draft-ietf-mpls-rsvpte-attributes-01.txt		draft-ietf-mpls-rsvpte-attributes-02.txt
	Network Working Group Adrian Farrel (Editor)		Network Working Group Adrian Farrel (Editor)
	Internet Draft Old Dog Consulting		Internet Draft Old Dog Consulting
	Category: Standards Track		Category: Standards Track
	Expires: June 2004 Dimitri Papadimitriou		Expires: July 2004 Dimitri Papadimitriou
	Alcatel		Alcatel
	Jean-Philippe Vasseur		Jean-Philippe Vasseur
	Cisco Systems, Inc.		Cisco Systems, Inc.
	Arthi Ayyangar		Arthi Ayyangar
	Juniper Networks		Juniper Networks
	December 2003		January 2004
	Encoding of Attributes for Multiprotocol Label Switching (MPLS)		Encoding of Attributes for Multiprotocol Label Switching (MPLS)
	Label Switched Path (LSP) Establishment Using RSVP-TE		Label Switched Path (LSP) Establishment Using RSVP-TE
	draft-ietf-mpls-rsvpte-attributes-01.txt		draft-ietf-mpls-rsvpte-attributes-02.txt
	Status of this Memo		Status of this Memo
	This document is an Internet-Draft and is in full conformance		This document is an Internet-Draft and is in full conformance
	with all provisions of Section 10 of RFC 2026 [RFC2026].		with all provisions of Section 10 of RFC 2026 [RFC2026].
	Internet-Drafts are working documents of the Internet		Internet-Drafts are working documents of the Internet Engineering
	Engineering Task Force (IETF), its areas, and its working		Task Force (IETF), its areas, and its working groups. Note that other
	groups. Note that other groups may also distribute working		groups may also distribute working documents as Internet-Drafts.
	documents as Internet-Drafts.
	Internet-Drafts are draft documents valid for a maximum of		Internet-Drafts are draft documents valid for a maximum of six months
	six months and may be updated, replaced, or obsoleted by		and may be updated, replaced, or obsoleted by other documents at any
	other documents at any time. It is inappropriate to use		time. It is inappropriate to use Internet-Drafts as reference
	Internet-Drafts as reference material or to cite them other		material or to cite them other than as "work in progress."
	than as "work in progress."
	The list of current Internet-Drafts can be accessed at		The list of current Internet-Drafts can be accessed at
	http://www.ietf.org/ietf/1id-abstracts.txt.		http://www.ietf.org/ietf/1id-abstracts.txt.
	The list of Internet-Draft Shadow Directories can be		The list of Internet-Draft Shadow Directories can be
	accessed at http://www.ietf.org/shadow.html.		accessed at http://www.ietf.org/shadow.html.
	Abstract		Abstract
	Multiprotocol Label Switching (MPLS) Label Switched Paths (LSPs) may		Multiprotocol Label Switching (MPLS) Label Switched Paths (LSPs) may
	be established using the Resource Reservation Protocol Traffic		be established using the Resource Reservation Protocol Traffic
	Engineering extensions (RSVP-TE). This protocol includes an object		Engineering extensions (RSVP-TE). This protocol includes an object
	(the SESSION_ATTRIBUTE object) which carries a flags field used to		(the SESSION_ATTRIBUTE object) which carries a flags field used to
	indicate options and attributes of the LSP. That flags field has		indicate options and attributes of the LSP. That flags field has
	eight bits allowing for eight options to be set.		eight bits allowing for eight options to be set. Recent proposals in
			many documents that extend RSVP-TE have suggested uses for each of
	Recent proposals in many documents that extend RSVP-TE for signaling		the previously unused bits.
	additional features and function for MPLS LSPs have suggested uses
	for each of the previously unused bits.
	This document defines a new object for RSVP-TE messages that allows		This document defines a new object for RSVP-TE messages that allows
	the signaling of further attribute bits and also the carriage of		the signaling of further attribute bits and also the carriage of
	arbitrary attribute parameters to make RSVP-TE easily extensible to		arbitrary attribute parameters to make RSVP-TE easily extensible to
	support new requirements. Additionally, this document defines a way		support new requirements. Additionally, this document defines a way
	to record the attributes applied to the LSP on a hop-by-hop basis.		to record the attributes applied to the LSP on a hop-by-hop basis.
			The object mechanisms defined in this document are equally applicable
			to Generalized MPLS (GMPLS) Packet Switch Capable (PSC) LSPs and to
			GMPLS non-PSC LSPs.
	0. Change History		0. Change History
	This section to be removed before publication.		This section to be removed before publication.
	0.1 Changes to 01 Version		0.1 Changes from 01 to 02 Version
			- Minor typographical changes.
			0.2 Changes from 00 to 01 Version
	- Change Attributes Flags TLV to be variable length so that more bits		- Change Attributes Flags TLV to be variable length so that more bits
	can easily be added in the future.		can easily be added in the future.
	- Define default behaviors for bits absent from the TLV and for		- Define default behaviors for bits absent from the TLV and for
	absence of the TLV.		absence of the TLV.
	- Clarify the IANA requirements for tracking Attributes Flags bits.		- Clarify the IANA requirements for tracking Attributes Flags bits.
	- Introduce RRO Attibutes Subobject and describe usage.		- Introduce RRO Attibutes Subobject and describe usage.
	- Move Fast Reroute reference to informational.		- Move Fast Reroute reference to informational.
	- Update security considerations to handle new RRO subobject		- Update security considerations to handle new RRO subobject
	- Remove section that explained the need for this document in		- Remove section that explained the need for this document in
	advance of any definitive bit definitions.		advance of any definitive bit definitions.
	- Tighten rules for processing LSP_ATTRIBUTES object in cases where		- Tighten rules for processing LSP_ATTRIBUTES object in cases where
	TLVs are unknown or unsupported.		TLVs are unknown or unsupported.
	- Clarify that LSP Attributes apply to individual LSPs and not to		- Clarify that LSP Attributes apply to individual LSPs and not to
	entire sessions.		entire sessions.
	1. Introduction and Problem Statement		1. Introduction and Problem Statement
	Multiprotocol Label Switching (MPLS) Label Switched Paths (LSPs)		Traffic Engineered Multiprotocol Label Switching (MPLS) Label
	[RFC3031] may be established using the RSVP-TE signaling protocol		Switched Paths (LSPs) [RFC3031] may be set up using the Path message
	[RFC3209]. This protocol uses the Path message to request that a LSP		of the RSVP-TE signaling protocol [RFC3209]. The Path message
	be set up. The Path message includes the SESSION_ATTRIBUTE object		includes the SESSION_ATTRIBUTE object which carries a flags field
	which carries a flags field used to indicate desired options and		used to indicate desired options and attributes of the LSP.
	attributes of the LSP.
	The flags field in the SESSION_ATTRIBUTE object has eight bits. Just		The flags field in the SESSION_ATTRIBUTE object has eight bits. Just
	three of those bits are assigned in [RFC3209]. A further two bits are		three of those bits are assigned in [RFC3209]. A further two bits are
	assigned in [FRR] for fast re-reroute functionality leaving only		assigned in [FRR] for fast re-reroute functionality leaving only
	three bits available. Several recent proposals and Internet Drafts		three bits available. Several recent proposals and Internet Drafts
	have demonstrated that there is a high demand for the use of the		have demonstrated that there is a high demand for the use of the
	other three bits. Some, if not all, of those proposals are likely to		other three bits. Some, if not all, of those proposals are likely to
	go forward as RFCs resulting in depletion or near depletion of the		go forward as RFCs resulting in depletion or near depletion of the
	flags field and a consequent difficulty in signaling new options and		flags field and a consequent difficulty in signaling new options and
	attributes that may be developed in the future.		attributes that may be developed in the future.
	This document defines a new object for RSVP-TE messages that allows		This document defines a new object for RSVP-TE messages that allows
	the signaling of further attributes bits. The new object is		the signaling of further attributes bits. The new object is
	constructed from TLVs, and a new TLV is defined to carry a variable		constructed from TLVs, and a new TLV is defined to carry a variable
	number of attributes bits. Because of the nature of the TLV		number of attributes bits. Because of the nature of the TLV
	construction the object is flexible and allows the future definition		construction the object is flexible and allows the future definition
	of:		of:
	- further sets of bits flags if further, distinct uses are discovered		- further bit flags if further, distinct uses are discovered
	- arbitrary options and attributes parameters carried as individual		- arbitrary options and attributes parameters carried as individual
	TLVs.		TLVs.
	Note that the LSP Attributes defined in this document are		Note that the LSP Attributes defined in this document are
	specifically scoped to an LSP. They may be set differently on		specifically scoped to an LSP. They may be set differently on
	separate LSPs within the same Session.		separate LSPs with the same Tunnel ID between the same source and
			destination (that is, within the same Session).
	It is noted that that some options and attributes do not need to be		It is noted that that some options and attributes do not need to be
	acted on by all Label Switched Routers (LSRs) along the path of the		acted on by all Label Switched Routers (LSRs) along the path of the
	LSP. In particular, these options and attributes may apply only to		LSP. In particular, these options and attributes may apply only to
	key LSRs on the path such as the ingress and egress. Special transit		key LSRs on the path such as the ingress and egress. Special transit
	LSRs, such as AS Border Routers (ASBRs) may also fall into this		LSRs, such as area or AS Border Routers (ABR/ASBRs) may also fall
	category. This means that the new options and attributes should be		into this category. This means that the new options and attributes
	signaled transparently, and only examined at those points that need		should be signaled transparently, and only examined at those points
	to act on them.		that need to act on them.
	On the other hand, other options and attributes may require action		On the other hand, other options and attributes may require action
	at all transit LSRs along the path of the LSP. Inability to support		at all transit LSRs along the path of the LSP. Inability to support
	the required attributes by one of those transit LSRs may require the		the required attributes by one of those transit LSRs may require the
	LSR to refuse the establishment of the LSP.		LSR to refuse the establishment of the LSP.
	These considerations are particularly important in the context		These considerations are particularly important in the context of
	backwards compatibility. In general, it should be possible to provide		backwards compatibility. In general, it should be possible to provide
	new MPLS services across a legacy network without upgrading those		new MPLS services across a legacy network without upgrading those
	LSRs that do not need to participate actively in the new services.		LSRs that do not need to participate actively in the new services.
	RSVP includes a way for unrecognized objects to be forwarded by		Note that options already specified for the SESSION_ATTRIBUTE object
	transit nodes without them refusing the protocol message and with the		in pre-existing RFCs are not migrated to the new mechanisms described
	objects being stripped from the protocol message (see [RFC2205]		in this documnet.
	section 3.10). This extends to RSVP-TE and provides a good way to
	ensure that only those LSRs that understand a particular object		RSVP includes a way for unrecognized objects to be transparently
	examine it.		forwarded by transit nodes without them refusing the incoming
			protocol messages and with the objects being stripped from the
			outgoing protocol message (see [RFC2205] section 3.10). This
			capability extends to RSVP-TE and provides a good way to ensure that
			only those LSRs that understand a particular object examine it.
	This document distinguishes between options and attributes that are		This document distinguishes between options and attributes that are
	only required at key LSRs along the path of the LSP, and those that		only required at key LSRs along the path of the LSP, and those that
	must be acted on by every LSR along the LSP. Two LSP Attributes		must be acted on by every LSR along the LSP. Two LSP Attributes
	objects are defined in this document: the first may be passed		objects are defined in this document: the first may be passed
	transparently by LSRs that do not recognize it, the second must cause		transparently by LSRs that do not recognize it, the second must cause
	LSP setup failure with the generation of a PathErr message if an LSR		LSP setup failure with the generation of a PathErr message with an
	does not recognize it.		appropriate Error Code if an LSR does not recognize it.
	Comments on this document should be made direct to the MPLS mailing
	list at mpls@uu.net.
	1.1 Applicability to Generalized MPLS		1.1 Applicability to Generalized MPLS
	The RSVP-TE signaling protocol also forms the basis of a signaling		The RSVP-TE signaling protocol also forms the basis of a signaling
	protocol for Generalized MPLS (GMPLS) as described in [RFC3471] and		protocol for Generalized MPLS (GMPLS) as described in [RFC3471] and
	[RFC3473]. The extensions described in this document are intended to		[RFC3473]. The extensions described in this document are intended to
	be equally applicable to MPLS and GMPLS.		be equally applicable to MPLS and GMPLS.
	1.2 A Rejected Alternate Solution		1.2 A Rejected Alternate Solution
	A rejected alternate solution was to define a new C-Type for the		A rejected alternate solution was to define a new C-Type for the
	existing SESSION_ATTRIBUTE object. This new C-Type could allow a		existing SESSION_ATTRIBUTE object. This new C-Type could allow a
	larger Flags field and address the immediate problem.		larger Flags field and address the immediate problem.
	This solution was rejected because:		This solution was rejected because:
			- A new C-Type is not backward compatible with deployed
	- A C-Type is not backward compatible with deployed implementations		implementations that expect to see a C-Type of 1 or 7. It is
	that expect to see a C-Type of 1 or 7. It is important that any		important that any solution be capable of carrying new attributes
	solution be capable of carrying new attributes transparently		transparently across legacy LSRs if those LSRs are not required to
	across legacy LSRs if those LSRs are not required to act on the		act on the attributes.
	attributes.
	- Support for arbitrary attributes parameters through TLVs would		- Support for arbitrary attributes parameters through TLVs would
	have meant a significant change of substance to the existing		have meant a significant change of substance to the existing
	object.		object.
	2. Terminology		2. Terminology
	This document uses terminology from the MPLS architecture document		This document uses terminology from the MPLS architecture document
	[RFC3031] and from the RSVP-TE protocol specification [RFC3209] which		[RFC3031] and from the RSVP-TE protocol specification [RFC3209] which
	inherits from the RSVP specification [RFC2205].		inherits from the RSVP specification [RFC2205].
	skipping to change at line 230		skipping to change at line 234
	Value		Value
	The data for the TLV padded as described above.		The data for the TLV padded as described above.
	3.1 Attributes Flags TLV		3.1 Attributes Flags TLV
	This document defines only one TLV type value. Type 1 indicates the		This document defines only one TLV type value. Type 1 indicates the
	Attributes Flags TLV. Other TLV types may be defined in future with		Attributes Flags TLV. Other TLV types may be defined in future with
	type values assigned by IANA.		type values assigned by IANA.
	The Attibutes Flags TLV may be present in an LSP_ATTRIBUTES object		The Attributes Flags TLV may be present in an LSP_ATTRIBUTES object
	and/or an LSP_REQUIRED_ATTRIBUTES object. The bits in the TLV		and/or an LSP_REQUIRED_ATTRIBUTES object. The bits in the TLV
	represent the same attributes regardeless of which object carries the		represent the same attributes regardless of which object carries the
	TLV. Documents that define individual bits MUST specify whether the		TLV. Documents that define individual bits MUST specify whether the
	bit may be set in one object or the other, or both.		bit may be set in one object or the other, or both. It is not
			expected that a bit will be set in both objects on a single Path
			message at the same time, but this is not ruled out by this document.
	The Attributes Flags TLV value field is a variable length array of		The Attributes Flags TLV value field is a variable length array of
	flags numbered from the MSB as bit zero. The length field for this		flags numbered from the MSB as bit zero. The length field for this
	TLV is always a multiple of 4 bytes, regardless of the number bits		TLV is always a multiple of 4 bytes, regardless of the number bits
	carried.		carried.
	Unassigned bits are considered as reserved and MUST be set to zero		Unassigned bits are considered as reserved and MUST be set to zero
	on transmission and ignored on receipt. Bits not contained in the		on transmission by the originator of the object. Bits not contained in the
	TLV MUST be assumed to be set to zero. If the TLV is absent either		TLV MUST be assumed to be set to zero. If the TLV is absent either
	because it is not contained in the LSP_ATTRIBUTES or LSP_REQUIRED_		because it is not contained in the LSP_ATTRIBUTES or LSP_REQUIRED_
	ATTRIBUTES object, or because those objects are themselves absent,		ATTRIBUTES object, or because those objects are themselves absent,
	all processing MUST be performed as though the bits were present		all processing MUST be performed as though the bits were present
	and set to zero.		and set to zero.
	No bits are defined in this document. The assignment of bits is		No bits are defined in this document. The assignment of bits is
	managed by IANA.		managed by IANA.
	4. LSP_ATTRIBUTES Object		4. LSP_ATTRIBUTES Object
	skipping to change at line 265		skipping to change at line 271
	support of an LSP, or to indicate the nature or use of an LSP where		support of an LSP, or to indicate the nature or use of an LSP where
	that information is not required to be acted on by all transit LSRs.		that information is not required to be acted on by all transit LSRs.
	Specifically, if an LSR does not support the object, it forwards it		Specifically, if an LSR does not support the object, it forwards it
	unexamined and unchanged. This facilitates the exchange of attributes		unexamined and unchanged. This facilitates the exchange of attributes
	across legacy networks that do not support this new object.		across legacy networks that do not support this new object.
	This object effectively extends the flags field in the SESSION_		This object effectively extends the flags field in the SESSION_
	ATTRIBUTE object and allows for the future inclusion of more complex		ATTRIBUTE object and allows for the future inclusion of more complex
	objects through TLVs.		objects through TLVs.
			Note that some function may require an LSR to inspect both the
			SESSION_ATTRIBUTE object, and the LSP_ATTRIBUTES or
			LSP_REQUIRED_ATTIBUTES object.
	The LSP_ATTRIBUTES object class is TBD of the form 11bbbbbb. This		The LSP_ATTRIBUTES object class is TBD of the form 11bbbbbb. This
	C-Num value (see section 7) ensures that LSRs that do not recognize		C-Num value (see section 7) ensures that LSRs that do not recognize
	the object pass it on transparently.		the object pass it on transparently.
	One C-Type is defined, C-Type = 1 for LSP Attributes.		One C-Type is defined, C-Type = 1 for LSP Attributes.
	This object is optional and may be placed on Path messages to convey		This object is optional and may be placed on Path messages to convey
	additional information about the desired attributes of the LSP.		additional information about the desired attributes of the LSP.
	4.1 Format		4.1 Format
	skipping to change at line 294		skipping to change at line 304
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	The Attributes TLVs are encoded as described in section 3.		The Attributes TLVs are encoded as described in section 3.
	4.2 Generic Processing Rules		4.2 Generic Processing Rules
	An LSR that does not support this object will pass it on unaltered		An LSR that does not support this object will pass it on unaltered
	because of the C-Num.		because of the C-Num.
	An LSR that does support this object, but does not recognize a TLV		An LSR that does support this object, but does not recognize a TLV
	type code carried in this object MUST pass the TLV on un-altered		type code carried in this object MUST pass the TLV on unaltered
	in the LSP_ATTRIBUTES object that it places in the Path message		in the LSP_ATTRIBUTES object that it places in the Path message
	that it sends downstream.		that it sends downstream.
	An LSR that does support this object and recognizes a TLV but does		An LSR that does support this object and recognizes a TLV but does
	not support the attribute defined by the TLV MUST act as specified in		not support the attribute defined by the TLV MUST act as specified in
	the document that defines the TLV.		the document that defines the TLV.
	An LSR that supports the Attributes Flags TLV, but does not		An LSR that supports the Attributes Flags TLV, but does not
	recognize a bit set in the Attributes Flags TLV MUST forward the		recognize a bit set in the Attributes Flags TLV MUST forward the
	TLV unchanged.		TLV unchanged.
	An LSR that supports the Attributes Flags TLV and recognizes a bit		An LSR that supports the Attributes Flags TLV and recognizes a bit
	that is set but does not support the indicated attribute MUST act as		that is set but does not support the indicated attribute MUST act as
	specified in the document that defines the bit.		specified in the document that defines the bit.
	5. LSP_REQUIRED_ATTRIBUTES Object		5. LSP_REQUIRED_ATTRIBUTES Object
	The LSP_REQUIRED_ATTRIBUTES object is used to signal attributes		The LSP_REQUIRED_ATTRIBUTES object is used to signal attributes
	required in support of a LSP, or to indicate the nature or use of		required in support of an LSP, or to indicate the nature or use of
	a LSP where that information MUST be inspected at each transit LSR.		an LSP where that information MUST be inspected at each transit LSR.
	Specifically, each transit LSR MUST examine the attributes in the		Specifically, each transit LSR MUST examine the attributes in the
	LSP_REQUIRED_ATTRIBUTES object and MUST NOT forward the object		LSP_REQUIRED_ATTRIBUTES object and MUST NOT forward the object
	transparently.		transparently.
	This object effectively extends the flags field in the SESSION_		This object effectively extends the flags field in the SESSION_
	ATTRIBUTE object and allows for the future inclusion of more complex		ATTRIBUTE object and allows for the future inclusion of more complex
	objects through TLVs. It complements the LSP_ATTRIBUTES object.		objects through TLVs. It complements the LSP_ATTRIBUTES object.
	The LSP_REQUIRED_ATTRIBUTES object class is TBD of the form 0bbbbbbb.		The LSP_REQUIRED_ATTRIBUTES object class is TBD of the form 0bbbbbbb.
	This C-Num value (see section 7) ensures that LSRs that do not		This C-Num value ensures that LSRs that do not
	recognize the object reject the LSP setup effectively saying that		recognize the object reject the LSP setup effectively saying that
	they do not support the attributes requested. This means that this		they do not support the attributes requested. This means that this
	object should only be used for attributes that require support at		object SHOULD only be used for attributes that require support at
	some transit LSRs and so require examination at all transit LSRs. See		some transit LSRs and so require examination at all transit LSRs. See
	section 4 for how end-to-end and selective attributes are signaled.		section 4 for how end-to-end and selective attributes are signaled.
	One C-Type is defined, C-Type = 1 for LSP Required Attributes.		One C-Type is defined, C-Type = 1 for LSP Required Attributes.
	This object is optional and may be placed on Path messages to convey		This object is optional and may be placed on Path messages to convey
	additional information about the desired attributes of the LSP.		additional information about the desired attributes of the LSP.
	5.1 Format		5.1 Format
	skipping to change at line 386		skipping to change at line 396
	path of the LSP. For example, an attribute may be requested in the		path of the LSP. For example, an attribute may be requested in the
	LSP_ATTRIBUTES object such that LSRs that do not support the object		LSP_ATTRIBUTES object such that LSRs that do not support the object
	are not required to support the attribute or provide the requested		are not required to support the attribute or provide the requested
	function. In this case, it may be useful to the ingress LSR to know		function. In this case, it may be useful to the ingress LSR to know
	which LSRs acted on the request and which ignored it.		which LSRs acted on the request and which ignored it.
	Additionally, there may be other qualities that need to be reported		Additionally, there may be other qualities that need to be reported
	on a hop-by-hop basis. These are currently indicated in the Flags		on a hop-by-hop basis. These are currently indicated in the Flags
	field of RRO subobjects. Since there are only eight bits available		field of RRO subobjects. Since there are only eight bits available
	in this field, and since some are already assigned and there is also		in this field, and since some are already assigned and there is also
	likely to an increase in allocations in new documents, there is a		likely to be an increase in allocations in new documents, there is a
	need for some other method to report per-hop attributes.		need for some other method to report per-hop attributes.
	6.2 RRO Attributes Subobject		6.2 RRO Attributes Subobject
	The RRO Attributes Subobject may be carried in the RECORD_ROUTE		The RRO Attributes Subobject may be carried in the RECORD_ROUTE
	object if it is present. The subobject uses the standard format of		object if it is present. The subobject uses the standard format of
	an RRO subobject.		an RRO subobject.
	The length is variable as for the Attributes Flags TLV. The content		The length is variable as for the Attributes Flags TLV. The content
	is the same as the Attribute Flags TLV - that is, it is a series of		is the same as the Attribute Flags TLV - that is, it is a series of
	skipping to change at line 433		skipping to change at line 443
	Attribute Flags		Attribute Flags
	The attribute flags recorded for the specific hop.		The attribute flags recorded for the specific hop.
	6.3 Procedures		6.3 Procedures
	6.3.1 Subobject Presence Rules		6.3.1 Subobject Presence Rules
	The Attributes subobject is pushed onto the RECORD_ROUTE object		The Attributes subobject is pushed onto the RECORD_ROUTE object
	immediately prior to pushing on the node's IP address. Thus, if		immediately prior to pushing the node's IP address or link
	label recording is being used, the Attributes subobject SHOULD be		identifier. Thus, if label recording is being used, the Attributes
	pushed onto the RECORD_ROUTE object after the Record Label		subobject SHOULD be pushed onto the RECORD_ROUTE object after the
	subobject(s).		Record Label subobject(s).
	A node MUST NOT push on a Attributes subobject without also		A node MUST NOT push an Attributes subobject on to the RECORD_ROUTE
	pushing on an IPv4 or IPv6 subobject.		object without also pushing an IPv4, IPv6 or Unnumbered Interface ID
			subobject.
	This means that an Attributes subobject is bound to the LSR		This means that an Attributes subobject is bound to the LSR
	identified by the IP address subobject found in the RRO immediately		identified by the subobject found in the RRO immediately before the
	before the Attributes subobject.		Attributes subobject.
	If the newly added subobject causes the RRO to be too big to fit in a		If the new subobject causes the RRO to be too big to fit in a Path
	Path (or Resv) message, the processing SHALL be as described in		(or Resv) message, the processing MUST be as described in [RFC3209].
	[RFC3209].
	If more than one Attributes subobject is found between a pair of		If more than one Attributes subobject is found between a pair of
	subobjects that identify LSRs, only the first one found SHALL have		subobjects that identify LSRs, only the first one found (that is, the
	any meaning within the context of this document. All such subobjects		nearest to the stop of the stack) SHALL have any meaning within the
	shall be forwarded unmodified by transit LSRs.		context of this document. All such subobjects MUST be forwarded
			unmodified by transit LSRs.
	6.3.2 Reporting Compliance with LSP Attributes		6.3.2 Reporting Compliance with LSP Attributes
	To report compliance with an attribute requested in the Attributes		To report compliance with an attribute requested in the Attributes
	Flags TLV, an LSR MAY set the corresponding bit (see section 7) in		Flags TLV, an LSR MAY set the corresponding bit (see section 7) in
	the Attributes subobject. To report non-compliance, an LSR MAY clear		the Attributes subobject. To report non-compliance, an LSR MAY clear
	the corresponding bit in the Attributes subobject.		the corresponding bit in the Attributes subobject.
	The requirement to report compliance MUST be specified in the		The requirement to report compliance MUST be specified in the
	document that defines the usage of any bit. This will reduce to a		document that defines the usage of any bit. This will reduce to a
	skipping to change at line 477		skipping to change at line 488
	To report a per-hop attribute, an LSR sets the appropriate bit in the		To report a per-hop attribute, an LSR sets the appropriate bit in the
	Attributes subobject.		Attributes subobject.
	The requirement to report a per-hop attribute MUST be specified in		The requirement to report a per-hop attribute MUST be specified in
	the document that defines the usage of the bit.		the document that defines the usage of the bit.
	6.3.4 Default Behavior		6.3.4 Default Behavior
	By default all bits in an Attibutes subobject SHOULD be set to zero.		By default all bits in an Attibutes subobject SHOULD be set to zero.
	If an Attribute subobject is not long enough to include a specific		If a received Attribute subobject is not long enough to include a
	bit, the bit MUST be assumed to be set to zero.		specific numbered bit, that bit MUST be treated as though present and
			as if set to zero.
	If the RRO subobject is not present for a hop in the LSP, all bits		If the RRO subobject is not present for a hop in the LSP, all bits
	MUST be assumed to be set to zero.		MUST be assumed to be set to zero.
	7. Summary of Attribute Bit Allocation		7. Summary of Attribute Bit Allocation
	This document defines two uses of per-LSP attribute flag bit fields.		This document defines two uses of per-LSP attribute flag bit fields.
	The bit numbering in the Attributes Flags TLV and the RRO Attributes		The bit numbering in the Attributes Flags TLV and the RRO Attributes
	subobject is identical. That is the same attribute is indicated by		subobject is identical. That is, the same attribute is indicated by
	the same bit in both places. This means that only a single registry		the same bit in both places. This means that only a single registry
	of bits is maintained.		of bits is maintained.
	The consequence is a degree of clarity in implementation and		The consequence is a degree of clarity in implementation and
	registration.		registration.
	Note, however, that it is not always the case that a bit will be used		Note, however, that it is not always the case that a bit will be used
	in both the Attributes Flags TLV and the RRO Attributes subobject.		in both the Attributes Flags TLV and the RRO Attributes subobject.
	For example, an attribute may be requested using the Attributes Flags		For example, an attribute may be requested using the Attributes Flags
	TLV, but there is no requirement to report the handling of the		TLV, but there is no requirement to report the handling of the
	attribute on a hop-by-hop basis. Conversely, there may be a		attribute on a hop-by-hop basis. Conversely, there may be a
	requirement to report the attributes of an LSP on a hop-by-hop basis,		requirement to report the attributes of an LSP on a hop-by-hop basis,
	but there is no corresponding request attribute.		but there is no corresponding request attribute.
	In these cases, a single bit number is still assigned for both the		In these cases, a single bit number is still assigned for both the
	Attributes Flags TLV and the RRO Attributes subobject. The document		Attributes Flags TLV and the RRO Attributes subobject even though the
	that defines the usage of the new bit MUST state in which places		bit may be irrelevant in either the Attributes Flags or the RRO
	it is used and MUST handle a default setting of zero.		Attributes subobject. The document that defines the usage of the new
			bit MUST state in which places it is used and MUST handle a default
			setting of zero.
	8. Message Formats		8. Message Formats
	The LSP_ATTRIBUTES object and the LSP_REQUIRED_ATTRIBUTES object MAY		The LSP_ATTRIBUTES object and the LSP_REQUIRED_ATTRIBUTES object MAY
	be carried in a Path message.		be carried in a Path message.
	The order of objects in RSVP-TE messages is recommended, but		The order of objects in RSVP-TE messages is recommended, but
	implementations must be capable of receiving the objects in any		implementations must be capable of receiving the objects in any
	meaningful order. The LSP_ATTRIBUTES object and LSP_REQUIRED_		meaningful order. The LSP_ATTRIBUTES object and LSP_REQUIRED_
	ATTRIBUTES objects are RECOMMENDED to be placed immediately after the		ATTRIBUTES objects are RECOMMENDED to be placed immediately after the
	SESSION_ATTRIBUTE object if it is present, or otherwise immediately		SESSION_ATTRIBUTE object if it is present, or otherwise immediately
	after the LABEL_REQUEST object.		after the LABEL_REQUEST object.
	If both the LSP_ATTRIBUTES object and the LSP_REQUIRED_ATTRIBUTES		If both the LSP_ATTRIBUTES object and the LSP_REQUIRED_ATTRIBUTES
	object are present, the LSP_REQUIRED_ATTRIBUTES object is RECOMMENDED		object are present, the LSP_REQUIRED_ATTRIBUTES object is RECOMMENDED
	to be placed first.		to be placed first.
	LSRs should be prepared to receive these objects in any order in any		LSRs SHOULD be prepared to receive these objects in any order in any
	position within a Path message. Subsequent instances of these objects		position within a Path message. Subsequent instances of these objects
	within a Path message SHOULD be ignored.		within a Path message SHOULD be ignored and those objects MUST be
			forwarded unchanged transparently.
	9. IANA Considerations		9. IANA Considerations
	9.1 New RSVP C-Nums and C-Types		9.1 New RSVP C-Nums and C-Types
	Two new RSVP C-Nums are defined in this document and should be		Two new RSVP C-Nums are defined in this document and should be
	assigned by IANA.		assigned by IANA.
	o LSP_ATTRIBUTES object		o LSP_ATTRIBUTES object
	skipping to change at line 569		skipping to change at line 584
	Recommended C-Type value 1.		Recommended C-Type value 1.
	9.2 New TLV Space		9.2 New TLV Space
	The two new objects referenced above are constructed from TLVs. Each		The two new objects referenced above are constructed from TLVs. Each
	TLV includes a 16-bit type identifier (the T-field). The same T-field		TLV includes a 16-bit type identifier (the T-field). The same T-field
	values are applicable to both objects.		values are applicable to both objects.
	IANA is requested to manage TLV type identifiers as follows:		IANA is requested to manage TLV type identifiers as follows:
	- TLV Type		- TLV Type (T-field value)
	- TLV Name		- TLV Name
	- Whether allowed on LSP_ATTRIBUTES object		- Whether allowed on LSP_ATTRIBUTES object
	- Whether allowed on LSP_REQUIRED_ATTRIBUTES object.		- Whether allowed on LSP_REQUIRED_ATTRIBUTES object.
	This document defines one TLV type as follows:		This document defines one TLV type as follows:
	- TLV Type = 1		- TLV Type = 1
	- TLV Name = Attributes Flags TLV		- TLV Name = Attributes Flags TLV
	- allowed on LSP_ATTRIBUTES object		- allowed on LSP_ATTRIBUTES object
	- allowed on LSP_REQUIRED_ATTRIBUTES object.		- allowed on LSP_REQUIRED_ATTRIBUTES object.
	skipping to change at line 601		skipping to change at line 616
	Each bit should be tracked with the following qualities:		Each bit should be tracked with the following qualities:
	- Bit number		- Bit number
	- Defining RFC		- Defining RFC
	- Name of bit		- Name of bit
	- Whether there is meaning in the Attibute Flags TLV (yes/no)		- Whether there is meaning in the Attibute Flags TLV (yes/no)
	- Whether there is meaning in the RRO Attributes Subobject (yes/no).		- Whether there is meaning in the RRO Attributes Subobject (yes/no).
	Note that this means that all bits in the Attribute Flags TLV and the		Note that this means that all bits in the Attribute Flags TLV and the
	RRO Attributes Subobject use the same bit number regardless of		RRO Attributes Subobject use the same bit number regardless of
	whether they are used in one or both places. Thus, only one list of		whether they are used in one or both places. Thus, only one list of
	bits is required to be maintained.		bits is required to be maintained. (It would be meaningless in the
			context of this document for a bit to have no meaning in neither the
			Attribute Flags TLV nor the RRO Attributes Subobject.)
	9.4 SESSION_ATTRIBUTE Flags Field		9.4 SESSION_ATTRIBUTE Flags Field
	This document does not make any alterations to the definition of the		This document does not make any alterations to the definition of the
	existing SESSION_ATTRIBUTE object nor to the definition of meanings		existing SESSION_ATTRIBUTE object nor to the definition of meanings
	assigned to the flags in the Flags field of that object. These flags		assigned to the flags in the Flags field of that object. These flags
	are assigned meanings in various other RFCs and Internet Drafts.		are assigned meanings in various other RFCs and Internet Drafts.
	It is suggested that IANA manage the allocation of meaning to the		It is suggested that IANA manage the allocation of meaning to the
	bits in the Flags field of the SESSION_ATTRIBUTE object to prevent		bits in the Flags field of the SESSION_ATTRIBUTE object to prevent
	skipping to change at line 660		skipping to change at line 677
	here. Note, however, that there is a tension between notifying the		here. Note, however, that there is a tension between notifying the
	head end of the LSP status at transit LSRs, and hiding the existence		head end of the LSP status at transit LSRs, and hiding the existence
	or identity of the transit LSRs.		or identity of the transit LSRs.
	11. Acknowledgements		11. Acknowledgements
	Credit to the OSPF Working Group for inspiration from their solution		Credit to the OSPF Working Group for inspiration from their solution
	to a similar problem.		to a similar problem.
	Thanks to Rahul Aggarwal for his careful review and support of this		Thanks to Rahul Aggarwal for his careful review and support of this
	work. Thanks also to Raymond Zhang, Kireeti Kompella and Philip		work. Thanks also to Raymond Zhang, Kireeti Kompella, Philip Matthews
	Matthews for their input.		and Jim Gibson for their input.
	12. Intellectual Property Consideration		12. Intellectual Property Consideration
	The IETF takes no position regarding the validity or scope		The IETF takes no position regarding the validity or scope
	of any intellectual property or other rights that might be		of any intellectual property or other rights that might be
	claimed to pertain to the implementation or use of the		claimed to pertain to the implementation or use of the
	technology described in this document or the extent to		technology described in this document or the extent to
	which any license under such rights might or might not be		which any license under such rights might or might not be
	available; neither does it represent that it has made any		available; neither does it represent that it has made any
	effort to identify any such rights. Information on the		effort to identify any such rights. Information on the
	skipping to change at line 718		skipping to change at line 735
	14. Informative References		14. Informative References
	[RFC2026] Bradner, S., "The Internet Standards Process		[RFC2026] Bradner, S., "The Internet Standards Process
	-- Revision 3", RFC 2026, October 1996.		-- Revision 3", RFC 2026, October 1996.
	[RFC3031] Rosen, E., Viswanathan, A., and Callon, R.,		[RFC3031] Rosen, E., Viswanathan, A., and Callon, R.,
	"Multiprotocol Label Switching		"Multiprotocol Label Switching
	Architecture", RFC 3031, January 2001.		Architecture", RFC 3031, January 2001.
	[INTER-AS] Vasseur, JP., Zhang, R., "Inter-AS MPLS Traffic		[INTER-AS] Vasseur, JP., Zhang, R., "Inter-AS MPLS Traffic
	Engineering", <draft-vasseur-inter-as-te-01.txt>,		Engineering", <draft-vasseur-inter-as-te-03.txt>,
	Internet Draft, work in progress.		Internet Draft, work in progress.
	[FRR] Pan, P. (Ed.), "Fast Reroute Extensions to RSVP-TE for		[FRR] Pan, P. (Ed.), "Fast Reroute Extensions to RSVP-TE for
	LSP Tunnels", <draft-ietf-mpls-rsvp-lsp-fastreroute-03		LSP Tunnels", <draft-ietf-mpls-rsvp-lsp-fastreroute-03
	.txt>, Internet Draft, work in progress.		.txt>, Internet Draft, work in progress.
	[OSPF-CAPS] Lindem, A., Shen, N., Aggarwal, R., Shaffer, S.,		[OSPF-CAPS] Lindem, A., Shen, N., Aggarwal, R., Shaffer, S.,
	Vasseur, JP., "Extensions to OSPF for Advertising		Vasseur, JP., "Extensions to OSPF for Advertising
	Optional Router Capabilities", <draft-ietf-ospf-cap-		Optional Router Capabilities", <draft-ietf-ospf-cap-
	00.txt>, Internet Draft, work in progress.		00.txt>, Internet Draft, work in progress.
	skipping to change at line 750		skipping to change at line 767
	EMail: adrian@olddog.co.uk		EMail: adrian@olddog.co.uk
	Dimitri Papadimitriou (Alcatel)		Dimitri Papadimitriou (Alcatel)
	Fr. Wellesplein 1,		Fr. Wellesplein 1,
	B-2018 Antwerpen, Belgium		B-2018 Antwerpen, Belgium
	Phone: +32 3 240-8491		Phone: +32 3 240-8491
	EMail: dimitri.papadimitriou@alcatel.be		EMail: dimitri.papadimitriou@alcatel.be
	Jean Philippe Vasseur		Jean Philippe Vasseur
	Cisco Systems, Inc.		Cisco Systems, Inc.
	300 Apollo Drive
	Chelmsford, MA 01824
	300 Beaver Brook Road		300 Beaver Brook Road
	Boxborough , MA - 01719		Boxborough , MA - 01719
	USA		USA
	EMail: jpv@cisco.com		EMail: jpv@cisco.com
	Arthi Ayyangar		Arthi Ayyangar
	Juniper Networks, Inc.		Juniper Networks, Inc.
	1194 N.Mathilda Ave		1194 N.Mathilda Ave
	Sunnyvale, CA 94089		Sunnyvale, CA 94089
	USA		USA
	EMail: arthi@juniper.net		EMail: arthi@juniper.net
	16. Full Copyright Statement		16. Full Copyright Statement
	Copyright (C) The Internet Society (2003). All Rights		Copyright (C) The Internet Society (2004). All Rights
	Reserved.		Reserved.
	This document and translations of it may be copied and		This document and translations of it may be copied and
	furnished to others, and derivative works that comment on		furnished to others, and derivative works that comment on
	or otherwise explain it or assist in its implementation may		or otherwise explain it or assist in its implementation may
	be prepared, copied, published and distributed, in whole or		be prepared, copied, published and distributed, in whole or
	in part, without restriction of any kind, provided that the		in part, without restriction of any kind, provided that the
	above copyright notice and this paragraph are included on		above copyright notice and this paragraph are included on
	all such copies and derivative works. However, this		all such copies and derivative works. However, this
	document itself may not be modified in any way, such as by		document itself may not be modified in any way, such as by
End of changes.
This html diff was produced by rfcdiff 1.23, available from http://www.levkowetz.com/ietf/tools/rfcdiff/