Network Working Group                                          Yiqun Cai
Internet Draft                                    Eric C. Rosen (Editor)
Intended Status: Informational                         IJsbrand Wijnands
Expires: April 24, 2012                              Cisco Systems, Inc.

                                                        October 24, 2011


         MVPN: S-PMSI Join Extensions for mLDP-Created Tunnels


               draft-rosen-l3vpn-spmsi-joins-mldp-03.txt

Abstract

   The specification for Multicast Virtual Private Networks (MVPN)
   contains an option that allows UDP-based "S-PMSI Join" messages to be
   used to bind particular customer multicast flows to particular
   tunnels through a service provider's network.  This document extends
   the MVPN specification so that these options can be used when the
   tunnel through the provider's network are Point-to-Multipoint Label
   Switched Paths.

Status of this Memo

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Copyright and License Notice

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   document authors. All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.



Table of Contents

 1          Specification of requirements  .........................   2
 2          Introduction  ..........................................   3
 3          S-PMSI Join Extensions  ................................   3
 3.1        mLDP P2MP P-Tunnels  ...................................   3
 3.2        Encapsulation of S-PMSI Joins in UDP Datagrams  ........   4
 4          IANA Considerations  ...................................   5
 5          Security Considerations  ...............................   5
 6          Acknowledgments  .......................................   5
 7          Authors' Addresses  ....................................   5
 8          Normative References  ..................................   6






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 [RFC2119].









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2. Introduction

   The Multicast Virtual Private Networks (MVPN) specification [MVPN]
   specifies "S-PMSI Join" messages, which are optionally used to bind
   particular customer multicast flows to particular tunnels through a
   service provider's network (P-tunnels).  However, the specification
   does not cover the case where the P-tunnels are Point-to-multipoint
   (P2MP) Label Switched Paths (LSPs) created by the Label Distribution
   Protocol (LDP) [mLDP].  This document extends [MVPN] by providing the
   specification for that case.  This document uses terminology defined
   in [MVPN]: C-Source, C-Group, C-flow, P-Group, (C-S,C-G)


3. S-PMSI Join Extensions

   The S-PMSI Join message is defined in section 7.4.2.2 of [MVPN].  In
   this specification, we define the "type 2" and "type 3" S-PMSI Joins,
   which are used when the S-PMSI tunnel is a P2MP LSP created by mLDP,
   and the tunnel is to carry C-flows of, respectively, IPv4 or IPv6
   multicast traffic.


3.1. mLDP P2MP P-Tunnels

        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            |    Reserved     |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                           C-Source
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+.......
       |                           C-Group
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+.......
       |                           FEC Element
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+.......
       |    Padding
       +-+-+-+-+-+-+-+.......



   Type (8 bits):

     - 2 if C-Source and C-Group are IPv4 addresses,

     - 3 if C-Source and C-Group are IPv6 addresses.

   Length (16 bits): the total number of octets in the Type, Length,
   Reserved and Value fields combined, rounded up to the next multiple



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   of 4, encoded as an unsigned binary integer.

   Reserved (8 bits):  This field SHOULD be zero when transmitted, and
   MUST be ignored when received.

   C-Source: address of the traffic source in the VPN

     - for type 2, a 32-bit IPv4 address

     - for type 3, a 128-bit IPv6 address

   C-Group: address of the traffic destination in the VPN

     - for type 2, a 32-bit IPv4 address

     - for type 3, a 128-bit IPv6 address

   FEC Element: this variable length field is a P2MP FEC element,
   encoded as specified in [mLDP].  (Note that this field is itself
   encoded with a type field and a length field, as specified in
   [mLDP].)

   Padding: 0-3 bytes, as needed for 32-bit alignment.  The padding
   bytes SHOULD be zero on transmission and MUST be ignored on
   reception.

   In S-PMSI Join messages, the use of an all-zero C-Source or C-Group
   field is to be interpreted as specifying a wild card value for the
   respective field.  A wild card represents all C-Source or C-group
   values of a particular address family (IPv4 or IPv6), as specified by
   the S-PMSI Join message type.


3.2. Encapsulation of S-PMSI Joins in UDP Datagrams

   All S-PMSI Joins are encapsulated in UDP datagrams.

   If a UDP datagram contains a type 2 S-PMSI Join, it MUST be sent in
   an IPv4 datagram.

   If a UDP datagram contains a type 3 S-PMSI Join, it MUST be sent in
   an IPv6 datagram, following the specification in [SPMSI_JOIN].









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4. IANA Considerations

   [MVPN] creates an IANA registry for the "S-PMSI Join Message Type
   Field". This document requires two new values:

     - The value 2 should be registered, and its description should read
       "mLDP P2MP S-PMSI for IPv4 traffic (unaggregated)".

     - The value 3 should be registered, and its description should read
       "mLDP P2MP S-PMSI for IPv6 traffic (unaggregated)".


5. Security Considerations

   There are no additional security considerations beyond those of
   [MVPN].


6. Acknowledgments

   The authors wish to thank DP Ayadevara, Arjen Boers, Rayen Mohanty,
   Rajesh Sharma, and Karthik Subramanian.


7. Authors' Addresses

   Yiqun Cai
   Cisco Systems, Inc.
   170 Tasman Drive
   San Jose, CA, 95134
   E-mail: ycai@cisco.co



   Eric C. Rosen
   Cisco Systems, Inc.
   1414 Massachusetts Avenue
   Boxborough, MA, 01719
   E-mail: erosen@cisco.com



   IJsbrand Wijnands
   Cisco Systems, Inc.
   De kleetlaan 6a Diegem 1831
   Belgium
   E-mail: ice@cisco.com




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8. Normative References

   [mLDP] "Label Distribution Protocol Extensions for
   Point-to-Multipoint and Multipoint-to-Multipoint Label Switched
   Paths", Minei, Kompella, Wijnands, Thomas,
   draft-ietf-mpls-ldp-p2mp-15.txt, August 2011

   [MVPN] "Multicast in MPLS/BGP IP VPNs", Rosen, Aggarwal, et. al.,
   draft-ietf-l3vpn-2547bis-mcast-10.txt, January 2010

   [RFC2119] "Key words for use in RFCs to Indicate Requirement
   Levels.", Bradner, March 1997

   [SPMSI_JOIN] "IPv6 MVPN Support Using PIM Control Plane and S-PMSI
   Join Messages", Cai, Rosen, Wijnands, draft-ietf-l3vpn-mvpn-spmsi-
   joins-02.txt, November 2010



































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