CCAMP Working Group Rakesh Gandhi, Ed. Internet-Draft Zafar Ali Intended status: Informational Gabriele Maria Galimberti Expires: September 7, 2014 Cisco Systems, Inc. Xian Zhang Huawei March 6, 2014 RSVP-TE Signaling For GMPLS Restoration LSP draft-gandhi-ccamp-gmpls-restoration-lsp-03 Abstract In transport networks, there are requirements where Generalized Multi-Protocol Label Switching (GMPLS) end-to-end recovery scheme needs to employ restoration LSP while keeping resources for the working and/or protecting LSPs reserved in the network after the failure. This draft describes Resource reSerVation Protocol - Traffic Engineering (RSVP-TE) signaling for GMPLS end-to-end recovery when using restoration LSP when failed LSP is not torn down. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. 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." Copyright Notice Copyright (c) 2014 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of gandhi, et al. Expires September 7, 2014 [Page 1] Internet-Draft RSVP-TE Signaling for Restoration LSP March 6, 2014 publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Conventions used in this document . . . . . . . . . . . . . . 5 3. Restoration LSP Signaling Procedure . . . . . . . . . . . . . 5 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 5. Security Considerations . . . . . . . . . . . . . . . . . . . 5 6. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 5 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6 7.1. Normative references . . . . . . . . . . . . . . . . . . . 6 7.2. Informative References . . . . . . . . . . . . . . . . . . 6 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 7 gandhi, et al. Expires September 7, 2014 [Page 2] Internet-Draft RSVP-TE Signaling for Restoration LSP March 6, 2014 1. Introduction Generalized Multi-Protocol Label Switching (GMPLS) extends MPLS to include support for different switching technologies [RFC3473]. These switching technologies provide several protection schemes [RFC4426][RFC4427] (e.g., 1+1, 1:N and M:N). GMPLS RSVP-TE signaling has been extended to support various recovery schemes to establish Label Switched Paths (LSPs) [RFC4872][RFC4873], typically working LSP and protecting LSP. [RFC4427] Section 7 specifies various schemes for GMPLS restoration. In GMPLS recovery schemes generally considered, restoration LSP is signaled after the failure has been detected and notified on the working LSP. In non-revertive recovery mode, working LSP is assumed to be removed from the network before restoration LSP is signaled. For revertive recovery mode, a restoration LSP is signaled while working LSP and/or protecting LSP are not torn down in control plane due to a failure. In transport networks, as working LSPs are typically signaled over a nominal path, service providers would like to keep resources associated with the working LSPs reserved. This is to make sure that the service (working LSP) can use the nominal path when the failure is repaired to provide deterministic behaviour and guaranteed Service Level Agreement (SLA). Consequently, revertive recovery mode is usually preferred by recovery schemes used in transport networks. As defined in [RFC4872] and being considered in this draft, "fully dynamic rerouting switches normal traffic to an alternate LSP that is not even partially established only after the working LSP failure occurs. The new alternate route is selected at the LSP head-end node, it may reuse resources of the failed LSP at intermediate nodes and may include additional intermediate nodes and/or links." One example of the recovery scheme considered in this draft is 1+R recovery. The 1+R recovery is exemplified in Figure 1. In this example, working LSP on path A-B-C-Z is pre-established. Typically after a failure detection and notification on the working LSP, a second LSP on path A-H-I-J-Z is established as a restoration LSP. Unlike protection LSP, restoration LSP is signaled per need basis. A --- B --- C --- Z \ / H --- I --- J Figure 1: An example of 1+R recovery scheme gandhi, et al. Expires September 7, 2014 [Page 3] Internet-Draft RSVP-TE Signaling for Restoration LSP March 6, 2014 During failure switchover with 1+R recovery scheme, in general, working LSP resources are not released and working and restoration LSPs coexist in the network. Nonetheless, working and restoration LSPs can share network resources. Typically when failure is recovered on the working LSP, restoration LSP is no longer required and torn down (e.g., revertive mode). Another example of the recovery scheme considered in this draft is 1+1+R. In 1+1+R, a restoration LSP is signaled for the working LSP and/or the protecting LSP after the failure has been detected and notified on the working LSP or the protecting LSP. The 1+1+R recovery is exemplified in Figure 2. In this example, working LSP on path A-B- C-Z and protecting LSP on path A-D-E-F-Z are pre- established. After a failure detection and notification on a working LSP or protecting LSP, a third LSP on path A-H-I-J-Z is established as a restoration LSP. The restoration LSP in this case provides protection against a second order failure. Restoration LSP is torn down when the failure on the working or protecting LSP is repaired. D --- E --- F / \ A --- B --- C --- Z \ / H --- I --- J Figure 2: An example of 1+1+R recovery scheme [RFC4872] Section 14 defines PROTECTION object for GMPLS recovery signaling. The PROTECTION object is used to identify primary and secondary LSPs using S bit and protecting and working LSPs using P bit. [RFC4872] and [RFC6689] define the usage of ASSOCIATION object for further associating GMPLS working and protecting LSPs. However, these existing methods do not specify how to identify restoration LSP when working/protecting LSPs are not torn down. This draft describes procedures for identifying the restoration LSP for GMPLS end-to-end recovery where working and protecting LSP resources are kept reserved in the network after the failure. gandhi, et al. Expires September 7, 2014 [Page 4] Internet-Draft RSVP-TE Signaling for Restoration LSP March 6, 2014 2. 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 [RFC2119]. 3. Restoration LSP Signaling Procedure Where GMPLS recovery scheme needs to employ restoration LSP while keeping resources for the working and/or protecting LSPs reserved in the network after the failure, restoration LSP is signaled with ASSOCIATION object with the association ID set to the LSP ID of the LSP it is restoring. For example, when a restoration LSP is signaled for a working LSP, the ASSOCIATION object in the restoration LSP contains the association ID set to the LSP ID of the working LSP. Similarly, when a restoration LSP is signaled for a protecting LSP, the ASSOCIATION object in the restoration LSP contains the association ID set to the LSP ID of the protecting LSP. The procedure for signaling the PROTECTION object is specified in [RFC4872] and is not changed by this document. Restoration LSP being used as a working LSP is signaled with P bit cleared and used as a protecting LSP is signaled with P bit set. GMPLS recovery scheme where the failed working LSP and/or protecting LSP need to be torn down follows the procedures defined in [RFC6689]. 4. IANA Considerations This document makes no request for IANA action. 5. Security Considerations This document introduces no additional security considerations. For a general discussion on MPLS and GMPLS related security issues, see the MPLS/GMPLS security framework [RFC5920]. In addition, the considerations specified in [RFC4872] will apply. 6. Acknowledgement The authors would like to thank George Swallow for the discussion on the GMPLS restoration. gandhi, et al. Expires September 7, 2014 [Page 5] Internet-Draft RSVP-TE Signaling for Restoration LSP March 6, 2014 7. References 7.1. Normative references [RFC2205] Braden, B., Zhang, L., Berson, S., Herzog, S., and S. Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1 Functional Specification", RFC 2205, September 1997. [RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. [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. [RFC6689] Berger, L, "Usage of the RSVP ASSOCIATION Object", RFC 6689, July 2012. 7.2. Informative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC4426] Lang, J., Rajagopalan B., and D.Papadimitriou, Editors, "Generalized Multiprotocol Label Switching (GMPLS) Recovery Functional Specification", RFC 4426, March 2006. [RFC4427] Mannie, E., Ed. and D. Papadimitriou, Ed., "Recovery (Protection and Restoration) Terminology for Generalized Multi-Protocol Label Switching, RFC 4427, March 2006. [RFC4873] Berger, L., Bryskin, I., Papadimitriou, D., and A. Farrel, "GMPLS Segment Recovery", RFC 4873, May 2007. [RFC5920] Fang, L., "Security Framework for MPLS and GMPLS Networks", RFC 5920, July 2010. gandhi, et al. Expires September 7, 2014 [Page 6] Internet-Draft RSVP-TE Signaling for Restoration LSP March 6, 2014 Authors' Addresses Rakesh Gandhi (editor) Cisco Systems, Inc. Email: rgandhi@cisco.com Zafar Ali Cisco Systems, Inc. Email: zali@cisco.com Gabriele Maria Galimberti Cisco Systems, Inc. Email: ggalimbe@cisco.com Xian Zhang Huawei Technologies Research Area F3-1B, Huawei Industrial Base, Shenzhen, 518129, China Email: zhang.xian@huawei.com gandhi, et al. Expires September 7, 2014 [Page 7]