IETF A. Rhodes Internet-Draft N. Neate Updates: 4872, 4873 (if approved) D. McWalter, Ed. Category: Standards track Data Connection Ltd Expires: March 28, 2009 September 24, 2008 RSVP-TE Recovery Signaling Fixes draft-rhodes-ccamp-rsvp-recovery-fix-00.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on March 28, 2009. Copyright Notice Copyright (C) The IETF Trust (2008). Abstract This document updates the ASSOCIATION object used in RSVP-TE signaling of End-to-End and Segment Recovery. This document solves problems with existing Segment Recovery procedures, and also makes possible recovery paths that cross addressing domain boundaries. Rhodes, et al. Expires March 28, 2009 [Page 1] Internet-Draft RSVP recovery signaling September 2008 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Solution Summary . . . . . . . . . . . . . . . . . . . . . . . 3 2.1 Reasoning . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2 Compatibility . . . . . . . . . . . . . . . . . . . . . . 4 3. ASSOCIATION object . . . . . . . . . . . . . . . . . . . . . . 4 3.1 Format . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.2 Association Type 1, Recovery . . . . . . . . . . . . . . . 5 3.3 Association Type 3, Segment Recovery . . . . . . . . . . . 5 3.4 Association Type 4, Inter-Domain Recovery . . . . . . . . 5 3.4.1 Type 4 Association Source identifiers . . . . . . . . 6 4. Security Considerations . . . . . . . . . . . . . . . . . . . 6 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 7 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7 7.1 Normative References . . . . . . . . . . . . . . . . . . . 7 7.2 Informative References . . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 7 Intellectual Property and Copyright Statements . . . . . . . . 9 Rhodes, et al. Expires March 28, 2009 [Page 2] Internet-Draft RSVP recovery signaling September 2008 1. Introduction This document changes RSVP-TE signaling procedures for [RFC4872] End- to-End Recovery and [RFC4873] Segment Recovery. This document contains one fix and one extension. The fix is to the problem described in [I-D.rhodes-rsvp-recovery- signaling] section 3.1, namely to remove the restriction that Segment Recovery repairs can only be be signaled successfully when the merge point is at the egress LSR of the protected LSP. The extension is for the requirement described in [I-D.rhodes-rsvp- recovery-signaling] section 3.2, namely to allow End-to-End and Segment Recovery paths to cross addressing domain boundaries. See [RFC5298] section 7 for further information. Other problems described in [I-D.rhodes-rsvp-recovery-signaling] are not addressed by this document. 2. Solution Summary [RFC4872] End-to-End Recovery use of Association Type 1 is unchanged. [RFC4873] Segment Recovery signaling use of Association Type 1 (Recovery) is deprecated. Association Type 3 (Segment Recovery) is introduced for use with [RFC4873] Segment Recovery. Its syntax is the same as Type 2, procedures are the same as those for Type 1. Association Type 4 (Inter-Domain Recovery) is introduced for use with [RFC4872] End-to-End Recovery and [RFC4873] Segment Recovery. It uses generic identifiers in place of router addresses that are meaningful only within an addressing domain. 2.1 Reasoning This section is explanatory, not normative. Association Type 3 can be used to associate LSPs from different sessions. It allows signaling of Segment Recovery paths with merge points other than the egress LSR of the protected LSP. This fixes the problem described in [I-D.rhodes-rsvp-recovery-signaling] section 3.1. Association Type 4 can be used to signal associations across domain boundaries, including addressing domain boundaries. Existing association types are not suitable for this task, as they contain an Rhodes, et al. Expires March 28, 2009 [Page 3] Internet-Draft RSVP recovery signaling September 2008 Association Source that is specified to be an address. Addresses cannot be propagated across addressing domain boundaries. This makes possible a variety of inter-domain signaling solutions, including ideas similar to path keys. See [RFC5298] section 7. 2.2 Compatibility This section is explanatory, not normative. This document makes extensions to the procedures defined in [RFC4872]. These extensions are compatible with existing deployments. This document makes changes to the procedures defined in [RFC4873]. These extensions are not compatible with existing deployments, if any exist. It would be possible to entirely deprecate Association Type 1 and mandate use of Association Type 3 for all intra-domain associations. This is not desirable for reasons of back-compatibility. 3. ASSOCIATION object The ASSOCIATION object is defined in [RFC4872]. [RFC4873] extended the use of Association Type 1 and introduced Association Type 2. This document replaces the [RFC4873] signaling procedures based on Association Type 1, and replaces them with Association Type 3. This document also extends the [RFC4872] [RFC4873] signaling procedures, allowing use of the alternative Association Type 4, which has benefits when recovery paths cross address domains. 3.1 Format Association Type: 16 bits Value Type ----- ---- 0 Reserved 1 Recovery 2 Resource Sharing 3 Segment Recovery 4 Inter-Domain Recovery This document makes no changes to Types 0 and 2. This document updates the use of Type 1, and introduces Types 3 and 4. Rhodes, et al. Expires March 28, 2009 [Page 4] Internet-Draft RSVP recovery signaling September 2008 See [RFC4872] for the definition of other fields and values. 3.2 Association Type 1, Recovery Use of Association Type 1 in [RFC4872] procedures is unchanged. Use of Association Type 1 in [RFC4873] procedures is deprecated. Association Type 1 SHOULD NOT be used for [RFC4873] Segment Recovery. 3.3 Association Type 3, Segment Recovery [RFC4873] procedures are updated to use Association Type 3 in place of Association Type 1. Association Type 3 is used for the same purpose as Association Type 1, namely to associate a recovery LSP with the LSP that it is protecting. Association Type 3 syntax is identical with Type 2. Association Source MUST be set to the originating node's router address. The Association ID MUST be set to a value that uniquely identifies the association of LSPs among associations from that Association Source. Association Type 3 can associate two or more LSPs. In the case of 1:N protection with extra-traffic, more than two LSPs will contain identical Association Type 3 objects. 3.4 Association Type 4, Inter-Domain Recovery [RFC4872] procedures are updated to allow the use of Association Type 4 in place of Association Type 1. [RFC4873] procedures are updated to allow the use of Association Type 4 in place of Association Type 3. Association Type 4 is intended for use where recovery paths cross address domain boundaries. However, Type 4 MAY be used for recovery paths that are wholly contained within a single addressing domain. Association Source MUST be set to a value that is unique to the originating node at all possible merge points, regardless of addressing domain. The Association ID MUST be set to a value that uniquely identifies the association of LSPs among associations from that Association Source at those merge points. Association Source MAY uniquely identify the originating node across the entire MPLS network. Several Association Source idenfifiers MAY be assigned to a single node. Rhodes, et al. Expires March 28, 2009 [Page 5] Internet-Draft RSVP recovery signaling September 2008 Association Source need not be an IP address. Either IPv4 or IPv6 ASSOCIATION objects MAY be used. An IPv6 ASSOCIATION object SHOULD be used for Association Type 4, even when originated from an IPv4- addressed domain. Association Type 4 can associate two or more LSPs. In the case of 1:N protection with extra-traffic, more than two LSPs will contain identical ASSOCIATION objects with Association Type 4. 3.4.1 Type 4 Association Source identifiers This section is explanatory, not normative. This document specifies only the RSVP-TE signaling procedures for inter-addressing-domain protection. This document does not define a new address type or identifier for use as a Type 4 Association Source. This document does not define whether such an identifier might be originated by management, PCEs, or some other entity. This document neither imposes nor denies a requirement to respect confidentiality of address domain topology and/or addressing when signaling inter-domain protection. 4. Security Considerations This document modifies RSVP-TE signaling. We assert that no new classes of threat are introduced. Inter-domain signaling introduces a danger that confidential topology information is exported from an addressing domain, perhaps implicitly. This is an existing threat, see [RFC5298] section 7. 5. IANA Considerations IANA is requested to assign the following values to the "Association Types" Registry (see [RFC4872]) in the "ASSOCIATION (object)" section of the "RSVP PARAMETERS" registry located at http://www.iana.org/assignments/rsvp-parameters. Value Type ----- ---- 3 Segment Recovery 4 Inter-Domain Recovery At the time of writing, the existing Association Types assigned by [RFC4872] and [RFC4873] do not appear in the RSVP PARAMETERS registry. Rhodes, et al. Expires March 28, 2009 [Page 6] Internet-Draft RSVP recovery signaling September 2008 6. Acknowledgements None yet. 7. References 7.1 Normative References [RFC4872] Lang, J., Rekhter, Y., and D. Papadimitriou, "RSVP-TE Extensions in Support of End-to-End Generalized Multi- Protocol Label Switching (GMPLS) Recovery", RFC 4872, May 2007. [RFC4873] Berger, L., Bryskin, I., Papadimitriou, D., and A. Farrel, "GMPLS Segment Recovery", RFC 4873, May 2007. 7.2 Informative References [I-D.rhodes-rsvp-recovery-signaling] Rhodes, A., Neate, N., and D. McWalter, "Language Tag MIB", draft-rhodes-rsvp-recovery-signaling-00 (work in progress), I-D Status active, August 2008. [RFC5298] Takeda, T., Farrel, A., Ikejiri, Y., and JP. Vasseur, "Analysis of Inter-Domain Label Switched Path (LSP) Recovery", RFC 5298, August 2008. Authors' Addresses Andrew Rhodes Data Connection Ltd 100 Church Street Enfield EN2 6BQ United Kingdom Email: adr@dataconnection.com Nic Neate Data Connection Ltd 100 Church Street Enfield EN2 6BQ United Kingdom Email: nhn@dataconnection.com Rhodes, et al. Expires March 28, 2009 [Page 7] Internet-Draft RSVP recovery signaling September 2008 David McWalter (editor) Data Connection Ltd 100 Church Street Enfield EN2 6BQ United Kingdom Email: dmcw@dataconnection.com Rhodes, et al. Expires March 28, 2009 [Page 8] Internet-Draft RSVP recovery signaling September 2008 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. 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Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Rhodes, et al. Expires March 28, 2009 [Page 9]