Bit Indexed Explicit Replication
|The information below is for an older proposed charter
Bit Indexed Explicit Replication WG
||Bit Indexed Explicit Replication
Start Chartering/Rechartering (Internal Steering Group/IAB Review)
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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, including
RFCs 8279 and 8296.
The focus of the BIER-WG is on deployment: transition, partial deployments,
applicability and management.
First and primarily, the BIER-WG will complete its work on:
1) Transition Mechanisms and Partial Deployments: 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. BIER
operation in networks where not all routers are BIER capable
should be addressed. How to handle routers supporting BIER with
different BitStringLengths should be addressed. Each new
mechanism should include an applicability statement that clearly
describes its utility and distinctions from already standardized
2) Applicability Statements: The WG will continue to work on
documents describing how BIER can be applied, as has been done
for MVPN. A document describing applicability to EVPN should be
3) Use Case: The WG will 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
5) Management models: The WG may work on YANG models to manage BIER.
The WG may work on support for controller-based architectures
6) Link-State Routing and BGP extensions: The BIER-WG has already
defined the basic information needed to set up the BIER
forwarding tables via advertisements in OSPFv2 and ISIS; the
extensions to OSPFv3 will be specified. Additional extensions
may be needed - for example, to support signaling additional
constraints that prune the topologies on which the computation
for BIER for a particular sub-domain. Any necessary extensions
to the IGP will be specified by the WG as Standards Track, in
cooperation with the LSR WG. The BIER-WG shall also specify the
extensions to support BIER for BGP when used as an IGP (see RFC
7938) and to provide BIER-specific information in BGP-LS, in
cooperation with IDR.
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 being defined
in draft-ietf-bier-te-arch; associated fundamental technology is included.
The BIER-WG will serve as a forum to discuss how BIER can be applied.
The BIER-WG will coordinate and collaborate with other WGs as needed. Specific
expected interactions include:
* mpls on the associated MPLS-based OAM mechanisms,
* lsr on OSPF and ISIS extensions to flood BIER-related information,
* babel on Babel extensions to support BIER,
* bess and idr on BGP extensions to flood BIER-related information and the
applicability of existing BGP-based mechanisms for providing multicast group
membership information, and
* pim and mboned on the applicability of and extensions to PIM, IGMP, and MLD to
support BIER operations and transition.