Extensions to OSPF for Source Label Distribution
draft-chen-ospf-source-label-distribution-00

Versions: 00                                                            
Network Working Group                                            M. Chen
Internet-Draft                                                    Huawei
Intended status: Standards Track                               G. Mirsky
Expires: August 17, 2014                                        Ericsson
                                                       February 13, 2014


            Extensions to OSPF for Source Label Distribution
              draft-chen-ospf-source-label-distribution-00

Abstract

   An MPLS Source Label (SL) is defined to identify a node that is (one
   of) the ingress LSRs to a specific LSP.  This document defines
   extensions to OSPF protocol for distribution of the mapping of an
   MPLS Source Label to an specific LSR.  Therefore, the egress and
   intermediate LSRs can determine from which LSR an MPLS packet is
   sent.

   This document also defines OSPF extensions to advertise the Source
   Label Capability (SLC) of each LSR that indicates whether an LSR can
   process the Source Label.  With the SLC, an ingress LSR can determine
   whether it is allowed to insert a Source Label into the label stack
   for a specific LSP.

Requirements Language

   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].

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
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   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on August 17, 2014.




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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
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   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Extensions to OSPF  . . . . . . . . . . . . . . . . . . . . .   3
   3.  Elements of Procedure . . . . . . . . . . . . . . . . . . . .   3
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   4
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   4
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .   4
     7.2.  Informative References  . . . . . . . . . . . . . . . . .   4
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   5

1.  Introduction

   The MPLS Source Label is defined in [I-D.chen-mpls-source-label], it
   is used to identify (one of) the ingress LSR(s) of an LSP.  To
   identify from where an MPLS packet is sent, a pure Source Label (SL)
   is not enough, it needs to know to which LSR a SL is correlated.
   Therefore, there needs a mechanism to distribute the mapping
   information between a SL and its correlated LSR.

   In addition, for an ingress LSR, before inserting a SL in the label
   stack of an LSP, it needs to know whether the egress LSR has the
   capability to process the SL, otherwise the packet will be dropped at
   the egress LSR.  The capability is called Source Label Capability
   (SLC).

   This document defines extensions to OSPF protocol to distribute SL to
   LSR mapping and advertise the SLC of each LSR.






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2.  Extensions to OSPF

   The Source Label TLV is defined to distribute the Source Label to
   ingress LSR mapping information and the SLC.  No sub-TLV is currently
   defined for the Source Label TLV.

   The Source Label TLV is advertised in an OSPF Router Information (RI)
   [RFC4790] Link State Advertisement (LSA), it has the following
   format:

        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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |              Type             |             Length            |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                           Router ID                           |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |        Reserved       |           Source Label                |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                    Figure 1 - OSPF Source Label TLV format

   The value of Type field is TBD1.

   The Length field defines the length of the Reserved and Source Label
   in octets, the value is 4.

   The Source Label field contains the Source Label that identifies the
   advertising LSR.

3.  Elements of Procedure

   The Source Label TLV is carried in the OSPF Router Information (RI)
   LSAs that is defined in [RFC4790].  All the procedures that defined
   in [RFC4790] are inherited here.

   The flooding scope of the Source Label TLV can be either area local
   or entire OSPF domain.  The flooding scope is controlled by the
   Opaque LSA type in OSPFv2 [RFC2370] and by the S1 and S2 bits in
   OSPFv3 [RFC2740].  If the flooding scope is area local, the Source
   Label TLV MUST be carried within an OSPFv2 Type 10 RI LSA or within
   an OSPFv3 RI LSA with the S1 bit set and the S2 bit clear.  If the
   flooding scope is the entire IGP domain, the Source Label TLV MUST be
   carried within an OSPFv2 Type 11 RI LSA or within an OSPFv3 RI LSA
   with the S1 bit clear and the S2 bit set.

   The Source Label TLV is an optional TLV.  Upon receipt the TLV, a
   router will silently ignore the TLV as defined in [RFC4790] if it



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   does not support it.  If Source Label TLV is not present that MUST be
   interpreted as signaling of non-support of SLC by the LSR.  Presence
   of a Source Label TLV MUST be interpreted as support of SLC by the
   LSR.  A Source Label TLV MUST appear only one time in an LSA.

4.  IANA Considerations

   IANA is requested to assign a new TLV code point for the Source Label
   TLV carried within the Router Information LSA.

   Type Value  TLV Name         Reference
   ----------  ---------------  --------------
   TBD1        Source Label     (this document)

5.  Security Considerations

   TBD.

6.  Acknowledgements

7.  References

7.1.  Normative References

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

   [RFC2370]  Coltun, R., "The OSPF Opaque LSA Option", RFC 2370, July
              1998.

   [RFC2740]  Coltun, R., Ferguson, D., and J. Moy, "OSPF for IPv6", RFC
              2740, December 1999.

   [RFC4790]  Newman, C., Duerst, M., and A. Gulbrandsen, "Internet
              Application Protocol Collation Registry", RFC 4790, March
              2007.

7.2.  Informative References

   [I-D.chen-mpls-source-label]
              Chen, M., Building, K., Li, Z., and L. Fang,
              "MultiProtocol Label Switching (MPLS) Source Label",
              draft-chen-mpls-source-label-01 (work in progress),
              October 2013.







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Authors' Addresses

   Mach(Guoyi) Chen
   Huawei

   Email: mach.chen@huawei.com


   Greg Mirsky
   Ericsson

   Email: Gregory.mirsky@ericsson.com







































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