derivedContent="14.2" format="counter" sectionFormat="of" target="section-14.2"/>.  <xref derivedContent="" format="title" sectionFormat="of" target="name-informative-references">Informative References</xref></t>
              </li>
            </ul>
          </li>
          <li pn="section-toc.1-1.15">
            <t indent="0" pn="section-toc.1-1.15.1"><xref derivedContent="" format="none" sectionFormat="of" target="section-appendix.a"/><xref derivedContent="" format="title" sectionFormat="of" target="name-acknowledgements">Acknowledgements</xref></t>
          </li>
          <li pn="section-toc.1-1.16">
            <t indent="0" pn="section-toc.1-1.16.1"><xref derivedContent="" format="none" sectionFormat="of" target="section-appendix.b"/><xref derivedContent="" format="title" sectionFormat="of" target="name-contributors">Contributors</xref></t>
          </li>
          <li pn="section-toc.1-1.17">
            <t indent="0" pn="section-toc.1-1.17.1"><xref derivedContent="" format="none" sectionFormat="of" target="section-appendix.c"/><xref derivedContent="" format="title" sectionFormat="of" target="name-authors-addresses">Authors' Addresses</xref></t>
          </li>
        </ul>
      </section>
    </toc>
  </front>
  <middle>
    <section anchor="intro" numbered="true" toc="include" removeInRFC="false" pn="section-1">
      <name slugifiedName="name-introduction">Introduction</name>
      <t indent="0" pn="section-1-1">Generally, Multiprotocol Label Switching Traffic Engineering
      (MPLS-TE) requires the corresponding network devices to support the Resource
      ReSerVation Protocol (RSVP) <xref target="RFC3209" format="default" sectionFormat="of" derivedContent="RFC3209"/> and the Label Distribution
      Protocol (LDP) <xref target="RFC5036" format="default" sectionFormat="of" derivedContent="RFC5036"/> to ensure
      End-to-End (E2E) traffic performance. But in Native IP network scenarios
      described in <xref target="RFC8735" format="default" sectionFormat="of" derivedContent="RFC8735"/>, there will be no such signaling
      protocol to synchronize the actions among different network devices. It
      is feasible to use the central control mode described in <xref target="RFC8283" format="default" sectionFormat="of" derivedContent="RFC8283"/> to correlate the forwarding behavior among different
      network devices.
      <xref target="RFC8821" format="default" sectionFormat="of" derivedContent="RFC8821"/> describes the architecture and
      solution philosophy for the E2E traffic assurance in the Native IP
      network via a solution based on multiple Border Gateway Protocol (BGP) sessions.
      It requires only the PCE to send the instructions to the Path Computation Clients (PCCs)
      to build multiple BGP sessions, distribute different prefixes on the
      established BGP sessions, and assign the different paths to the BGP next
      hops.</t>
      <t indent="0" pn="section-1-2">This document describes the corresponding Path Computation Element
      Communication Protocol (PCEP) extensions to transfer the key information
      about the BGP peer, peer prefix advertisement, and explicit peer route
      on on-path routers.</t>
    </section>
    <section numbered="true" toc="include" removeInRFC="false" pn="section-2">
      <name slugifiedName="name-conventions-used-in-this-do">Conventions Used in This Document</name>
      <t indent="0" pn="section-2-1">
    The key words "<bcp14>MUST</bcp14>", "<bcp14>MUST NOT</bcp14>", "<bcp14>REQUIRED</bcp14>", "<bcp14>SHALL</bcp14>", "<bcp14>SHALL NOT</bcp14>", "<bcp14>SHOULD</bcp14>", "<bcp14>SHOULD NOT</bcp14>", "<bcp14>RECOMMENDED</bcp14>", "<bcp14>NOT RECOMMENDED</bcp14>",
    "<bcp14>MAY</bcp14>", and "<bcp14>OPTIONAL</bcp14>" in this document are to be interpreted as
    described in BCP 14 <xref target="RFC2119" format="default" sectionFormat="of" derivedContent="RFC2119"/> <xref target="RFC8174" format="default" sectionFormat="of" derivedContent="RFC8174"/> 
    when, and only when, they appear in all capitals, as shown here.
      </t>
      <section numbered="true" toc="include" removeInRFC="false" pn="section-2.1">
        <name slugifiedName="name-use-of-rbnf">Use of RBNF</name>
        <t indent="0" pn="section-2.1-1">The message formats in this document are illustrated using Routing
        Backus-Naur Form (RBNF) encoding, as specified in <xref target="RFC5511" format="default" sectionFormat="of" derivedContent="RFC5511"/>. The use of RBNF is illustrative only and may elide
        certain important details; the normative specification of messages is
        found in the prose description. If there is any divergence between the
        RBNF and the prose, the prose is considered authoritative.</t>
      </section>
      <section numbered="true" toc="include" removeInRFC="false" pn="section-2.2">
        <name slugifiedName="name-experimental-status-conside">Experimental Status Consideration</name>
        <t indent="0" pn="section-2.2-1">The procedures outlined in this document are experimental. The
        experiment aims to explore the use of PCE (and PCEP) for E2E
        traffic assurance in Native IP networks through multiple BGP sessions.
        Additional implementation is necessary to gain a deeper understanding
        of the operational impact, scalability, and stability of the mechanism
        described. Feedback from deployments will be crucial in determining
        whether this specification should advance from Experimental to the
        IETF Standards Track.</t>
      </section>
    </section>
    <section numbered="true" toc="include" removeInRFC="false" pn="section-3">
      <name slugifiedName="name-terminology">Terminology</name>
      <t indent="0" pn="section-3-1">This document uses the following terms defined in <xref target="RFC5440" format="default" sectionFormat="of" derivedContent="RFC5440"/>: PCC, PCE, and PCEP.</t>
      <t indent="0" pn="section-3-2">Additionally, the following terminology is used in this document:</t>
      <dl spacing="normal" newline="false" indent="3" pn="section-3-3">
        <dt pn="section-3-3.1">BPI:</dt>
        <dd pn="section-3-3.2">BGP Peer Info</dd>
        <dt pn="section-3-3.3">CCDR:</dt>
        <dd pn="section-3-3.4">Centralized Control Dynamic Routing</dd>
        <dt pn="section-3-3.5">CCI:</dt>
        <dd pn="section-3-3.6">Central Controller Instructions (defined in <xref target="RFC9050" format="default" sectionFormat="of" derivedContent="RFC9050"/>)</dd>
        <dt pn="section-3-3.7">E2E:</dt>
        <dd pn="section-3-3.8">End-to-End</dd>
        <dt pn="section-3-3.9">EPR:</dt>
        <dd pn="section-3-3.10">Explicit Peer Route</dd>
        <dt pn="section-3-3.11">Native IP network:</dt>
        <dd pn="section-3-3.12">Network that forwards traffic based solely on
          the IP address, instead of another indicator, for example, MPLS,
          etc.</dd>
        <dt pn="section-3-3.13">PCECC:</dt>
        <dd pn="section-3-3.14">PCE as a Central Controller (defined in <xref target="RFC8283" format="default" sectionFormat="of" derivedContent="RFC8283"/>)</dd>
        <dt pn="section-3-3.15">PPA:</dt>
        <dd pn="section-3-3.16">Peer Prefix Advertisement</dd>
        <dt pn="section-3-3.17">PST:</dt>
        <dd pn="section-3-3.18">Path Setup Type (defined in <xref target="RFC8408" format="default" sectionFormat="of" derivedContent="RFC8408"/>)</dd>
        <dt pn="section-3-3.19">SRP:</dt>
        <dd pn="section-3-3.20">Stateful PCE Request Parameter (defined in <xref target="RFC8231" format="default" sectionFormat="of" derivedContent="RFC8231"/>)</dd>
        <dt pn="section-3-3.21">RR:</dt>
        <dd pn="section-3-3.22">Route Reflector</dd>
      </dl>
    </section>
    <section numbered="true" toc="include" removeInRFC="false" pn="section-4">
      <name slugifiedName="name-capability-advertisement">Capability Advertisement</name>
      <section numbered="true" toc="include" removeInRFC="false" pn="section-4.1">
        <name slugifiedName="name-open-message">Open Message</name>
        <t indent="0" pn="section-4.1-1">During the PCEP Initialization Phase, PCEP speakers (PCE or PCC)
        advertise their support of Native IP extensions.</t>
        <t indent="0" pn="section-4.1-2">This document defines a new Path Setup Type (PST) <xref target="RFC8408" format="default" sectionFormat="of" derivedContent="RFC8408"/> for Native IP, as follows: </t>
        <ul spacing="normal" bare="false" empty="false" indent="3" pn="section-4.1-3">
          <li pn="section-4.1-3.1">PST = 4: Path is a Native IP TE path as per <xref target="RFC8821" format="default" sectionFormat="of" derivedContent="RFC8821"/>.</li>
        </ul>
        <t indent="0" pn="section-4.1-4">A PCEP speaker <bcp14>MUST</bcp14> indicate its support of the function described
        in this document by sending a PATH-SETUP-TYPE-CAPABILITY TLV in the
        OPEN object with this new PST included in the PST list.</t>
        <t indent="0" pn="section-4.1-5"><xref target="RFC9050" format="default" sectionFormat="of" derivedContent="RFC9050"/> defined the PCECC-CAPABILITY sub-TLV to
        exchange information about the PCEP speakers' PCECC capability. A new flag is
        defined in the PCECC-CAPABILITY sub-TLV for Native IP:</t>
        <t indent="0" pn="section-4.1-6">N (NATIVE-IP-TE-CAPABILITY - 1 bit - 30): When set to 1 by a PCEP
        speaker, this flag indicates that the PCEP speaker is capable of TE in
        a Native IP network, as specified in this document. Both the PCC and
        PCE <bcp14>MUST</bcp14> set this flag to support this extension.</t>
        <t indent="0" pn="section-4.1-7">If a PCEP speaker receives the PATH-SETUP-TYPE-CAPABILITY TLV with
        the newly defined PST, but without the N bit set in
        PCECC-CAPABILITY sub-TLV, it <bcp14>MUST</bcp14>:</t>
        <ul spacing="normal" bare="false" empty="false" indent="3" pn="section-4.1-8">
          <li pn="section-4.1-8.1">
            <t indent="0" pn="section-4.1-8.1.1">send a PCErr message with Error-Type=10 (Reception of an
            invalid object) and Error-value=39 (PCECC NATIVE-IP-TE-CAPABILITY
            bit is not set) and</t>
          </li>
          <li pn="section-4.1-8.2">
            <t indent="0" pn="section-4.1-8.2.1">terminate the PCEP session.</t>
          </li>
        </ul>
        <t indent="0" pn="section-4.1-9">If a PCEP speaker receives the PATH-SETUP-TYPE-CAPABILITY TLV with
        the newly defined PST, but without the PCECC-CAPABILITY
        sub-TLV, it <bcp14>MUST</bcp14>:</t>
        <ul spacing="normal" bare="false" empty="false" indent="3" pn="section-4.1-10">
          <li pn="section-4.1-10.1">
            <t indent="0" pn="section-4.1-10.1.1">send a PCErr message with Error-Type=10 (Reception of an invalid
            object) and Error-value=33 (Missing PCECC Capability sub-TLV) and</t>
          </li>
          <li pn="section-4.1-10.2">
            <t indent="0" pn="section-4.1-10.2.1">terminate the PCEP session.</t>
          </li>
        </ul>
        <t indent="0" pn="section-4.1-11">If one or both speakers (PCE and PCC) have not indicated the
        support for Native IP, the PCEP extensions for the Native IP <bcp14>MUST NOT</bcp14>
        be used. If a Native IP operation is attempted when both speakers have
        not agreed on the OPEN messages, the receiver of the message <bcp14>MUST</bcp14>:</t>
        <ul spacing="normal" bare="false" empty="false" indent="3" pn="section-4.1-12">
          <li pn="section-4.1-12.1">
            <t indent="0" pn="section-4.1-12.1.1">send a PCErr message with Error-Type=19 (Invalid Operation) and
            Error-value=29 (Attempted Native IP operations when the
            capability was not advertised) and</t>
          </li>
          <li pn="section-4.1-12.2">
            <t indent="0" pn="section-4.1-12.2.1">terminate the PCEP session.</t>
          </li>
        </ul>
      </section>
    </section>
    <section toc="include" numbered="true" removeInRFC="false" pn="section-5">
      <name slugifiedName="name-pcep-messages">PCEP Messages</name>
      <t indent="0" pn="section-5-1">The PCECC Native IP TE solution uses the existing PCE Label Switched Path
      (LSP) Initiate Request message (PCInitiate) <xref target="RFC8281" format="default" sectionFormat="of" derivedContent="RFC8281"/>
      and PCE Report message (PCRpt) <xref target="RFC8231" format="default" sectionFormat="of" derivedContent="RFC8231"/> to establish
      multiple BGP sessions, deploy the E2E Native IP TE path,
      and advertise route prefixes among different BGP
      sessions. A new PST for Native IP is used to indicate the path setup
      based on TE in Native IP networks.</t>
      <t indent="0" pn="section-5-2">The extended PCInitiate message described in <xref target="RFC9050" format="default" sectionFormat="of" derivedContent="RFC9050"/>
      is used to download or remove the Central Controller Instructions
      (CCI). <xref target="RFC9050" format="default" sectionFormat="of" derivedContent="RFC9050"/> specifies an object called CCI for the
      encoding of the central controller's instructions. This document
      specifies a new CCI Object-Type for Native IP. The PCEP messages are
      extended in this document to handle the PCECC operations for Native IP.
      Three new PCEP objects (BGP Peer Info (BPI), Explicit Peer Route
      (EPR), and Peer Prefix Advertisement (PPA)) are defined in
      this document. Refer to <xref target="Obj-Def-Sec" format="default" sectionFormat="of" derivedContent="Section 7"/> for detailed object
      definitions. All PCEP procedures specified in <xref target="RFC9050" format="default" sectionFormat="of" derivedContent="RFC9050"/>
      continue to apply unless specified otherwise.</t>
      <section anchor="SEC_PCInitiate" toc="include" numbered="true" removeInRFC="false" pn="section-5.1">
        <name slugifiedName="name-the-pcinitiate-message">The PCInitiate Message</name>
        <t indent="0" pn="section-5.1-1">The PCInitiate message defined in <xref target="RFC8281" format="default" sectionFormat="of" derivedContent="RFC8281"/> and
        extended in <xref target="RFC9050" format="default" sectionFormat="of" derivedContent="RFC9050"/> is further extended to support
        Native IP CCI.</t>
        <t indent="0" pn="section-5.1-2">The format of the extended PCInitiate message is as follows:
        </t>
        <sourcecode name="" type="rbnf" markers="false" pn="section-5.1-3">
     &lt;PCInitiate Message&gt; ::= &lt;Common Header&gt;
                              &lt;PCE-initiated-lsp-list&gt;
</sourcecode>
        <t indent="0" pn="section-5.1-4">Where:</t>
        <sourcecode name="" type="rbnf" markers="false" pn="section-5.1-5">
     &lt;Common Header&gt; is defined in RFC 5440

     &lt;PCE-initiated-lsp-list&gt; ::= &lt;PCE-initiated-lsp-request&gt;
                                  [&lt;PCE-initiated-lsp-list&gt;]

     &lt;PCE-initiated-lsp-request&gt; ::=
                          (&lt;PCE-initiated-lsp-instantiation&gt;|
                           &lt;PCE-initiated-lsp-deletion&gt;|
                           &lt;PCE-initiated-lsp-central-control&gt;)

     &lt;PCE-initiated-lsp-central-control&gt; ::= &lt;SRP&gt;
                                             &lt;LSP&gt;
                                             &lt;cci-list&gt;

     &lt;cci-list&gt; ::=  &lt;CCI&gt;
                     [&lt;BPI&gt;|&lt;EPR&gt;|&lt;PPA&gt;]
                     [&lt;cci-list&gt;]

</sourcecode>
        <t indent="0" pn="section-5.1-6">Where:</t>
        <ul spacing="normal" bare="false" empty="false" indent="3" pn="section-5.1-7">
          <li pn="section-5.1-7.1">
            <t indent="0" pn="section-5.1-7.1.1">&lt;PCE-initiated-lsp-instantiation&gt; and
            &lt;PCE-initiated-lsp-deletion&gt; are as per <xref target="RFC8281" format="default" sectionFormat="of" derivedContent="RFC8281"/>.</t>
          </li>
          <li pn="section-5.1-7.2">
            <t indent="0" pn="section-5.1-7.2.1">The LSP and SRP objects are defined in <xref target="RFC8231" format="default" sectionFormat="of" derivedContent="RFC8231"/>.</t>
          </li>
        </ul>
        <t indent="0" pn="section-5.1-8">When the PCInitiate message is used for Native IP instructions,
        i.e., when the CCI Object-Type is 2, the SRP, LSP, and CCI objects <bcp14>MUST</bcp14>
        be present. Error handling for missing SRP, LSP, or CCI objects <bcp14>MUST</bcp14> be
        performed as specified in <xref target="RFC9050" format="default" sectionFormat="of" derivedContent="RFC9050"/>. Additionally,
        exactly one object among the BPI, EPR, or PPA objects <bcp14>MUST</bcp14> be present.
        The PCEP-specific LSP
   identifier (PLSP-ID) and Symbolic Path Name TLVs are set as per the existing
        rules in <xref target="RFC8231" format="default" sectionFormat="of" derivedContent="RFC8231"/>, <xref target="RFC8281" format="default" sectionFormat="of" derivedContent="RFC8281"/>, and <xref target="RFC9050" format="default" sectionFormat="of" derivedContent="RFC9050"/>. The Symbolic Path Name is used by the PCE/PCC to
        uniquely identify the E2E Native IP TE path. The related Native IP
        instructions with BPI, EPR, or PPA objects are identified by the same
        Symbolic Path Name.</t>
        <t indent="0" pn="section-5.1-9">If none of the BPI, EPR, or PPA objects are present, the receiving
        PCC <bcp14>MUST</bcp14> send a PCErr message with Error-Type=6 (Mandatory Object
        missing) and Error-value=19 (Native IP object missing).	If there is
        more than one BPI, EPR, or PPA object present, the
        receiving PCC <bcp14>MUST</bcp14> send a PCErr message with Error-Type=19 (Invalid
        Operation) and Error-value=22 (Only one BPI, EPR, or PPA object can be
        included in this message).</t>
        <t indent="0" pn="section-5.1-10">When the PCInitiate message is not used for Native IP instructions,
        i.e., when the CCI Object-Type is not equal to 2, the BPI, EPR, and PPA
        objects <bcp14>SHOULD NOT</bcp14> be present. If present, they <bcp14>MUST</bcp14> be ignored by the
        receiver.</t>
        <t indent="0" pn="section-5.1-11">To clean up the existing Native IP instructions, the SRP object
        <bcp14>MUST</bcp14> set the R (remove) bit.</t>
      </section>
      <section anchor="SEC_PCRpt" toc="include" numbered="true" removeInRFC="false" pn="section-5.2">
        <name slugifiedName="name-the-pcrpt-message">The PCRpt Message</name>
        <t indent="0" pn="section-5.2-1">The PCRpt message is used to acknowledge the Native IP instructions
        received from the central controller (PCE) as well as during the State
        Synchronization phase.</t>
        <t indent="0" pn="section-5.2-2">The format of the PCRpt message is as follows: </t>
        <sourcecode name="" type="rbnf" markers="false" pn="section-5.2-3">
      &lt;PCRpt Message&gt; ::= &lt;Common Header&gt;
                          &lt;state-report-list&gt;
</sourcecode>
        <t indent="0" pn="section-5.2-4">Where:</t>
        <sourcecode name="" type="rbnf" markers="false" pn="section-5.2-5">
      &lt;state-report-list&gt; ::= &lt;state-report&gt;[&lt;state-report-list&gt;]

      &lt;state-report&gt; ::= (&lt;lsp-state-report&gt;|
                          &lt;central-control-report&gt;)

      &lt;lsp-state-report&gt; ::= [&lt;SRP&gt;]
                             &lt;LSP&gt;
                             &lt;path&gt;

      &lt;central-control-report&gt; ::= [&lt;SRP&gt;]
                                   &lt;LSP&gt;
                                   &lt;cci-list&gt;

      &lt;cci-list&gt; ::=  &lt;CCI&gt;
                     [&lt;BPI&gt;|&lt;EPR&gt;|&lt;PPA&gt;]
                     [&lt;cci-list&gt;]
</sourcecode>
        <t indent="0" pn="section-5.2-6">Where:</t>
        <ul spacing="normal" bare="false" empty="false" indent="3" pn="section-5.2-7">
          <li pn="section-5.2-7.1">&lt;path&gt; is as per <xref target="RFC8231" format="default" sectionFormat="of" derivedContent="RFC8231"/>.</li>
          <li pn="section-5.2-7.2">The LSP and SRP objects are also defined in <xref target="RFC8231" format="default" sectionFormat="of" derivedContent="RFC8231"/>.</li>
        </ul>
        <t indent="0" pn="section-5.2-8">The error handling for missing CCI objects is as per <xref target="RFC9050" format="default" sectionFormat="of" derivedContent="RFC9050"/>. Furthermore, one and only one BPI,
        EPR, or PPA object <bcp14>MUST</bcp14> be present.</t>
        <t indent="0" pn="section-5.2-9">If none of the BPI, EPR, or PPA objects are present, the receiving
        PCE <bcp14>MUST</bcp14> send a PCErr message with Error-Type=6 (Mandatory Object
        missing) and Error-value=19 (Native IP object missing). If there is
        more than one BPI, EPR, or PPA object present, the
        receiving PCE <bcp14>MUST</bcp14> send a PCErr message with Error-Type=19 (Invalid
        Operation) and Error-value=22 (Only one BPI, EPR, or PPA object can be
        included in this message).</t>
        <t indent="0" pn="section-5.2-10">When the PCInitiate message is not used for Native IP instructions,
        i.e., when the CCI Object-Type is not equal to 2, the BPI, EPR, and PPA
        objects <bcp14>SHOULD NOT</bcp14> be present. If present, they <bcp14>MUST</bcp14> be ignored by the
        receiver.</t>
      </section>
    </section>
    <section numbered="true" toc="include" removeInRFC="false" pn="section-6">
      <name slugifiedName="name-pcecc-native-ip-te-procedur">PCECC Native IP TE Procedures</name>
      <t indent="0" pn="section-6-1">The detailed procedures for the TE in the Native IP environment are
      described in the following sections.</t>
      <section anchor="BGPSess" numbered="true" toc="include" removeInRFC="false" pn="section-6.1">
        <name slugifiedName="name-bgp-session-establishment-p">BGP Session Establishment Procedures</name>
        <t indent="0" pn="section-6.1-1">The PCInitiate and PCRpt message pair is used to exchange the
        configuration parameters for a BGP peer session. This pair of PCEP
        messages are exchanged between a PCE and each BGP peer (acting as the PCC),
        which needs to establish a BGP session. After the BGP peer session has
        been initiated via this pair of PCEP messages, the BGP session
        establishes and operates in a normal fashion. The BGP peers can be
        used for External BGP (EBGP) peers or Internal BGP (IBGP) peers. For
        IBGP connection topologies, the Route Reflector (RR) is required.</t>
        <t indent="0" pn="section-6.1-2">The PCInitiate message is sent to the BGP router and/or RR (which
        are acting as the PCC).</t>
        <t indent="0" pn="section-6.1-3">The RR topology for a single Autonomous System (AS) is shown in
        <xref target="fig-1" format="default" sectionFormat="of" derivedContent="Figure 1"/>. The BGP routers R1, R3, and R7 are within a single AS. R1
        and R7 are BGP RR clients, and R3 is an RR. The PCInitiate message is
        sent to the BGP routers R1, R3, and R7, which need to establish a BGP
        session.</t>
        <t indent="0" pn="section-6.1-4">PCInitiate message creates an autoconfiguration function for these
        BGP peers by providing the indicated Peer AS and the Local/Peer IP
        Address.</t>
        <t indent="0" pn="section-6.1-5">When the PCC receives the BPI and CCI objects (with the R bit set to
        0 in the SRP object) in the PCInitiate message, the PCC <bcp14>SHOULD</bcp14> try to
        establish the BGP session with the indicated Peer as per the AS and
        Local/Peer IP Address.</t>
        <t indent="0" pn="section-6.1-6">During the establishment procedure, the PCC <bcp14>MUST</bcp14> report 
        the status of the BGP session to the PCE via the PCRpt message, with the status
        field in the BPI object set to the appropriate value and the
        corresponding SRP and CCI objects included.</t>
        <t indent="0" pn="section-6.1-7">When the PCC receives this message with the R bit set to 1 in the
        SRP object in the PCInitiate message, the PCC <bcp14>MUST</bcp14> clear the BGP
        configuration and tear down the BGP session that is indicated by the
        BPI object.</t>
        <t indent="0" pn="section-6.1-8">When the PCC successfully clears the specified BGP session
        configuration, it <bcp14>MUST</bcp14> report the result via the PCRpt message, with
        the BPI object and the corresponding SRP and CCI
        objects included.</t>
        <figure anchor="fig-1" align="left" suppress-title="false" pn="figure-1">
          <name slugifiedName="name-bgp-session-establishment-pr">BGP Session Establishment Procedures (R3 acts as the RR)</name>
          <artwork name="" type="" align="center" alt="" pn="section-6.1-9.1">
                  +------------------+
      +-----------&gt;       PCE        &lt;----------+
      |           +--------^---------+          |
      |                    |                    |
      |             PCInitiate/PCRpt            |
      |                    |                    |
      |               +----v--+                 |
      +---------------+ R3(RR)+-----------------+
      |               +-------+                 |
PCInitiate/PCRpt                         PCInitiate/PCRpt
      |                                         |
     +v-+          +--+          +--+         +-v+
     |R1+----------+R5+----------+R6+---------+R7|
     ++-+          +-++          +--+         +-++
      |              |                          |
      |            +--+          +--+           |
      +------------+R2+----------+R4+-----------+
                   +--+          +--+
</artwork>
        </figure>
        <t indent="0" pn="section-6.1-10">The message peers, message types, message key parameters, and
        procedures in the above figure are shown below:</t>
        <figure anchor="fig-2" align="left" suppress-title="false" pn="figure-2">
          <name slugifiedName="name-message-information-and-pro">Message Information and Procedures</name>
          <artwork name="" type="" align="center" alt="" pn="section-6.1-11.1">
              +-------+                                       +-------+
              |PCC    |                                       |  PCE  |
              |R1     |                                       +-------+
       +------|       |                                            |
       | PCC  +-------+                                            |
       | R3     | |   (For R1/R3 BGP Session on R1)                |
+------|        | |&lt;-PCInitiate,CC-ID=X,Symbolic Path Name=Class A-|
|      |        | |BPI Object(Peer AS, Local_IP=R1_A, Peer_IP=R3_A)|
|PCC   +--------+ |                                                |
|R7      |  |     |----PCRpt,CC-ID=X(Symbolic Path Name=Class A)--&gt;|
|        |  |     |BPI Object(Peer AS, Local_IP=R1_A, Peer_IP=R3_A)|
+--------+  |                                                      |
    |       |          (For R1/R3 BGP Session on R3)               |
    |       |&lt;--PCInitiate,CC-ID=Y1,Symbolic Path Name=Class A-----|
    |       |      BPI Object(Peer AS, Local_IP=R3_A, Peer_IP=R1_A)|
    |       |---PCRpt,CC-ID=Y1,Symbolic Path Name=Class A---------&gt;|
    |       |      BPI Object(Peer AS, Local_IP=R3_A, Peer_IP=R1_A)|
    |       |                                                      |
    |       |          (For R3/R7 BGP Session on R3)               |
    |       |&lt;--PCInitiate,CC-ID=Y2,Symbolic Path Name=Class A-----|
    |       |  BPI Object(Peer AS, Local_IP=R3_A, Peer_IP=R7_A)    |
    |       |----PCRpt,CC-ID=Y2,Symbolic Path Name=Class A--------&gt;|
    |       |  BPI Object(Peer AS, Local_IP=R3_A, Peer_IP=R7_A)    |
    |                                                              |
    |                  (For R3/R7 BGP Session on R7)               |
    |&lt;--PCInitiate,CC-ID=Z,Symbolic Path Name=Class A--------------|
    |            BPI Object(Peer AS, Local_IP=R7_A, Peer_IP=R3_A)  |
    |---PCRpt,CC-ID=Z,Symbolic Path Name=Class A------------------&gt;|
    |            BPI Object(Peer AS, Local_IP=R7_A, Peer_IP=R3_A)  |
</artwork>
        </figure>
        <t indent="0" pn="section-6.1-12">The Local/Peer IP Address <bcp14>MUST</bcp14> be dedicated to the usage of the
        Native IP TE solution and <bcp14>MUST NOT</bcp14> be used by other BGP sessions that
        are established manually or in other ways. If the Local IP Address or
        Peer IP Address within the BPI object is used in other existing BGP
        sessions, the PCC <bcp14>MUST</bcp14> report such an error situation via a PCErr
        message with:</t>
        <ul spacing="normal" bare="false" empty="false" indent="3" pn="section-6.1-13">
          <li pn="section-6.1-13.1">
            <t indent="0" pn="section-6.1-13.1.1">Error-Type=33 (Native IP TE failure) and Error-value=1 (Local
            IP is in use) or</t>
          </li>
          <li pn="section-6.1-13.2">
            <t indent="0" pn="section-6.1-13.2.1">Error-Type=33 (Native IP TE failure) and Error-value=2 (Remote
            IP is in use).</t>
          </li>
        </ul>
        <t indent="0" pn="section-6.1-14">The detailed Error-Types and Error-values are defined in <xref target="NewErrorTypeAndValue" format="default" sectionFormat="of" derivedContent="Section 8"/>.</t>
        <t indent="0" pn="section-6.1-15">If the established BGP session is broken, the PCC <bcp14>MUST</bcp14> report such
        information via a PCRpt message with the status field set to "BGP
        session down" in the associated BPI object. The error code field
        within the BPI object <bcp14>SHOULD</bcp14> indicate the reason that leads to the BGP
        session being down. In the future, when the BGP session is up again,
        the PCC <bcp14>MUST</bcp14> report that as well via the PCRpt message with the status
        field set to "BGP Session Established".</t>
      </section>
      <section anchor="BGPEx" numbered="true" toc="include" removeInRFC="false" pn="section-6.2">
        <name slugifiedName="name-explicit-route-establishmen">Explicit Route Establishment Procedures</name>
        <t indent="0" pn="section-6.2-1">The explicit route establishment procedures can be used by a PCE to
        install a route on the PCC, using the PCInitiate and PCRpt message
        pair. Such explicit routes operate the same as static routes installed
        by network management protocols (e.g., Network Configuration Protocol
        (NETCONF) / YANG). The procedures of such explicit route addition and
        removal <bcp14>MUST</bcp14> be controlled by the PCE in a specific order so that the
        pathways are established without loops.</t>
        <t indent="0" pn="section-6.2-2">For the purpose of explicit route addition, the PCInitiate message
        ought to be sent to every router on the explicit path. In the example,
        for the explicit route from R1 to R7, the PCInitiate message is sent
        to R1, R2, and R4, as shown in <xref target="fig-3" format="default" sectionFormat="of" derivedContent="Figure 3"/>. For the explicit route from R7
        to R1, the PCInitiate message is sent to R7, R4, and R2, as shown in
        <xref target="fig-5" format="default" sectionFormat="of" derivedContent="Figure 5"/>.</t>
        <t indent="0" pn="section-6.2-3">When the PCC receives the EPR and the CCI object (with the R bit
        set to 0 in the SRP object) in the PCInitiate message, the PCC <bcp14>SHOULD</bcp14>
        install the explicit route to the peer in the RIB/FIB.</t>
        <t indent="0" pn="section-6.2-4">When the PCC successfully installs the explicit route to the peer,
        it <bcp14>MUST</bcp14> report the result via the PCRpt message, with the EPR object
        and the corresponding SRP and CCI objects included.</t>
        <t indent="0" pn="section-6.2-5">When the PCC receives the EPR and the CCI object with the R bit set
        to 1 in the SRP object in the PCInitiate message, the PCC <bcp14>MUST</bcp14> remove
        the explicit route to the peer that is indicated by the EPR
        object.</t>
        <t indent="0" pn="section-6.2-6">When the PCC has removed the explicit route that is indicated by
        this object, it <bcp14>MUST</bcp14> report the result via the PCRpt message, with the
        EPR object and the corresponding SRP and CCI objects included.</t>
        <figure anchor="fig-3" align="left" suppress-title="false" pn="figure-3">
          <name slugifiedName="name-explicit-route-establish-pr">Explicit Route Establish Procedures (from R1 to R7)</name>
          <artwork name="" type="" align="center" alt="" pn="section-6.2-7.1">
                +------------------+
     +----------&gt;       PCE        +
     |          +----^-----------^-+
     |               |           |
     |               |           |
     |               | +------+  |
     +---------------|-+R3(RR)+--|-------------+
PCInitiate/PCRpt     | +------+  |             |
     |               |           |             |
    +v-+      +--+   |           |   +--+    +--+
    |R1+------+R5+---+-----------|---+R6+----+R7|
    ++-+      +--+   |           |   +--+    +-++
     |     PCInitiate/PCRpt  PCInitiate/PCRpt  |
     |               |           |             |
     |            +--v--+     +--v-+           |
     +------------+- R2 +-----+ R4 +-----------+
                  +--+--+     +--+-+
</artwork>
        </figure>
        <t indent="0" pn="section-6.2-8">The message peers, message types, message key parameters, and
        procedures in the above figure are shown below:</t>
        <figure anchor="fig-4" align="left" suppress-title="false" pn="figure-4">
          <name slugifiedName="name-message-information-and-proc">Message Information and Procedures</name>
          <artwork name="" type="" align="center" alt="" pn="section-6.2-9.1">
              +-------+                                       +-------+
              |PCC    |                                       |  PCE  |
              |R4     |                                       +-------+
       +------|       |                                           |
       | PCC  +-------+                                           |
       | R2     | |        (EPR route on R4)                      |
+------|        | |&lt;-PCInitiate,CC-ID=Z,Symbolic Path Name=Class A|
|      |        | |   EPR Object(Peer Address=R7_A, Next Hop=R7_A)|
|PCC   +--------+ |                                               |
|R1      |  |     |----PCRpt,CC-ID=Z,Symbolic Path Name=Class A--&gt;|
|        |  |     |   EPR Object(Peer Address=R7_A, Next Hop=R7_A)|
+--------+  |                                                     |
    |       |              (EPR route on R2)                      |
    |       |&lt;--PCInitiate,CC-ID=Y,Symbolic Path Name=Class A-----|
    |       |   EPR Object(Peer Address=R7_A, Next Hop=R4_A)      |
    |       |----PCRpt,CC-ID=Y,Symbolic Path Name=Class A--------&gt;|
    |       |   EPR Object(Peer Address=R7_A, Next Hop=R4_A)      |
    |       |                                                     |
    |                                                             |
    |                      (EPR route on R1)                      |
    |&lt;--PCInitiate,CC-ID=X,Symbolic Path Name=Class A-------------|
    |              EPR Object(Peer Address=R7_A, Next Hop=R2_A)   |
    |---PCRpt,CC-ID=X1(Symbolic Path Name=Class A)---------------&gt;|
    |              EPR Object(Peer Address=R7_A, Next Hop=R2_A)   |
</artwork>
        </figure>
        <figure anchor="fig-5" align="left" suppress-title="false" pn="figure-5">
          <name slugifiedName="name-explicit-route-establish-pro">Explicit Route Establish Procedures (from R7 to R1)</name>
          <artwork name="" type="" align="center" alt="" pn="section-6.2-10.1">
            +------------------+
            +       PCE        &lt;-----------+
            +----^-----------^-+           |
                 |           |             |
                 |           |             |
                 | +------+  |             |
 +-----------------+R3(RR)+--|-------------+
 |               | +------+  |       PCInitiate/PCRpt
 |               |           |             |
+--+      +--+   |           |   +--+    +-v+
|R1+------+R5+---+-----------|---+R6+----+R7|
++-+      +--+   |           |   +--+    +-++
 |       PCInitiate/PCRpt PCInitiate/PCRpt |
 |               |           |             |
 |            +--v--+     +--v-+           |
 +------------+- R2 +-----+ R4 +-----------+
              +--+--+     +--+-+
</artwork>
        </figure>
        <t indent="0" pn="section-6.2-11">The message peers, message types, message key parameters, and
        procedures in the above figure are shown below:</t>
        <figure anchor="fig-6" align="left" suppress-title="false" pn="figure-6">
          <name slugifiedName="name-explicit-route-establish-proc">Explicit Route Establish Procedures (from R7 to R1)</name>
          <artwork name="" type="" align="center" alt="" pn="section-6.2-12.1">
              +-------+                                       +-------+
              |PCC    |                                       |  PCE  |
              |R2     |                                       +-------+
       +------|       |                                           |
       | PCC  +-------+                                           |
       | R4     | |        (EPR route on R2)                      |
+------|        | |&lt;-PCInitiate,CC-ID=X,Symbolic Path Name=Class A|
|      |        | |  EPR Object(Peer Address=R1_A, Next Hop=R1_A) |
|PCC   +--------+ |                                               |
|R7      |  |     |----PCRpt,CC-ID=X,Symbolic Path Name=Class A--&gt;|
|        |  |     |  EPR Object(Peer Address=R1_A, Next Hop=R1_A) |
+--------+  |                                                     |
    |       |              (EPR route on R4)                      |
    |       |&lt;--PCInitiate,CC-ID=Y,Symbolic Path Name=Class A-----|
    |       |   EPR Object(Peer Address=R1_A, Next Hop=R2_A)      |
    |       |----PCRpt,CC-ID=Y,Symbolic Path Name=Class A--------&gt;|
    |       |   EPR Object(Peer Address=R1_A, Next Hop=R2_A)      |
    |       |                                                     |
    |                                                             |
    |                      (EPR route on R7)                      |
    |&lt;--PCInitiate,CC-ID=Z,Symbolic Path Name=Class A-------------|
    |   EPR Object(Peer Address=R1_A, Next Hop=R4_A)              |
    |---PCRpt,CC-ID=Z,Symbolic Path Name=Class A-----------------&gt;|
    |   EPR Object(Peer Address=R1_A, Next Hop=R4_A)              |
</artwork>
        </figure>
        <t indent="0" pn="section-6.2-13">To avoid the transient loop while deploying the explicit peer
        route, the EPR object <bcp14>MUST</bcp14> be sent to the PCCs in the reverse order of
        the E2E path. To remove the explicit peer route, the EPR object <bcp14>MUST</bcp14>
        be sent to the PCCs in the same order as the E2E path.</t>
        <t indent="0" pn="section-6.2-14">To accomplish ECMP effects, the PCE can send multiple EPR/CCI
        objects to the same node, with the same route priority and peer
        address value but a different next-hop address.</t>
        <t indent="0" pn="section-6.2-15">The PCC <bcp14>MUST</bcp14> verify that the next-hop address is reachable. In case
        of failure, the PCC <bcp14>MUST</bcp14> send the corresponding error via a PCErr
        message, with the error information: Error-Type=33 (Native IP TE
        failure) and Error-value=3 (Explicit Peer Route Error).</t>
        <t indent="0" pn="section-6.2-16">When the peer info is not the same as the peer info that is
        indicated in the BPI object in the PCC for the same path that is
        identified by Symbolic Path Name TLV, a PCErr message <bcp14>MUST</bcp14> be
        reported, with the error information Error-Type=33 (Native IP TE
        failure) and Error-value=4 (EPR/BPI Peer Info mismatch). Note that the
        same error can be used in case no BPI is received at the PCC.</t>
        <t indent="0" pn="section-6.2-17">If the PCE needs to update the path, it <bcp14>MUST</bcp14> first instruct the new
        CCI with the updated EPR corresponding to the new next hop to use and then
        instruct the removal of the older CCI.</t>
      </section>
      <section anchor="BGPPrefix" numbered="true" toc="include" removeInRFC="false" pn="section-6.3">
        <name slugifiedName="name-bgp-prefix-advertisement-pr">BGP Prefix Advertisement Procedures</name>
        <t indent="0" pn="section-6.3-1">The detailed procedures for BGP prefix advertisement are shown
        below, using the PCInitiate and PCRpt message pair.</t>
        <t indent="0" pn="section-6.3-2">The PCInitiate message <bcp14>SHOULD</bcp14> be sent to the PCC that acts as a BGP
        peer edge router only. In the example, it is sent to R1 and R7,
        respectively.</t>
        <t indent="0" pn="section-6.3-3">When the PCC receives the PPA and the CCI object (with the R bit
        set to 0 in the SRP object) in the PCInitiate message, the PCC <bcp14>SHOULD</bcp14>
        send the prefixes indicated in this object to the identified BGP peer
        via the corresponding BGP session <xref target="RFC4271" format="default" sectionFormat="of" derivedContent="RFC4271"/>.</t>
        <t indent="0" pn="section-6.3-4">When the PCC has successfully sent the prefixes to the appointed
        BGP peer, it <bcp14>MUST</bcp14> report the result via the PCRpt messages, with the
        PPA object and the corresponding SRP and CCI objects included.</t>
        <t indent="0" pn="section-6.3-5">When the PCC receives the PPA and the CCI object with the R bit set
        to 1 in the SRP object in the PCInitiate message, the PCC <bcp14>MUST</bcp14>
        withdraw the prefix advertisement to the peer indicated by this
        object.</t>
        <t indent="0" pn="section-6.3-6">When the PCC successfully withdraws the prefixes that are indicated
        by this object, it <bcp14>MUST</bcp14> report the result via the PCRpt message, with
        the PPA object and the corresponding SRP and CCI
        objects included.</t>
        <figure anchor="fig-7" align="left" suppress-title="false" pn="figure-7">
          <name slugifiedName="name-bgp-prefix-advertisement-pro">BGP Prefix Advertisement Procedures</name>
          <artwork name="" type="" align="center" alt="" pn="section-6.3-7.1">
                 +------------------+
      +----------&gt;       PCE        &lt;-----------+
      |          +------------------+           |
      |                  +--+                   |
      +------------------+R3+-------------------+
PCInitiate/PCRpt         +--+             PCInitiate/PCRpt
      |                                         |
     +v-+          +--+          +--+         +-v+
     |R1+----------+R5+----------+R6+---------+R7|
     ++-+          +--+          +--+         +-++
 (BGP Router)                           (BGP Router)
      |                                         |
      |                                         |
      |            +--+          +--+           |
      +------------+R2+----------+R4+-----------+
                   +--+          +--+
</artwork>
        </figure>
        <t indent="0" pn="section-6.3-8">The message peers, message types, message key parameters, and
        procedures in the above figure are shown below:</t>
        <figure anchor="fig-8" align="left" suppress-title="false" pn="figure-8">
          <name slugifiedName="name-message-information-and-proce">Message Information and Procedures</name>
          <artwork name="" type="" align="center" alt="" pn="section-6.3-9.1">
       +-------+                                      +-------+
       |PCC    |                                      |  PCE  |
       |R1     |                                      +-------+
+------|       |                                           |
| PCC  +-------+                                           |
| R7     | |   (Instruct R1 to advertise Prefix 1_A to R7) |
|        | |&lt;-PCInitiate,CC-ID=X,Symbolic Path Name=Class A|
|        | |  PPA Object(Peer IP=R7_A, Prefix=1_A)         |
+--------+ |                                               |
     |     |----PCRpt,CC-ID=X,Symbolic Path Name=Class A--&gt;|
     |     |    PPA Object(Peer IP=R7_A, Prefix=1_A)       |
     |                                                     |
     |     (Instruct R7 to advertise Prefix 7_A to R1 )    |
     |&lt;--PCInitiate,CC-ID=Z,Symbolic Path Name=Class A-----|
     |         PPA Object(Peer IP=R1_A, Prefix=7_A)        |
     |----PCRpt,CC-ID=Z,Symbolic Path Name=Class A--------&gt;|
     |              PPA Object(Peer IP=R1_A, Prefix=7_A)   |
     |                                                     |
</artwork>
        </figure>
        <t indent="0" pn="section-6.3-10">The AFI/SAFI for the corresponding BGP session <bcp14>SHOULD</bcp14> match the
        Peer Prefix Advertisement Object-Type, i.e., AFI/SAFI <bcp14>SHOULD</bcp14> be 1/1 for the
        IPv4 prefix and 2/1 for the IPv6 prefix. In case of mismatch, an
        error, i.e., Error-Type=33 (Native IP TE failure) and Error-value=5 (BPI/PPA
        Address Family mismatch), <bcp14>MUST</bcp14> be reported via the PCErr message.</t>
        <t indent="0" pn="section-6.3-11">When the peer info is not the same as the peer info that is
        indicated in the BPI object in the PCC for the same path that is
        identified by Symbolic Path Name TLV, an error, i.e., Error-Type=33 (Native
        IP TE failure) and Error-value=6 (PPA/BPI Peer Info mismatch), <bcp14>MUST</bcp14> be
        reported via the PCErr message. Note that the same error can be used
        in case no BPI is received at the PCC.</t>
      </section>
      <section numbered="true" toc="include" removeInRFC="false" pn="section-6.4">
        <name slugifiedName="name-selection-of-the-raw-mode-a">Selection of the Raw Mode and Tunnel Mode Forwarding Strategy</name>
        <t indent="0" pn="section-6.4-1">Normally, when the above procedures are finished, the user traffic
        will be forwarded via the appointed path, but the forwarding will be
        based solely on the destination of user traffic.
	If traffic is coming into the network
        from different attached points but to the same destination,
        they could share the priority path, which may not be the
        initial desire. For example, as illustrated in <xref target="fig-1" format="default" sectionFormat="of" derivedContent="Figure 1"/>, the initial
        aim is to ensure that traffic enters the network via R1 and exits the
        network at R7 via R5-R6-R7. If some traffic enters the network via the
        R2 router, passes through R5, and exits at R7, they may share the
        priority path among R5-R6-R7, which may not be the desired effect.</t>
        <t indent="0" pn="section-6.4-2">The above normal traffic forwarding behavior is clarified as a Raw
        mode forwarding strategy. Such a mode can only achieve the moderate
        traffic path control effect. To achieve the strict traffic path
        control effect, the entry point <bcp14>MUST</bcp14> tunnel the user traffic from the
        entry point of the network to the exit point of the network, which is
        also between the BGP peer established via <xref target="BGPSess" format="default" sectionFormat="of" derivedContent="Section 6.1"/>.
        Such forwarding behavior is called the Tunnel mode forwarding
        strategy. For simplicity, the IP-in-IP tunnel type <xref target="RFC2003" format="default" sectionFormat="of" derivedContent="RFC2003"/> is used between the BGP peers by default.</t>
        <t indent="0" pn="section-6.4-3">The selection of Raw mode and Tunnel mode forwarding strategies are
        controlled via the T bit in the BPI object, which is defined in <xref target="BPI_Object" format="default" sectionFormat="of" derivedContent="Section 7.2"/></t>
      </section>
      <section numbered="true" toc="include" removeInRFC="false" pn="section-6.5">
        <name slugifiedName="name-cleanup">Cleanup</name>
        <t indent="0" pn="section-6.5-1">To remove the Native IP state from the PCC, the PCE <bcp14>MUST</bcp14> send
        explicit CCI cleanup instructions for PPA, EPR, and BPI objects,
        respectively, with the R bit set in the SRP object. If the PCC
        receives a PCInitiate message but does not recognize the Native IP
        information in the CCI, the PCC <bcp14>MUST</bcp14> generate a PCErr message with
        Error-Type=19 (Invalid Operation) and Error-value=30 (Unknown
        Native IP Info) and <bcp14>MUST</bcp14> include the SRP object to specify the error
        is for the corresponding cleanup (via a PCInitiate message).</t>
      </section>
      <section numbered="true" toc="include" removeInRFC="false" pn="section-6.6">
        <name slugifiedName="name-other-procedures">Other Procedures</name>
        <t indent="0" pn="section-6.6-1">The handling of the State Synchronization, redundant PCEs,
        redelegation, and cleanup is the same as other CCIs as specified in
        <xref target="RFC9050" format="default" sectionFormat="of" derivedContent="RFC9050"/>.</t>
      </section>
    </section>
    <section anchor="Obj-Def-Sec" numbered="true" toc="include" removeInRFC="false" pn="section-7">
      <name slugifiedName="name-new-pcep-objects">New PCEP Objects</name>
      <t indent="0" pn="section-7-1">One new CCI Object-Type and three new PCEP objects are defined in
      this document. All new PCEP objects are as per <xref target="RFC5440" format="default" sectionFormat="of" derivedContent="RFC5440"/>.</t>
      <section anchor="CCI" numbered="true" toc="include" removeInRFC="false" pn="section-7.1">
        <name slugifiedName="name-cci-object">CCI Object</name>
        <t indent="0" pn="section-7.1-1">The Central Control Instructions (CCI) Object (defined in <xref target="RFC9050" format="default" sectionFormat="of" derivedContent="RFC9050"/>) is used by the PCE to specify the forwarding
        instructions. This document defines another Object-Type for Native IP
        procedures.</t>
        <t indent="0" pn="section-7.1-2">The CCI Object-Type is 2 for Native IP, as follows: </t>
        <figure anchor="fig-9" align="left" suppress-title="false" pn="figure-9">
          <name slugifiedName="name-cci-object-for-native-ip">CCI Object for Native IP</name>
          <artwork name="" type="" align="center" alt="" pn="section-7.1-3.1">
 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                            CC-ID                              |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|          Reserved             |             Flags             |
+---------------------------------------------------------------+
|                                                               |
//                        Optional TLVs                        //
|                                                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
</artwork>
        </figure>
        <t indent="0" pn="section-7.1-4">The CC-ID field is as described in <xref target="RFC9050" format="default" sectionFormat="of" derivedContent="RFC9050"/>. The
        following fields are defined for CCI Object-Type 2.</t>
        <dl newline="false" spacing="normal" indent="3" pn="section-7.1-5">
          <dt pn="section-7.1-5.1">Reserved:</dt>
          <dd pn="section-7.1-5.2">2 bytes. Set to zero while sending and
            ignored on receipt.</dd>
          <dt pn="section-7.1-5.3">Flags:</dt>
          <dd pn="section-7.1-5.4">2 bytes. Used to carry any additional
            information about the Native IP CCI. Currently, no flag bits are
            defined. Unassigned flags are set to zero while sending and
            ignored on receipt.</dd>
        </dl>
        <t indent="0" pn="section-7.1-6">Optional TLVs may be included within the CCI object body. The
        Symbolic Path Name TLV <xref target="RFC8231" format="default" sectionFormat="of" derivedContent="RFC8231"/> <bcp14>MUST</bcp14> be included in
        the CCI Object-Type 2 to identify the E2E TE path in the Native IP
        environment.</t>
      </section>
      <section anchor="BPI_Object" numbered="true" toc="include" removeInRFC="false" pn="section-7.2">
        <name slugifiedName="name-bgp-peer-info-object">BGP Peer Info Object</name>
        <t indent="0" pn="section-7.2-1">The BGP Peer Info (BPI) object is used to specify the information about
        the peer with which the PCC wants to establish the BGP session. This
        object is included and sent to the source and destination router of
        the E2E path in case there is no Route Reflection (RR) involved. If
        the RR is used between the source and destination routers, then such
        information is sent to the source router, RR, and destination router,
        respectively.</t>
        <t indent="0" pn="section-7.2-2">By default, the Local/Peer IP Address <bcp14>MUST</bcp14> be a unicast address and
        dedicated to the usage of the Native IP TE solution and <bcp14>MUST NOT</bcp14> be
        used by other BGP sessions that are established by manual or other
        configuration mechanisms.</t>
        <t indent="0" pn="section-7.2-3">The BGP Peer Info Object-Class is 46.</t>
        <t indent="0" pn="section-7.2-4">The BGP Peer Info Object-Type is 1 for IPv4 and 2 for IPv6.</t>
        <t indent="0" pn="section-7.2-5">The format of the BGP Peer Info object body for IPv4
        (Object-Type=1) is as follows:</t>
        <figure anchor="fig-10" align="left" suppress-title="false" pn="figure-10">
          <name slugifiedName="name-bgp-peer-info-object-body-f">BGP Peer Info Object Body Format for IPv4</name>
          <artwork name="" type="" align="center" alt="" pn="section-7.2-6.1">
 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                      Peer AS Number                           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|   ETTL        |     Status    |   Error Code  |    Flag     |T|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                    Local IP Address                           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                    Peer IP Address                            |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//                    Optional TLVs                            //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
</artwork>
        </figure>
        <t indent="0" pn="section-7.2-7">The format of the BGP Peer Info object body for IPv6
        (Object-Type=2) is as follows:</t>
        <figure anchor="fig-11" align="left" suppress-title="false" pn="figure-11">
          <name slugifiedName="name-bgp-peer-info-object-body-fo">BGP Peer Info Object Body Format for IPv6</name>
          <artwork name="" type="" align="center" alt="" pn="section-7.2-8.1">
 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                      Peer AS Number                           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|   ETTL        |      Status   |   Error Code  |    Flag     |T|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                                                               |
|               Local IP Address (16 bytes)                     |
|                                                               |
|                                                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                                                               |
|               Peer IP Address (16 bytes)                      |
|                                                               |
|                                                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//                    Optional TLVs                            //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
</artwork>
        </figure>
        <dl spacing="normal" newline="false" indent="3" pn="section-7.2-9">
          <dt pn="section-7.2-9.1">Peer AS Number:</dt>
          <dd pn="section-7.2-9.2">4 bytes. Indicates the AS number of the Remote
  Peer. Note that if 2-byte AS numbers are in use, the low-order bits (16
  through 31) are used, and the high-order bits (0 through 15) are set to
  zero.</dd>
          <dt pn="section-7.2-9.3">ETTL:</dt>
          <dd pn="section-7.2-9.4">1 byte. EBGP Time To Live. Indicates the multi-hop count
  for the EBGP session. It should be 0 and ignored when Local AS and Peer AS
  are the same.</dd>
          <dt pn="section-7.2-9.5">Status:</dt>
          <dd pn="section-7.2-9.6">
            <t indent="0" pn="section-7.2-9.6.1">1 byte. Indicates the BGP session status between the
  peers.  Its values are defined below:</t>
            <dl spacing="normal" newline="false" indent="3" pn="section-7.2-9.6.2">
              <dt pn="section-7.2-9.6.2.1">0:</dt>
              <dd pn="section-7.2-9.6.2.2">Reserved</dd>
              <dt pn="section-7.2-9.6.2.3">1:</dt>
              <dd pn="section-7.2-9.6.2.4">BGP Session Established</dd>
              <dt pn="section-7.2-9.6.2.5">2:</dt>
              <dd pn="section-7.2-9.6.2.6">BGP Session Establishment In Progress</dd>
              <dt pn="section-7.2-9.6.2.7">3:</dt>
              <dd pn="section-7.2-9.6.2.8">BGP Session Down</dd>
              <dt pn="section-7.2-9.6.2.9">4-255:</dt>
              <dd pn="section-7.2-9.6.2.10">Reserved</dd>
            </dl>
          </dd>
          <dt pn="section-7.2-9.7">Error Code:</dt>
          <dd pn="section-7.2-9.8">
            <t indent="0" pn="section-7.2-9.8.1">1 byte. Indicates the reason that the BGP session
  can't be established.</t>
            <dl spacing="normal" newline="false" indent="3" pn="section-7.2-9.8.2">
              <dt pn="section-7.2-9.8.2.1">0:</dt>
              <dd pn="section-7.2-9.8.2.2">Unspecific</dd>
              <dt pn="section-7.2-9.8.2.3">1:</dt>
              <dd pn="section-7.2-9.8.2.4">ASes do not match, BGP Session Failure</dd>
              <dt pn="section-7.2-9.8.2.5">2:</dt>
              <dd pn="section-7.2-9.8.2.6">Peer IP can't be reached, BGP Session Failure</dd>
              <dt pn="section-7.2-9.8.2.7">3-255:</dt>
              <dd pn="section-7.2-9.8.2.8">Reserved</dd>
            </dl>
          </dd>
          <dt pn="section-7.2-9.9">Flag:</dt>
          <dd pn="section-7.2-9.10">
            <t indent="0" pn="section-7.2-9.10.1">1 byte.</t>
            <t indent="0" pn="section-7.2-9.10.2">Currently, only bit 7 (T bit) is defined. When the T bit is set, the
  traffic <bcp14>SHOULD</bcp14> be sent in the IP-in-IP tunnel (the tunnel source is
  the Local IP Address, and the tunnel destination is the Peer IP Address). When the T bit is
  cleared, the traffic is sent via its original source and destination
  address. The Tunnel mode (i.e., the T bit is set) is used when the operator wants to
  ensure only the traffic from the specified (entry, exit) pair, and the Raw
  mode (i.e., the T bit is clear) is used when the operator wants to ensure traffic from
  any entry to the specified destination.  Unassigned flags are set to zero
  while sending and ignored on receipt.</t>
          </dd>
          <dt pn="section-7.2-9.11">Local IP Address(4/16 bytes):</dt>
          <dd pn="section-7.2-9.12">Unicast IP address of the local
  router, used to peer with another end router. When the Object-Type is 1, the
  length is 4 bytes; when the Object-Type is 2, the length is 16 bytes.</dd>
          <dt pn="section-7.2-9.13">Peer IP Address(4/16 bytes):</dt>
          <dd pn="section-7.2-9.14">Unicast IP address of the peer
  router, used to peer with the local router. When the Object-Type is 1, the
  length is 4 bytes; when the Object-Type is 2, the length is 16 bytes.</dd>
          <dt pn="section-7.2-9.15">Optional TLVs:</dt>
          <dd pn="section-7.2-9.16">TLVs that are associated with this object; can be
  used to convey other necessary information for dynamic BGP session
  establishment. No TLVs are currently defined.</dd>
        </dl>
        <t indent="0" pn="section-7.2-10">When the PCC receives a BPI object, with Object-Type=1, it <bcp14>SHOULD</bcp14>
        try to establish a BGP session with the peer in AFI/SAFI=1/1.</t>
        <t indent="0" pn="section-7.2-11">When the PCC receives a BPI object, with Object-Type=2, it <bcp14>SHOULD</bcp14>
        try to establish a BGP session with the peer in AFI/SAFI=2/1.</t>
      </section>
      <section numbered="true" toc="include" removeInRFC="false" pn="section-7.3">
        <name slugifiedName="name-explicit-peer-route-object">Explicit Peer Route Object</name>
        <t indent="0" pn="section-7.3-1">The Explicit Peer Route (EPR) object is defined to specify the explicit
        peer route to the corresponding peer address on each device that is on
        the E2E Native IP TE path. This Object ought to be sent to all the
        devices on the path that are calculated by the PCE. Although the object
        is named "Explicit Peer Route", it can be seen that the
        routes it installs are simply host routes. The use of this object to
        install host routes for any purpose other than reaching the
        corresponding peer address on each device that is on the E2E Native IP
        TE path is outside the scope of this specification.</t>
        <t indent="0" pn="section-7.3-2">By default, the path established by this object <bcp14>MUST</bcp14> have higher
        priority than the other paths calculated by the dynamic IGP protocol and
        <bcp14>MUST</bcp14> have lower priority than the static route configured by manual,
        NETCONF, or any other static means.</t>
        <t indent="0" pn="section-7.3-3">The Explicit Peer Route Object-Class is 47.</t>
        <t indent="0" pn="section-7.3-4">The Explicit Peer Route Object-Type is 1 for IPv4 and 2 for IPv6.</t>
        <t indent="0" pn="section-7.3-5">The format of the Explicit Peer Route object body for IPv4
        (Object-Type=1) is as follows:</t>
        <figure anchor="fig-12" align="left" suppress-title="false" pn="figure-12">
          <name slugifiedName="name-explicit-peer-route-object-">Explicit Peer Route Object Body Format for IPv4</name>
          <artwork name="" type="" align="center" alt="" pn="section-7.3-6.1">
 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|       Route Priority        |          Reserved               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                       Peer IPv4 Address                       |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|               Next Hop IPv4 Address to the Peer               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//                    Optional TLVs                            //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
</artwork>
        </figure>
        <t indent="0" pn="section-7.3-7">The format of the Explicit Peer Route object body for IPv6
        (Object-Type=2) is as follows:</t>
        <figure anchor="fig-13" align="left" suppress-title="false" pn="figure-13">
          <name slugifiedName="name-explicit-peer-route-object-b">Explicit Peer Route Object Body Format for IPv6</name>
          <artwork name="" type="" align="center" alt="" pn="section-7.3-8.1">
 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|       Route Priority        |           Reserved              |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                                                               |
|                       Peer IPv6 Address                       |
|                                                               |
|                                                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                                                               |
|                Next Hop IPv6 Address to the Peer              |
|                                                               |
|                                                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//                    Optional TLVs                            //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
</artwork>
        </figure>
        <dl newline="false" spacing="normal" indent="3" pn="section-7.3-9">
          <dt pn="section-7.3-9.1">Route Priority:</dt>
          <dd pn="section-7.3-9.2">2 bytes. The priority of this explicit
          route.  The higher priority <bcp14>SHOULD</bcp14> be preferred by
          the device. This field is used to indicate the preferred path at
          each hop.</dd>
          <dt pn="section-7.3-9.3">Reserved:</dt>
          <dd pn="section-7.3-9.4">Set to zero while sending and ignored on receipt.</dd>
          <dt pn="section-7.3-9.5">Peer (IPv4/IPv6) Address:</dt>
          <dd pn="section-7.3-9.6">Peer address for the BGP
          session (4/16 bytes).</dd>
          <dt pn="section-7.3-9.7">Next Hop (IPv4/IPv6) Address to the Peer:</dt>
          <dd pn="section-7.3-9.8">Indicates
          the next-hop address (4/16 bytes) to the corresponding peer
          address.</dd>
          <dt pn="section-7.3-9.9">Optional TLVs:</dt>
          <dd pn="section-7.3-9.10">TLVs that are associated with this
          object; can be used to convey other necessary information for
          explicit peer path establishment. No TLVs are currently defined.</dd>
        </dl>
      </section>
      <section numbered="true" toc="include" removeInRFC="false" pn="section-7.4">
        <name slugifiedName="name-peer-prefix-advertisement-o">Peer Prefix Advertisement Object</name>
        <t indent="0" pn="section-7.4-1">The Peer Prefix Advertisement (PPA) object is defined to specify the IP
        prefixes that are advertised to the corresponding peer. This object
        only needs to be included and sent to the source/destination router of
        the E2E path.</t>
        <t indent="0" pn="section-7.4-2">The prefix information included in this object <bcp14>MUST</bcp14> only be
        advertised to the indicated peer and <bcp14>SHOULD NOT</bcp14> be advertised to
        other BGP peers.</t>
        <t indent="0" pn="section-7.4-3">The Peer Prefix Advertisement Object-Class is 48.</t>
        <t indent="0" pn="section-7.4-4">The Peer Prefix Advertisement Object-Type is 1 for IPv4 and 2 for
        IPv6.</t>
        <t indent="0" pn="section-7.4-5">The format of the Peer Prefix Advertisement object body for IPv4 is as
        follows:</t>
        <figure anchor="fig-14" align="left" suppress-title="false" pn="figure-14">
          <name slugifiedName="name-peer-prefix-advertisement-ob">Peer Prefix Advertisement Object Body Format for IPv4</name>
          <artwork name="" type="" align="center" alt="" pn="section-7.4-6.1">
 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                  Peer IPv4 Address                            |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| No. of Prefix |                  Reserved                     |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                  IPv4 Prefix #1                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Prefix #1 Len  |                  Reserved                     |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                               :                               |
|                               :                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                  IPv4 Prefix #n                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Prefix #n Len  |                  Reserved                     |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//                    Optional TLVs                            //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
</artwork>
        </figure>
        <t indent="0" pn="section-7.4-7">The format of the Peer Prefix Advertisement object body for IPv6 is as
        follows:</t>
        <figure anchor="fig-15" align="left" suppress-title="false" pn="figure-15">
          <name slugifiedName="name-peer-prefix-advertisement-obj">Peer Prefix Advertisement Object Body Format for IPv6</name>
          <artwork name="" type="" align="center" alt="" pn="section-7.4-8.1">
 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                                                               |
|                  Peer IPv6 Address                            |
|                                                               |
|                                                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| No. of Prefix |                  Reserved                     |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                  IPv6 Prefix #1                               |
|                                                               |
|                                                               |
|                                                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Prefix #1 Len  |                  Reserved                     |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                               :                               |
|                               :                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                  IPv6 Prefix #n                               |
|                                                               |
|                                                               |
|                                                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Prefix #n Len  |                  Reserved                     |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//                    Optional TLVs                            //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
</artwork>
        </figure>
        <dl newline="true" indent="3" spacing="normal" pn="section-7.4-9">
          <dt pn="section-7.4-9.1">Common Fields:</dt>
          <dd pn="section-7.4-9.2">
            <dl newline="false" spacing="normal" indent="3" pn="section-7.4-9.2.1">
              <dt pn="section-7.4-9.2.1.1">No. of Prefix:</dt>
              <dd pn="section-7.4-9.2.1.2">1 byte. Identifies the
              number of prefixes that are advertised to the peer in the PPA
              object.</dd>
              <dt pn="section-7.4-9.2.1.3">Reserved:</dt>
              <dd pn="section-7.4-9.2.1.4">3 bytes. Ought to be set to zero
              while sending and ignored on receipt.</dd>
              <dt pn="section-7.4-9.2.1.5">Prefix Len:</dt>
              <dd pn="section-7.4-9.2.1.6">1 byte. Identifies the length
              of the prefix.</dd>
              <dt pn="section-7.4-9.2.1.7">Optional TLVs:</dt>
              <dd pn="section-7.4-9.2.1.8">TLVs that are associated with this
              object; can be used to convey other necessary information for
              prefix advertisement. No TLVs are currently defined.</dd>
            </dl>
          </dd>
          <dt pn="section-7.4-9.3">For IPv4:</dt>
          <dd pn="section-7.4-9.4">
            <dl newline="false" spacing="normal" indent="3" pn="section-7.4-9.4.1">
              <dt pn="section-7.4-9.4.1.1">Peer IPv4 Address:</dt>
              <dd pn="section-7.4-9.4.1.2">4 bytes. Identifies the
              Peer IPv4 Address that the associated prefixes will be sent
              to.</dd>
              <dt pn="section-7.4-9.4.1.3">IPv4 Prefix:</dt>
              <dd pn="section-7.4-9.4.1.4">4 bytes. Identifies the prefix
              that will be sent to the peer identified by the Peer IPv4
              Address.</dd>
            </dl>
          </dd>
          <dt pn="section-7.4-9.5">For IPv6:</dt>
          <dd pn="section-7.4-9.6">
            <dl newline="false" spacing="normal" indent="3" pn="section-7.4-9.6.1">
              <dt pn="section-7.4-9.6.1.1">Peer IPv6 Address:</dt>
              <dd pn="section-7.4-9.6.1.2">16 bytes. Identifies the
              Peer IPv6 Address that the associated prefixes will be sent
              to.</dd>
              <dt pn="section-7.4-9.6.1.3">IPv6 Prefix:</dt>
              <dd pn="section-7.4-9.6.1.4">Identifies the prefix that will be
              sent to the peer identified by the Peer IPv6 Address.</dd>
            </dl>
          </dd>
        </dl>
        <t indent="0" pn="section-7.4-10">If in the future a requirement is identified to advertise IPv4
          prefixes towards an IPv6 peering address or IPv6 prefixes towards an
          IPv4 peering address, then a new Peer Prefix Advertisement
          Object-Type can be defined for these purposes.</t>
      </section>
    </section>
    <section anchor="NewErrorTypeAndValue" numbered="true" toc="include" removeInRFC="false" pn="section-8">
      <name slugifiedName="name-new-error-type-and-error-va">New Error-Type and Error-Values Defined</name>
      <t indent="0" pn="section-8-1">A PCEP-ERROR object is used to report a PCEP error and is
      characterized by an Error-Type that specifies that type of error and an
      Error-value that provides additional information about the error. An
      additional Error-Type and several Error-values are defined to represent
      the errors related to the newly defined objects that are related to
      Native IP TE procedures. See <xref target="err-type-value-reg" format="default" sectionFormat="of" derivedContent="Table 4"/> for the newly defined
      Error-Type and Error-values.</t>
    </section>
    <section anchor="BGP_Considerations" numbered="true" toc="include" removeInRFC="false" pn="section-9">
      <name slugifiedName="name-bgp-considerations">BGP Considerations</name>
      <t indent="0" pn="section-9-1">This document defines procedures and objects to create the BGP
      sessions and to advertise the associated prefixes dynamically. Only the key
      information, for example, Peer IP Addresses, and Peer AS numbers are
      exchanged via the PCEP. Other parameters that are needed for
      the BGP session setup <bcp14>SHOULD</bcp14> be derived from their default values.</t>
      <t indent="0" pn="section-9-2">When the PCE sends out the PCInitiate message with the BPI object
      embedded to establish the BGP session between the PCC peers, the PCC
      <bcp14>SHOULD</bcp14> report the BGP session status. For instance, the PCC could
      respond with "BGP Session Establishment In Progress" initially and, on
      session establishment, send another PCRpt message with the state updated
      to "BGP Session Established". If there is any error during the BGP
      session establishment, the PCC <bcp14>SHOULD</bcp14> indicate the reason with the
      appropriate status value set in the BPI object.</t>
      <t indent="0" pn="section-9-3">Upon receiving such key information, the BGP module on the PCC <bcp14>SHOULD</bcp14>
      try to accomplish the task appointed by the PCEP and report the
      successful status to the PCEP modules after the session is set up.</t>
      <t indent="0" pn="section-9-4">There is no influence on the current implementation of the BGP Finite
      State Machine (FSM). PCEP focuses only on the success and failure
      status of the BGP session and acts upon such information
      accordingly.</t>
      <t indent="0" pn="section-9-5">The error-handling procedures related to incorrect BGP parameters are
      specified in Sections <xref target="BGPSess" format="counter" sectionFormat="of" derivedContent="6.1"/>, <xref target="BGPEx" format="counter" sectionFormat="of" derivedContent="6.2"/>, and <xref target="BGPPrefix" format="counter" sectionFormat="of" derivedContent="6.3"/>.</t>
    </section>
    <section numbered="true" toc="include" removeInRFC="false" pn="section-10">
      <name slugifiedName="name-deployment-considerations">Deployment Considerations</name>
      <t indent="0" pn="section-10-1">The information transferred in this document is mainly used for the
      BGP session setup, explicit route deployment, and prefix
      distribution. The planning, allocation, and distribution of the peer
      addresses within IGP need to be accomplished in advance, and they are
      out of the scope of this document.</t>
      <t indent="0" pn="section-10-2">The communication of PCE and PCC described in this document <bcp14>MUST</bcp14>
      follow the State Synchronization procedures described in <xref target="RFC8232" format="default" sectionFormat="of" derivedContent="RFC8232"/>, i.e., treat the three newly defined objects (BPI, EPR, and
      PPA) associated with the same Symbolic Path Name as the attribute of the
      same path in the LSP Database (LSP-DB).</t>
      <t indent="0" pn="section-10-3">When the PCE detects that one or some of the PCCs are out of its control, it
      <bcp14>MUST</bcp14> recompute and redeploy the traffic engineering path for Native IP
      on the currently active PCCs. The PCE <bcp14>MUST</bcp14> ensure the avoidance of the
      possible transient loop in such node failure when it deploys the
      explicit peer route on the PCCs.</t>
      <t indent="0" pn="section-10-4">In case of a PCE failure, a new PCE can gain control over the Central
      Controller Instructions as described in <xref target="RFC9050" format="default" sectionFormat="of" derivedContent="RFC9050"/>.</t>
      <t indent="0" pn="section-10-5">As per the PCEP procedures in <xref target="RFC8281" format="default" sectionFormat="of" derivedContent="RFC8281"/>, the State
      Timeout Interval timer is used to ensure that a PCE failure does not
      result in automatic and immediate disruption for the services.
      Similarly, as per <xref target="RFC9050" format="default" sectionFormat="of" derivedContent="RFC9050"/>, the Central Controller
      Instructions are not removed immediately upon PCE failure. Instead, they
      could be redelegated to the new PCE before the expiration of this
      timer or be cleaned up on the expiration of this timer. This allows for
      network cleanup without manual intervention. The PCC supports the
      removal of CCI as one of the behaviors applied on the expiration of the
      State Timeout Interval timer.</t>
    </section>
    <section numbered="true" toc="include" removeInRFC="false" pn="section-11">
      <name slugifiedName="name-manageability-consideration">Manageability Considerations</name>
      <section numbered="true" toc="include" removeInRFC="false" pn="section-11.1">
        <name slugifiedName="name-control-of-function-and-pol">Control of Function and Policy</name>
        <t indent="0" pn="section-11.1-1">A PCE or PCC implementation <bcp14>SHOULD</bcp14> allow the PCECC Native IP
        capability to be enabled/disabled as part of the global
        configuration.</t>
      </section>
      <section numbered="true" toc="include" removeInRFC="false" pn="section-11.2">
        <name slugifiedName="name-information-and-data-models">Information and Data Models</name>
        <t indent="0" pn="section-11.2-1"><xref target="RFC7420" format="default" sectionFormat="of" derivedContent="RFC7420"/> describes the PCEP MIB; this MIB could be
        extended to get the PCECC Native IP capability status. The PCEP YANG module
        <xref target="I-D.ietf-pce-pcep-yang" format="default" sectionFormat="of" derivedContent="YANG-PCEP"/> could be extended to
        enable/disable the PCECC Native IP capability.</t>
      </section>
      <section numbered="true" toc="include" removeInRFC="false" pn="section-11.3">
        <name slugifiedName="name-liveness-detection-and-moni">Liveness Detection and Monitoring</name>
        <t indent="0" pn="section-11.3-1">Mechanisms defined in this document do not imply any new liveness
        detection and monitoring requirements beyond those already listed in
	<xref target="RFC5440" format="default" sectionFormat="of" derivedContent="RFC5440"/>. The operator relies on existing IP
        liveness detection and monitoring.</t>
      </section>
      <section numbered="true" toc="include" removeInRFC="false" pn="section-11.4">
        <name slugifiedName="name-verify-correct-operations">Verify Correct Operations</name>
        <t indent="0" pn="section-11.4-1">Verification of the mechanisms defined in this document can be
        built on those already listed in <xref target="RFC5440" format="default" sectionFormat="of" derivedContent="RFC5440"/>, <xref target="RFC8231" format="default" sectionFormat="of" derivedContent="RFC8231"/>, and <xref target="RFC9050" format="default" sectionFormat="of" derivedContent="RFC9050"/>. Further, the operator
        needs to be able to verify the status of BGP sessions and prefix
        advertisements.</t>
      </section>
      <section numbered="true" toc="include" removeInRFC="false" pn="section-11.5">
        <name slugifiedName="name-requirements-on-other-proto">Requirements on Other Protocols</name>
        <t indent="0" pn="section-11.5-1">Mechanisms defined in this document require the interaction with
        BGP. <xref target="BGP_Considerations" format="default" sectionFormat="of" derivedContent="Section 9"/> describes in detail the
        considerations regarding the BGP. During the BGP session
        establishment, the Local/Peer IP Address <bcp14>MUST</bcp14> be dedicated to the
        usage of the Native IP TE solution and <bcp14>MUST NOT</bcp14> be used by other BGP
        sessions that are established manually or in other ways.</t>
      </section>
      <section numbered="true" toc="include" removeInRFC="false" pn="section-11.6">
        <name slugifiedName="name-impact-on-network-operation">Impact on Network Operations</name>
        <t indent="0" pn="section-11.6-1"><xref target="RFC8821" format="default" sectionFormat="of" derivedContent="RFC8821"/> describes the various deployment
        considerations in CCDR architecture and their impact on network
        operations.</t>
      </section>
    </section>
    <section numbered="true" toc="include" removeInRFC="false" pn="section-12">
      <name slugifiedName="name-security-considerations">Security Considerations</name>
      <t indent="0" pn="section-12-1">In this setup, the BGP sessions, prefix advertisement, and explicit
      peer route establishment are all controlled by the PCE. See <xref target="RFC4271" format="default" sectionFormat="of" derivedContent="RFC4271"/> for classical BGP
      implementation security considerations and <xref target="RFC4272" format="default" sectionFormat="of" derivedContent="RFC4272"/> for classical BGP
      vulnerabilities analysis. Security considerations in <xref target="RFC5440" format="default" sectionFormat="of" derivedContent="RFC5440"/> for the basic PCEP, <xref target="RFC8231" format="default" sectionFormat="of" derivedContent="RFC8231"/> for
      PCEP extension for stateful PCE, and <xref target="RFC8281" format="default" sectionFormat="of" derivedContent="RFC8281"/> for
      PCE-initiated LSP setup <bcp14>SHOULD</bcp14> be considered. To prevent a bogus PCE
      from sending harmful messages to the network nodes, the network devices
      <bcp14>SHOULD</bcp14> authenticate the PCE and ensure a secure communication channel
      between them. Thus, the mechanisms described in <xref target="RFC8253" format="default" sectionFormat="of" derivedContent="RFC8253"/>
      for the usage of TLS for PCEP and <xref target="RFC9050" format="default" sectionFormat="of" derivedContent="RFC9050"/> for
      protection against malicious PCEs <bcp14>SHOULD</bcp14> be used.</t>
      <t indent="0" pn="section-12-2">If the default values discussed in <xref target="BGP_Considerations" format="default" sectionFormat="of" derivedContent="Section 9"/> aren't enough and securing the BGP
      transport is required (for example, by using TCP Authentication Option (TCP-AO) <xref target="RFC5925" format="default" sectionFormat="of" derivedContent="RFC5925"/>),
      a suitable value can be provided through the addition of optional TLVs to the BGP Peer
      Info object that conveys the necessary additional information (for
      example, a key chain <xref target="RFC8177" format="default" sectionFormat="of" derivedContent="RFC8177"/> name).</t>
    </section>
    <section numbered="true" toc="include" removeInRFC="false" pn="section-13">
      <name slugifiedName="name-iana-considerations">IANA Considerations</name>
      <section numbered="true" toc="include" removeInRFC="false" pn="section-13.1">
        <name slugifiedName="name-pcep-path-setup-types">PCEP Path Setup Types</name>
        <t indent="0" pn="section-13.1-1"><xref target="RFC8408" format="default" sectionFormat="of" derivedContent="RFC8408"/> created the "PCEP
        Path Setup Types" registry within the "Path
        Computation Element Protocol (PCEP) Numbers" registry group. IANA has 
        allocated a new codepoint
        within this registry, as follows:</t>
        <table align="center" pn="table-1">
          <name slugifiedName="name-pcep-path-setup-types-regis">PCEP Path Setup Types Registry</name>
          <thead>
            <tr>
              <th align="left" colspan="1" rowspan="1">Value</th>
              <th align="left" colspan="1" rowspan="1">Description</th>
              <th align="left" colspan="1" rowspan="1">Reference</th>
            </tr>
          </thead>
          <tbody>
            <tr>
              <td align="left" colspan="1" rowspan="1">4</td>
              <td align="left" colspan="1" rowspan="1">Native IP TE Path</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
          </tbody>
        </table>
      </section>
      <section numbered="true" toc="include" removeInRFC="false" pn="section-13.2">
        <name slugifiedName="name-pcecc-capability-sub-tlv-fl">PCECC-CAPABILITY Sub-TLV Flag Field</name>
        <t indent="0" pn="section-13.2-1"><xref target="RFC9050" format="default" sectionFormat="of" derivedContent="RFC9050"/> created the "PCECC-CAPABILITY sub-TLV" registry within the "Path
        Computation Element Protocol (PCEP) Numbers" registry group to manage the
        value of the PCECC-CAPABILITY sub-TLV's 32-bit Flag field. IANA
	has allocated a new bit position within this registry, as
        follows:</t>
        <table align="center" pn="table-2">
          <name slugifiedName="name-pcecc-capability-sub-tlv-re">PCECC-CAPABILITY Sub-TLV Registry</name>
          <thead>
            <tr>
              <th align="left" colspan="1" rowspan="1">Bit</th>
              <th align="left" colspan="1" rowspan="1">Name</th>
              <th align="left" colspan="1" rowspan="1">Reference</th>
            </tr>
          </thead>
          <tbody>
            <tr>
              <td align="left" colspan="1" rowspan="1">30</td>
              <td align="left" colspan="1" rowspan="1">Native IP</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
          </tbody>
        </table>
      </section>
      <section numbered="true" toc="include" removeInRFC="false" pn="section-13.3">
        <name slugifiedName="name-pcep-objects">PCEP Objects</name>
        <t indent="0" pn="section-13.3-1">IANA has allocated new codepoints in the "PCEP Objects"
        registry, as follows:</t>
        <table align="center" pn="table-3">
          <name slugifiedName="name-pcep-objects-registry">PCEP Objects Registry</name>
          <thead>
            <tr>
              <th align="left" colspan="1" rowspan="1">Object-Class Value</th>
              <th align="left" colspan="1" rowspan="1">Name</th>
              <th align="left" colspan="1" rowspan="1">Object-Type</th>
              <th align="left" colspan="1" rowspan="1">Reference</th>
            </tr>
          </thead>
          <tbody>
            <tr>
              <td align="left" colspan="1" rowspan="1">44</td>
              <td align="left" colspan="1" rowspan="1">CCI Object-Type</td>
              <td align="left" colspan="1" rowspan="1">2: Native IP</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td rowspan="3" align="left" colspan="1">46</td>
              <td rowspan="3" align="left" colspan="1">BGP Peer Info Object-Type</td>
              <td align="left" colspan="1" rowspan="1">0: Reserved</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td align="left" colspan="1" rowspan="1">1: IPv4 address</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td align="left" colspan="1" rowspan="1">2: IPv6 address</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td rowspan="3" align="left" colspan="1">47</td>
              <td rowspan="3" align="left" colspan="1">Explicit Peer Route Object-Type</td>
              <td align="left" colspan="1" rowspan="1">0: Reserved</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td align="left" colspan="1" rowspan="1">1: IPv4 address</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td align="left" colspan="1" rowspan="1">2: IPv6 address</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td rowspan="3" align="left" colspan="1">48</td>
              <td rowspan="3" align="left" colspan="1">Peer Prefix Advertisement Object-Type</td>
              <td align="left" colspan="1" rowspan="1">0: Reserved</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td align="left" colspan="1" rowspan="1">1: IPv4 address</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td align="left" colspan="1" rowspan="1">2: IPv6 address</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
          </tbody>
        </table>
      </section>
      <section numbered="true" toc="include" anchor="pcep-err-ob" removeInRFC="false" pn="section-13.4">
        <name slugifiedName="name-pcep-error-objects">PCEP-Error Objects</name>
        <t indent="0" pn="section-13.4-1">IANA has allocated a new Error-Type and several Error-values
        in the "PCEP-ERROR Object Error Types and Values" registry within
        the "Path Computation Element Protocol (PCEP) Numbers" registry group, as follows:</t>
        <table anchor="err-type-value-reg" align="center" pn="table-4">
          <name slugifiedName="name-pcep-error-object-error-typ">PCEP-ERROR Object Error Types and Values Registry</name>
          <thead>
            <tr>
              <th align="left" colspan="1" rowspan="1">Error-Type</th>
              <th align="left" colspan="1" rowspan="1">Meaning</th>
              <th align="left" colspan="1" rowspan="1">Error-value</th>
              <th align="left" colspan="1" rowspan="1">Reference</th>
            </tr>
          </thead>
          <tbody>
            <tr>
              <td align="left" colspan="1" rowspan="1">6</td>
              <td align="left" colspan="1" rowspan="1">Mandatory Object missing</td>
              <td align="left" colspan="1" rowspan="1">19: Native IP object missing</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td align="left" colspan="1" rowspan="1">10</td>
              <td align="left" colspan="1" rowspan="1">Reception of an invalid object</td>
              <td align="left" colspan="1" rowspan="1">39: PCECC NATIVE-IP-TE-CAPABILITY bit is not set</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td rowspan="3" align="left" colspan="1">19</td>
              <td rowspan="3" align="left" colspan="1">Invalid Operation</td>
              <td align="left" colspan="1" rowspan="1"> 22: Only one BPI, EPR, or PPA object can be included in this message</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td align="left" colspan="1" rowspan="1">29: Attempted Native IP operations when the capability was not advertised</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td align="left" colspan="1" rowspan="1">30: Unknown Native IP Info</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td rowspan="7" align="left" colspan="1">33</td>
              <td rowspan="7" align="left" colspan="1">Native IP TE failure</td>
              <td align="left" colspan="1" rowspan="1">0: Unassigned</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td align="left" colspan="1" rowspan="1">1: Local IP is in use</td>
              <td align="left" colspan="1" rowspan="1">RFC9757</td>
            </tr>
            <tr>
              <td align="left" colspan="1" rowspan="1">2: Remote IP is in use</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td align="left" colspan="1" rowspan="1">3: Explicit Peer Route Error</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td align="left" colspan="1" rowspan="1">4: EPR/BPI Peer Info mismatch</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td align="left" colspan="1" rowspan="1">5: BPI/PPA Address Family mismatch</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td align="left" colspan="1" rowspan="1">6: PPA/BPI Peer Info mismatch</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
          </tbody>
        </table>
        <t indent="0" pn="section-13.4-3">The reference for each new Error-Type/Error-value should be set to this
        document.</t>
      </section>
      <section numbered="true" toc="include" removeInRFC="false" pn="section-13.5">
        <name slugifiedName="name-cci-object-flag-field">CCI Object Flag Field</name>
        <t indent="0" pn="section-13.5-1">IANA has created the "CCI Object Flag Field
        for Native IP" registry to manage the
        16-bit Flag field of the new CCI object. New values are to be assigned by
	IETF Review <xref target="RFC8126" format="default" sectionFormat="of" derivedContent="RFC8126"/>. Each bit should
	be tracked with the following qualities:</t>
        <ul spacing="normal" bare="false" empty="false" indent="3" pn="section-13.5-2">
          <li pn="section-13.5-2.1">bit number (counting from bit 0 as the most significant bit
          and bit 15 as the least significant bit)</li>
          <li pn="section-13.5-2.2">capability description</li>
          <li pn="section-13.5-2.3">defining RFC</li>
        </ul>
        <t indent="0" pn="section-13.5-3">Currently, no flags are assigned.</t>
      </section>
      <section numbered="true" toc="include" removeInRFC="false" pn="section-13.6">
        <name slugifiedName="name-bpi-object-status-codes">BPI Object Status Codes</name>
        <t indent="0" pn="section-13.6-1">IANA has created the "BPI Object Status
        Code Field" registry within the "Path Computation Element Protocol (PCEP)
        Numbers" registry group. New values are assigned by IETF Review <xref target="RFC8126" format="default" sectionFormat="of" derivedContent="RFC8126"/>. Each value should be tracked with the following
        qualities: value, meaning, and defining RFC. The following values are
        defined in this document:</t>
        <table align="center" pn="table-5">
          <name slugifiedName="name-bpi-object-status-code-fiel">BPI Object Status Code Field Registry</name>
          <thead>
            <tr>
              <th align="left" colspan="1" rowspan="1">Value</th>
              <th align="left" colspan="1" rowspan="1">Meaning</th>
              <th align="left" colspan="1" rowspan="1">Reference</th>
            </tr>
          </thead>
          <tbody>
            <tr>
              <td align="left" colspan="1" rowspan="1">0</td>
              <td align="left" colspan="1" rowspan="1">Reserved</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td align="left" colspan="1" rowspan="1">1</td>
              <td align="left" colspan="1" rowspan="1">BGP Session Established</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td align="left" colspan="1" rowspan="1">2</td>
              <td align="left" colspan="1" rowspan="1">BGP Session Establishment In Progress</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td align="left" colspan="1" rowspan="1">3</td>
              <td align="left" colspan="1" rowspan="1">BGP Session Down</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td align="left" colspan="1" rowspan="1">4-255</td>
              <td align="left" colspan="1" rowspan="1">Unassigned</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
          </tbody>
        </table>
      </section>
      <section numbered="true" toc="include" removeInRFC="false" pn="section-13.7">
        <name slugifiedName="name-bpi-object-error-codes">BPI Object Error Codes</name>
        <t indent="0" pn="section-13.7-1">IANA has created the "BPI Object Error
        Code Field" registry within the "Path Computation Element Protocol (PCEP)
        Numbers" registry group. New values are assigned by IETF Review <xref target="RFC8126" format="default" sectionFormat="of" derivedContent="RFC8126"/>. Each value should be tracked with the following
        qualities: value, meaning, and defining RFC. The following values are
        defined in this document:</t>
        <table align="center" pn="table-6">
          <name slugifiedName="name-bpi-object-error-code-field">BPI Object Error Code Field Registry</name>
          <thead>
            <tr>
              <th align="left" colspan="1" rowspan="1">Value</th>
              <th align="left" colspan="1" rowspan="1">Meaning</th>
              <th align="left" colspan="1" rowspan="1">Reference</th>
            </tr>
          </thead>
          <tbody>
            <tr>
              <td align="left" colspan="1" rowspan="1">0</td>
              <td align="left" colspan="1" rowspan="1">Reserved</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td align="left" colspan="1" rowspan="1">1</td>
              <td align="left" colspan="1" rowspan="1">ASes do not match - BGP Session Failure</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td align="left" colspan="1" rowspan="1">2</td>
              <td align="left" colspan="1" rowspan="1">Peer IP can't be reached - BGP Session Failure</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
            <tr>
              <td align="left" colspan="1" rowspan="1">3-255</td>
              <td align="left" colspan="1" rowspan="1">Unassigned</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
          </tbody>
        </table>
      </section>
      <section numbered="true" toc="include" removeInRFC="false" pn="section-13.8">
        <name slugifiedName="name-bpi-object-flag-field">BPI Object Flag Field</name>
        <t indent="0" pn="section-13.8-1">IANA has created the "BPI Object Flag Field" registry
        within the "Path Computation Element Protocol (PCEP) Numbers" registry group.
        New values are to be assigned by IETF Review <xref target="RFC8126" format="default" sectionFormat="of" derivedContent="RFC8126"/>.
        Each bit should be tracked with the following qualities:</t>
        <ul spacing="normal" bare="false" empty="false" indent="3" pn="section-13.8-2">
          <li pn="section-13.8-2.1">
            <t indent="0" pn="section-13.8-2.1.1">bit number (counting from bit 0 as the most significant
            bit)</t>
          </li>
          <li pn="section-13.8-2.2">
            <t indent="0" pn="section-13.8-2.2.1">capability description</t>
          </li>
          <li pn="section-13.8-2.3">
            <t indent="0" pn="section-13.8-2.3.1">defining RFC</t>
          </li>
        </ul>
        <t indent="0" pn="section-13.8-3">The following values are defined in this document:</t>
        <table align="center" pn="table-7">
          <name slugifiedName="name-bpi-object-flag-field-regis">BPI Object Flag Field Registry</name>
          <thead>
            <tr>
              <th align="left" colspan="1" rowspan="1">Bit</th>
              <th align="left" colspan="1" rowspan="1">Meaning</th>
              <th align="left" colspan="1" rowspan="1">Reference</th>
            </tr>
          </thead>
          <tbody>
            <tr>
              <td align="left" colspan="1" rowspan="1">0-6</td>
              <td colspan="2" align="left" rowspan="1">Unassigned</td>
            </tr>
            <tr>
              <td align="left" colspan="1" rowspan="1">7</td>
              <td align="left" colspan="1" rowspan="1">T (IP-in-IP) bit</td>
              <td align="left" colspan="1" rowspan="1">RFC 9757</td>
            </tr>
          </tbody>
        </table>
      </section>
    </section>
  </middle>
  <back>
    <displayreference target="I-D.ietf-pce-pcep-yang" to="YANG-PCEP"/>
    <references pn="section-14">
      <name slugifiedName="name-references">References</name>
      <references pn="section-14.1">
        <name slugifiedName="name-normative-references">Normative References</name>
        <reference anchor="RFC2003" target="https://www.rfc-editor.org/info/rfc2003" quoteTitle="true" derivedAnchor="RFC2003">
          <front>
            <title>IP Encapsulation within IP</title>
            <author fullname="C. Perkins" initials="C." surname="Perkins"/>
            <date month="October" year="1996"/>
            <abstract>
              <t indent="0">This document specifies a method by which an IP datagram may be encapsulated (carried as payload) within an IP datagram. [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="2003"/>
          <seriesInfo name="DOI" value="10.17487/RFC2003"/>
        </reference>
        <reference anchor="RFC2119" target="https://www.rfc-editor.org/info/rfc2119" quoteTitle="true" derivedAnchor="RFC2119">
          <front>
            <title>Key words for use in RFCs to Indicate Requirement Levels</title>
            <author fullname="S. Bradner" initials="S." surname="Bradner"/>
            <date month="March" year="1997"/>
            <abstract>
              <t indent="0">In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.</t>
            </abstract>
          </front>
          <seriesInfo name="BCP" value="14"/>
          <seriesInfo name="RFC" value="2119"/>
          <seriesInfo name="DOI" value="10.17487/RFC2119"/>
        </reference>
        <reference anchor="RFC4271" target="https://www.rfc-editor.org/info/rfc4271" quoteTitle="true" derivedAnchor="RFC4271">
          <front>
            <title>A Border Gateway Protocol 4 (BGP-4)</title>
            <author fullname="Y. Rekhter" initials="Y." role="editor" surname="Rekhter"/>
            <author fullname="T. Li" initials="T." role="editor" surname="Li"/>
            <author fullname="S. Hares" initials="S." role="editor" surname="Hares"/>
            <date month="January" year="2006"/>
            <abstract>
              <t indent="0">This document discusses the Border Gateway Protocol (BGP), which is an inter-Autonomous System routing protocol.</t>
              <t indent="0">The primary function of a BGP speaking system is to exchange network reachability information with other BGP systems. This network reachability information includes information on the list of Autonomous Systems (ASes) that reachability information traverses. This information is sufficient for constructing a graph of AS connectivity for this reachability from which routing loops may be pruned, and, at the AS level, some policy decisions may be enforced.</t>
              <t indent="0">BGP-4 provides a set of mechanisms for supporting Classless Inter-Domain Routing (CIDR). These mechanisms include support for advertising a set of destinations as an IP prefix, and eliminating the concept of network "class" within BGP. BGP-4 also introduces mechanisms that allow aggregation of routes, including aggregation of AS paths.</t>
              <t indent="0">This document obsoletes RFC 1771. [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="4271"/>
          <seriesInfo name="DOI" value="10.17487/RFC4271"/>
        </reference>
        <reference anchor="RFC5440" target="https://www.rfc-editor.org/info/rfc5440" quoteTitle="true" derivedAnchor="RFC5440">
          <front>
            <title>Path Computation Element (PCE) Communication Protocol (PCEP)</title>
            <author fullname="JP. Vasseur" initials="JP." role="editor" surname="Vasseur"/>
            <author fullname="JL. Le Roux" initials="JL." role="editor" surname="Le Roux"/>
            <date month="March" year="2009"/>
            <abstract>
              <t indent="0">This document specifies the Path Computation Element (PCE) Communication Protocol (PCEP) for communications between a Path Computation Client (PCC) and a PCE, or between two PCEs. Such interactions include path computation requests and path computation replies as well as notifications of specific states related to the use of a PCE in the context of Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS) Traffic Engineering. PCEP is designed to be flexible and extensible so as to easily allow for the addition of further messages and objects, should further requirements be expressed in the future. [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="5440"/>
          <seriesInfo name="DOI" value="10.17487/RFC5440"/>
        </reference>
        <reference anchor="RFC5511" target="https://www.rfc-editor.org/info/rfc5511" quoteTitle="true" derivedAnchor="RFC5511">
          <front>
            <title>Routing Backus-Naur Form (RBNF): A Syntax Used to Form Encoding Rules in Various Routing Protocol Specifications</title>
            <author fullname="A. Farrel" initials="A." surname="Farrel"/>
            <date month="April" year="2009"/>
            <abstract>
              <t indent="0">Several protocols have been specified in the Routing Area of the IETF using a common variant of the Backus-Naur Form (BNF) of representing message syntax. However, there is no formal definition of this version of BNF.</t>
              <t indent="0">There is value in using the same variant of BNF for the set of protocols that are commonly used together. This reduces confusion and simplifies implementation.</t>
              <t indent="0">Updating existing documents to use some other variant of BNF that is already formally documented would be a substantial piece of work.</t>
              <t indent="0">This document provides a formal definition of the variant of BNF that has been used (that we call Routing BNF) and makes it available for use by new protocols. [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="5511"/>
          <seriesInfo name="DOI" value="10.17487/RFC5511"/>
        </reference>
        <reference anchor="RFC5925" target="https://www.rfc-editor.org/info/rfc5925" quoteTitle="true" derivedAnchor="RFC5925">
          <front>
            <title>The TCP Authentication Option</title>
            <author fullname="J. Touch" initials="J." surname="Touch"/>
            <author fullname="A. Mankin" initials="A." surname="Mankin"/>
            <author fullname="R. Bonica" initials="R." surname="Bonica"/>
            <date month="June" year="2010"/>
            <abstract>
              <t indent="0">This document specifies the TCP Authentication Option (TCP-AO), which obsoletes the TCP MD5 Signature option of RFC 2385 (TCP MD5). TCP-AO specifies the use of stronger Message Authentication Codes (MACs), protects against replays even for long-lived TCP connections, and provides more details on the association of security with TCP connections than TCP MD5. TCP-AO is compatible with either a static Master Key Tuple (MKT) configuration or an external, out-of-band MKT management mechanism; in either case, TCP-AO also protects connections when using the same MKT across repeated instances of a connection, using traffic keys derived from the MKT, and coordinates MKT changes between endpoints. The result is intended to support current infrastructure uses of TCP MD5, such as to protect long-lived connections (as used, e.g., in BGP and LDP), and to support a larger set of MACs with minimal other system and operational changes. TCP-AO uses a different option identifier than TCP MD5, even though TCP-AO and TCP MD5 are never permitted to be used simultaneously. TCP-AO supports IPv6, and is fully compatible with the proposed requirements for the replacement of TCP MD5. [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="5925"/>
          <seriesInfo name="DOI" value="10.17487/RFC5925"/>
        </reference>
        <reference anchor="RFC7420" target="https://www.rfc-editor.org/info/rfc7420" quoteTitle="true" derivedAnchor="RFC7420">
          <front>
            <title>Path Computation Element Communication Protocol (PCEP) Management Information Base (MIB) Module</title>
            <author fullname="A. Koushik" initials="A." surname="Koushik"/>
            <author fullname="E. Stephan" initials="E." surname="Stephan"/>
            <author fullname="Q. Zhao" initials="Q." surname="Zhao"/>
            <author fullname="D. King" initials="D." surname="King"/>
            <author fullname="J. Hardwick" initials="J." surname="Hardwick"/>
            <date month="December" year="2014"/>
            <abstract>
              <t indent="0">This memo defines a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, it describes managed objects for modeling of the Path Computation Element Communication Protocol (PCEP) for communications between a Path Computation Client (PCC) and a Path Computation Element (PCE), or between two PCEs.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="7420"/>
          <seriesInfo name="DOI" value="10.17487/RFC7420"/>
        </reference>
        <reference anchor="RFC8126" target="https://www.rfc-editor.org/info/rfc8126" quoteTitle="true" derivedAnchor="RFC8126">
          <front>
            <title>Guidelines for Writing an IANA Considerations Section in RFCs</title>
            <author fullname="M. Cotton" initials="M." surname="Cotton"/>
            <author fullname="B. Leiba" initials="B." surname="Leiba"/>
            <author fullname="T. Narten" initials="T." surname="Narten"/>
            <date month="June" year="2017"/>
            <abstract>
              <t indent="0">Many protocols make use of points of extensibility that use constants to identify various protocol parameters. To ensure that the values in these fields do not have conflicting uses and to promote interoperability, their allocations are often coordinated by a central record keeper. For IETF protocols, that role is filled by the Internet Assigned Numbers Authority (IANA).</t>
              <t indent="0">To make assignments in a given registry prudently, guidance describing the conditions under which new values should be assigned, as well as when and how modifications to existing values can be made, is needed. This document defines a framework for the documentation of these guidelines by specification authors, in order to assure that the provided guidance for the IANA Considerations is clear and addresses the various issues that are likely in the operation of a registry.</t>
              <t indent="0">This is the third edition of this document; it obsoletes RFC 5226.</t>
            </abstract>
          </front>
          <seriesInfo name="BCP" value="26"/>
          <seriesInfo name="RFC" value="8126"/>
          <seriesInfo name="DOI" value="10.17487/RFC8126"/>
        </reference>
        <reference anchor="RFC8174" target="https://www.rfc-editor.org/info/rfc8174" quoteTitle="true" derivedAnchor="RFC8174">
          <front>
            <title>Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words</title>
            <author fullname="B. Leiba" initials="B." surname="Leiba"/>
            <date month="May" year="2017"/>
            <abstract>
              <t indent="0">RFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings.</t>
            </abstract>
          </front>
          <seriesInfo name="BCP" value="14"/>
          <seriesInfo name="RFC" value="8174"/>
          <seriesInfo name="DOI" value="10.17487/RFC8174"/>
        </reference>
        <reference anchor="RFC8231" target="https://www.rfc-editor.org/info/rfc8231" quoteTitle="true" derivedAnchor="RFC8231">
          <front>
            <title>Path Computation Element Communication Protocol (PCEP) Extensions for Stateful PCE</title>
            <author fullname="E. Crabbe" initials="E." surname="Crabbe"/>
            <author fullname="I. Minei" initials="I." surname="Minei"/>
            <author fullname="J. Medved" initials="J." surname="Medved"/>
            <author fullname="R. Varga" initials="R." surname="Varga"/>
            <date month="September" year="2017"/>
            <abstract>
              <t indent="0">The Path Computation Element Communication Protocol (PCEP) provides mechanisms for Path Computation Elements (PCEs) to perform path computations in response to Path Computation Client (PCC) requests.</t>
              <t indent="0">Although PCEP explicitly makes no assumptions regarding the information available to the PCE, it also makes no provisions for PCE control of timing and sequence of path computations within and across PCEP sessions. This document describes a set of extensions to PCEP to enable stateful control of MPLS-TE and GMPLS Label Switched Paths (LSPs) via PCEP.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="8231"/>
          <seriesInfo name="DOI" value="10.17487/RFC8231"/>
        </reference>
        <reference anchor="RFC8232" target="https://www.rfc-editor.org/info/rfc8232" quoteTitle="true" derivedAnchor="RFC8232">
          <front>
            <title>Optimizations of Label Switched Path State Synchronization Procedures for a Stateful PCE</title>
            <author fullname="E. Crabbe" initials="E." surname="Crabbe"/>
            <author fullname="I. Minei" initials="I." surname="Minei"/>
            <author fullname="J. Medved" initials="J." surname="Medved"/>
            <author fullname="R. Varga" initials="R." surname="Varga"/>
            <author fullname="X. Zhang" initials="X." surname="Zhang"/>
            <author fullname="D. Dhody" initials="D." surname="Dhody"/>
            <date month="September" year="2017"/>
            <abstract>
              <t indent="0">A stateful Path Computation Element (PCE) has access to not only the information disseminated by the network's Interior Gateway Protocol (IGP) but also the set of active paths and their reserved resources for its computation. The additional Label Switched Path (LSP) state information allows the PCE to compute constrained paths while considering individual LSPs and their interactions. This requires a State Synchronization mechanism between the PCE and the network, the PCE and Path Computation Clients (PCCs), and cooperating PCEs. The basic mechanism for State Synchronization is part of the stateful PCE specification. This document presents motivations for optimizations to the base State Synchronization procedure and specifies the required Path Computation Element Communication Protocol (PCEP) extensions.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="8232"/>
          <seriesInfo name="DOI" value="10.17487/RFC8232"/>
        </reference>
        <reference anchor="RFC8253" target="https://www.rfc-editor.org/info/rfc8253" quoteTitle="true" derivedAnchor="RFC8253">
          <front>
            <title>PCEPS: Usage of TLS to Provide a Secure Transport for the Path Computation Element Communication Protocol (PCEP)</title>
            <author fullname="D. Lopez" initials="D." surname="Lopez"/>
            <author fullname="O. Gonzalez de Dios" initials="O." surname="Gonzalez de Dios"/>
            <author fullname="Q. Wu" initials="Q." surname="Wu"/>
            <author fullname="D. Dhody" initials="D." surname="Dhody"/>
            <date month="October" year="2017"/>
            <abstract>
              <t indent="0">The Path Computation Element Communication Protocol (PCEP) defines the mechanisms for the communication between a Path Computation Client (PCC) and a Path Computation Element (PCE), or among PCEs. This document describes PCEPS -- the usage of Transport Layer Security (TLS) to provide a secure transport for PCEP. The additional security mechanisms are provided by the transport protocol supporting PCEP; therefore, they do not affect the flexibility and extensibility of PCEP.</t>
              <t indent="0">This document updates RFC 5440 in regards to the PCEP initialization phase procedures.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="8253"/>
          <seriesInfo name="DOI" value="10.17487/RFC8253"/>
        </reference>
        <reference anchor="RFC8281" target="https://www.rfc-editor.org/info/rfc8281" quoteTitle="true" derivedAnchor="RFC8281">
          <front>
            <title>Path Computation Element Communication Protocol (PCEP) Extensions for PCE-Initiated LSP Setup in a Stateful PCE Model</title>
            <author fullname="E. Crabbe" initials="E." surname="Crabbe"/>
            <author fullname="I. Minei" initials="I." surname="Minei"/>
            <author fullname="S. Sivabalan" initials="S." surname="Sivabalan"/>
            <author fullname="R. Varga" initials="R." surname="Varga"/>
            <date month="December" year="2017"/>
            <abstract>
              <t indent="0">The Path Computation Element Communication Protocol (PCEP) provides mechanisms for Path Computation Elements (PCEs) to perform path computations in response to Path Computation Client (PCC) requests.</t>
              <t indent="0">The extensions for stateful PCE provide active control of Multiprotocol Label Switching (MPLS) Traffic Engineering Label Switched Paths (TE LSPs) via PCEP, for a model where the PCC delegates control over one or more locally configured LSPs to the PCE. This document describes the creation and deletion of PCE-initiated LSPs under the stateful PCE model.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="8281"/>
          <seriesInfo name="DOI" value="10.17487/RFC8281"/>
        </reference>
        <reference anchor="RFC8408" target="https://www.rfc-editor.org/info/rfc8408" quoteTitle="true" derivedAnchor="RFC8408">
          <front>
            <title>Conveying Path Setup Type in PCE Communication Protocol (PCEP) Messages</title>
            <author fullname="S. Sivabalan" initials="S." surname="Sivabalan"/>
            <author fullname="J. Tantsura" initials="J." surname="Tantsura"/>
            <author fullname="I. Minei" initials="I." surname="Minei"/>
            <author fullname="R. Varga" initials="R." surname="Varga"/>
            <author fullname="J. Hardwick" initials="J." surname="Hardwick"/>
            <date month="July" year="2018"/>
            <abstract>
              <t indent="0">A Path Computation Element (PCE) can compute Traffic Engineering (TE) paths through a network; these paths are subject to various constraints. Currently, TE paths are Label Switched Paths (LSPs) that are set up using the RSVP-TE signaling protocol. However, other TE path setup methods are possible within the PCE architecture. This document proposes an extension to the PCE Communication Protocol (PCEP) to allow support for different path setup methods over a given PCEP session.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="8408"/>
          <seriesInfo name="DOI" value="10.17487/RFC8408"/>
        </reference>
        <reference anchor="RFC9050" target="https://www.rfc-editor.org/info/rfc9050" quoteTitle="true" derivedAnchor="RFC9050">
          <front>
            <title>Path Computation Element Communication Protocol (PCEP) Procedures and Extensions for Using the PCE as a Central Controller (PCECC) of LSPs</title>
            <author fullname="Z. Li" initials="Z." surname="Li"/>
            <author fullname="S. Peng" initials="S." surname="Peng"/>
            <author fullname="M. Negi" initials="M." surname="Negi"/>
            <author fullname="Q. Zhao" initials="Q." surname="Zhao"/>
            <author fullname="C. Zhou" initials="C." surname="Zhou"/>
            <date month="July" year="2021"/>
            <abstract>
              <t indent="0">The Path Computation Element (PCE) is a core component of Software-Defined Networking (SDN) systems.</t>
              <t indent="0">A PCE as a Central Controller (PCECC) can simplify the processing of a distributed control plane by blending it with elements of SDN and without necessarily completely replacing it. Thus, the Label Switched Path (LSP) can be calculated/set up/initiated and the label-forwarding entries can also be downloaded through a centralized PCE server to each network device along the path while leveraging the existing PCE technologies as much as possible.</t>
              <t indent="0">This document specifies the procedures and Path Computation Element Communication Protocol (PCEP) extensions for using the PCE as the central controller for provisioning labels along the path of the static LSP.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="9050"/>
          <seriesInfo name="DOI" value="10.17487/RFC9050"/>
        </reference>
      </references>
      <references pn="section-14.2">
        <name slugifiedName="name-informative-references">Informative References</name>
        <reference anchor="RFC3209" target="https://www.rfc-editor.org/info/rfc3209" quoteTitle="true" derivedAnchor="RFC3209">
          <front>
            <title>RSVP-TE: Extensions to RSVP for LSP Tunnels</title>
            <author fullname="D. Awduche" initials="D." surname="Awduche"/>
            <author fullname="L. Berger" initials="L." surname="Berger"/>
            <author fullname="D. Gan" initials="D." surname="Gan"/>
            <author fullname="T. Li" initials="T." surname="Li"/>
            <author fullname="V. Srinivasan" initials="V." surname="Srinivasan"/>
            <author fullname="G. Swallow" initials="G." surname="Swallow"/>
            <date month="December" year="2001"/>
            <abstract>
              <t indent="0">This document describes the use of RSVP (Resource Reservation Protocol), including all the necessary extensions, to establish label-switched paths (LSPs) in MPLS (Multi-Protocol Label Switching). Since the flow along an LSP is completely identified by the label applied at the ingress node of the path, these paths may be treated as tunnels. A key application of LSP tunnels is traffic engineering with MPLS as specified in RFC 2702. [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="3209"/>
          <seriesInfo name="DOI" value="10.17487/RFC3209"/>
        </reference>
        <reference anchor="RFC4272" target="https://www.rfc-editor.org/info/rfc4272" quoteTitle="true" derivedAnchor="RFC4272">
          <front>
            <title>BGP Security Vulnerabilities Analysis</title>
            <author fullname="S. Murphy" initials="S." surname="Murphy"/>
            <date month="January" year="2006"/>
            <abstract>
              <t indent="0">Border Gateway Protocol 4 (BGP-4), along with a host of other infrastructure protocols designed before the Internet environment became perilous, was originally designed with little consideration for protection of the information it carries. There are no mechanisms internal to BGP that protect against attacks that modify, delete, forge, or replay data, any of which has the potential to disrupt overall network routing behavior.</t>
              <t indent="0">This document discusses some of the security issues with BGP routing data dissemination. This document does not discuss security issues with forwarding of packets. This memo provides information for the Internet community.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="4272"/>
          <seriesInfo name="DOI" value="10.17487/RFC4272"/>
        </reference>
        <reference anchor="RFC5036" target="https://www.rfc-editor.org/info/rfc5036" quoteTitle="true" derivedAnchor="RFC5036">
          <front>
            <title>LDP Specification</title>
            <author fullname="L. Andersson" initials="L." role="editor" surname="Andersson"/>
            <author fullname="I. Minei" initials="I." role="editor" surname="Minei"/>
            <author fullname="B. Thomas" initials="B." role="editor" surname="Thomas"/>
            <date month="October" year="2007"/>
            <abstract>
              <t indent="0">The architecture for Multiprotocol Label Switching (MPLS) is described in RFC 3031. A fundamental concept in MPLS is that two Label Switching Routers (LSRs) must agree on the meaning of the labels used to forward traffic between and through them. This common understanding is achieved by using a set of procedures, called a label distribution protocol, by which one LSR informs another of label bindings it has made. This document defines a set of such procedures called LDP (for Label Distribution Protocol) by which LSRs distribute labels to support MPLS forwarding along normally routed paths. [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="5036"/>
          <seriesInfo name="DOI" value="10.17487/RFC5036"/>
        </reference>
        <reference anchor="RFC8177" target="https://www.rfc-editor.org/info/rfc8177" quoteTitle="true" derivedAnchor="RFC8177">
          <front>
            <title>YANG Data Model for Key Chains</title>
            <author fullname="A. Lindem" initials="A." role="editor" surname="Lindem"/>
            <author fullname="Y. Qu" initials="Y." surname="Qu"/>
            <author fullname="D. Yeung" initials="D." surname="Yeung"/>
            <author fullname="I. Chen" initials="I." surname="Chen"/>
            <author fullname="J. Zhang" initials="J." surname="Zhang"/>
            <date month="June" year="2017"/>
            <abstract>
              <t indent="0">This document describes the key chain YANG data model. Key chains are commonly used for routing protocol authentication and other applications requiring symmetric keys. A key chain is a list containing one or more elements containing a Key ID, key string, send/accept lifetimes, and the associated authentication or encryption algorithm. By properly overlapping the send and accept lifetimes of multiple key chain elements, key strings and algorithms may be gracefully updated. By representing them in a YANG data model, key distribution can be automated.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="8177"/>
          <seriesInfo name="DOI" value="10.17487/RFC8177"/>
        </reference>
        <reference anchor="RFC8283" target="https://www.rfc-editor.org/info/rfc8283" quoteTitle="true" derivedAnchor="RFC8283">
          <front>
            <title>An Architecture for Use of PCE and the PCE Communication Protocol (PCEP) in a Network with Central Control</title>
            <author fullname="A. Farrel" initials="A." role="editor" surname="Farrel"/>
            <author fullname="Q. Zhao" initials="Q." role="editor" surname="Zhao"/>
            <author fullname="Z. Li" initials="Z." surname="Li"/>
            <author fullname="C. Zhou" initials="C." surname="Zhou"/>
            <date month="December" year="2017"/>
            <abstract>
              <t indent="0">The Path Computation Element (PCE) is a core component of Software- Defined Networking (SDN) systems. It can compute optimal paths for traffic across a network and can also update the paths to reflect changes in the network or traffic demands.</t>
              <t indent="0">PCE was developed to derive paths for MPLS Label Switched Paths (LSPs), which are supplied to the head end of the LSP using the Path Computation Element Communication Protocol (PCEP).</t>
              <t indent="0">SDN has a broader applicability than signaled MPLS traffic-engineered (TE) networks, and the PCE may be used to determine paths in a range of use cases including static LSPs, segment routing, Service Function Chaining (SFC), and most forms of a routed or switched network. It is, therefore, reasonable to consider PCEP as a control protocol for use in these environments to allow the PCE to be fully enabled as a central controller.</t>
              <t indent="0">This document briefly introduces the architecture for PCE as a central controller, examines the motivations and applicability for PCEP as a control protocol in this environment, and introduces the implications for the protocol. A PCE-based central controller can simplify the processing of a distributed control plane by blending it with elements of SDN and without necessarily completely replacing it.</t>
              <t indent="0">This document does not describe use cases in detail and does not define protocol extensions: that work is left for other documents.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="8283"/>
          <seriesInfo name="DOI" value="10.17487/RFC8283"/>
        </reference>
        <reference anchor="RFC8735" target="https://www.rfc-editor.org/info/rfc8735" quoteTitle="true" derivedAnchor="RFC8735">
          <front>
            <title>Scenarios and Simulation Results of PCE in a Native IP Network</title>
            <author fullname="A. Wang" initials="A." surname="Wang"/>
            <author fullname="X. Huang" initials="X." surname="Huang"/>
            <author fullname="C. Kou" initials="C." surname="Kou"/>
            <author fullname="Z. Li" initials="Z." surname="Li"/>
            <author fullname="P. Mi" initials="P." surname="Mi"/>
            <date month="February" year="2020"/>
            <abstract>
              <t indent="0">Requirements for providing the End-to-End (E2E) performance assurance are emerging within the service provider networks. While there are various technology solutions, there is no single solution that can fulfill these requirements for a native IP network. In particular, there is a need for a universal E2E solution that can cover both intra- and inter-domain scenarios.</t>
              <t indent="0">One feasible E2E traffic-engineering solution is the addition of central control in a native IP network. This document describes various complex scenarios and simulation results when applying the Path Computation Element (PCE) in a native IP network. This solution, referred to as Centralized Control Dynamic Routing (CCDR), integrates the advantage of using distributed protocols and the power of a centralized control technology, providing traffic engineering for native IP networks in a manner that applies equally to intra- and inter-domain scenarios.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="8735"/>
          <seriesInfo name="DOI" value="10.17487/RFC8735"/>
        </reference>
        <reference anchor="RFC8821" target="https://www.rfc-editor.org/info/rfc8821" quoteTitle="true" derivedAnchor="RFC8821">
          <front>
            <title>PCE-Based Traffic Engineering (TE) in Native IP Networks</title>
            <author fullname="A. Wang" initials="A." surname="Wang"/>
            <author fullname="B. Khasanov" initials="B." surname="Khasanov"/>
            <author fullname="Q. Zhao" initials="Q." surname="Zhao"/>
            <author fullname="H. Chen" initials="H." surname="Chen"/>
            <date month="April" year="2021"/>
            <abstract>
              <t indent="0">This document defines an architecture for providing traffic engineering in a native IP network using multiple BGP sessions and a Path Computation Element (PCE)-based central control mechanism. It defines the Centralized Control Dynamic Routing (CCDR) procedures and identifies needed extensions for the Path Computation Element Communication Protocol (PCEP).</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="8821"/>
          <seriesInfo name="DOI" value="10.17487/RFC8821"/>
        </reference>
        <reference anchor="I-D.ietf-pce-pcep-yang" target="https://datatracker.ietf.org/doc/html/draft-ietf-pce-pcep-yang-30" quoteTitle="true" derivedAnchor="YANG-PCEP">
          <front>
            <title>A YANG Data Model for Path Computation Element Communications Protocol (PCEP)</title>
            <author initials="D." surname="Dhody" fullname="Dhruv Dhody">
              <organization showOnFrontPage="true">Huawei</organization>
            </author>
            <author initials="V. P." surname="Beeram" fullname="Vishnu Pavan Beeram">
              <organization showOnFrontPage="true">Juniper Networks</organization>
            </author>
            <author initials="J." surname="Hardwick" fullname="Jonathan Hardwick">
         </author>
            <author initials="J." surname="Tantsura" fullname="Jeff Tantsura">
              <organization showOnFrontPage="true">Nvidia</organization>
            </author>
            <date month="January" day="26" year="2025"/>
            <abstract>
              <t indent="0">   This document defines a YANG data model for the management of the
   Path Computation Element communications Protocol (PCEP) for
   communications between a Path Computation Client (PCC) and a Path
   Computation Element (PCE), or between two PCEs.

              </t>
            </abstract>
          </front>
          <seriesInfo name="Internet-Draft" value="draft-ietf-pce-pcep-yang-30"/>
          <refcontent>Work in Progress</refcontent>
        </reference>
      </references>
    </references>
    <section numbered="false" toc="include" removeInRFC="false" pn="section-appendix.a">
      <name slugifiedName="name-acknowledgements">Acknowledgements</name>
      <t indent="0" pn="section-appendix.a-1">Thanks to <contact fullname="Mike Koldychev"/>, <contact fullname="Susan       Hares"/>, <contact fullname="Siva Sivabalan"/>, and <contact fullname="Adam Simpson"/> for their valuable suggestions and
      comments.</t>
    </section>
    <section numbered="false" toc="include" removeInRFC="false" pn="section-appendix.b">
      <name slugifiedName="name-contributors">Contributors</name>
      <t indent="0" pn="section-appendix.b-1"><contact fullname="Ren Tan"/> and <contact fullname="Dhruv Dhody"/> have contributed to this document.</t>
    </section>
    <section anchor="authors-addresses" numbered="false" removeInRFC="false" toc="include" pn="section-appendix.c">
      <name slugifiedName="name-authors-addresses">Authors' Addresses</name>
      <author fullname="Aijun Wang" initials="A" surname="Wang">
        <organization showOnFrontPage="true">China Telecom</organization>
        <address>
          <postal>
            <street>Beiqijia Town, Changping District</street>
            <city>Beijing</city>
            <code>102209</code>
            <country>China</country>
          </postal>
          <email>wangaijun@tsinghua.org.cn</email>
        </address>
      </author>
      <author fullname="Boris Khasanov" initials="B" surname="Khasanov">
        <organization abbrev="" showOnFrontPage="true">MTS Web Services (MWS)</organization>
        <address>
          <postal>
            <street>Andropova av., 18/9</street>
            <city>Moscow</city>
            <code>115432</code>
            <country>Russian Federation</country>
          </postal>
          <email>bhassanov@yahoo.com</email>
        </address>
      </author>
      <author fullname="Sheng Fang" initials="S" surname="Fang">
        <organization abbrev="" showOnFrontPage="true">Huawei Technologies</organization>
        <address>
          <postal>
            <street>Huawei Bld., No.156 Beiqing Rd.</street>
            <city>Beijing</city>
            <country>China</country>
          </postal>
          <email>fsheng@huawei.com</email>
        </address>
      </author>
      <author fullname="Chun Zhu" initials="C" surname="Zhu">
        <organization showOnFrontPage="true">ZTE Corporation</organization>
        <address>
          <postal>
            <street>50 Software Avenue, Yuhua District</street>
            <city>Nanjing</city>
            <region>Jiangsu</region>
            <code>210012</code>
            <country>China</country>
          </postal>
          <email>zhu.chun1@zte.com.cn</email>
        </address>
      </author>
    </section>
  </back>
</rfc>
