Internet DRAFT - draft-kebler-bess-sa-pref

draft-kebler-bess-sa-pref



BESS                                                      R. Kebler, Ed.
Internet-Draft                                                  J. Zhang
Intended status: Standards Track                        Juniper Networks
Expires: September 10, 2015                                  A. Dolganow
                                                             J. Kotalwar
                                                          Alcatel-Lucent
                                                                H. Sipra
                                                                  Google
                                                           March 9, 2015


          MVPN UMH Procedure Based on Source Active A-D Route
                      draft-kebler-bess-sa-pref-00

Abstract

   This document define new procedures to use Source-Active A-D routes
   to influence the UMH selection procedures at a downstream PE in
   certain deployments.  These procedures allow some greater flexibility
   to influence the UMH selection based on more than just the unicast
   route to the source.

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
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   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."

   This Internet-Draft will expire on September 10, 2015.

Copyright Notice

   Copyright (c) 2015 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
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents



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   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Applicability . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Procedure Details . . . . . . . . . . . . . . . . . . . . . .   3
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   3
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   4
   7.  Normative References  . . . . . . . . . . . . . . . . . . . .   4
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   4

1.  Introduction

   It may be desirable to influence the UMH selection result for a given
   customer multicast group, without influencing the UMH procedures for
   all the other customer groups with the same source.  For example, if
   it is desirable for traffic to be chosen for S1,G1 from ingress PE,
   and for S1,G2 for a different ingress PE, it is not possible to
   accomplish with the exisitng UMH procedures that are based solely on
   the Source address.

   Consider the case when an Anycast source address is being used to
   source the content from two headends.  If the content were preferred
   from one headend for certain groups, and the other headend for other
   groups based on some policy on the ingress PEs depending on the
   particular groups, then this would not be possible with a source
   based UMH method.

   This document define new procedures to use Source-Active A-D routes
   to influence the UMH selection procedures at an egress PE, taking
   both the Source and Group into account to allow greater flexibility
   in the UMH procedures.

   As defined in RFC 6514, An ingress PE will advertise a (C-S,C-G)
   Source Active A-D route if it receives a PIM Register message or MSDP
   message saying that C-S is a source for C-G.  When advertising the
   Source-Active A-D route, a policy can be applied at the ingress PEs
   (e.g., BGP communities) to help influence the BGP route selection of
   the egress PEs.  The ingress PE can be configured to include some
   communities to the Source-Active A-D routes based on that policy.
   The egress PEs can then be configured to set the route preference
   based on the received communities.  The exact details on procedures



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   to influence BGP route selection are outside the scope of this
   document.  The selected Source Active A-D route will then be used to
   influence the UMH selection.

2.  Applicability

   These procedures are applicable only when procedures in Section 10 of
   RFC 6513 are being used to "Eliminate PE-PE Distribution of (C-*,C-G)
   State".  Furthermore, the procedures in this document are restricted
   to the case when the ingress PEs are configured either MSDP or as RP.
   The typical use-case would be an IPTV deployment when a headend is
   located behind a set of PEs and those PEs can be configured as RPs or
   MSDP peers.  These procedures are not applicable for groups in the
   SSM range.

3.  Procedure Details

   RFC 6513 describes procedures to build the "UMH Route Candidate Set"
   and then select the single route from the set to be the "Selected UMH
   Route".  The procedures are modified to prefer, from the "UMH Route
   Candidate Set", the Upstream PE that has advertised the best (as
   determined by the BGP route selection procedures) Source-Active A-D
   route.

   It may not be obvious on how to match the UMH candidate to the
   originator of the Source-Active A-D route since the NLRI of the
   Source Active A-D route does not specify the originator of the route.
   For MVPN procedures, refer to the extranet draft
   [I-D.ietf-bess-mvpn-extranet] (section 7.4).  For Global
   Table Multicast (GTM) procedures, refer to the GTM draft
   [I-D.ietf-bess-mvpn-global-table-mcast]  (section 2.8.1).

   If the UMH is selected solely based on best Source Active A-D route
   without considering the UMH Route Candidate Set as defined in RFC
   6514, then it would have the drawback that a UMH may be chosen which
   does not have reachability to the source through a vrf interface.
   Also, it may take some time for an RP to determine that the source
   has stopped sending traffic and the unicast reachability may converge
   before the Source Active A-D routes are withdrawn.  As a result,
   using the UMH Route Candidate Set as the base can improve the
   convergence on the egress PEs.

4.  IANA Considerations

   None






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5.  Security Considerations

   There are no security considerations for this design other than what
   is already in the base MVPN specifications.

6.  Acknowledgements

   The authors want to thank Eric Rosen for his review and useful
   feedback.

7.  Normative References

   [I-D.ietf-bess-mvpn-extranet]
              Rekhter, Y., Rosen, E., Aggarwal, R., Cai, Y., Henderickx,
              W., Morin, T., Muley, P., Qiu, R., and I. Wijnands,
              "Extranet Multicast in BGP/IP MPLS VPNs", draft-ietf-bess-
              mvpn-extranet-00 (work in progress), November 2014.

   [I-D.ietf-bess-mvpn-global-table-mcast]
              Zhang, J., Giuliano, L., Rosen, E., Subramanian, K.,
              Pacella, D., and J. Schiller, "Global Table Multicast with
              BGP-MVPN Procedures", draft-ietf-bess-mvpn-global-table-
              mcast-00 (work in progress), November 2014.

   [RFC6513]  Rosen, E. and R. Aggarwal, "Multicast in MPLS/BGP IP
              VPNs", RFC 6513, February 2012.

   [RFC6514]  Aggarwal, R., Rosen, E., Morin, T., and Y. Rekhter, "BGP
              Encodings and Procedures for Multicast in MPLS/BGP IP
              VPNs", RFC 6514, February 2012.

Authors' Addresses

   Robert Kebler (editor)
   Juniper Networks
   10 Technology Park Drive
   Westford, MA  01886
   USA

   Email: rkebler@juniper.net











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   Jeffrey Zhang
   Juniper Networks
   10 Technology Park Drive
   Westford, MA  01886
   USA

   Email: zzhang@juniper.net


   Andrew Dolganow
   Alcatel-Lucent
   600 March Rd.
   Ottawa, Ontario  K2K 2E6
   Canada

   Email: andrew.dolganow@alcatel-lucent.com


   Jayant Kotalwar
   Alcatel-Lucent
   701 East Middlefield Rd
   Mountain View, California  94043
   United States

   Email: jayant.kotalwar@alcatel-lucent.com


   Hassan Sipra
   Google

   Email: hisipra@google.com




















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