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Versions: 00 01 02 03 04 05 06 07 08 09 10 11 12 RFC 4203

Network Working Group                                K. Kompella, Editor
Internet Draft                                       Y. Rekhter,  Editor
Category: Standards Track                               Juniper Networks
Updates: 3630                                               October 2003
Expires: April 2004


               OSPF Extensions in Support of Generalized
                     Multi-Protocol Label Switching

             draft-ietf-ccamp-ospf-gmpls-extensions-12.txt


Status of this Memo

   This document is an Internet-Draft and is in full conformance with
   all provisions of Section 10 of RFC2026.

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Copyright Notice

   Copyright (C) The Internet Society (2003).  All Rights Reserved.













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Abstract

   This document specifies encoding of extensions to the OSPF routing
   protocol in support of Generalized Multi-Protocol Label Switching.


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].


1. 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].

   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

1.1. 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 Identifier                        |



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      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                  Link Remote Identifier                       |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   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".

1.2. 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.







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1.3. 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                 |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        ............                           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                  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.

1.4. 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              |



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      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |        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 [IEEE], 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.




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   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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                  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.


2. 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



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   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
   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.


3. 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                             -+



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      |                             ...                               |

   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.


4. 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: +1.408.972.3720
   Email: jdrake@calient.net


   Greg Bernstein
   Ciena Corporation
   10480 Ridgeview Court
   Cupertino, CA 94014
   Phone: +1.408.366.4713
   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







Kompella, Rekhter, Editors   Standards Track                    [Page 8]

Internet Draft          OSPF Extensions for GMPLS           October 2003


   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: +1.732.923.4264
   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




5. Acknowledgements

   The authors would like to thank Suresh Katukam, Jonathan Lang,
   Quaizar Vohra, and Alex Zinin for their comments on the draft.


6. Security Considerations

   This document specifies the contents of Opaque LSAs in OSPFv2.  As
   Opaque LSAs are not used for SPF computation or normal routing, the
   extensions specified here have no direct effect on IP routing.
   Tampering with GMPLS TE LSAs may have an effect on the underlying
   transport (optical and/or SONET-SDH) network.  [OSPF-TE] suggests
   mechanisms such as [OSPF-SIG] to protect the transmission of this
   information, and those or other mechanisms should be used to secure
   and/or authenticate the information carried in the Opaque LSAs.













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IANA Considerations

   The memo introduces 4 new sub-TLVs of the TE Link TLV in the TE
   Opaque LSA for OSPF v2; [OSPF-TE] says that the sub-TLVs of the TE
   Link TLV in the range 10-32767 must be assigned by Expert Review, and
   must be registered with IANA.

   The memo has four suggested values for the four sub-TLVs of the TE
   Link TLV; it is strongly recommended that the suggested values be
   granted, as there are interoperable implementations using these
   values.


Normative References

   [GMPLS-ROUTING] Kompella, K., and Rekhter, Y. (Editors), "Routing
       Extensions in Support of Generalized Multi-Protocol Label
       Switching", (work in progress) [draft-ietf-ccamp-gmpls-
       routing-08.txt]

   [GMPLS-RSVP] Berger, L., (Editor), "Generalized Multi-Protocol Label
       Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic
       Engineering (RSVP-TE) Extensions", RFC 3473, January 2003

   [GMPLS-SIG] Berger, L. (Editor), "Generalized Multi-Protocol Label
       Switching (GMPLS) Signaling Functional Description", RFC 3471,
       January 2003

   [IEEE] IEEE, "IEEE Standard for Binary Floating-Point Arithmetic",
       Standard 754-1985, 1985 (ISBN 1-5593-7653-8).

   [OSPF] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998.

   [OSPF-RESTART] Moy, J., Pillay-Esnault, P., Lindem, A., "Graceful
       OSPF Restart", (work in progress) [draft-ietf-ospf-hitless-
       restart-08.txt]

   [OSPF-SIG] Murphy, S., Badger, M., and B. Wellington, "OSPF with
       Digital Signatures", RFC 2154, June 1997.

   [OSPF-TE] Katz, D., Kompella, K. and Yeung, D., "Traffic Engineering
       (TE) Extensions to OSPF Version 2", RFC 3630, September 2003.

   [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
       Requirement Levels", BCP 14, RFC 2119, March 1997.






Kompella, Rekhter, Editors   Standards Track                   [Page 10]

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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


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