draft-ietf-ospf-te-link-attr-reuse-11.txt		draft-ietf-ospf-te-link-attr-reuse-12.txt
	LSR Working Group P. Psenak, Ed.		LSR Working Group P. Psenak, Ed.
	Internet-Draft L. Ginsberg		Internet-Draft L. Ginsberg
	Intended status: Standards Track Cisco Systems		Intended status: Standards Track Cisco Systems
	Expires: November 8, 2020 W. Henderickx		Expires: November 20, 2020 W. Henderickx
	Nokia		Nokia
	J. Tantsura		J. Tantsura
	Apstra		Apstra
	J. Drake		J. Drake
	Juniper Networks		Juniper Networks
	May 7, 2020		May 19, 2020
	OSPF Link Traffic Engineering Attribute Reuse		OSPF Link Traffic Engineering Attribute Reuse
	draft-ietf-ospf-te-link-attr-reuse-11.txt		draft-ietf-ospf-te-link-attr-reuse-12.txt
	Abstract		Abstract
	Existing traffic engineering related link attribute advertisements		Existing traffic engineering related link attribute advertisements
	have been defined and are used in RSVP-TE deployments. Since the		have been defined and are used in RSVP-TE deployments. Since the
	original RSVP-TE use case was defined, additional applications (e.g.,		original RSVP-TE use case was defined, additional applications (e.g.,
	Segment Routing Traffic Engineering, Loop Free Alternate) have been		Segment Routing Traffic Engineering, Loop Free Alternate) have been
	defined which also make use of the link attribute advertisements. In		defined which also make use of the link attribute advertisements. In
	cases where multiple applications wish to make use of these link		cases where multiple applications wish to make use of these link
	attributes the current advertisements do not support application		attributes the current advertisements do not support application
	skipping to change at page 1, line 46 ¶		skipping to change at page 1, line 46 ¶
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at https://datatracker.ietf.org/drafts/current/.		Drafts is at https://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		Internet-Drafts are draft documents valid for a maximum of six months
	and may be updated, replaced, or obsoleted by other documents at any		and may be updated, replaced, or obsoleted by other documents at any
	time. It is inappropriate to use Internet-Drafts as reference		time. It is inappropriate to use Internet-Drafts as reference
	material or to cite them other than as "work in progress."		material or to cite them other than as "work in progress."
	This Internet-Draft will expire on November 8, 2020.		This Internet-Draft will expire on November 20, 2020.
	Copyright Notice		Copyright Notice
	Copyright (c) 2020 IETF Trust and the persons identified as the		Copyright (c) 2020 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
	This document is subject to BCP 78 and the IETF Trust's Legal		This document is subject to BCP 78 and the IETF Trust's Legal
	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
	(https://trustee.ietf.org/license-info) in effect on the date of		(https://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	skipping to change at page 4, line 48 ¶		skipping to change at page 4, line 48 ¶
	1. Advertisement of the link attributes does not make the link part		1. Advertisement of the link attributes does not make the link part
	of the RSVP-TE topology. It avoids any conflicts and is fully		of the RSVP-TE topology. It avoids any conflicts and is fully
	compatible with [RFC3630] and [RFC5329].		compatible with [RFC3630] and [RFC5329].
	2. The OSPFv2 TE Opaque LSA and OSPFv3 Intra-Area-TE-LSA remains		2. The OSPFv2 TE Opaque LSA and OSPFv3 Intra-Area-TE-LSA remains
	truly opaque to OSPFv2 and OSPFv3 as originally defined in		truly opaque to OSPFv2 and OSPFv3 as originally defined in
	[RFC3630] and [RFC5329] respectively. Their contents are not		[RFC3630] and [RFC5329] respectively. Their contents are not
	inspected by OSPF, that acts as a pure transport.		inspected by OSPF, that acts as a pure transport.
	3. There is clear distinction between link attributes used by RSVP-		3. There is a clear distinction between link attributes used by
	TE and link attributes used by other OSPFv2 or OSPFv3		RSVP-TE and link attributes used by other OSPFv2 or OSPFv3
	applications.		applications.
	4. All link attributes that are used by other applications are		4. All link attributes that are used by other applications are
	advertised in a single LSA, the Extended Link Opaque LSA in		advertised in a single LSA, the Extended Link Opaque LSA in
	OSPFv2 or the OSPFv3 E-Router-LSA [RFC8362] in OSPFv3.		OSPFv2 or the OSPFv3 E-Router-LSA [RFC8362] in OSPFv3.
	The disadvantage of this approach is that in rare cases, the same		The disadvantage of this approach is that in rare cases, the same
	link attribute is advertised in both the TE Opaque and Extended Link		link attribute is advertised in both the TE Opaque and Extended Link
	Attribute LSAs in OSPFv2 or the Intra-Area-TE-LSA and E-Router-LSA in		Attribute LSAs in OSPFv2 or the Intra-Area-TE-LSA and E-Router-LSA in
	OSPFv3.		OSPFv3.
	Extended Link Opaque LSA [RFC7684] and E-Router-LSA [RFC8362] are		Extended Link Opaque LSA [RFC7684] and E-Router-LSA [RFC8362] are
	used to advertise any link attributes used for non-RSVP-TE		used to advertise any link attributes used for non-RSVP-TE
	applications in OSPFv2 or OSPFv3 respectively, including those that		applications in OSPFv2 or OSPFv3 respectively, including those that
	have been originally defined for RSVP-TE applications (See		have been originally defined for RSVP-TE applications (See
	Section 6).		Section 6).
	TE link attributes used for RSVP-TE/GMPLS continue use OSPFv2 TE		TE link attributes used for RSVP-TE/GMPLS continue to use OSPFv2 TE
	Opaque LSA [RFC3630] and OSPFv3 Intra-Area-TE-LSA [RFC5329].		Opaque LSA [RFC3630] and OSPFv3 Intra-Area-TE-LSA [RFC5329].
	The format of the link attribute TLVs that have been defined for		The format of the link attribute TLVs that have been defined for
	RSVP-TE applications will be kept unchanged even when they are used		RSVP-TE applications will be kept unchanged even when they are used
	for non-RSVP-TE applications. Unique code points are allocated for		for non-RSVP-TE applications. Unique code points are allocated for
	these link attribute TLVs from the OSPFv2 Extended Link TLV Sub-TLV		these link attribute TLVs from the OSPFv2 Extended Link TLV Sub-TLV
	Registry [RFC7684] and from the OSPFv3 Extended LSA Sub-TLV Registry		Registry [RFC7684] and from the OSPFv3 Extended LSA Sub-TLV Registry
	[RFC8362], as specified in Section 14.		[RFC8362], as specified in Section 14.
	5. Advertisement of Application Specific Values		5. Advertisement of Application Specific Values
	skipping to change at page 6, line 12 ¶		skipping to change at page 6, line 12 ¶
	Extended Link TLV and OSPFv3 Router-Link TLV. It has the following		Extended Link TLV and OSPFv3 Router-Link TLV. It has the following
	format:		format:
	0 1 2 3		0 1 2 3
	0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1		0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Type | Length |		| Type | Length |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| SABM Length | UDABM Length | Reserved |		| SABM Length | UDABM Length | Reserved |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Standard Application Identifier Bit-Mask |		| Standard Application Identifier Bit Mask |
	+- -+		+- -+
	| ... |		| ... |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| User Defined Application Identifier Bit-Mask |		| User Defined Application Identifier Bit Mask |
	+- -+		+- -+
	| ... |		| ... |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Link Attribute sub-sub-TLVs |		| Link Attribute sub-sub-TLVs |
	+- -+		+- -+
	| ... |		| ... |
	where:		where:
	Type: 10 (OSPFv2), 11 (OSPFv3)		Type: 10 (OSPFv2), 11 (OSPFv3)
	Length: variable		Length: variable
	SABM Length: Standard Application Identifier Bit-Mask Length in		SABM Length: Standard Application Identifier Bit Mask Length in
	octets. The legal values are 0, 4 or 8. If the Standard		octets. The value MUST be 0, 4 or 8. If the Standard Application
	Application Bit-Mask is not present, the Standard Application Bit-		Bit Mask is not present, the Standard Application Bit Mask Length
	Mask Length MUST be set to 0.		MUST be set to 0.
	UDABM Length: User Defined Application Identifier Bit-Mask Length		UDABM Length: User Defined Application Identifier Bit Mask Length
	in octets. The legal values are 0, 4 or 8. If the User Defined		in octets. The legal values are 0, 4 or 8. If the User Defined
	Application Bit-Mask is not present, the User Defined Application		Application Bit Mask is not present, the User Defined Application
	Bit-Mask Length MUST be set to 0.		Bit Mask Length MUST be set to 0.
	Standard Application Identifier Bit-Mask: Optional set of bits,		Standard Application Identifier Bit Mask: Optional set of bits,
	where each bit represents a single standard application. Bits are		where each bit represents a single standard application. Bits are
	defined in [I-D.ietf-isis-te-app]. The bits are repeated here for		defined in [I-D.ietf-isis-te-app]. The bits are repeated here for
	informational purpose:		informational purpose:
	Bit-0 (R-bit): RSVP-TE		Bit-0 (R-bit): RSVP-TE
	Bit-1 (S-bit): Segment Routing TE		Bit-1 (S-bit): Segment Routing TE
	Bit-2 (F-bit): Loop Free Alternate (LFA). Includes all LFA		Bit-2 (F-bit): Loop Free Alternate (LFA). Includes all LFA
	types		types
	User Defined Application Identifier Bit-Mask: Optional set of		User Defined Application Identifier Bit Mask: Optional set of
	bits, where each bit represents a single user defined application.		bits, where each bit represents a single user defined application.
	If the SABM or UDABM length is other than 0, 4, or 8, the ASLA sub-		If the SABM or UDABM length is other than 0, 4, or 8, the ASLA sub-
	TLV MUST be ignored by the receiver.		TLV MUST be ignored by the receiver.
	Standard Application Identifier Bits are defined/sent starting with		Standard Application Identifier Bits are defined/sent starting with
	Bit 0. Undefined bits MUST be transmitted as 0 and MUST be ignored		Bit 0. Undefined bits MUST be transmitted as 0 and MUST be ignored
	on receipt. Bits that are NOT transmitted MUST be treated as if they		on receipt. Bits that are NOT transmitted MUST be treated as if they
	are set to 0 on receipt. Bits that are not supported by an		are set to 0 on receipt. Bits that are not supported by an
	implementation MUST be ignored on receipt.		implementation MUST be ignored on receipt.
	User Defined Application Identifier Bits have no relationship to		User Defined Application Identifier Bits have no relationship to
	Standard Application Identifier Bits and are NOT managed by IANA or		Standard Application Identifier Bits and are NOT managed by IANA or
	any other standards body. It is recommended that bits are used		any other standards body. It is recommended that bits are used
	starting with Bit 0 so as to minimize the number of octets required		starting with Bit 0 so as to minimize the number of octets required
	to advertise all UDAs.		to advertise all UDAs.
	If the link attribute advertisement is limited to be used by a		If the link attribute advertisement is limited to be used by a
	specific set of applications, corresponding Bit-Masks MUST be present		specific set of applications, corresponding Bit Masks MUST be present
	and application specific bit(s) MUST be set for all applications that		and application specific bit(s) MUST be set for all applications that
	use the link attributes advertised in the ASLA sub-TLV.		use the link attributes advertised in the ASLA sub-TLV.
	Application Bit-Masks apply to all link attributes that support		Application Bit Masks apply to all link attributes that support
	application specific values and are advertised in the ASLA sub-TLV.		application specific values and are advertised in the ASLA sub-TLV.
	The advantage of not making the Application Bit-Masks part of the		The advantage of not making the Application Bit Masks part of the
	attribute advertisement itself is that the format of any previously		attribute advertisement itself is that the format of any previously
	defined link attributes can be kept and reused when advertising them		defined link attributes can be kept and reused when advertising them
	in the ASLA sub-TLV.		in the ASLA sub-TLV.
	If the same attribute is advertised in more than single ASLA sub-TLVs		If the same attribute is advertised in more than single ASLA sub-TLVs
	with the application listed in the Application Bit-Masks, the		with the application listed in the Application Bit Masks, the
	application SHOULD use the first instance of advertisement and ignore		application SHOULD use the first instance of advertisement and ignore
	any subsequent advertisements of that attribute.		any subsequent advertisements of that attribute.
	This document defines the initial set of link attributes that MUST		This document defines the initial set of link attributes that MUST
	use the ASLA sub-TLV if advertised in the OSPFv2 Extended Link TLV or		use the ASLA sub-TLV if advertised in the OSPFv2 Extended Link TLV or
	in the OSPFv3 Router-Link TLV. Documents which define new link		in the OSPFv3 Router-Link TLV. Documents which define new link
	attributes MUST state whether the new attributes support application		attributes MUST state whether the new attributes support application
	specific values and as such MUST be advertised in an ASLA sub-TLV.		specific values and as such MUST be advertised in an ASLA sub-TLV.
	The link attributes that MUST be advertised in ASLA sub-TLVs are:		The link attributes that MUST be advertised in ASLA sub-TLVs are:
	skipping to change at page 10, line 46 ¶		skipping to change at page 10, line 46 ¶
	8. Considerations for Extended TE Metrics		8. Considerations for Extended TE Metrics
	[RFC7471] defines a number of dynamic performance metrics associated		[RFC7471] defines a number of dynamic performance metrics associated
	with a link. It is conceivable that such metrics could be measured		with a link. It is conceivable that such metrics could be measured
	specific to traffic associated with a specific application.		specific to traffic associated with a specific application.
	Therefore this document includes support for advertising these link		Therefore this document includes support for advertising these link
	attributes specific to a given application. However, in practice it		attributes specific to a given application. However, in practice it
	may well be more practical to have these metrics reflect the		may well be more practical to have these metrics reflect the
	performance of all traffic on the link regardless of application. In		performance of all traffic on the link regardless of application. In
	such cases, advertisements for these attributes can be associated		such cases, advertisements for these attributes can be associated
	with all of the applications utilizing that link, for example, by		with all of the applications utilizing that link. This can be done
	listing all applications in the Application Bit-Mask.		either by explicitly specifying the applications in the Application
			Identifier Bit Mask or by using a zero length Application Identifier
			Bit Mask.
	9. Local Interface IPv6 Address Sub-TLV		9. Local Interface IPv6 Address Sub-TLV
	The Local Interface IPv6 Address Sub-TLV is an application		The Local Interface IPv6 Address Sub-TLV is an application
	independent attribute of the link that is defined in [RFC5329].		independent attribute of the link that is defined in [RFC5329].
	Because it is an application independent attribute, it MUST NOT be		Because it is an application independent attribute, it MUST NOT be
	advertised in the ASLA sub-TLV. Instead, it MAY be advertised as a		advertised in the ASLA sub-TLV. Instead, it MAY be advertised as a
	sub-TLV of the OSPFv3 E-Router-LSA Router-Link TLV [RFC8362].		sub-TLV of the OSPFv3 E-Router-LSA Router-Link TLV [RFC8362].
	To advertise the Local Interface IPv6 Address Sub-TLV in the OSPFv3		To advertise the Local Interface IPv6 Address Sub-TLV in the OSPFv3
	skipping to change at page 12, line 34 ¶		skipping to change at page 12, line 34 ¶
	12. Deployment Considerations		12. Deployment Considerations
	12.1. Use of Legacy RSVP-TE LSA Advertisements		12.1. Use of Legacy RSVP-TE LSA Advertisements
	Bit Identifiers for Standard Applications are defined in Section 5.		Bit Identifiers for Standard Applications are defined in Section 5.
	All of the identifiers defined in this document are associated with		All of the identifiers defined in this document are associated with
	applications which were already deployed in some networks prior to		applications which were already deployed in some networks prior to
	the writing of this document. Therefore, such applications have been		the writing of this document. Therefore, such applications have been
	deployed using the RSVP-TE LSA advertisements. The Standard		deployed using the RSVP-TE LSA advertisements. The Standard
	Applications defined in this document MAY continue to use RSVP-TE LSA		Applications defined in this document may continue to use RSVP-TE LSA
	advertisements for a given link so long as at least one of the		advertisements for a given link so long as at least one of the
	following conditions is true:		following conditions is true:
	The application is RSVP-TE		The application is RSVP-TE
	The application is SRTE or LFA and RSVP-TE is not deployed		The application is SRTE or LFA and RSVP-TE is not deployed
	anywhere in the network		anywhere in the network
	The application is SRTE or LFA, RSVP-TE is deployed in the		The application is SRTE or LFA, RSVP-TE is deployed in the
	network, and both the set of links on which SRTE and/or LFA		network, and both the set of links on which SRTE and/or LFA
	skipping to change at page 18, line 38 ¶		skipping to change at page 18, line 38 ¶
	Thanks to Alvaro Retana for his detailed review and comments.		Thanks to Alvaro Retana for his detailed review and comments.
	17. References		17. References
	17.1. Normative References		17.1. Normative References
	[I-D.ietf-isis-te-app]		[I-D.ietf-isis-te-app]
	Ginsberg, L., Psenak, P., Previdi, S., Henderickx, W., and		Ginsberg, L., Psenak, P., Previdi, S., Henderickx, W., and
	J. Drake, "IS-IS TE Attributes per application", draft-		J. Drake, "IS-IS TE Attributes per application", draft-
	ietf-isis-te-app-12 (work in progress), March 2020.		ietf-isis-te-app-13 (work in progress), May 2020.
	[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,
	<https://www.rfc-editor.org/info/rfc2119>.		<https://www.rfc-editor.org/info/rfc2119>.
	[RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328,		[RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328,
	DOI 10.17487/RFC2328, April 1998,		DOI 10.17487/RFC2328, April 1998,
	<https://www.rfc-editor.org/info/rfc2328>.		<https://www.rfc-editor.org/info/rfc2328>.
	skipping to change at page 20, line 8 ¶		skipping to change at page 20, line 8 ¶
	[RFC8362] Lindem, A., Roy, A., Goethals, D., Reddy Vallem, V., and		[RFC8362] Lindem, A., Roy, A., Goethals, D., Reddy Vallem, V., and
	F. Baker, "OSPFv3 Link State Advertisement (LSA)		F. Baker, "OSPFv3 Link State Advertisement (LSA)
	Extensibility", RFC 8362, DOI 10.17487/RFC8362, April		Extensibility", RFC 8362, DOI 10.17487/RFC8362, April
	2018, <https://www.rfc-editor.org/info/rfc8362>.		2018, <https://www.rfc-editor.org/info/rfc8362>.
	17.2. Informative References		17.2. Informative References
	[I-D.ietf-spring-segment-routing-policy]		[I-D.ietf-spring-segment-routing-policy]
	Filsfils, C., Sivabalan, S., Voyer, D., Bogdanov, A., and		Filsfils, C., Sivabalan, S., Voyer, D., Bogdanov, A., and
	P. Mattes, "Segment Routing Policy Architecture", draft-		P. Mattes, "Segment Routing Policy Architecture", draft-
	ietf-spring-segment-routing-policy-06 (work in progress),		ietf-spring-segment-routing-policy-07 (work in progress),
	December 2019.		May 2020.
	[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,		[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
	and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP		and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
	Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001,		Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001,
	<https://www.rfc-editor.org/info/rfc3209>.		<https://www.rfc-editor.org/info/rfc3209>.
	[RFC4552] Gupta, M. and N. Melam, "Authentication/Confidentiality		[RFC4552] Gupta, M. and N. Melam, "Authentication/Confidentiality
	for OSPFv3", RFC 4552, DOI 10.17487/RFC4552, June 2006,		for OSPFv3", RFC 4552, DOI 10.17487/RFC4552, June 2006,
	<https://www.rfc-editor.org/info/rfc4552>.		<https://www.rfc-editor.org/info/rfc4552>.
End of changes. 21 change blocks.
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