Network Working Group K. Kompella (Editor) Internet Draft Y. Rekhter (Editor) Category: Standards Track Juniper Networks Expires: February 2003 August 2002 OSPF Extensions in Support of Generalized MPLS draft-ietf-ccamp-ospf-gmpls-extensions-08.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 Standards Track [Page 1] Internet Draft Standards Track August 2002 Abstract This document specifies encoding of extensions to the OSPF routing protocol in support of Generalized Multi-Protocol Label Switching. Summary for Sub-IP Area (This section to be removed before publication.) 0.1. Summary This document specifies encoding of extensions to the OSPF 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 the CCAMP or OSPF box. 0.3. Why is it Targeted at this WG This draft is targeted at the CCAMP or the OSPF WG, because this draft specifies the extensions to the OSPF routing protocols in support of GMPLS, because GMPLS is within the scope of the CCAMP WG, and because OSPF is within the scope of the OSPF WG. 0.4. Justification The WG should consider this document as it specifies the extensions to the OSPF 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 Standards Track [Page 2] Internet Draft Standards Track August 2002 2. Introduction This document specifies extensions to the OSPF routing protocol in support of carrying link state information for Generalized Multi- Protocol Label Switching (GMPLS). The set of required enhancements to OSPF are outlined in [GMPLS-ROUTING]. 3. OSPF Routing Enhancements In this section we define the enhancements to the TE properties of GMPLS TE links that can be announced in OSPF TE LSAs. The Traffic Engineering (TE) LSA, which is an opaque LSA with area flooding scope [OSPF-TE], has only one top-level Type/Length/Value (TLV) triplet and has one or more nested sub-TLVs for extensibility. The top-level TLV can take one of two values (1) Router Address or (2) Link. In this document, we enhance the sub-TLVs for the Link TLV in support of GMPLS. Specifically, we add the following sub-TLVs to the Link TLV: Sub-TLV Type Length Name 11 8 Link Local/Remote Identifiers 14 4 Link Protection Type 15 variable Interface Switching Capability Descriptor 16 variable Shared Risk Link Group 3.1. Link Local/Remote Identifiers A Link Local/Remote Identifiers is a sub-TLV of the Link TLV. The type of this sub-TLV is 11, 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ A node can communicate its Link Local Identifier to its neighbor using a link local Opaque LSA, as described in Section "Exchanging Link Local TE Information". Kompella, Rekhter, Editors Standards Track [Page 3] Internet Draft Standards Track August 2002 3.2. Link Protection Type The Link Protection Type is a sub-TLV of the Link TLV. The type of this sub-TLV is 14, and length is four octets. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |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 remaining three octets 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 Link TLV. 3.3. Shared Risk Link Group (SRLG) The SRLG is a sub-TLV (of type 16) of the Link TLV. The length is the length of the list in octets. The value is an unordered list of 32 bit numbers that are the SRLGs that the link belongs to. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Shared Risk Link Group Value | Kompella, Rekhter, Editors Standards Track [Page 4] Internet Draft Standards Track August 2002 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ............ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Shared Risk Link Group Value | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ This sub-TLV carries the Shared Risk Link Group information (see Section "Shared Risk Link Group Information" of [GMPLS-ROUTING]). The SRLG sub-TLV may occur at most once within the Link TLV. 3.4. Interface Switching Capability Descriptor The Interface Switching Capability Descriptor is a sub-TLV (of type 15) of the Link 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 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) Kompella, Rekhter, Editors Standards Track [Page 5] Internet Draft Standards Track August 2002 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, Interface MTU, and padding. 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 | Padding | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 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. The padding is 2 octets, and is used to make the Interface Switching Capability Descriptor sub-TLV 32-bits aligned. It SHOULD be set to zero by the sender and SHOULD be ignored by the receiver. 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, an indication whether the interface supports Standard or Arbitrary SONET/SDH, and padding. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Kompella, Rekhter, Editors Standards Track [Page 6] Internet Draft Standards Track August 2002 | Minimum LSP Bandwidth | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Indication | Padding | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 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. The padding is 3 octets, and is used to make the Interface Switching Capability Descriptor sub-TLV 32-bits aligned. It SHOULD be set to zero by the sender and SHOULD be ignored by the receiver. 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 Link TLV. 4. Implications on Graceful Restart The restarting node should follow the OSPF restart procedures [OSPF- RESTART], and the RSVP-TE restart procedures [GMPLS-RSVP]. When a restarting node is going to originate its TE LSAs, the TE LSAs containing Link TLV should be originated with 0 unreserved bandwidth, Traffic Engineering metric set to 0xffffffff, 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 containing Link TLV 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 Kompella, Rekhter, Editors Standards Track [Page 7] Internet Draft Standards Track August 2002 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. 5. Exchanging Link Local TE Information It is often useful for a node to communicate some Traffic Engineering information for a given interface to its neighbors on that interface. One example of this is a Link Local Identifier. If nodes X and Y are connected by an unnumbered point-to-point interface I, then X's Link Local Identifier for I is Y's Link Remote Identifier for I. X can communicate its Link Local Identifer for I by exchanging with Y a TE link local opaque LSA described below. Note that this information need only be exchanged over interface I, hence the use of a link local Opaque LSA. A TE Link Local LSA is an opaque LSA of type 9 (link-local flooding scope) with Opaque Type [TBD] and Opaque ID of 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | LS age | Options | 9 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Opaque Type | Opaque ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Advertising Router | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | LS sequence number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | LS checksum | length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | +- TLVs -+ | ... | The format of the TLVs that make up the body of the TE Link Local LSA is the same as that of the TE TLVs: a 2-octet Type field followed by a 2-octet Length field which indicates the length of the Value field in octets. The Value field is zero-padded at the end to a four octet boundary. The only TLV defined here is the Link Local Identifier TLV, with Type 1, Length 4 and Value the 32 bit Link Local Identifier for the link over which the TE Link Local LSA is exchanged. Kompella, Rekhter, Editors Standards Track [Page 8] Internet Draft Standards Track August 2002 6. Normative References [OSPF-TE] Katz, D., Yeung, D. and Kompella, K., "Traffic Engineering Extensions to OSPF", (work in progress) [GMPLS-SIG] Berger, L., and Ashwood-Smith, P. (Editors), "Generalized MPLS - Signaling Functional Description", (work in progress) [GMPLS-RSVP] Berger, L., and Ashwood-Smith, P. (Editors), "Generalized MPLS Signaling - RSVP-TE Extensions", (work in progress) [GMPLS-ROUTING] Kompella, K., and Rekhter, Y. (Editors), "Routing Extensions in Support of Generalized MPLS", (work in progress) [OSPF-RESTART] Moy, J., "Hitless OSPF Restart", (work in progress) [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. 7. Security Considerations The sub-TLVs proposed in this document do not raise any new security concerns. 8. Acknowledgements The authors would like to thank Suresh Katukam, Jonathan Lang, Quaizar Vohra, and Alex Zinin for their comments on the draft. 9. Contributors Ayan Banerjee Calient Networks 5853 Rue Ferrari San Jose, CA 95138 Phone: +1.408.972.3645 Email: abanerjee@calient.net Kompella, Rekhter, Editors Standards Track [Page 9] Internet Draft Standards Track August 2002 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 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 Kompella, Rekhter, Editors Standards Track [Page 10] Internet Draft Standards Track August 2002 10. 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 11. 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 Standards Track [Page 11] Internet Draft Standards Track August 2002 Full Copyright Statement Copyright (C) The Internet Society (2002). All Rights Reserved. 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