CCAMP Working Group Zafar Ali Reshad Rahman Danny Prairie Cisco Systems D. Papadimitriou Alcatel Internet Draft Category: BCP Expires: October 2004 April 2004 Node ID based RSVP Hello: A Clarification Statement draft-ali-ccamp-rsvp-node-id-based-hello-01.txt Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. 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 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. Abstract Use of node-id based RSVP Hello messages is implied in a number of cases, e.g., when data and control plan are separated, when TE links are unnumbered. Furthermore, when link level failure detection is performed by some means other than RSVP Hellos, use of node-id based Hellos is optimal for detecting signaling adjacency failure for RSVP- TE. Nonetheless, this implied behavior is unclear and this document formalizes use of node-id based RSVP Hello sessions as a best current practice (BCP) in some scenarios. Z. Ali, et al. Page 1 4/16/2004 [Page 1] draft-ali-ccamp-rsvp-node-id-based-hello-01.txt April 2004 Conventions used in this document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119]. Routing Area ID Summary (This section to be removed before publication.) SUMMARY This document clarifies use of node-id based RSVP Hellos. WHERE DOES IT FIT IN THE PICTURE OF THE ROUTING AREA WORK? This work fits in the context of [RFC 3209] and [RFC 3473]. WHY IS IT TARGETED AT THIS WG? This document is targeted at ccamp as it clarifies procedures in [RFC 3209] and [RFC 3473], related to use of RSVP-TE Hello protocol. RELATED REFERENCES Please refer to the reference section. Table of Contents 1. Terminology....................................................2 2. Introduction...................................................3 3. Node-id based RSVP Hellos......................................3 4. Backward Compatibility Note....................................4 5. Security Considerations........................................4 6. Acknowledgements...............................................4 7. IANA Considerations............................................5 8. Reference......................................................5 8.1 Normative Reference........................................5 8.2 Informative Reference......................................5 9. Author's Addresses.............................................5 1. Terminology Node-id: Router-id as advertised in the Router Address TLV for OSPF [OSPF-TE] and Traffic Engineering router ID TLV for ISIS [ISIS-TE]. Z. Ali, et al. Page 2 4/16/2004 [Page 2] draft-ali-ccamp-rsvp-node-id-based-hello-01.txt April 2004 Node-id based Hello Session: A Hello session such that local and remote node-ids are used in the source and destination fields of the Hello packet, respectively. Interface bounded Hello Session: A Hello session such that local and remote addresses of the interface in question are used in the source and destination fields of the Hello packet, respectively. 2. Introduction The RSVP Hello message exchange was introduced in [RFC 3209]. The usage of RSVP Hello has been extended in [RFC 3473] to support RSVP Graceful Restart (GR) procedures. Specifically, [RFC 3473] specifies the use of the RSVP Hellos for GR procedures for Generalized MPLS (GMPLS). GMPLS introduces the notion of control plane and data plane separation. In other words, in GMPLS networks, the control plane information is carried over a control network whose end-points are IP capable, and which may be physically or logically disjoint from the data bearer links it controls. One of the consequences of separation of data bearer links from control channels is that RSVP Hellos are not terminated on data bearer linksÆ interfaces even if (some of) those are numbered. Instead RSVP hellos are terminated at the control channel (IP-capable) end-points. The latter MAY be identified by the value assigned to the node hosting these control channels i.e. Node- Id. Consequently, the use of RSVP Hellos for GR applications introduces a need for clarifying the behavior and usage of node-id based Hellos. Even in the case of packet MPLS, when link failure detection is performed by some means other than RSVP Hellos (e.g., [BFD]), the use of node-id based Hellos is also optimal for detection of signaling adjacency failures for RSVP-TE. Similarly, when all TE links between neighbor nodes are unnumbered, it is implied that the nodes will use node-id based Hellos for detection of signaling adjacency failures. This document also clarifies the use of node-id based Hellos when all or a sub-set of TE links are unnumbered. This draft also clarifies use of node-id based Hellos in these scenarios. 3. Node-id based RSVP Hellos A node-id based Hello session is established through the exchange of RSVP Hello messages such that local and remote node-ids are respectively used in the source and destination fields of Hello packets. Here, node-id refers to a router-id as defined in the Router Address TLV for OSPF [OSPF-TE] and the Traffic Engineering router ID TLV for ISIS [ISIS-TE]. This section formalizes a procedure for establishing node-id based Hello sessions. Z. Ali, et al. Page 3 4/16/2004 [Page 3] draft-ali-ccamp-rsvp-node-id-based-hello-01.txt April 2004 If a node wishes to establish a node-id based RSVP Hello session with its neighbor, it sends a Hello message with its node-id in the source IP address field of the Hello packet. Furthermore, the node also puts the neighborÆs node-id in the destination address field of the IP packet. When a node receives a Hello packet where the destination IP address is its local node-id as advertised in the IGP-TE topology, the node MUST use its node-id in replying to the Hello message. In other words, nodes must ensure that the node-ids used in RSVP Hello messages are those derived/contained in the IGP-TE topology. Furthermore, a node can only run one node-id based RSVP Hello session per IGP instance (i.e., per node-id pair) with its neighbor. In the case of packet MPLS, when link failure detection is performed by some means other than RSVP Hellos, use of node-id based Hellos is also optimal in detecting signaling adjacency failures, e.g., for RSVP GR procedure. Similarly, if all interfaces between a pair of nodes are unnumbered, the optimal way to use RSVP to detect signaling adjacency failure is to run node-id based Hellos. Furthermore, in the case of optical network with single or multiple, numbered or unnumbered control channels, use of node-id based Hellos for detecting signaling adjacency failure is also optimal. Therefore, when link failure detection is performed by some means other than RSVP Hellos, or if all interfaces between a pair of nodes are unnumbered, or in GMPLS network with data and control plane separation, a node MUST run node-id based Hellos for detection of signaling adjacency failure for RSVP-TE. Nonetheless, if it is desirable to distinguish between signaling adjacency and link failures, node id based Hellos can co-exist with interface bound Hellos messages. Similarly, if a pair of nodes share numbered and unnumbered TE links, node id and interface based Hellos can co-exist. 4. Backward Compatibility Note The procedure presented in this document is backward compatible with both [RFC3209] and [RFC3473]. 5. Security Considerations This document does not introduce new security issues. The security considerations pertaining to the original [RFC3209] remain relevant. 6. Acknowledgements Z. Ali, et al. Page 4 4/16/2004 [Page 4] draft-ali-ccamp-rsvp-node-id-based-hello-01.txt April 2004 We would like to thank Anca Zamfir, Jean-Louis Le Roux, Arthi Ayyangar and Carol Iturralde for their useful comments and suggestions. 7. IANA Considerations None. 8. Reference 8.1 Normative Reference [RFC2205] "Resource ReSerVation Protocol (RSVP) - Version 1, Functional Specification", RFC 2205, Braden, et al, September 1997. [RFC3209] "Extensions to RSVP for LSP Tunnels", D. Awduche, et al, RFC 3209, December 2001. [RFC3471] Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description, RFC 3471, L. Berger, et al, January 2003. [RFC3473] "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP- TE) Extensions", RFC 3473, L. Berger, et al, January 2003. [RFC2119] "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119, S. Bradner, March 1997. 8.2 Informative Reference [OSPF-TE] Katz, D., Yeung, D., Kompella, K., "Traffic Engineering Extensions to OSPF Version 2", RFC 3630. [ISIS-TE] Li, T., Smit, H., "IS-IS extensions for Traffic Engineering", draft-ietf-isis-traffic-05.txt (work in progress). [BFD] Katz, D., and Ward, D., "Bidirectional Forwarding Detection", draft-katz-ward-bfd-01.txt (work in progress). 9. Author's Addresses Zafar Ali Cisco Systems Inc. 100 South Main St. #200 Ann Arbor, MI 48104, USA. Z. Ali, et al. Page 5 4/16/2004 [Page 5] draft-ali-ccamp-rsvp-node-id-based-hello-01.txt April 2004 Phone: (734) 276-2459 Email: zali@cisco.com Reshad Rahman Cisco Systems Inc. 2000 Innovation Dr., Kanata, Ontario, K2K 3E8, Canada. Phone: (613)-254-3519 Email: dprairie@cisco.com Danny Prairie Cisco Systems Inc. 2000 Innovation Dr., Kanata, Ontario, K2K 3E8, Canada. Phone: (613)-254-3519 Email: rrahman@cisco.com Dimitri Papadimitriou (Alcatel) Fr. Wellesplein 1, B-2018 Antwerpen, Belgium Phone: +32 3 240-8491 Email: dimitri.papadimitriou@alcatel.be Full Copyright Statement Copyright (C) The Internet Society (2004). This document is subject to the rights, licenses and restrictions contained in BCP 78 and except as set forth therein, the authors retain all their rights. This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Intellectual Property 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 Z. Ali, et al. Page 6 4/16/2004 [Page 6] draft-ali-ccamp-rsvp-node-id-based-hello-01.txt April 2004 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. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf- ipr@ietf.org. Z. Ali, et al. Page 7 4/16/2004 [Page 7]