Bit Indexed Explicit Replication

Document Proposed charter Bit Indexed Explicit Replication WG (bier)
Title Bit Indexed Explicit Replication
Last updated 2018-02-08
State Internal review Rechartering
WG State Active
IESG Responsible AD Alia Atlas
Charter Edit AD Alia Atlas
Telechat date On agenda of 2018-02-22 IESG telechat
Has enough positions to pass.
Send notices to (None)


The BIER (Bit Index Explicit Replication) Working Group has defined
an architecture [RFC 8279] for  multicast forwarding that uses an
encapsulation [RFC 8296] that can be used on MPLS or Ethernet transport.
The BIER-WG is now chartered to produce Standards Track RFCs and to
update or do a Status Change for those RFCs previously published as
Experimental (RFC 8279, RFC 8296, etc.).

First and primarily, the BIER-WG will complete its work on:
  1) Transition Mechanisms: The WG will describe how BIER
     can be introduced in existing multicast networks to shift multicast
     delivery either end-to-end or in part of a network from mechanisms
     such as PIM, ng-MVPN, etc. A minimum of the necessary mechanisms
     to support incremental deployment and/or managing
     different BIER mask-length compatibility may be defined.
     Operation of BIER in non-congruent topologies, i.e.
     topologies where not all routers are BIER capable can
     also be addressed. In addition to tunneling solutions, other
     approaches to make BIER deployable in such environments
     can be worked on. Each such mechanism must include an
     applicability statement to differentiate its necessity from
     other proposed mechanisms.
  2) Applicability Statements: The WG will describe how BIER can
     be applied to multicast L3VPN and to EVPN. This draft will
     describe what mechanism is used to communicate the group
     membership between the ingress router and the egress routers,
     what scalability considerations may arise, and any deployment
     considerations. The WG will work on additional applicability
     statements, as needed, describing how BIER can be applied.
  3) Use Case: The WG may produce one use-case document that clearly
     articulates the potential benefits of BIER for different use-cases.
  4) Manageability and OAM: The WG will describe how OAM will work in
     a BIER domain and what simplifications BIER offers for managing the
     multicast traffic. A strong preference will be given to extensions to
     existing protocols.
  5) Management models: The WG may work on YANG models and, as needed,
     management APIs to support common manageability.
  6) IGP extensions. When a BIER domain falls within a "link state IGP"
     network, the information needed to set up the BIER forwarding tables
     (e.g., the mapping between a given bit position and a given egress
     router) may be carried in the link state advertisements of the IGP.
     The link state advertisements may also carry other information related
     to forwarding (e.g., the IGP may support multiple topologies, in which
     case it may be necessary to advertise which topologies are to be used
     for BIER forwarding). Any necessary extensions to the IGP will be
     specified by the WG as Standards Track, in cooperation with the LSR WG.

The BIER-WG is additionally chartered to start Standards Track work on:
  7) BIER in IPv6 :  A mechanism to use BIER natively in IPv6 may be
     standardized if coordinated with the 6MAN WG and with understood
  8) BIER Traffic Engineering:  An architecture for BIER-TE is defined
     in draft-ietf-bier-te-arch; associated fundamental technology is included.
  9) Extensions to support BIER in multi-area IGP Deployments

The BIER-WG is chartered to investigate the following topics. The adoption
of any Standards Track drafts will require a milestone approved by the
responsible Area Director.
  10) Novel uses of the BIER bitmap: There are a variety of proposals for
      additional algorithms and other uses of the BIER bitmap and
      encapsulation beyond BIER and BIER-TE.
  11) BIER between Autonomous Domains:   With understood applicability,
      these scenarios may be investigated.
  12) Use of BIER in Controller-based Architectures:  How might controllers
      be used to provide calculated BIRTs and/or BIFTs tables to BFRs?
  13) Applicability of BIER to Applications: The WG may advise on the
      applicability of BIER to various applications.

The BIER-WG will coordinate with several different working groups and
must include the relevant other working groups during working group
last call on the relevant drafts. BIER-WG will coordinate with MPLS-WG
on the associated MPLS-based OAM mechanisms. BIER-WG will coordinate with
LSR-WG on extensions to flood BIER-related information. BIER-WG will
advise BABEL-WG on Babel extensions to support BIER. BIER-WG will
coordinate with BESS-WG and IDR-WG on the applicability of existing
BGP-based mechanisms for providing multicast group membership information.
BIER-WG will coordinate with PIM-WG on the applicability of and extensions
to PIM, IGMP, and MLD to support BIER operations and transition; BIER-WG
will work directly on the applicability statements, as needed.

Proposed milestones

No milestones for charter found.