rfc8007v1.txt		rfc8007.txt
	skipping to change at page 2, line 36		skipping to change at page 2, line 36
	5. CI/T Object Properties and Encoding . . . . . . . . . . . . . 16		5. CI/T Object Properties and Encoding . . . . . . . . . . . . . 16
	5.1. CI/T Objects . . . . . . . . . . . . . . . . . . . . . . 16		5.1. CI/T Objects . . . . . . . . . . . . . . . . . . . . . . 16
	5.1.1. CI/T Commands . . . . . . . . . . . . . . . . . . . . 16		5.1.1. CI/T Commands . . . . . . . . . . . . . . . . . . . . 16
	5.1.2. Trigger Status Resources . . . . . . . . . . . . . . 17		5.1.2. Trigger Status Resources . . . . . . . . . . . . . . 17
	5.1.3. Trigger Collections . . . . . . . . . . . . . . . . . 18		5.1.3. Trigger Collections . . . . . . . . . . . . . . . . . 18
	5.2. Properties of CI/T Objects . . . . . . . . . . . . . . . 20		5.2. Properties of CI/T Objects . . . . . . . . . . . . . . . 20
	5.2.1. Trigger Specification . . . . . . . . . . . . . . . . 20		5.2.1. Trigger Specification . . . . . . . . . . . . . . . . 20
	5.2.2. Trigger Type . . . . . . . . . . . . . . . . . . . . 21		5.2.2. Trigger Type . . . . . . . . . . . . . . . . . . . . 21
	5.2.3. Trigger Status . . . . . . . . . . . . . . . . . . . 22		5.2.3. Trigger Status . . . . . . . . . . . . . . . . . . . 22
	5.2.4. PatternMatch . . . . . . . . . . . . . . . . . . . . 22		5.2.4. PatternMatch . . . . . . . . . . . . . . . . . . . . 22
	5.2.5. Absolute Time . . . . . . . . . . . . . . . . . . . . 23		5.2.5. Absolute Time . . . . . . . . . . . . . . . . . . . . 24
	5.2.6. Error Description . . . . . . . . . . . . . . . . . . 24		5.2.6. Error Description . . . . . . . . . . . . . . . . . . 24
	5.2.7. Error Code . . . . . . . . . . . . . . . . . . . . . 24		5.2.7. Error Code . . . . . . . . . . . . . . . . . . . . . 25
	6. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 25		6. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 25
	6.1. Creating Triggers . . . . . . . . . . . . . . . . . . . . 25		6.1. Creating Triggers . . . . . . . . . . . . . . . . . . . . 26
	6.1.1. Preposition . . . . . . . . . . . . . . . . . . . . . 25		6.1.1. Preposition . . . . . . . . . . . . . . . . . . . . . 26
	6.1.2. Invalidate . . . . . . . . . . . . . . . . . . . . . 27		6.1.2. Invalidate . . . . . . . . . . . . . . . . . . . . . 27
	6.2. Examining Trigger Status . . . . . . . . . . . . . . . . 28		6.2. Examining Trigger Status . . . . . . . . . . . . . . . . 28
	6.2.1. Collection of All Triggers . . . . . . . . . . . . . 28		6.2.1. Collection of All Triggers . . . . . . . . . . . . . 28
	6.2.2. Filtered Collections of Trigger Status Resources . . 29		6.2.2. Filtered Collections of Trigger Status Resources . . 29
	6.2.3. Individual Trigger Status Resources . . . . . . . . . 31		6.2.3. Individual Trigger Status Resources . . . . . . . . . 31
	6.2.4. Polling for Changes in Status . . . . . . . . . . . . 33		6.2.4. Polling for Changes in Status . . . . . . . . . . . . 33
	6.2.5. Deleting Trigger Status Resources . . . . . . . . . . 36		6.2.5. Deleting Trigger Status Resources . . . . . . . . . . 36
	6.2.6. Error Reporting . . . . . . . . . . . . . . . . . . . 37		6.2.6. Error Reporting . . . . . . . . . . . . . . . . . . . 37
	7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 38		7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 38
	7.1. CDNI Payload Type Parameter Registrations . . . . . . . . 38		7.1. CDNI Payload Type Parameter Registrations . . . . . . . . 38
	skipping to change at page 6, line 20		skipping to change at page 6, line 20
	The remainder of this document describes the messages, Trigger Status		The remainder of this document describes the messages, Trigger Status
	Resources, and collections of Trigger Status Resources in more		Resources, and collections of Trigger Status Resources in more
	detail.		detail.
	2.1. Timing of Triggered Activity		2.1. Timing of Triggered Activity
	Timing of the execution of CI/T Commands is under the dCDN's control,		Timing of the execution of CI/T Commands is under the dCDN's control,
	including its start time and pacing of the activity in the network.		including its start time and pacing of the activity in the network.
	CI/T invalidate and purge commands MUST be applied to all data		CI/T "invalidate" and "purge" commands MUST be applied to all data
	acquired before the command was accepted by the dCDN. The dCDN		acquired before the command was accepted by the dCDN. The dCDN
	SHOULD NOT apply CI/T invalidate and purge commands to data acquired		SHOULD NOT apply CI/T "invalidate" and "purge" commands to data
	after the CI/T Command was accepted, but this may not always be		acquired after the CI/T Command was accepted, but this may not always
	achievable, so the uCDN cannot count on that.		be achievable, so the uCDN cannot count on that.
	If the uCDN wishes to invalidate or purge content and then		If the uCDN wishes to invalidate or purge content and then
	immediately pre-position replacement content at the same URLs, it		immediately pre-position replacement content at the same URLs, it
	SHOULD ensure that the dCDN has completed the invalidate/purge before		SHOULD ensure that the dCDN has completed the invalidate/purge before
	initiating the prepositioning. Otherwise, there is a risk that the		initiating the prepositioning. Otherwise, there is a risk that the
	dCDN pre-positions the new content, then immediately invalidates or		dCDN pre-positions the new content, then immediately invalidates or
	purges it (as a result of the two uCDN requests running in parallel).		purges it (as a result of the two uCDN requests running in parallel).
	Because the CI/T Command timing is under the dCDN's control, the dCDN		Because the CI/T Command timing is under the dCDN's control, the dCDN
	implementation can choose whether to apply CI/T invalidate and purge		implementation can choose whether to apply CI/T "invalidate" and
	commands to content acquisition that has already started when the		"purge" commands to content acquisition that has already started when
	command is received.		the command is received.
	2.2. Scope of Triggered Activity		2.2. Scope of Triggered Activity
	Each CI/T Command can operate on multiple metadata and content URLs.		Each CI/T Command can operate on multiple metadata and content URLs.
	Multiple representations of an HTTP resource may share the same URL.		Multiple representations of an HTTP resource may share the same URL.
	CI/T Trigger Commands that invalidate or purge metadata or content		CI/T Trigger Commands that invalidate or purge metadata or content
	apply to all resource representations with matching URLs.		apply to all resource representations with matching URLs.
	2.2.1. Multiple Interconnected CDNs		2.2.1. Multiple Interconnected CDNs
	skipping to change at page 7, line 20		skipping to change at page 7, line 20
	intermediate CDN, or via more than one intermediate CDN.		intermediate CDN, or via more than one intermediate CDN.
	CI/T Commands originating in the single source uCDN affect metadata		CI/T Commands originating in the single source uCDN affect metadata
	and content in all dCDNs; however, in a diamond configuration, it may		and content in all dCDNs; however, in a diamond configuration, it may
	not be possible for the dCDN to determine which uCDN it acquired		not be possible for the dCDN to determine which uCDN it acquired
	content from. In this case, a dCDN MUST allow each uCDN from which		content from. In this case, a dCDN MUST allow each uCDN from which
	it may have acquired the content to act upon that content using CI/T		it may have acquired the content to act upon that content using CI/T
	Commands.		Commands.
	In all other cases, a dCDN MUST reject CI/T Commands from a uCDN that		In all other cases, a dCDN MUST reject CI/T Commands from a uCDN that
	acts on another uCDN's data by using, for example, HTTP 403		attempts to act on another uCDN's content by using, for example,
	("Forbidden").		HTTP 403 ("Forbidden").
	Security considerations are discussed further in Section 8.		Security considerations are discussed further in Section 8.
	The diamond configuration may lead to inefficient interactions, but		The diamond configuration may lead to inefficient interactions, but
	the interactions are otherwise harmless. For example:		the interactions are otherwise harmless. For example:
	o When the uCDN issues an invalidate CI/T Command, a dCDN will		o When the uCDN issues an "invalidate" CI/T Command, a dCDN will
	receive that command from multiple directly connected uCDNs. The		receive that command from multiple directly connected uCDNs. The
	dCDN may schedule multiple those commands separately, and the last		dCDN may schedule multiple such commands separately, and the last
	may affect content already revalidated following execution of the		scheduled command may affect content already revalidated following
	invalidate command scheduled first.		execution of the "invalidate" command that was scheduled first.
	o If one of a dCDN's directly connected uCDNs loses its rights to		o If one of a dCDN's directly connected uCDNs loses its rights to
	distribute content, it may issue a CI/T purge command. That purge		distribute content, it may issue a CI/T "purge" command. That
	may affect content the dCDN could retain because it's distributed		purge may affect content the dCDN could retain because it's
	by another directly connected uCDN. But, that content can be		distributed by another directly connected uCDN. But, that content
	reacquired by the dCDN from the remaining uCDN.		can be reacquired by the dCDN from the remaining uCDN.
	o When the uCDN originating an item of content issues a CI/T purge		o When the uCDN originating an item of content issues a CI/T purge
	followed by a preposition, two directly connected uCDNs will pass		followed by a preposition, two directly connected uCDNs will pass
	those commands to a dCDN. That dCDN implementation need not merge		those commands to a dCDN. That dCDN implementation need not merge
	those operations or notice the repetition, in which case the purge		those operations or notice the repetition, in which case the purge
	issued by one uCDN will complete before the other. The first uCDN		issued by one uCDN will complete before the other. The first uCDN
	to finish its purge may then forward the preposition trigger, and		to finish its purge may then forward the "preposition" trigger,
	content pre-positioned as a result might be affected by the		and content pre-positioned as a result might be affected by the
	still-running purge issued by the other uCDN. However, the dCDN		still-running purge issued by the other uCDN. However, the dCDN
	will reacquire that content as needed, or when it's asked to		will reacquire that content as needed, or when it's asked to
	pre-position the content by the second uCDN. A dCDN		pre-position the content by the second uCDN. A dCDN
	implementation could avoid this interaction by knowing which uCDN		implementation could avoid this interaction by knowing which uCDN
	it acquired the content from, or it could minimize the		it acquired the content from, or it could minimize the
	consequences by recording the time at which the invalidate/purge		consequences by recording the time at which the
	command was received and not applying it to content acquired after		"invalidate"/"purge" command was received and not applying it to
	that time.		content acquired after that time.
	2.3. Trigger Results		2.3. Trigger Results
	Possible states for a Trigger Status Resource are defined in		Possible states for a Trigger Status Resource are defined in
	Section 5.2.3.		Section 5.2.3.
	The CI/T Trigger Command MUST NOT be reported as "complete" until all		The CI/T Trigger Command MUST NOT be reported as "complete" until all
	actions have been completed successfully. The reasons for failure,		actions have been completed successfully. The reasons for failure,
	and URLs or patterns affected, SHOULD be enumerated in the Trigger		and URLs or patterns affected, SHOULD be enumerated in the Trigger
	Status Resource. For more details, see Section 4.7.		Status Resource. For more details, see Section 4.7.
	skipping to change at page 11, line 15		skipping to change at page 11, line 15
	the same URLs is expected to have finished.		the same URLs is expected to have finished.
	If the dCDN is able to track the execution of CI/T Commands and a		If the dCDN is able to track the execution of CI/T Commands and a
	CI/T Command is queued by the dCDN for later action, the "status"		CI/T Command is queued by the dCDN for later action, the "status"
	property of the Trigger Status Resource MUST be "pending". Once		property of the Trigger Status Resource MUST be "pending". Once
	processing has started, the status MUST be "active". Finally, once		processing has started, the status MUST be "active". Finally, once
	the CI/T Command is complete, the status MUST be set to "complete" or		the CI/T Command is complete, the status MUST be set to "complete" or
	"failed".		"failed".
	A CI/T Trigger Command may result in no activity in the dCDN if, for		A CI/T Trigger Command may result in no activity in the dCDN if, for
	example, it is an invalidate or purge request for data the dCDN has		example, it is an "invalidate" or "purge" request for data the dCDN
	not yet acquired, or a pre-position request for data that it has		has not yet acquired, or a "pre-position" request for data that it
	already acquired and that is still valid. In this case, the status		has already acquired and that is still valid. In this case, the
	of the Trigger Status Resource MUST be "processed" or "complete", and		status of the Trigger Status Resource MUST be "processed" or
	the Trigger Status Resource MUST be added to the dCDN's collection of		"complete", and the Trigger Status Resource MUST be added to the
	Complete Trigger Status Resources.		dCDN's collection of Complete Trigger Status Resources.
	Once created, Trigger Status Resources can be canceled or deleted by		Once created, Trigger Status Resources can be canceled or deleted by
	the uCDN, but not modified. The dCDN MUST reject PUT and POST		the uCDN, but not modified. The dCDN MUST reject PUT and POST
	requests from the uCDN to Trigger Status Resources by responding with		requests from the uCDN to Trigger Status Resources by responding with
	an appropriate HTTP status code -- for example, 405 ("Method Not		an appropriate HTTP status code -- for example, 405 ("Method Not
	Allowed").		Allowed").
	4.2. Checking Status		4.2. Checking Status
	The uCDN has two ways to check the progress of CI/T Commands it has		The uCDN has two ways to check the progress of CI/T Commands it has
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	upon or the uCDN chooses to cancel it.		upon or the uCDN chooses to cancel it.
	4.8. Content URLs		4.8. Content URLs
	If content URLs are transformed by an intermediate CDN in a cascade,		If content URLs are transformed by an intermediate CDN in a cascade,
	that intermediate CDN MUST similarly transform URLs in CI/T Commands		that intermediate CDN MUST similarly transform URLs in CI/T Commands
	it passes to its dCDN.		it passes to its dCDN.
	When processing Trigger Specifications, CDNs MUST ignore the URL		When processing Trigger Specifications, CDNs MUST ignore the URL
	scheme (HTTP or HTTPS) in comparing URLs. For example, for a CI/T		scheme (HTTP or HTTPS) in comparing URLs. For example, for a CI/T
	invalidate or purge command, content MUST be invalidated or purged		"invalidate" or "purge" command, content MUST be invalidated or
	regardless of the protocol clients used to request it.		purged regardless of the protocol clients used to request it.
	5. CI/T Object Properties and Encoding		5. CI/T Object Properties and Encoding
	The CI/T Commands, Trigger Status Resources, and Trigger Collections,		The CI/T Commands, Trigger Status Resources, and Trigger Collections,
	as well as their properties, are encoded using JSON, as defined in		as well as their properties, are encoded using JSON, as defined in
	Sections 5.1.1, 5.1.2, and 5.2.1. They MUST use the MIME media type		Sections 5.1.1, 5.1.2, and 5.1.3. They MUST use the MIME media type
	"application/cdni", with parameter "ptype" values as defined below		"application/cdni", with parameter "ptype" values as defined below
	and in Section 7.1.		and in Section 7.1.
	Names in JSON are case sensitive. The names and literal values		Names in JSON are case sensitive. The names and literal values
	specified in the present document MUST always use lowercase.		specified in the present document MUST always use lowercase.
	JSON types, including "object", "array", "number", and "string", are		JSON types, including "object", "array", "number", and "string", are
	defined in [RFC7159].		defined in [RFC7159].
	Unrecognized name/value pairs in JSON objects SHOULD NOT be treated		Unrecognized name/value pairs in JSON objects SHOULD NOT be treated
	skipping to change at page 22, line 25		skipping to change at page 22, line 25
	| | erase the associated data. |		| | erase the associated data. |
	| purge | A request for the dCDN to erase metadata or |		| purge | A request for the dCDN to erase metadata or |
	| | content. After servicing the request, the |		| | content. After servicing the request, the |
	| | specified data MUST NOT be held on the dCDN (the |		| | specified data MUST NOT be held on the dCDN (the |
	| | dCDN should reacquire the metadata or content from |		| | dCDN should reacquire the metadata or content from |
	| | the uCDN if it needs it). |		| | the uCDN if it needs it). |
	+-------------+-----------------------------------------------------+		+-------------+-----------------------------------------------------+
	5.2.3. Trigger Status		5.2.3. Trigger Status
	Trigger Status describes the current status of a Trigger. It MUST be		Trigger Status describes the current status of the triggered
	one of the JSON strings in the following table:		activity. It MUST be one of the JSON strings in the following table:
	+-----------+-------------------------------------------------------+		+-----------+-------------------------------------------------------+
	| JSON | Description |		| JSON | Description |
	| String | |		| String | |
	+-----------+-------------------------------------------------------+		+-----------+-------------------------------------------------------+
	| pending | The CI/T Trigger Command has not yet been acted upon. |		| pending | The CI/T Trigger Command has not yet been acted upon. |
	| active | The CI/T Trigger Command is currently being acted |		| active | The CI/T Trigger Command is currently being acted |
	| | upon. |		| | upon. |
	| complete | The CI/T Trigger Command completed successfully. |		| complete | The CI/T Trigger Command completed successfully. |
	| processed | The CI/T Trigger Command has been accepted, and no |		| processed | The CI/T Trigger Command has been accepted, and no |
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	A PatternMatch consists of a string pattern to match against a URI,		A PatternMatch consists of a string pattern to match against a URI,
	and flags describing the type of match.		and flags describing the type of match.
	It is encoded as a JSON object with the following name/value pairs:		It is encoded as a JSON object with the following name/value pairs:
	Name: pattern		Name: pattern
	Description: A pattern for URI matching.		Description: A pattern for URI matching.
	Value: A JSON string representing the pattern. The pattern may		Value: A JSON string representing the pattern. The pattern can
	contain the wildcards "*" and "?", where "*" matches any		contain the wildcards * and ?, where * matches any sequence of
	sequence of characters (including the empty string) and "?"		[RFC3986] pchar or "/" characters (including the empty string)
	matches exactly one character. The three literals "\", "*",		and ? matches exactly one [RFC3986] pchar character. The three
	and "?" MUST be escaped as "\\", "\*", and "\?".		literals $, * and ? MUST be escaped as $$, $* and $? (where $
			is the designated escape character). All other characters are
			treated as literals.
	Mandatory: Yes.		Mandatory: Yes.
	Name: case-sensitive		Name: case-sensitive
	Description: Flag indicating whether or not case-sensitive		Description: Flag indicating whether or not case-sensitive
	matching should be used.		matching should be used.
	Value: One of the JSON values "true" (the matching is case		Value: One of the JSON values "true" (the matching is case
	sensitive) or "false" (the matching is case insensitive).		sensitive) or "false" (the matching is case insensitive).
	skipping to change at page 25, line 14		skipping to change at page 25, line 22
	The following error codes are defined by this document and MUST be		The following error codes are defined by this document and MUST be
	supported by an implementation of the CI/T interface.		supported by an implementation of the CI/T interface.
	+--------------+----------------------------------------------------+		+--------------+----------------------------------------------------+
	| Error Code | Description |		| Error Code | Description |
	+--------------+----------------------------------------------------+		+--------------+----------------------------------------------------+
	| emeta | The dCDN was unable to acquire metadata required |		| emeta | The dCDN was unable to acquire metadata required |
	| | to fulfill the request. |		| | to fulfill the request. |
	| econtent | The dCDN was unable to acquire content (CI/T |		| econtent | The dCDN was unable to acquire content (CI/T |
	| | preposition commands only). |		| | "preposition" commands only). |
	| eperm | The uCDN does not have permission to issue the |		| eperm | The uCDN does not have permission to issue the |
	| | CI/T Command (for example, the data is owned by |		| | CI/T Command (for example, the data is owned by |
	| | another CDN). |		| | another CDN). |
	| ereject | The dCDN is not willing to fulfill the CI/T |		| ereject | The dCDN is not willing to fulfill the CI/T |
	| | Command (for example, a preposition request for |		| | Command (for example, a "preposition" request for |
	| | content at a time when the dCDN would not accept |		| | content at a time when the dCDN would not accept |
	| | Request Routing requests from the uCDN). |		| | Request Routing requests from the uCDN). |
	| ecdn | An internal error in the dCDN or one of its dCDNs. |		| ecdn | An internal error in the dCDN or one of its dCDNs. |
	| ecanceled | The uCDN canceled the request. |		| ecanceled | The uCDN canceled the request. |
	| eunsupported | The Trigger Specification contained a "type" that |		| eunsupported | The Trigger Specification contained a "type" that |
	| | is not supported by the dCDN. No action was taken |		| | is not supported by the dCDN. No action was taken |
	| | by the dCDN other than to create a Trigger Status |		| | by the dCDN other than to create a Trigger Status |
	| | Resource in state "failed". |		| | Resource in state "failed". |
	+--------------+----------------------------------------------------+		+--------------+----------------------------------------------------+
	6. Examples		6. Examples
	The following subsections provide examples of different CI/T objects		The following subsections provide examples of different CI/T objects
	encoded as JSON.		encoded as JSON.
	Discovery of the triggers interface is out of scope for this		Discovery of the CI/T interface is out of scope for this document.
	document. In an implementation, all CI/T URLs are under the control		In an implementation, all CI/T URLs are under the control of the
	of the dCDN. The uCDN MUST NOT attempt to ascribe any meaning to		dCDN. The uCDN MUST NOT attempt to ascribe any meaning to individual
	individual elements of the path.		elements of the path.
	In examples in this section, the URL "https://dcdn.example.com/		In examples in this section, the URL "https://dcdn.example.com/
	triggers" is used as the location of the collection of all Trigger		triggers" is used as the location of the collection of all Trigger
	Status Resources, and the CDN PID of the uCDN is "AS64496:1".		Status Resources, and the CDN PID of the uCDN is "AS64496:1".
	6.1. Creating Triggers		6.1. Creating Triggers
	Examples of the uCDN triggering activity in the dCDN:		Examples of the uCDN triggering activity in the dCDN:
	6.1.1. Preposition		6.1.1. Preposition
	Below is an example of a CI/T preposition command -- a POST to the		Below is an example of a CI/T "preposition" command -- a POST to the
	collection of all Trigger Status Resources.		collection of all Trigger Status Resources.
	Note that "metadata.patterns" and "content.patterns" are not allowed		Note that "metadata.patterns" and "content.patterns" are not allowed
	in a preposition Trigger Specification.		in a preposition Trigger Specification.
	REQUEST:		REQUEST:
	POST /triggers HTTP/1.1		POST /triggers HTTP/1.1
	User-Agent: example-user-agent/0.1		User-Agent: example-user-agent/0.1
	Host: dcdn.example.com		Host: dcdn.example.com
	skipping to change at page 27, line 13		skipping to change at page 27, line 22
	],		],
	"metadata.urls": [		"metadata.urls": [
	"https://metadata.example.com/a/b/c"		"https://metadata.example.com/a/b/c"
	],		],
	"type": "preposition"		"type": "preposition"
	}		}
	}		}
	6.1.2. Invalidate		6.1.2. Invalidate
	Below is an example of a CI/T invalidate command -- another POST to		Below is an example of a CI/T "invalidate" command -- another POST to
	the collection of all Trigger Status Resources. This instructs the		the collection of all Trigger Status Resources. This instructs the
	dCDN to revalidate the content at "https://www.example.com/a/		dCDN to revalidate the content at "https://www.example.com/a/
	index.html", as well as any metadata and content whose URLs are		index.html", as well as any metadata and content whose URLs are
	prefixed by "https://metadata.example.com/a/b/" using		prefixed by "https://metadata.example.com/a/b/" using
	case-insensitive matching, and "https://www.example.com/a/b/" using		case-insensitive matching, and "https://www.example.com/a/b/" using
	case-sensitive matching, respectively.		case-sensitive matching, respectively.
	REQUEST:		REQUEST:
	POST /triggers HTTP/1.1		POST /triggers HTTP/1.1
	skipping to change at page 28, line 36		skipping to change at page 28, line 46
	"pattern": "https://metadata.example.com/a/b/*"		"pattern": "https://metadata.example.com/a/b/*"
	}		}
	],		],
	"type": "invalidate"		"type": "invalidate"
	}		}
	}		}
	6.2. Examining Trigger Status		6.2. Examining Trigger Status
	Once Trigger Status Resources have been created, the uCDN can check		Once Trigger Status Resources have been created, the uCDN can check
	their status as shown in these examples.		their status as shown in the following examples.
	6.2.1. Collection of All Triggers		6.2.1. Collection of All Triggers
	The uCDN can fetch the collection of all Trigger Status Resources it		The uCDN can fetch the collection of all Trigger Status Resources it
	has created that have not yet been deleted or removed as expired.		has created that have not yet been deleted or removed as expired.
	After creation of the "preposition" and "invalidate" triggers shown		After creation of the "preposition" and "invalidate" triggers shown
	above, this collection might look as follows:		above, this collection might look as follows:
	REQUEST:		REQUEST:
	GET /triggers HTTP/1.1		GET /triggers HTTP/1.1
	User-Agent: example-user-agent/0.1		User-Agent: example-user-agent/0.1
	Host: dcdn.example.com		Host: dcdn.example.com
	Accept: */*		Accept: */*
	skipping to change at page 40, line 8		skipping to change at page 40, line 8
	requests into the dCDN and to inspect its own CI/T requests and their		requests into the dCDN and to inspect its own CI/T requests and their
	current states. The CI/T interface does not allow access to, or		current states. The CI/T interface does not allow access to, or
	modification of, the uCDN or dCDN metadata relating to content		modification of, the uCDN or dCDN metadata relating to content
	delivery or to the content itself. It can only control the presence		delivery or to the content itself. It can only control the presence
	of that metadata in the dCDN, and the processing work and network		of that metadata in the dCDN, and the processing work and network
	utilization involved in ensuring that presence.		utilization involved in ensuring that presence.
	By examining pre-positioning requests to a dCDN, and correctly		By examining pre-positioning requests to a dCDN, and correctly
	interpreting content and metadata URLs, an attacker could learn the		interpreting content and metadata URLs, an attacker could learn the
	uCDN's or content owner's predictions for future content popularity.		uCDN's or content owner's predictions for future content popularity.
	By examining invalidate or purge requests, an attacker could learn		By examining "invalidate" or "purge" requests, an attacker could
	about changes in the content owner's catalog.		learn about changes in the content owner's catalog.
	By injecting CI/T Commands, an attacker or a misbehaving uCDN would		By injecting CI/T Commands, an attacker or a misbehaving uCDN would
	generate work in the dCDN and uCDN as they process those requests.		generate work in the dCDN and uCDN as they process those requests.
	So would a man-in-the-middle attacker modifying valid CI/T Commands		So would a man-in-the-middle attacker modifying valid CI/T Commands
	generated by the uCDN. In both cases, that would decrease the dCDN's		generated by the uCDN. In both cases, that would decrease the dCDN's
	caching efficiency by causing it to unnecessarily acquire or		caching efficiency by causing it to unnecessarily acquire or
	reacquire content metadata and/or content.		reacquire content metadata and/or content.
	A dCDN implementation of CI/T MUST restrict the actions of a uCDN to		A dCDN implementation of CI/T MUST restrict the actions of a uCDN to
	the data corresponding to that uCDN. Failure to do so would allow		the data corresponding to that uCDN. Failure to do so would allow
	skipping to change at page 42, line 32		skipping to change at page 42, line 32
	[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate		[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
	Requirement Levels", BCP 14, RFC 2119,		Requirement Levels", BCP 14, RFC 2119,
	DOI 10.17487/RFC2119, March 1997,		DOI 10.17487/RFC2119, March 1997,
	<http://www.rfc-editor.org/info/rfc2119>.		<http://www.rfc-editor.org/info/rfc2119>.
	[RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818,		[RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818,
	DOI 10.17487/RFC2818, May 2000,		DOI 10.17487/RFC2818, May 2000,
	<http://www.rfc-editor.org/info/rfc2818>.		<http://www.rfc-editor.org/info/rfc2818>.
			[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
			Resource Identifier (URI): Generic Syntax", STD 66,
			RFC 3986, DOI 10.17487/RFC3986, January 2005,
			<http://www.rfc-editor.org/info/rfc3986>.
	[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an		[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
	IANA Considerations Section in RFCs", BCP 26, RFC 5226,		IANA Considerations Section in RFCs", BCP 26, RFC 5226,
	DOI 10.17487/RFC5226, May 2008,		DOI 10.17487/RFC5226, May 2008,
	<http://www.rfc-editor.org/info/rfc5226>.		<http://www.rfc-editor.org/info/rfc5226>.
	[RFC6707] Niven-Jenkins, B., Le Faucheur, F., and N. Bitar, "Content		[RFC6707] Niven-Jenkins, B., Le Faucheur, F., and N. Bitar, "Content
	Distribution Network Interconnection (CDNI) Problem		Distribution Network Interconnection (CDNI) Problem
	Statement", RFC 6707, DOI 10.17487/RFC6707, September		Statement", RFC 6707, DOI 10.17487/RFC6707, September
	2012, <http://www.rfc-editor.org/info/rfc6707>.		2012, <http://www.rfc-editor.org/info/rfc6707>.
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