Babel routing protocol
charter-ietf-babel-00-04

Babel is a loop-avoiding, distance vector routing protocol with good
provisions for dynamically computed link metrics. It is robust even in
the presence of link metric oscillations and the failure of
transitivity. The core of the Babel protocol and security extensions
are described in Experimental Independent Stream RFCs 6126, 7557, and
7298.

These RFCs are the basis of three independent, open source
implementations. There is some production deployment of these
implementations, notably in hybrid networks (networks that include
classical, wired parts with meshy radio bits) and in global overlay
networks (networks built out of large numbers of tunnels spanning
continents).

The Working Group will focus on moving the Babel protocol to IETF
Proposed Standard with IETF review. This includes clarifying RFC 6126
and integrating RFC 7557 and feedback provided by independent
implementations, and resolving comments. It is not a requirement that
the Babel protocol produced is backwards compatible with RFC 6126. It
is a requirement that Babel support at least one profile that is
auto-configuring. Other documents that are relevant to the above work
can also be produced. Particular emphasis will be placed
on work needed for a Proposed Standard routing protocol, such as
ensuring manageability and strong security. Link metric measurement or
link metric calculation procedures significantly more complex that
those currently in Babel are out of scope.

Work Items:

• Produce a revision of RFC 6126 suitable for publication as a
  Proposed Standard
  -- incorporate in the revision developments since RFC 6126
  -- resolve technical issues found
  -- include in the base specification the extensibility work in
  RFC 7557
  -- support auto-configuration
  -- consider any important changes based on experience with Babel to
  date.

• Address security needs for BABEL. This may include using the
  techniques in RFC 7298, or other alternatives. Security may be
  included in the base spec or the base spec may normatively reference a
  separate Proposed Standard specification. This is required as part of
  moving Babel to Proposed Standard.

• Address manageability of Babel by producing an informational model
  for use by other network management such as the Broadband Forum
  TR-069, and a YANG data module based on that information model. This
  YANG data module to be consistent with the ongoing effort to use YANG
  data modules in the Routing Area. This work is required as part of
  moving Babel to Proposed Standard.

• As the Proposed Standard version of Babel is completed, an
  Applicability Statement should be finalized to guide those potentially
  interested in deploying Babel. This Applicability Statement may
  include deployment advice and will be published as an RFC.

• Coordinate with other Working Groups, such as the HOMENET WG for
  likely applicability, the RTGWG and V6OPS WG about Source-Specific
  Routing to support IPv6 multihoming, the PIM WG for discussion around
  multicast, and the MANET WG for considerations around wireless.

• Liaise as necessary with the Broadband Forum to facilitate use of the
  Babel management Information Model for TR-069.

• The Working Group should document its ongoing implementation
  experience with Babel, so that new WG participants can understand the
  state that is driving this work and the experience driving changes.
  This documentation may be on the Working Group's wiki, in
  an internet-draft that isn't expected to be published as an RFC, or a combination.

• As a secondary focus, the Working Group may work on multicast
  aspects of Babel. This may include discussion of any potential issues
  for supporting Babel running with PIM-SM in an auto-configuration
  profile. It may include exploring Babel carrying separate metrics for
  multicast. It may even include discussion and consultation with the PIM
  WG about Babel providing the ability to build multicast routing
  tables. With AD and WG agreement, once an approach is understood,
  then a milestone may be added for an associated document targeted as
  Proposed Standard.

• As a secondary focus, the Working Group may work on documents
  defining source specific routing extensions for Babel as a way of handling
  IPv6 multihoming.

Thus, the Working Group will produce a Proposed Standard Babel
specification, including or paired with a suitable Proposed Standard
specification covering the security mechanism(s) for BABEL. It will
also produce a management information and data model for BABEL as a
Proposed Standard RFC. An applicability statement will be produced as
an Informational RFC.