Network Working Group K. Kompella (Editor) Internet Draft Y. Rekhter (Editor) Category: Informational Juniper Networks Expires: February 2003 August 2002 IS-IS Extensions in Support of Generalized MPLS draft-ietf-isis-gmpls-extensions-14.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/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. Copyright Notice Copyright (C) The Internet Society (2002). All Rights Reserved. Kompella, Rekhter, Editors Informational [Page 1] Internet Draft IS-IS Extensions for GMPLS August 2002 Abstract This document specifies encoding of extensions to the IS-IS routing protocol in support of Generalized Multi-Protocol Label Switching. Summary for Sub-IP Area (To be removed before publication) 0.1. Summary This document specifies encoding of extensions to the IS-IS routing protocol in support of Generalized Multi-Protocol Label Switching (GMPLS). The description of the extensions is specified in [GMPLS- ROUTING]. 0.2. Where does it fit in the Picture of the Sub-IP Work This work fits squarely in either CCAMP or IS-IS boxes. 0.3. Why is it Targeted at this WG This draft is targeted at either the CCAMP or IS-IS WGs, because this draft specifies the extensions to the IS-IS routing protocols in support of GMPLS, because GMPLS is within the scope of CCAMP WG, and because IS-IS is within the scope of the IS-IS WG. 0.4. Justification The WG should consider this document as it specifies the extensions to the IS-IS routing protocols in support of GMPLS. 1. Specification of Requirements 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]. Kompella, Rekhter, Editors Informational [Page 2] Internet Draft IS-IS Extensions for GMPLS August 2002 2. Introduction This document specifies extensions to the IS-IS routing protocol in support of carrying link state information for Generalized Multi- Protocol Label Switching (GMPLS). The set of required enhancements to IS-IS are outlined in [GMPLS-ROUTING]. 3. IS-IS Routing Enhancements In this section we define the enhancements to the TE properties of GMPLS TE links that can be announced in IS-IS TE LSAs. In this document, we enhance the sub-TLVs for the extended IS reachability TLV (see [ISIS-TE]) in support of GMPLS. Specifically, we add the following sub-TLVs: Sub-TLV Type Length Name 4 4 Link Local/Remote Identifiers 20 2 Link Protection Type 21 variable Interface Switching Capability Descriptor We further add one new TLV to the TE LSAs. TLV Type Length Name 138 variable Shared Risk Link Group 3.1. Link Local/Remote Identifiers A Link Local Interface Identifiers is a sub-TLV of the extended IS reachability TLV. The type of this sub-TLV is 4, and length is eight octets. The value field of this sub-TLV contains four octets of Link Local Identifier followed by four octets of Link Remote Idenfier (see Section "Support for unnumbered links" of [GMPLS-ROUTING]). If the Link Remote Identifier is unknown, it is set to 0. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Local Idenfiier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Link Remote Idenfiier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Kompella, Rekhter, Editors Informational [Page 3] Internet Draft IS-IS Extensions for GMPLS August 2002 3.2. Link Protection Type The Link Protection Type is is a sub-TLV (of type 20) of the extended IS reachability TLV, with length two octets. 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Protection Cap | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ The first octet is a bit vector describing the protection capabilities of the link (see Section "Link Protection Type" of [GMPLS-ROUTING]). They are: 0x01 Extra Traffic 0x02 Unprotected 0x04 Shared 0x08 Dedicated 1:1 0x10 Dedicated 1+1 0x20 Enhanced 0x40 Reserved 0x80 Reserved The second octet SHOULD be set to zero by the sender, and SHOULD be ignored by the receiver. The Link Protection Type sub-TLV may occur at most once within the extended IS reachability TLV. 3.3. Interface Switching Capability Descriptor The Interface Switching Capability Descriptor is a sub-TLV (of type 21) of the extended IS reachability TLV. The length is the length of value field in octets. The format of the value field is as shown below: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Switching Cap | Encoding | Reserved | Kompella, Rekhter, Editors Informational [Page 4] Internet Draft IS-IS Extensions for GMPLS August 2002 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max LSP Bandwidth at priority 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max LSP Bandwidth at priority 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max LSP Bandwidth at priority 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max LSP Bandwidth at priority 3 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max LSP Bandwidth at priority 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max LSP Bandwidth at priority 5 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max LSP Bandwidth at priority 6 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max LSP Bandwidth at priority 7 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Switching Capability-specific information | | (variable) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ The Switching Capability (Switching Cap) field contains one of the following values: 1 Packet-Switch Capable-1 (PSC-1) 2 Packet-Switch Capable-2 (PSC-2) 3 Packet-Switch Capable-3 (PSC-3) 4 Packet-Switch Capable-4 (PSC-4) 51 Layer-2 Switch Capable (L2SC) 100 Time-Division-Multiplex Capable (TDM) 150 Lambda-Switch Capable (LSC) 200 Fiber-Switch Capable (FSC) The Encoding field contains one of the values specified in Section 3.1.1 of [GMPLS-SIG]. Maximum LSP Bandwidth is encoded as a list of eight 4 octet fields in the IEEE floating point format, with priority 0 first and priority 7 last. The units are bytes (not bits!) per second. The content of the Switching Capability specific information field depends on the value of the Switching Capability field. When the Switching Capability field is PSC-1, PSC-2, PSC-3, or PSC-4, the Switching Capability specific information field includes Minimum LSP Bandwidth and Interface MTU. Kompella, Rekhter, Editors Informational [Page 5] Internet Draft IS-IS Extensions for GMPLS August 2002 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Minimum LSP Bandwidth | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Interface MTU | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ The Minimum LSP Bandwidth is is encoded in a 4 octets field in the IEEE floating point format. The units are bytes (not bits!) per second. The Interface MTU is encoded as a 2 octets integer. When the Switching Capability field is L2SC, there is no Switching Capability specific information field present. When the Switching Capability field is TDM, the Switching Capability specific information field includes Minimum LSP Bandwidth and an indication whether the interface supports Standard or Arbitrary SONET/SDH. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Minimum LSP Bandwidth | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Indication | +-+-+-+-+-+-+-+-+ The Minimum LSP Bandwidth is encoded in a 4 octets field in the IEEE floating point format. The units are bytes (not bits!) per second. The indication whether the interface supports Standard or Arbitrary SONET/SDH is encoded as 1 octet. The value of this octet is 0 if the interface supports Standard SONET/SDH, and 1 if the interface supports Arbitrary SONET/SDH. When the Switching Capability field is LSC, there is no Switching Capability specific information field present. To support interfaces that have more than one Interface Switching Capability Descriptor (see Section "Interface Switching Capability Descriptor" of [GMPLS-ROUTING]) the Interface Switching Capability Descriptor sub-TLV may occur more than once within the extended IS reachability TLV. Kompella, Rekhter, Editors Informational [Page 6] Internet Draft IS-IS Extensions for GMPLS August 2002 3.4. Shared Risk Link Group TLV The SRLG TLV (of type 138 TBD) contains a data structure consisting of: 6 octets of System ID 1 octet of Pseudonode Number 1 octet Flag 4 octets of IPv4 interface address or 4 octets of a Link Local Identifier 4 octets of IPv4 neighbor address or 4 octets of a Link Remote Identifier and a list of SRLG values, where each element in the list has 4 octets. The length of this TLV is 16 + 4 * (number of SRLG values). The Least Significant Bit of the Flag octet indicates whether the interface is numbered (set to 1), or unnumbered (set to 0). All other bits are reserved and should be set to 0. The neighbor is identified by its System Id (6-octets), plus one octet to indicate the pseudonode number if the neighbor is on a LAN interface. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | System ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | System ID (cont.) | Pseudonode num| Flags | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 interface address/Link Local Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 neighbors address/Link Remote Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Shared Risk Link Group Value | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ............ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Shared Risk Link Group Value | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ This TLV carries the Shared Risk Link Group information (see Section "Shared Risk Link Group Information" of [GMPLS-ROUTING]). Kompella, Rekhter, Editors Informational [Page 7] Internet Draft IS-IS Extensions for GMPLS August 2002 3.5. Link Identifier for Unnumbered Interfaces Link Identifies are exchanged in the Extended Local Circuit ID field of the "Point-to-Point Three-Way Adjacency" IS-IS Option type [ISIS-3way]. 4. Implications on Graceful Restart The restarting node should follow the ISIS restart procedures [ISIS- RESTART], and the RSVP-TE restart procedures [GMPLS-RSVP]. When the restarting node is going to originate its TE LSAs, these LSAs should be originated with 0 unreserved bandwidth, Traffic Engineering Default metric set to 0xffffff, and if the Link has LSC or FSC as its Switching Capability then also with 0 as Max LSP Bandwidth, until the node is able to determine the amount of unreserved resources taking into account the resources reserved by the already established LSPs that have been preserved across the restart. Once the restarting node determines the amount of unreserved resources, taking into account the resources reserved by the already established LSPs that have been preserved across the restart, the node should advertise these resources in its TE LSAs. In addition in the case of a planned restart prior to restarting, the restarting node SHOULD originate the TE LSAs with 0 as unreserved bandwidth, and if the Link has LSC or FSC as its Switching Capability then also with 0 as Max LSP Bandwidth. This would discourage new LSP establishment through the restarting router. Neighbors of the restarting node should continue advertise the actual unreserved bandwidth on the TE links from the neighbors to that node. Regular graceful restart should not be aborted if a TE LSA or TE topology changes. TE graceful restart need not be aborted if a TE LSA or TE topology changes. Kompella, Rekhter, Editors Informational [Page 8] Internet Draft IS-IS Extensions for GMPLS August 2002 5. Normative References [ISIS-TE] Smit, H., Li, T., "IS-IS Extensions for Traffic Engineering", (work in progress) [GMPLS-SIG] Ashwood-Smith, P., and Berger, L. (Editors), "Generalized MPLS - Signaling Functional Description", (work in progress) [GMPLS-ROUTING] Kompella, K., and Rekhter, Y. (Editors), "Routing Extensions in Support of Generalized MPLS", (work in progress) [GMPLS-RSVP] Ashwood-Smith, P., and Berger, L. (Editors), "Generalized MPLS Signaling - RSVP-TE Extensions", (work in progress) [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [ISIS-3way] Katz, D., and Saluja, R., "Three-Way Handshake for IS-IS Point-to-Point Adjacencies", (work in progress) [ISIS-RESTART] Shand, M., "Restart signaling for ISIS", (work in progress) 6. Security Considerations The extensions proposed in this document do not raise any new security concerns. 7. Acknowledgements The authors would like to thank Jim Gibson, Suresh Katukam, Jonathan Lang and Quaizar Vohra for their comments on the draft. Kompella, Rekhter, Editors Informational [Page 9] Internet Draft IS-IS Extensions for GMPLS August 2002 8. Contributors Ayan Banerjee Calient Networks 5853 Rue Ferrari San Jose, CA 95138 Phone: +1.408.972.3645 Email: abanerjee@calient.net John Drake Calient Networks 5853 Rue Ferrari San Jose, CA 95138 Phone: (408) 972-3720 Email: jdrake@calient.net Greg Bernstein Ciena Corporation 10480 Ridgeview Court Cupertino, CA 94014 Phone: (408) 366-4713 Email: greg@ciena.com Don Fedyk Nortel Networks Corp. 600 Technology Park Drive Billerica, MA 01821 Phone: +1-978-288-4506 Email: dwfedyk@nortelnetworks.com Eric Mannie Independent Consultant E-mail: eric_mannie@hotmail.com Debanjan Saha Tellium Optical Systems 2 Crescent Place P.O. Box 901 Ocean Port, NJ 07757 Phone: (732) 923-4264 Email: dsaha@tellium.com Kompella, Rekhter, Editors Informational [Page 10] Internet Draft IS-IS Extensions for GMPLS August 2002 Vishal Sharma Metanoia, Inc. 335 Elan Village Lane, Unit 203 San Jose, CA 95134-2539 Phone: +1 408-943-1794 Email: v.sharma@ieee.org 9. Authors' Information Kireeti Kompella Juniper Networks, Inc. 1194 N. Mathilda Ave Sunnyvale, CA 94089 Email: kireeti@juniper.net Yakov Rekhter Juniper Networks, Inc. 1194 N. Mathilda Ave Sunnyvale, CA 94089 Email: yakov@juniper.net 10. Intellectual Property Rights Notices The IETF takes no position regarding the validity or scope of any intellectual property 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; neither does it represent that it has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards-related documentation can be found in BCP-11. Copies of claims of rights made available for publication 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 implementors or users of this specification can be obtained from the IETF Secretariat. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights which may cover technology that may be required to practice this standard. Please address the information to the IETF Executive Director. Kompella, Rekhter, Editors Informational [Page 11] Internet Draft IS-IS Extensions for GMPLS August 2002 Full Copyright Statement Copyright (C) The Internet Society (2002). All Rights Reserved. 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