Network Working Group M. Boucadair Internet-Draft C. Jacquenet Intended status: Standards Track France Telecom Expires: November 30, 2013 May 29, 2013 Connectivity Provisioning Negotiation Protocol (CPNP) draft-boucadair-connectivity-provisioning-protocol-00 Abstract This document specifies the Connectivity Provisioning Negotiation Protocol (CPNP) which is used to facilitate the dynamic negotiation of connectivity provisioning parameters between a Customer and a Provider. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119]. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on November 30, 2013. Copyright Notice Copyright (c) 2013 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents Boucadair & Jacquenet Expires November 30, 2013 [Page 1] Internet-Draft CPNP May 2013 carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Order Processing Models . . . . . . . . . . . . . . . . . . . 4 4. Functional Elements . . . . . . . . . . . . . . . . . . . . . 5 5. Sample Use Cases . . . . . . . . . . . . . . . . . . . . . . 6 6. Deployment Models . . . . . . . . . . . . . . . . . . . . . . 7 7. Protocol Overview . . . . . . . . . . . . . . . . . . . . . . 7 7.1. Client/Server Communication . . . . . . . . . . . . . . . 7 7.2. Server Discovery . . . . . . . . . . . . . . . . . . . . 7 7.3. Policy Configuration on the CPNP Server . . . . . . . . . 8 7.4. CPNP Negotiation Model . . . . . . . . . . . . . . . . . 9 7.5. CPNP Session . . . . . . . . . . . . . . . . . . . . . . 10 7.6. Extended CPNP Session . . . . . . . . . . . . . . . . . . 11 7.7. CPNP Transaction . . . . . . . . . . . . . . . . . . . . 11 7.8. CPNP Operations . . . . . . . . . . . . . . . . . . . . . 11 7.9. Connectivity Provisioning Documents . . . . . . . . . . . 12 7.10. Child Connectivity Provisioning Quotation Orders . . . . 13 7.11. State Management . . . . . . . . . . . . . . . . . . . . 14 7.11.1. On The Client Side . . . . . . . . . . . . . . . . . 14 7.11.2. On The Server Side . . . . . . . . . . . . . . . . . 15 7.12. CPNP Timers . . . . . . . . . . . . . . . . . . . . . . . 17 8. CPNP Objects . . . . . . . . . . . . . . . . . . . . . . . . 17 8.1. Attributes . . . . . . . . . . . . . . . . . . . . . . . 17 8.1.1. CUSTOMER_ORDER_IDENTIFIER . . . . . . . . . . . . . . 17 8.1.2. PROVIDER_ORDER_IDENTIFIER . . . . . . . . . . . . . . 18 8.1.3. TRANSACTION_ID . . . . . . . . . . . . . . . . . . . 18 8.1.4. NONCE . . . . . . . . . . . . . . . . . . . . . . . . 18 8.1.5. EXPECTED_RESPONSE_DATE . . . . . . . . . . . . . . . 18 8.1.6. EXPECTED_OFFER_DATE . . . . . . . . . . . . . . . . . 18 8.1.7. VALIDITY_DATE . . . . . . . . . . . . . . . . . . . . 18 8.1.8. CONNECTIVITY_PROVISIONING_DOCUMENT . . . . . . . . . 19 8.1.9. Information Elements . . . . . . . . . . . . . . . . 19 8.2. Operation Messages . . . . . . . . . . . . . . . . . . . 20 8.2.1. PROVISION . . . . . . . . . . . . . . . . . . . . . . 20 8.2.2. PROCESSING . . . . . . . . . . . . . . . . . . . . . 21 8.2.3. OFFER . . . . . . . . . . . . . . . . . . . . . . . . 21 8.2.4. ACCEPT . . . . . . . . . . . . . . . . . . . . . . . 22 8.2.5. ACK . . . . . . . . . . . . . . . . . . . . . . . . . 22 8.2.6. DECLINE . . . . . . . . . . . . . . . . . . . . . . . 23 8.2.7. CANCEL . . . . . . . . . . . . . . . . . . . . . . . 24 Boucadair & Jacquenet Expires November 30, 2013 [Page 2] Internet-Draft CPNP May 2013 8.2.8. WITHDRAW . . . . . . . . . . . . . . . . . . . . . . 24 8.2.9. UPDATE . . . . . . . . . . . . . . . . . . . . . . . 25 8.2.10. FAIL . . . . . . . . . . . . . . . . . . . . . . . . 26 9. Message Validation . . . . . . . . . . . . . . . . . . . . . 27 9.1. On The Client Side . . . . . . . . . . . . . . . . . . . 27 9.2. On The Server Side . . . . . . . . . . . . . . . . . . . 27 10. Theory of Operations . . . . . . . . . . . . . . . . . . . . 28 10.1. Client Behavior . . . . . . . . . . . . . . . . . . . . 28 10.1.1. Order Negotiation Cycle . . . . . . . . . . . . . . 28 10.1.2. Order Withdrawal Cycle . . . . . . . . . . . . . . . 30 10.1.3. Order Update Cycle . . . . . . . . . . . . . . . . . 30 10.2. Server Behavior . . . . . . . . . . . . . . . . . . . . 30 10.2.1. Order Processing . . . . . . . . . . . . . . . . . . 30 10.2.2. Order Withdrawal . . . . . . . . . . . . . . . . . . 31 10.2.3. Order Update . . . . . . . . . . . . . . . . . . . . 32 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 32 12. Security Considerations . . . . . . . . . . . . . . . . . . . 32 13. References . . . . . . . . . . . . . . . . . . . . . . . . . 33 13.1. Normative References . . . . . . . . . . . . . . . . . . 33 13.2. Informative References . . . . . . . . . . . . . . . . . 33 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 34 1. Introduction [I-D.boucadair-connectivity-provisioning-profile] describes a Connectivity Provisioning Profile (CPP) template to capture connectivity requirements to be met by a transport infrastructure for the delivery of services (e.g., Voice over IP, IPTV, VPN services). The CPP profile defines the set of IP transfer guarantees to be offered by the underlying transport network together with a reachability scope and capacity needs. This document defines the Connectivity Provisioning Negotiation Protocol (CPNP) that is meant to dynamically exchange and negotiate the connectivity provisioning parameters between a Customer and a Provider. CPNP is a tool that introduces automation in the service negotiation and activation procedures, thus fostering the overall service delivery process. CPNP can be seen as a component of the dynamic negotiation meta-domain described in Section 3.4 of [I-D.sin-sdnrg-sdn-approach]. As a reminder, several proposals have been made in the past by the community (e.g., COPS-SLS, SrNP (Service Negotiation Protocol), DSNP (Dynamic Service Negotiation Protocol, RNAP (Resource Negotiation and Pricing Protocol), SNAP (Service Negotiation and Acquisition Protocol), etc.). None of these proposals has been standardized by IETF. It is out of the scope of this document to elaborate on the differences between CPNP and the aforementioned proposals. Boucadair & Jacquenet Expires November 30, 2013 [Page 3] Internet-Draft CPNP May 2013 2. Terminology This document makes use of the following terms: o Customer: is a business role which denotes an entity that is involved in the definition and the possible negotiation of a Connectivity Provisioning Agreement with a Network Provider. This contract is captured in a dedicated CPP (Connectivity Provisioning Profile, [I-D.boucadair-connectivity-provisioning-profile]) template, which specifies (among other information): the sites to be connected, border nodes, outsourced operations (e.g., routing). The right to invoke the connectivity service may be delegated by the Customer to third-party End Users, or brokering services. o Network Provider (or Provider): owns and administers one or many transport domain(s) (typically Autonomous System (AS)) composed of IP switching and transmission resources (e.g., routing, switching, forwarding, etc.). Network Providers are responsible for ensuring connectivity services (e.g., offering global or restricted reachability). Connectivity services offered to Customers are captured in contracts from which are derived the technology- specific clauses and policies to be enforced by the components involved in the connectivity service delivery. Offered connectivity services are not restricted to IP. 3. Order Processing Models There are basically two models for customer's order processing purposes: 1. Frozen model: The Customer cannot negotiate the parameters of the connectivity service delivered by a Provider. After consulting a service portfolio, the Customer selects the offer he/she wants to subscribe and places an order to the Provider. Order handling is quite simple on the Provider side because the service is not customized as per customer's requirements, but rather pre- designed to target a group of customers having similar requirements (and who therefore share the same Customer Provisioning Profile). 2. Negotiation-based model: Unlike the frozen model, the Customer documents his/her requirements in some kind of request for quotation which is then sent to one or several Providers. Solicited Providers then check whether they can address these requirements or not, and get back to the Customer accordingly, possibly with an offer that may not exactly match customer's requirements (e.g., a 100 Mbps connection cannot be provisioned given the amount of available resources, but an 80 Mbps Boucadair & Jacquenet Expires November 30, 2013 [Page 4] Internet-Draft CPNP May 2013 connection can be provided). A negotiation between the Customer and the Provider then follows, and an order is placed by the Customer eventually, upon completion of the negotiation phase. Even if the frozen model could also yield the instantiation of a CPP template and CPNP could be used to display the said CPP to the customer and confirm the order is being processed/delivered, etc., this document focuses on the negotiation-based model. Order processing management on the Network Provider's side is usually connected with the following functional blocks: o Network Provisioning (including Order Activation, Network Planning, etc.) o AAA o Sales-related functional blocks (e.g., billing, Customers credit checks validation, etc.) o Network Impact Analysis CPNP does not assume any specific knowledge about these functional blocks, but the instantiation of the connectivity provisioning requests may be conditioned by the information manipulated by some of these blocks. For example, the resources that can be allocated to accommodate the customer's requirements may depend on the network planning policy as well as the number of orders to be processed simultaneously over a given period of time. This document does not elaborate on how Customers are identified and managed by the Provider's Information System. 4. Functional Elements The following functional elements are defined in the context of CPNP: o Client: denotes a software instance that sends CPNP requests and receives CPNP responses. The current operations that can be performed by a CPNP client are listed below: 1. Create a connectivity provisioning quotation order. 2. Cancel an ongoing connectivity provisioning quotation order under negotiation. 3. Withdraw a pre-negotiated connectivity provisioning order. Boucadair & Jacquenet Expires November 30, 2013 [Page 5] Internet-Draft CPNP May 2013 4. Update a pre-negotiated connectivity provisioning order. o Server: denotes a software instance that receives CPNP requests and sends back CPNP responses accordingly. The CPNP server is responsible for the following operations: 1. Network provision quotation order handling. 2. Cancel an ongoing connectivity provisioning quotation order. 3. Handling of a connectivity provisioning order withdrawal. 5. Sample Use Cases A list of CPNP use cases is provided below: o [RFC4176] introduces the L3VPN Service Order Management functional block which is responsible for managing the requests initiated by the Customers and tracks the status of the completion of the related operations. CPNP can be used between the Customer and the Provider to negotiate L3VPN service parameters. A CPNP server could therefore be part of the L3VPN Service Order Management functional block discussed in [RFC4176]. o CPNP can be used between two adjacent domains to deliver IP interconnect services (e.g., enable, update, disconnect). For example, two ASes can be connected via several interconnection points. CPNP can be used between these ASes to upgrade existing links, request additional resources, provision a new interconnection point, etc. o An integrated Provider can use CPNP to rationalize connectivity provisioning needs related to its service portfolio. A CPNP server function is used by network operations teams. A CPNP interface to invoke CPNP negotiation cycles is exposed to service management teams. o Service Providers can initiate connectivity provisioning requests towards Network Providers using CPNP. Multiple CPNP ordering cycles can be initiated by a Service Provider towards multiple Network Providers. Only a subset of these orders may be put into effect. Boucadair & Jacquenet Expires November 30, 2013 [Page 6] Internet-Draft CPNP May 2013 6. Deployment Models Several CPNP deployment models can be envisaged. Two examples are listed below: o The Customer deploys a CPNP client while one or several CPNP servers are deployed by the Provider. o The Customer does not enable any CPNP client. The Provider maintains a Customer Order Management portal. The Customer can initiate connectivity provisioning quotation orders via the portal; appropriate CPNP messages are then generated and sent to the relevant CPNP server. In this model, both the CPNP client and CPNP server are under the responsibility of the same administrative entity (i.e., Network Provider). Once the negotiation of connectivity provisioning parameters is completed and an order has been placed by the Customer accordingly, the actual network provisioning operations are initiated. The specification of corresponding dynamic resource allocation and policy enforcement schemes, as well as how CPNP servers interact with network provisioning functional blocks are out of the scope of this document. This document does not make any assumption about the CPNP deployment model either. 7. Protocol Overview 7.1. Client/Server Communication CPNP is a client/server protocol which runs over UDP. No permanent CPNP session needs to be maintained between the client and the server. There is no need to run CPNP over a reliable transport mode because CPNP messages are acknowledged. The server uses CPNP_PORT (see Section 11) to bind the CPNP service. CPNP client sends messages to CPNP_PORT. The same port is used as the source port of the request sent to the server to document service requirements, and must be used by the client to listen to messages sent by the server. CPNP messages can also be transported over DTLS [RFC6347]. 7.2. Server Discovery Boucadair & Jacquenet Expires November 30, 2013 [Page 7] Internet-Draft CPNP May 2013 The CPNP client can be configured with the CPNP server using manual or dynamic configuration means. For example, Providers may configure dedicated SRV records ([RFC2782]). Discussions about how the client discovers its server(s) are out of the scope of this document. The document assumes a CPNP server can be reached by the CPNP client, thanks to some configuration means. 7.3. Policy Configuration on the CPNP Server As an input to the CPNP server's decision-making process, the CPNP server is connected to various external modules such as: Customer Profiles, Network Topology, Network Resource Management, Orders Repository, AAA or Network Provisioning Manager (an example is shown in Figure 1). +-------------------------------------------------------+ | Administrative Blocks (e.g., Billing, Charging) | +--------------------------------------+----------------+ . . . . . . . . . . . . . . . . . . . .|. . . . . . . . . .Order Handling Management | . . +-------------------+ +-------------+--------------+ . . |Network Topology DB+--+ CPNP Server | . . +-------------------+ +-+---+---+---+---+-----+----+ . . | | | | | | . . +------------------------+-+ | | | | | . . | Network Dimensioning | | | | | | . . | & Planning | | | | | | . . +--------------------------+ | | | | | . . +----------------------------+-+ | | | +---+----+ . . | | | | | | AAA | . . | Network +------------+ | | | +--------+ . . | Resource | +------------+-+ | +-+----------+ . . | Management | | Customer | | | Orders | . . | | | Profiles | | | Repository | . . +-----------------+ +--------------+ | +------------+ . . . . . . . . . . . . . . . . . . . . .|. . . . . . . . . +--------------------------------------+----------------+ | Network Provisioning Manager | +-------------------------------------------------------+ Figure 1: Order Handling Management Functional Block These external modules provide inputs to the CPNP server, so that it can: o Check whether a customer is entitled to initiate the connectivity provisioning quotation request. Boucadair & Jacquenet Expires November 30, 2013 [Page 8] Internet-Draft CPNP May 2013 o Check whether a customer is entitled to cancel the order o Check whether administrative data (e.g., billing-related information) have been verified before starting handling the request o Check whether network capacity is available or additional capacity is required o Receive guidelines from network design and sales blocks (e.g., cost, increase network usage, threshold of how many CPP templates can be processed over a given period of time as a function of the nature of the service to be delivered, etc.) o Transfer completed orders to network provisioning blocks o Etc. The above list of CPNP server operations is not exhaustive. The following order handling modes can be also configured on the server: 1. Fully automated mode: This mode does not require any action from the administrator when receiving a request for a service. The server can execute its decision-making process related to the orders received and generate corresponding offers. 2. Administrative validation checking: Some or all server's operations are subject to administrative validation procedures. This mode requires an action from the administrator for every request received by the CPNP server. CPNP methods which can be automatically handled or subject to one or several validation administrative checks can be configured on the server. 7.4. CPNP Negotiation Model CPNP adopts a Quotation Order/Offer/Answer model where: 1. The client specifies its requirements via a connectivity provisioning quotation order (CPQO). 2. The server makes an offer to either address the requirements of the CPQO or suggests a counter-proposal that partially addresses the requirements of the CPQO or declines the CPQO. 3. The client either accepts or declines the offer. Boucadair & Jacquenet Expires November 30, 2013 [Page 9] Internet-Draft CPNP May 2013 Only one Offer/Answer stage is assumed within one single CPNP transaction (Section 7.7). Nevertheless, multiple CPNP transactions can be undertaken by the CPNP client (see Figure 2). +------+ +------+ +------+ +------+ |Client| |Server| |Client| |Server| +------+ +------+ +------+ +------+ |==== Quotation Order=====>| |==== Quotation Order======>| |<====Make an offer========| |<=====Make an offer========| |=========Accept==========>| |=========Decline==========>| 1-Step Successful Negotiation 1-Step Failed Negotiation Cycle Cycle +------+ +------+ +------+ +------+ |Client| |Server| |Client| |Server| +------+ +------+ +------+ +------+ |==Quotation Order(CPDa)==>| |==Quotation Order(CPD1)==>| |<====Make an offer========| |<=====Make an offer=======| |========Decline==========>| |=========Decline=========>| |==Quotation Order(CPDb)==>| |==Quotation Order(CPD2)==>| |<====Make an offer========| |<=====Make an offer=======| |=========Accept==========>| |=========Decline=========>| |==Quotation Order(CPD3)==>| |<=====Make an offer=======| |=========Decline=========>| |==Quotation Order(CPD4)==>| |<==Fail to make an offer==| N-Step Negotiation Cycle: N-Step Negotiation Cycle: Successful Negotiation Failed Negotiation Figure 2: Overall Negotiation Process 7.5. CPNP Session Both the client and servers maintains the following CPNP transport session information: A CPNP session is identified by the following items: o IP address of the client o Client's port number o IP address of the server o Server's port number Boucadair & Jacquenet Expires November 30, 2013 [Page 10] Internet-Draft CPNP May 2013 7.6. Extended CPNP Session An extended CPNO session denotes a 4-uplet defined as follows o CPNP session o Customer Order Identifier o Provider Order Identifier o Transaction-ID 7.7. CPNP Transaction A CPNP transaction occurs between a client and a server and comprises all CPNP messages, from the first request sent by the client to the server until a final response sent by the server to the client and which completes the transaction. The CPNP transaction is bound to a CPNP session. Because multiple CPNP transactions can be maintained by the CPNP client, the client must assign an identifier to uniquely identify a given transaction. This identifier is denoted as Transaction-ID. The Transaction-ID must be randomly assigned, according to the best current practice for generating random numbers [RFC4086] that cannot be guessed easily. Transaction-ID is used as part of the validation of CPNP responses received by the client. Using cryptographically random Transaction-IDs provides some protection against session hijacking. 7.8. CPNP Operations The current CPNP operations are listed below. They may be augmented, depending on the nature of some transactions or because of security considerations that may suggest a CPNP client/server authentication phase before negotiation begins. o PROVISION: This operation is used to initiate a connectivity provisioning quotation order. Upon receipt of a PROVISION request, the server may response with a PROCESSING, OFFER or a FAIL message. o PROCESSING: This operation is used to inform the remote party the message was received and that the order quotation or the offer is being processed. Boucadair & Jacquenet Expires November 30, 2013 [Page 11] Internet-Draft CPNP May 2013 o OFFER: This operation is used by the server to inform the client about an Offer that is supposed to best accommodate the requirements indicated in the PROVISION message. o ACCEPT: This operation is used to confirm the acceptance of an offer made by the server. o ACK: This operation is used by the server to acknowledge the receipt of an ACCEPT or WITHDRAW message. o DECLINE: This operation is used by a client to reject an offer made by the server. o CANCEL: This operation is used by the client to cancel an ongoing connectivity provisioning quotation order. o WITHDRAW: This operation is used by the client to withdraw a pre- negotiated connectivity provisioning order. o UPDATE: This operation is used by the client to update an existing connectivity provisioning order. For example, this method can be invoked to add a new site. This method will trigger a new negotiation cycle. o FAIL: This operation is used by the server when it cannot accommodate the requirements documented in the CPQO conveyed in the PROVISION message. This operation can also be used by a server to inform the client about an error encountered when processing the received message. The message includes the status code which provides more information about the error. 7.9. Connectivity Provisioning Documents CPNP makes use of several flavors of Connectivity Provisioning Documents (CPD). All these documents follow the CPP template described in [I-D.boucadair-connectivity-provisioning-profile]. o Requested Connectivity Provisioning Document: refers to the CPD included by a CPNP client in a PROVISION request. o Offered Connectivity Provisioning Document: This document is included by a CPNP server in an OFFER message. This information reflects the proposal of the server to accommodate all or a subset of the clauses depicted in a CPD. A validity date is associated with the offer. Boucadair & Jacquenet Expires November 30, 2013 [Page 12] Internet-Draft CPNP May 2013 o Agreed Connectivity Provisioning Document: If the client accepts the offer, the offered CPD is included in an ACCEPT message. This CPD is also included in an ACK message. Figure 3 shows a typical CPNP transaction and the use of Connectivity Provisioning Documents: +------+ +------+ |Client| |Server| +------+ +------+ |======PROVISION (Requested CPD)=====>| |<============PROCESSING==============| |<========OFFER (Offered CPD)=========| |=============PROCESSING=============>| |=========ACCEPT (Agreed CPD)========>| |<=========ACK (Agreed CPD)===========| Figure 3: Connectivity Provisioning Documents 7.10. Child Connectivity Provisioning Quotation Orders If the server detects network resources from another network provider need to be allocated in order to accommodate the requirements described in a CPQO (e.g., context of an inter-domain VPN service where additional PE router resources need to be allocated), the server may generate child CPQOs to request the appropriate network provisioning operations (see Figure 4). In such situation, the server behaves as a CPNP client. The server must also associate the parent order with its child CPQOs. This is typically achieved by locally adding the reference of the child CPQO to the parent order. +------+ +--------+ +--------+ |Client| |Server A| |Server B| +------+ +--------+ +--------+ | | | |=====PROVISION=====>| | |<====PROCESSING=====| | | |=====PROVISION=====>| | |<====PROCESSING=====| | |<=======OFFER=======| | |=====PROCESSING====>| | |=======ACCEPT======>| | |<=======ACK=========| |<=======OFFER=======| | |<====PROCESSING=====| | |=======ACCEPT======>| | |<=======ACK=========| | Boucadair & Jacquenet Expires November 30, 2013 [Page 13] Internet-Draft CPNP May 2013 Figure 4: Example of Child Orders 7.11. State Management Both the client and the server maintain repositories to store ongoing orders. Contracted orders can be stored in the same repositories or be stored in a dedicated one (e.g., Connectivity Provisioning Agreements). Timestamps are also logged for any state change. 7.11.1. On The Client Side The following lists the states which can be associated with a given order on the client's side: o Created: when the order has been created. It is not handled by the client until the administrator allows to process it. o AwaitingProcessing: when the administrator ordered to process an order and this order is not handled yet. o CPQOSent: when the CPQO has been sent to the server. o ServerProcessing: when the server has confirmed the receipt of the order. o OfferReceived: when an offer has been received from the server. o OfferProcessing: when a received offer is currently processed by the client. o AcceptSent: when the client confirmed the offer to the server. o AcceptAck: when the offer is acknowledged by the server. o Cancelled: when the order has failed or has been cancelled. +------------------+ | Created |-----------------+ +------------------+ | | | v | +------------------+ | |AwaitingProcessing|----------------+| +------------------+ || | || PROVISION || v || +------------------+ || | CPQOSent |---CANCEL------+|| +------------------+ vvv | +-----+ PROCESSING | | v | | +------------------+ CANCEL | C | | ServerProcessing |------------>| A | +------------------+ FAIL | N | Boucadair & Jacquenet Expires November 30, 2013 [Page 14] Internet-Draft CPNP May 2013 | | C | | | E | OFFER | L | | | L | v | E | +------------------+ | D | | OfferReceived |---CANCEL--->| | +------------------+ | | | PROCESSING +-----+ v ^^^ +------------------+ ||| | OfferProcessing |---DECLINE-----+|| +------------------+ || | ACCEPT || v || +------------------+ || | AcceptSent |---CANCEL-------+| +------------------+ | | ACK | v | +------------------+ | | AcceptAck |---WITHDRAW------+ +------------------+ Figure 5: CPNP Finite State Machine (Client Side) 7.11.2. On The Server Side The following lists the states which can be associated with a given order on the server's side: o CPQOReceived: when the connectivity provisioning quotation order request has been received from the client. o AwaitingProcessing: when the order request is being processed by the server. An action from the server administrator may be needed. o OfferProposed: when the request has been successfully handled and an offer has been sent to the requesting client. o ProcessingReceived: when the server received a PROCESSING for an offer sent to the client. o AcceptReceived: when the server received a confirm for the offer from the client. o AcceptAck: when the server acknowledged the offer to the client. o Cancelled: when the order request has failed or has been cancelled. Associate resources must be released in the latter case. o ChildCreated: when a child CPQO has been created because resources from another network provider are needed. Boucadair & Jacquenet Expires November 30, 2013 [Page 15] Internet-Draft CPNP May 2013 o ChildCPQOSent: when a child CPQO has been sent to another server. o ChildServerProcessing: when a child CPQO is currently processed by another server. o ChildOfferReceived: when an offer has been received to a child CPQO. o ChildOfferProcessing: when a received offer is currently processed. o ChildAcceptSent: when the child offer is confirmed to another server. o ChildAcceptAck: when the child offer is acknowledged by another server. +------------------+ +---------------------| ChildCreated | | +------------------+ v | ^ +------------------+ | | | ChildCPQOSent |----------------+| P +------------------+ || R | || O PROVISION || V v || I +--------------------+ +---------------------+ CANCEL || S | CPQOReceived | |ChildServerProcessing|------------+|| I +--------------------+ +---------------------+ FAIL vvv O | | | +-----+ N CANCEL | PROCESSING | |<---|-------+ PROCESSING v | | | v +------------------+ | | +------------------------+ |ChildOfferReceived|----CANCEL---| C |<--| AwaitingProcessing | +------------------+ | A | +------------------------+ | | N | ^ | OFFER OFFER | C | | +------------------+ | | E | ::= ... ::= ... ::= ::= ... ::= 8.1.9. Information Elements An Information Element is an optional object which can be included in a CPNP message. 8.1.9.1. Customer Description The client may include administrative information such as: o Name o Contact Information The format of this Information Element is as follows: Boucadair & Jacquenet Expires November 30, 2013 [Page 19] Internet-Draft CPNP May 2013 ::= ::= [] [ ...] 8.1.9.2. Provider Description The server may include administrative information in an offer such as: o Name o AS Number o Contact Information The format of this Information Element is as follows: ::= [] 8.1.9.3. Negotiation Options The client may include some negotiation options such as: o Cost: the client may include an empty or a preferred COST attribute to request the cost from the server. The server will provide the cost information in the response. o Setup purpose: A client may request to setup a connectivity only for testing purposes during a limited period. The order can be extended to become permanent if the client was satisfied during the test period. This operation is achieved using UPDATE method. Other negotiation options may be defined in the future. The format of this Information Element is as follows: ::= [][] 8.2. Operation Messages This section specifies the RBNF format of CPNP operation messages. 8.2.1. PROVISION The format of PROVISION message is shown below: ::= Boucadair & Jacquenet Expires November 30, 2013 [Page 20] Internet-Draft CPNP May 2013 [] [...] A PROVISION message must include an order identifier which is generated by the client. Because several orders can be issued to several servers, the PROVISION message must also include a Transaction-ID. The message may include an EXPECTED_RESPONSE_DATE which indicates by when the client is expecting to receive an offer from the server. PROVISION message must also include a requested connectivity provisioning document. When the client sends the PROVISION message to the server, the state of the order changes to "CPQOSent". 8.2.2. PROCESSING The format of PROCESSING Message is shown below: ::= [] Upon receipt of a PROVISION message, the server proceeds with parsing rules (see Section 9). If no error is encountered, the server generates a PROCESSING response to the client to indicate the CPQO has been received and it is being processed. The server must generate an order identifier which identifies the order in its local order repository. The server MUST copy the content of CUSTOMER_ORDER_IDENTIFIER and TRANSACTION_ID fields as conveyed in the PROVISION message. The server may include an EXPECTED_OFFER_DATE by when it expects to make an offer to the client. Upon receipt of a PROCESSING message, the client verifies whether it has issued a CPQO to that server and which contains the CUSTOMER_ORDER_IDENTIFIER and TRANSACTION_ID. If no such CPQO is found, the PROCESSING message is silently ignored. If a CPQO is found, the client may check if it accepts the EXPECTED_OFFER_DATE and then, it changes to state of the order to "ServerProcessing". 8.2.3. OFFER The format of OFFER message is shown below: Boucadair & Jacquenet Expires November 30, 2013 [Page 21] Internet-Draft CPNP May 2013 ::= [...] The server answers with an OFFER message to a PROVISION request received from the client. The offer will be considered as rejected by the client if no confirmation (ACCEPT message sent by the client) is received by the server before the expiration of the validity date. 8.2.4. ACCEPT The format of ACCEPT message is shown below: ::= [...] This message is used by a client to confirm the acceptance of an offer received from a server. The fields of this message are copied from the received OFFER message. 8.2.5. ACK The format of ACK message is shown below: ::= [...] Boucadair & Jacquenet Expires November 30, 2013 [Page 22] Internet-Draft CPNP May 2013 This message is issued by the server to close a CPNP transaction. In particular, this message is sent as a response to an ACCEPT, WITHDRAW, DECLINE, or CANCEL message. The ACK message must include the copy of the Connectivity Provisioning Document as stored by the server, in particular: o A copy of the requested/offered CPD is included by the server if it successfully handled a CANCEL message. o A copy of the updated CPD is included by the server if it successfully handled an UPDATE message. o A copy of the offered CPD is included by the server if it successfully handled an ACCEPT message in the context of a PROVISION transaction. o An empty CPD is included by the server if it successfully handled a DECLINE message. 8.2.6. DECLINE The format of DECLINE message is shown below: ::= The client can issue a DECLINE message to reject an offer. CUSTOMER_ORDER_IDENTIFIER, PROVIDER_ORDER_IDENTIFIER and TRANSACTION_ID are used by the server as keys to find the corresponding order. If an order matches, the server changes the state of this order to "Cancelled" and then returns an ACK with a copy of the requested CPD to the requesting client. If no order is found, the server returns a FAIL message to the requesting client. A flow example is shown in Figure 7. +------+ +------+ |Client| |Server| +------+ +------+ |======PROVISION (Requested CPD)=====>| |<============PROCESSING==============| |<========OFFER (Offered CPD)=========| |=============PROCESSING=============>| |===============DECLINE==============>| |<================ACK=================| Boucadair & Jacquenet Expires November 30, 2013 [Page 23] Internet-Draft CPNP May 2013 Figure 7: DECLINE Flow Example 8.2.7. CANCEL The format of CANCEL message is shown below: ::= [] The client can issue a CANCEL message at any stage during the CPNP negotiation process. CUSTOMER_ORDER_IDENTIFIER and TRANSACTION_ID are used by the server as keys to find the corresponding order. If an order matches, the server changes the state of this order to "Cancelled" and then returns an ACK with a copy of the requested CPD to the requesting client. If no order is found, the server returns a FAIL message to the requesting client. 8.2.8. WITHDRAW The format of WITHDRAW message is shown below: ::= [] [...] This message is used to withdraw an offer already subscribed by the Customer. Figure 8 shows a typical usage of this message. +------+ +------+ |Client| |Server| +------+ +------+ |===========WITHDRAW (CPD)===========>| |<============PROCESSING==============| |<==========ACK (Empty CPD)===========| Figure 8: WITHDRAW Flow Example Boucadair & Jacquenet Expires November 30, 2013 [Page 24] Internet-Draft CPNP May 2013 The CPNP must include the same CUSTOMER_ORDER_IDENTIFIER, PROVIDER_ORDER_IDENTIFIER, and NONCE as those used when creating the order. Upon receipt of a WITHDRAW message, the server checks whether an order matching the request is found. If an order is found, the state of the order is changed to "Cancelled" and an ACK message including an Empty CPD is returned to the requesting client. If no order is found, the server returns a FAIL message to the requesting client. 8.2.9. UPDATE The format of UPDATE message is shown below: ::= [...] This message is sent by the CPNP client to update an existing connectivity provisioning agreement. The CPNP must include the same CUSTOMER_ORDER_IDENTIFIER, PROVIDER_ORDER_IDENTIFIER, and NONCE as those used when creating the order. The CPNP client includes a new CPD which integrates the requested modifications. A new Transaction_ID must be assigned by the client. Upon receipt of an UPDATE message, the server checks whether an order, having state "Completed", matches CUSTOMER_ORDER_IDENTIFIER, PROVIDER_ORDER_IDENTIFIER, and NONCE. o If no order is found, the CPNP server generates a FAIL error with the appropriate error code. o If an order is found, the server checks whether it can honor the request: * A FAIL message is sent to the client if the server cannot honor the request. The client may initiate a new CPQO negotiation cycle. Boucadair & Jacquenet Expires November 30, 2013 [Page 25] Internet-Draft CPNP May 2013 * An OFFER message including the updated connectivity provisioning document is sent to the client. For example, the server maintains an order for provisioning a VPN service that connects sites A, B and C. If the client sends an UPDATE message to remove site C, only sites A and B will be included in the OFFER sent by the server to the requesting client. A flow chart that illustrates the use of UPDATE operation is shown in Figure 9. +------+ +------+ |Client| |Server| +------+ +------+ |=========UPDATE (Diff CPD)==========>| |<============PROCESSING==============| |<========OFFER (Updated CPD)=========| |=========ACCEPT (Updated CPD)=======>| |<=========ACK (Updated CPD)==========| Figure 9: UPDATE Flow Example 8.2.10. FAIL The format of FAIL message is shown below: ::= This message is sent in the following cases: o The server can not honor an order received from the client (i.e., received in a PROVISION or UPDATE request). o The server encounters an error when processing a CPNP request received from the client. The status code indicates the error code. The following codes are currently supported; other codes will be defined in future versions of the document: o 1 (Validation Error): The message can not be validated (see Section 9). o 2 (Authentication Required): the request cannot be handled because authentication is required. Boucadair & Jacquenet Expires November 30, 2013 [Page 26] Internet-Draft CPNP May 2013 o 3 (Administratively prohibited): the request can not be handled because of administrative policies. o 4 (Out of Resources): the request can not be honored because there is not enough capacity. o 5 (Network Presence): the request can not be honored because there is no network presence. 9. Message Validation Both client and server proceed with CPNP message validation. The following tables summarize the validation checks to be followed. 9.1. On The Client Side Operation Validation Checks --------------- ----------------------------------------------------- PROCESSING {Source IP address, source port, destination IP address, destination port, Transaction-ID, Customer Order Identifier} must match an existing CPQO with a state set to "CPQOSent". OFFER {Source IP address, source port, destination IP address, destination port, Transaction-ID, Customer Order Identifier} must match an existing order with state set to "CPQOSent" or {Source IP address, source port, destination IP address, destination port, Transaction-ID, Customer Order Identifier, Provider Order Identifier} must match an existing order with a state set to "ServerProcessing". ACK (PROVISION {Source IP address, source port, destination IP Transaction) address, destination port, Transaction-ID, Customer Order Identifier, Provider Order Identifier, Offered Connectivity Provisioning Order} must match an order with a state set to "AcceptSent". ACK (UPDATE {Source IP address, source port, destination IP Transaction) address, destination port, Transaction-ID, Customer Order Identifier, Provider Order Identifier, Updated Connectivity Provisioning Order} must match an order with a state set to "AcceptSent". ACK (WITHDRAW {Source IP address, source port, destination IP Transaction) address, destination port, Transaction-ID, Customer Order Identifier, Provider Order Identifier, Empty Connectivity Provisioning Order} must match an order with a state set to "Cancelled". 9.2. On The Server Side Boucadair & Jacquenet Expires November 30, 2013 [Page 27] Internet-Draft CPNP May 2013 Method Validation Checks ----------- --------------------------------------------------------- PROVISION The source IP address passes existing access filters (if any). ACCEPT {Source IP address, source port, destination IP address, destination port, Transaction-ID, Customer Order Identifier, Provider Order Identifier, Nonce, Offered Connectivity Provisioning Order} must match an order with state set to "OfferProposed" or "ProcessngReceived". DECLINE {Source IP address, source port, destination IP address, destination port, Transaction-ID, Customer Order Identifier, Provider Order Identifier, Nonce} must match an order with state set to "OfferProposed" or "ProcessngReceived". UPDATE The source IP address passes existing access filters (if any) and {Customer Order Identifier, Provider Order Identifier, Nonce} must match an existing order with state "Completed". WITHDRAW The source IP address passes existing access filters (if any) and {Customer Order Identifier, Provider Order Identifier, Nonce} must match an existing order with state "Completed". 10. Theory of Operations Both CPNP client and server proceeds to message validation checks as specified in Section 9. 10.1. Client Behavior 10.1.1. Order Negotiation Cycle To place a connectivity provisioning quotation order, the client initiates first a local order object identified by a unique identifier assigned by the client. The state of the quotation order is set to "Created". The client then generates a PROVISION request which includes the assigned identifier, possibly an Expected Response Date, a Transaction-ID and a Requested Connectivity Provisioning Document. The client may include additional Information Elements such as Negotiation Options. The client may be configured to not enforce negotiation checks on EXPECTED_OFFER_DATE; if so no EXPECTED_RESP_TIMER attribute (or EXPECTED_RESP_TIMER set to infinite) should be included in the quotation order. Boucadair & Jacquenet Expires November 30, 2013 [Page 28] Internet-Draft CPNP May 2013 Once the request is sent to the server, the state of the request is set to "CPQOSent" and a timer, if a response time is included in the quotation order, is set to the expiration date as included in the PROVISION request. The client also maintains a copy of the extended transport session details used to generate the PROVISION request. The CPNP client must listen on the same port number that it used to send the PROVISION request. If no answer is received from the server before the retransmission timer expires (i.e., RETRANS_TIMER), the client proceeds to retransmission until maximum retry is reached (i.e., 3 times). If a FAIL message is received, the client may decide to issue another (corrected) request towards the same server, cancel the local order, or contact another server. The behavior of the client depends on the error code returned by the server in the FAIL message. If a PROCESSING message matching the CPNP transport session is received, the client updates the CPNP session with the PROVIDER_ORDER_IDENTIFIER information. If the client does not accept the expected offer date that may have been indicated in the PROCESSING message, the client may decide to cancel the quotation order. If the client accepts the EXPECTED_OFFER_DATE, it changes the state of the order to "ServerProcessing" and sets a timer to the value of EXPECTED_OFFER_DATE. If no offer is made before the timer expires, the client changes the state of the order to "Cancelled". If an OFFER message matching the extended CPNP session is received, the client checks if a PROCESSING message having the same PROVIDER_ORDER_IDENTIFIER has been received from the server. If a PROCESSING message was already received for the same order but the PROVIDER_ORDER_IDENTIFIER does not match the identifier included in the OFFER message, the client ignores silently the message. If a PROCESSING message having the same PROVIDER_ORDER_IDENTIFIER was already received and matches the CPNP transaction identifier, the client changes the state of the order to "OfferReceived" and sets a timer to the value of VALIDITY_DATE indicated in the OFFER message. If an offer is received from the server (i.e., as documented in an OFFER message), the client may accept or reject the offer. The client accepts the offer by generating an ACCEPT message which confirms that the client agrees to subscribe to the offer documented in the OFFER message; the state of the order is passed to "AcceptSent". The transaction is terminated if an ACK message is received from the server. If no ACK is received from the server, the client proceeds with the re-transmission of the ACCEPT message. Boucadair & Jacquenet Expires November 30, 2013 [Page 29] Internet-Draft CPNP May 2013 The client may also decide to reject the offer by sending a DECLINE message. The state of the order is set by the client to "Cancelled". If an offer is not acceptable by the client, the client may decide to contact a new server or submit another order to the same server. Guidelines to issue an updated order or terminate the negotiation are specific to the client. 10.1.2. Order Withdrawal Cycle A client may withdraw a completed order. This is achieved by issuing a WITHDRAW message. This message must include Customer Order Identifier, Provider Identifier and Nonce returned during the order negotiation cycle specified in Section 10.1.1. If no ACK is received from the server, the client proceeds with the re-transmission of the message. 10.1.3. Order Update Cycle A client may update a completed order. This is achieved by issuing an UPDATE message. This message must include Customer Order Identifier, Provider Order Identifier and Nonce returned during the order negotiation cycle specified in Section 10.1.1. The client must include in the UPDATE message an updated CPD with the requested changes. Subsequent messages exchange is similar to what is documented in Section 10.1.1. 10.2. Server Behavior 10.2.1. Order Processing Upon receipt of a PROVISION message from a client, the server sets a CPNP session, stores Transaction-ID and generates a Provider Order Identifier. Once preliminary validation checks are completed ( Section 9), the server may return a PROCESSING message to notify the client the quotation order is received and it is under processing; the server may include an expected offer date to notify the client by when an offer will be proposed. An order with state "AwaitingProcessing" is created by the server. The server runs its decision-making process to decide which offer it can make to honor the received order. The offer should be made before the expected offer date expires. If the server cannot honor the request, it sends backs a FAIL message with the appropriate error code. Boucadair & Jacquenet Expires November 30, 2013 [Page 30] Internet-Draft CPNP May 2013 If the server can honor the request, it creates an OFFER message. The server must indicate the Transaction-ID, Customer Order Identifier as indicated in the PROVISION message, and the Provider Order Identifier generated for this order. The server must also include Nonce and the offered Connectivity Provisioning Document. The server includes an offer validity date as well. Once sent to the client, the server changes the state of the order to "OfferSent" and a timer set to the validity date is initiated. If the server determines that additional network resources from another network provider are needed to accommodate a quotation order, it will create child CPQO(s) and will behave as a CPNP client to negotiate child CPQO(s) with possible partnering providers (see Figure 4). If no PROCESSING, ACCEPT or DECLINE message is received before the expiry of the RETRANS_TIMER, the server re-sends the same offer to the client. This procedure is repeated until maximum retry is reached. If an ACCEPT message is received before the offered validity date expires, the server proceeds with validation checks as specified in Section 9. The state of the corresponding order is passed to "AcceptReceived". The server sends back an ACK message to terminate the order processing cycle. If a CANCEL/DECLINE message is received, the server proceeds with the cancellation of the order. The state of the order is then passed to "Cancelled". 10.2.2. Order Withdrawal A client may withdraw a completed order by issuing a WITHDRAW message. Upon receipt of a WITHDRAW message, the server proceeds with the validation checks, as specified in Section 9. o If the checks fail, a FAIL message is sent back to the client with the appropriate error code. o If the checks succeed, the server clears the clauses of the Connectivity Provisioning Document, changes the state of the order to "Cancelled", and sends back an ACK message with an Empty Connectivity Provisioning Document. Boucadair & Jacquenet Expires November 30, 2013 [Page 31] Internet-Draft CPNP May 2013 10.2.3. Order Update A client may update an order by issuing an UPDATE message. Upon receipt of an UPDATE message, the server proceeds with the validation checks as specified in Section 9. o If the checks fail, a FAIL message is sent back to the client with the appropriate error code. o Subsequent messages exchange is similar to what is specified in Section 10.1.1. The server should generate a new Nonce value to be included in the offer made to the client. 11. IANA Considerations Authors of the document request IANA to assign a UDP port for CPNP. A registry for CPNP methods should be created. The following codes are reserved: 1: PROVISION 2: PROCESSING 3: OFFER 4: ACCEPT 5: DECLINE 6: ACK 7: CANCEL 8: WITHDRAW 9: UPDATE A register for CPNP errors should be created. The following codes are reserved: 1: Validation Error 2: Authentication Required 3: Administratively prohibited 4: Out of Resources 5: Network Presence Error 12. Security Considerations Means to defend the server against denial-of-service attacks MUST be enabled. For example, access control lists (ACLs) can be enforced on the client, the server or the network in between, to allow a trusted client to communicate with a trusted server. The client and the server SHOULD be mutually authenticated. Out of band mechanisms can be used instead of integrating them into CPNP. Boucadair & Jacquenet Expires November 30, 2013 [Page 32] Internet-Draft CPNP May 2013 The client MUST silently discard CPNP responses received from unknown CPNP servers. The use of a randomly generated Transaction-ID makes it hard to forge a response from a server with a spoofed IP address belonging the legitimate CPNP server. Furthermore, CPNP messages from the server must also include correct identifiers of the orders. Two order identifiers are used: one generated by the client and the second one is generated by the server. Only authorized clients MUST be able to modify existing CPNP orders. The use of a randomly generated Nonce by the server makes it hard to modify an order on behalf of a third-party. 13. References 13.1. Normative References [RFC1123] Braden, R., "Requirements for Internet Hosts - Application and Support", STD 3, RFC 1123, October 1989. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC4086] Eastlake, D., Schiller, J., and S. Crocker, "Randomness Requirements for Security", BCP 106, RFC 4086, June 2005. [RFC5511] Farrel, A., "Routing Backus-Naur Form (RBNF): A Syntax Used to Form Encoding Rules in Various Routing Protocol Specifications", RFC 5511, April 2009. 13.2. Informative References [I-D.boucadair-connectivity-provisioning-profile] Boucadair, M., Jacquenet, C., and N. Wang, "IP/MPLS Connectivity Provisioning Profile", draft-boucadair- connectivity-provisioning-profile-02 (work in progress), September 2012. [I-D.sin-sdnrg-sdn-approach] Boucadair, M. and C. Jacquenet, "Software-Defined Networking: A Service Provider's Perspective", draft-sin- sdnrg-sdn-approach-02 (work in progress), April 2013. [RFC2782] Gulbrandsen, A., Vixie, P., and L. Esibov, "A DNS RR for specifying the location of services (DNS SRV)", RFC 2782, February 2000. [RFC4176] El Mghazli, Y., Nadeau, T., Boucadair, M., Chan, K., and A. Gonguet, "Framework for Layer 3 Virtual Private Boucadair & Jacquenet Expires November 30, 2013 [Page 33] Internet-Draft CPNP May 2013 Networks (L3VPN) Operations and Management", RFC 4176, October 2005. [RFC6347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer Security Version 1.2", RFC 6347, January 2012. Authors' Addresses Mohamed Boucadair France Telecom Rennes 35000 France Email: mohamed.boucadair@orange.com Christian Jacquenet France Telecom Rennes 35000 France Email: christian.jacquenet@orange.com Boucadair & Jacquenet Expires November 30, 2013 [Page 34]