The BIER (Bit Index Explicit Replication) Working Group has defined an architecture [RFC 8279] for a dedicated multi-point forwarding plane that can use a variety of encapsulations. Current encapsulation specifications are [RFC 8296] that can be used on MPLS or Ethernet transport, which has received an Ethertype assignment [0xAB37] from the IEEE, and [draft-ietf-bier-bierin6] as proposed standard solution for native IPv6 encapsulation. The BIER-WG is chartered to produce Standards Track RFCs, including the status update for 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 define mechanisms to integrate BIER into existing multicast networks, enabling partial or end-to-end adoption alongside protocols like PIM and ng-MVPN, addressing scenarios with non-BIER-capable routers, mixed BitStringLengths, and varying encapsulations. This includes connecting legacy multicast islands over a BIER core, the mixing of BIER-capable routers with non-BIER routers within the same domain, and introducing BIER-only replication points as part of a legacy multicast network. This work is to include all connection and transition mechanisms to be specified.

Applicability statements will clarify the utility and distinctions of these mechanisms from existing standards.

2) Applicability Statements: Building on prior work (e.g., MVPN [RFC 8556], EVPN/BUM [RFC 9624]), the WG will continue developing applicability statements to articulate BIER’s use in specific scenarios.

3) Use Case Documentation: The WG will produce a comprehensive use-case document [draft-ietf-bier-use-cases] highlighting the benefits of BIER across different applications.

4) Manageability and OAM: The WG will specify mechanisms for Operations, Administration, and Maintenance (OAM) within BIER domains, emphasizing extensions to existing protocols and documenting manageability simplifications [draft-ietf-bier-oam-requirements].

5) Management Models: Development of YANG models for BIER, as captured in [draft-ietf-bier-bier-yang], will be prioritized to standardize management practices.

6) Link-State Routing and BGP Extensions: The WG will specify extensions for OSPFv3 [draft-ietf-bier-ospfv3-extensions] and explore additional IGP extensions for constrained topologies. Cooperation with LSR, IDR, and BESS will ensure alignment with related BGP and IGP efforts.

7) Forwarding Plane Mechanisms for BIER Traffic Engineering: The WG will define forwarding plane structures (e.g., BIFT) for engineered multicast trees, excluding PCE work.

8) Data-center/AI replication solutions: The working group may adopt work addressing requirements and solutions for data-center and AI fabric replication using BIER

9) Extending BIER scalability: The WG will address scalability requirements and solutions for BIER replication, ie [draft-zzhang-bier-unmasked-bier]

Additionally, the WG will coordinate with related working groups, including MPLS, LSR, BABEL, BESS, IDR, PIM, MBONED, PCE, and TEAS, to ensure alignment and interoperability in areas such as OAM, routing extensions, multicast membership management, and architecture for BIER-TE forwarding. These collaborations will support the advancement of BIER as a scalable and efficient solution for multicast forwarding.

This charter reflects the commitment of the BIER-WG to provide practical, interoperable, and standardized mechanisms for BIER in modern networks.