BGP Enabled Services
charter-ietf-bess-01-00

BGP is established as a protocol for provisioning and operating Layer-3
(routed) Virtual Private Networks (L3VPNs) and Layer-2 Virtual Private
Networks (L2VPNs).

The BGP Enabled Services (BESS) working group is responsible for defining,
specifying, and extending network services over a packet switched
network (PSN) where the VPN signaling uses BGP. In particular, the working
group will work on the following services:

• BGP-enabled IP VPN solutions (based on RFC4364, RFC4659, RFC6513,
  RFC6514 and RFC9252) for supporting unicast and multicast provider-provisioned
  L3VPNs.
• BGP-enabled L2VPNs (based on RFC 4664, RFC7432 and RFC9252). Only
  types of L2VPN that utilize BGP for discovery, signaling, or for some
  other purposes related to the VPN are in scope. L2VPN solutions that
  do not utilize BGP for any of these purposes are out of scope of the
  BESS working group. Any contention in placement of the work will be
  resolved by the chairs and responsible Area Directors.
• BGP-enabled VPN solutions for use in data center networking.
  This work includes consideration of VPN scaling issues and
  mechanisms applicable to such environments.
• Extensions to BGP-enabled VPN solutions to enable interworking
  between BGP L3VPNs and BGP L2VPNs.

The working group may also suggest new services to be supported by BGP
and these may be added to the working group charter subject to
rechartering, and they will not be adopted in the working group until such
rechartering.

The WG will focus primarily on producing BGP protocol specifications for
services in its charter. The WG will work on informational documents only
related to operational and deployment aspects of the services for which the
WG is also producing the protocols specifications.

As part of enhancing and maintaining the services that the WG has
specified, the following is a list of specific aspects that the WG is
expected to work on:

a) BGP signaling related to the discovery of service endpoints and their
capabilities that are related to the service.
b) The exchange of service routes and their provisioning.
c) Scaling and convergence improvements
d) Interworking between different services
e) Definition of YANG models for provisioning and operations
f) Redundancy, multi-homing, load-balancing, and similar resiliency
mechanisms
g) BGP signaling related to multicast services. This includes BGP
components that are also applicable to the underlay PSN and that are
detailed in specifications already adopted at the time of this
charter revision.
h) Specifications for BGP-enabled VPN solutions for SD-WAN environments
that are already adopted at the time of this charter revision.

The Working Group will not define new data plane or forwarding
encapsulations. Instead, it will leverage existing encapsulations,
including but not limited to IP-based mechanisms (e.g., IP-in-IP, VXLAN,
GENEVE, SRv6) and MPLS. OAM mechanisms related to services within the scope
of the WG may be considered, following coordination with the Working Groups
responsible for the underlying data plane technologies.

The WG is expected to coordinate closely with the IDR WG. Extensions impacting
the core BGP protocol, such as modifications to the BGP finite state machine, message
formats, best-path selection procedures, or the definition of new path
attributes, must be cross-posted to the IDR WG for review. While
discussions may take place on the BESS WG mailing list, such work remains
subject to coordination with IDR.

The WG will also liaise with other relevant WGs, including but not limited
to MPLS, SPRING, 6man, NVO3, and BFD, as appropriate. This coordination
aims to ensure architectural consistency, alignment of data plane
considerations, and interoperability of OAM procedures for BGP-based VPN
solutions.