Multicast using Bit Index Explicit Replication
draft-ietf-bier-architecture-08

Document Type Active Internet-Draft (bier WG)
Last updated 2017-09-20 (latest revision 2017-09-13)
Replaces draft-wijnands-bier-architecture
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Intended RFC status Experimental
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Internet Engineering Task Force                        IJ. Wijnands, Ed.
Internet-Draft                                       Cisco Systems, Inc.
Intended status: Experimental                              E. Rosen, Ed.
Expires: March 17, 2018                           Juniper Networks, Inc.
                                                             A. Dolganow
                                                                   Nokia
                                                           T. Przygienda
                                                  Juniper Networks, Inc.
                                                               S. Aldrin
                                                            Google, Inc.
                                                      September 13, 2017

             Multicast using Bit Index Explicit Replication
                    draft-ietf-bier-architecture-08

Abstract

   This document specifies a new architecture for the forwarding of
   multicast data packets.  It provides optimal forwarding of multicast
   packets through a "multicast domain".  However, it does not require a
   protocol for explicitly building multicast distribution trees, nor
   does it require intermediate nodes to maintain any per-flow state.
   This architecture is known as "Bit Index Explicit Replication"
   (BIER).  When a multicast data packet enters the domain, the ingress
   router determines the set of egress routers to which the packet needs
   to be sent.  The ingress router then encapsulates the packet in a
   BIER header.  The BIER header contains a bitstring in which each bit
   represents exactly one egress router in the domain; to forward the
   packet to a given set of egress routers, the bits corresponding to
   those routers are set in the BIER header.  The procedures for
   forwarding a packet based on its BIER header are specified in this
   document.  Elimination of the per-flow state and the explicit tree-
   building protocols results in a considerable simplification.

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 https://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

Wijnands, et al.         Expires March 17, 2018                 [Page 1]
Internet-Draft             Multicast with BIER            September 2017

   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 March 17, 2018.

Copyright Notice

   Copyright (c) 2017 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
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   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  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  The BFR Identifier and BFR-Prefix . . . . . . . . . . . . . .   6
   3.  Encoding BFR Identifiers in BitStrings  . . . . . . . . . . .   7
   4.  Layering  . . . . . . . . . . . . . . . . . . . . . . . . . .  10
     4.1.  The Routing Underlay  . . . . . . . . . . . . . . . . . .  10
     4.2.  The BIER Layer  . . . . . . . . . . . . . . . . . . . . .  11
     4.3.  The Multicast Flow Overlay  . . . . . . . . . . . . . . .  12
   5.  Advertising BFR-ids and BFR-Prefixes  . . . . . . . . . . . .  12
   6.  BIER Intra-Domain Forwarding Procedures . . . . . . . . . . .  14
     6.1.  Overview  . . . . . . . . . . . . . . . . . . . . . . . .  14
     6.2.  BFR Neighbors . . . . . . . . . . . . . . . . . . . . . .  16
     6.3.  The Bit Index Routing Table . . . . . . . . . . . . . . .  16
     6.4.  The Bit Index Forwarding Table  . . . . . . . . . . . . .  17
     6.5.  The BIER Forwarding Procedure . . . . . . . . . . . . . .  18
     6.6.  Examples of BIER Forwarding . . . . . . . . . . . . . . .  20
       6.6.1.  Example 1 . . . . . . . . . . . . . . . . . . . . . .  21
       6.6.2.  Example 2 . . . . . . . . . . . . . . . . . . . . . .  22
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