INTERNET DRAFT Expiration Date: September 2002 Chetan Kumar S Wipro Technologies Sunil Kumar Wipro Technologies March 2002 Signalling LSPID's in OSPF TE draft-chetan-lspid-ospf-00.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 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/1id-abstracts.html The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html Abstract This draft introduces new a sub TLV to OSPF TE extensions to signal the LSPID (Label Switch Path ID) of an LSP (Label Switch Path). This information can be used by any mechanism (normally constraint based path calculation (CSPF) procedures) to calculate paths that may contain LSPID's as one its Explict Route Objects. chetan,sunil Expires September 2002 [Page 1] Internet Draft draft-chetan-lspid-ospf-00.txt March 2002 1. Conventions Used in this Document CRLDP : Constraint-Based LDP CSPF : Constraint Shortest Path First LDP : Label Distribution Protocol E-LSPs : Explicitly routed LSPs ERO : Explicit Route Object ERTLV : Explicit Route TLV 2. Introduction This document introduces an additional traffic engineering attribute describing LSPID (Label Switch Path ID) [CRLDP] to TE parameters documented in [OSPF-TE]. LSPID could be used by the CSPF path computation mechanism to generate Explicit Route Objects that may include LSPID as one of the objects. LSPID of an LSP tunnel is described as one of the Sub-TLVs in the Link TLV for the tunnel. Note: The LSPs can be advertised into IGP by other ways as described in [UNNUM] [LSP-HIER]. 3. Overview CR-LDP provides a mechanism to setup LSPs based on constraint routing. Explicit Label Switch Paths (E-LSP) which are constrained by a set of Explicit Route Objects (ERO) are essential requirements of traffic engineering. CRLDP specifies four different EROs for signalling, viz. IPv4 prefix, IPv6 prefix, Autonomous system number and LSPID. LSPID is a unique identifier of a CR-LSP within an MPLS network. When an ERO that contains LSPID ERTLV is carried in the CRLDP label request the path selected would be tunneled(/spliced) through this CRLSP. A TE path can normally be calculated using a high level software objects like CSPF, which may reside on a single node, which has the complete information about nodes and tunnels in the network. Automated procedures to calculate a constrained based path help in reducing a lot of administrative overhead. Moreover, administratively selected paths may be inconsistent or illogical due to operator error and the selected paths may not be optimal. Some of the advantages of automating the CSPF calculations are as follows. chetan,sunil Expires September 2002 [Page 2] Internet Draft draft-chetan-lspid-ospf-00.txt March 2002 a) A new LSP request can be triggered automatically on failure of an existing LSP. b) A single node can perform CSPF calculation and provide optimized paths in the whole network. c) Easy inter-operations with various vendor implementations that signal the path attributes. However none of the existing IGP protocols, with their extensions there of, carry the information about the LSPID therby forcing operator interventions for setting up paths that pass through LSP tunnels. Administrator will have to know apriori, the LSPIDs in the MPLS network domain and update the same in the ERO's calculated by the CSPF. In this draft we add LSPID sub TLV to the OSPF TE extensions to signal the LSPID TLV into the IGP. This provides CSPF object or any other mechanism with the complete information to construct the EROs. 3. LSPID Sub-TLV The Link TLV describes a single link. The following sub-TLVs are currently defined in [OSPF-TE]: 1 - Link type (1 octet) 2 - Link ID (4 octets) 3 - Local interface IP address (4 octets) 4 - Remote interface IP address (4 octets) 5 - Traffic engineering metric (4 octets) 6 - Maximum bandwidth (4 octets) 7 - Maximum reservable bandwidth (4 octets) 8 - Unreserved bandwidth (32 octets) 9 - Resource class/color (4 octets) 32768-32772 - Reserved for Cisco-specific extensions This document introduces LSPID sub-TLV. LSPID Sub-TLV specifies LSPID of the tunnel being advertised in the LINK TLV. Type field for LSPID sub-TLV is TBD (refer section 7). This sub-TLV is of length 6 octets. The value of this TLV is as defined in the CRLDP specifications which is composed of LSP tunnel ingress LSR Router ID (or any of its own IPv4 addresses), Refer to [CRLDP] for more information. chetan,sunil Expires September 2002 [Page 3] ^L Internet Draft draft-chetan-lspid-ospf-00.txt March 2002 6. Security Considerations This document raises no new security issues for OSPF. The security mechanisms already proposed for OSPF may be used. 7. IANA Considerations The type value for the LSPID is to be obtained from IANA. 8. Acknowledgments Authors would like to thank RaviShankar, Nagabhusna and Venkat for discussion on the idea. 9. References [CRLDP] Jamoussi, et al., "Constraint-Based LSP Setup using LDP" RFC 3212, January 2002. [LSP-HIER] Kireeti Kompella, Yakov Rekhter, "LSP Hierarchy with Generalized MPLS TE" (work in progress). [OSPF-TE] Dave Katz, Derek Yeung, Kireeti Kompella, "Traffic Engineering Extensions to OSPF", (work in progress) [UNNUM] Kireeti Kompella, Yakov Rekhter, Alan Kullberg "Signalling Unnumbered Links in CR-LDP", (work in progress). 10. Author's Address Chetan Kumar S Wipro Technologies Hosur Road, Bomanahalli Bangalore-5600 India Phone : 91-80-5732296 Fax : 91-11-5732296 Email : chetan.kumar@wipro.com Sunil Kumar Wipro Technologies Hosur Road, Bomanahalli Bangalore-5600 India Phone : 91-80-5732296 Fax : 91-11-5732296 Email : sunil.kum@wipro.com chetan,sunil Expires September 2002 [Page 4] Internet Draft draft-chetan-lspid-ospf-00.txt March 2002 10. Full Copyright Statement Copyright (C) The Internet Society (date). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. chetan,sunil Expires September 2002 [Page 5]