Link State Routing

Document Charter Link State Routing WG (lsr)
Title Link State Routing
Last updated 2021-03-10
State Approved
WG State Active
IESG Responsible AD John Scudder
Charter Edit AD John Scudder
Send notices to (None)


The Link-State Routing (LSR) Working Group is chartered to document
current protocol implementation practices and improvements, protocol usage
scenarios, maintenance and extensions of the link-state interior gateway
routing protocols (IGPs) - specifically IS-IS, OSPFv2, and OSPFv3. The LSR
Working Group was formed by merging the isis and ospf WGs and assigning all
their existing adopted work at the time of chartering to LSR.

IS-IS is an IGP specified and standardized by ISO through ISO 10589:2002 and
additional RFC standards with extensions to support IP that has been deployed
in the Internet for decades.  For the IS-IS protocol, LSR-WG’s work is focused
on IP routing, currently based on the agreement in RFC 3563 with ISO/JTC1/SC6.
The LSR-WG will interact with other standards bodies that have responsibility
for standardizing IS-IS. LSR-WG will continue to support Layer 2 routing (for
example TRILL work) as needed.

OSPFv2 [RFC 2328 and extensions], is an IGP that has been deployed in the
Internet for decades. OSPFv3 [RFC5340 and extensions] provides OSPF for IPv6
and IPv4 [RFC5838] which can be delivered over IPv6 or IPv4 [RFC 7949].

The LSR Working Group will generally manage its specific work items by
milestones agreed with the responsible Area Director.

In addition to ongoing maintenance, the following topics are specific
work-items for the WG.

1) Improve OSPF support for IPv6  and create at least parity with IPv4
    by adding OSPFv3 extensions using the OSPFv3 Extended LSAs.

2) Extensions needed for Segment Routing and associated architectural changes

3) YANG models for the management of IS-IS, OSPFv2, and OSPFv3 and extensions

4) Extensions for source-destination routing

5) Improvements to flooding (and other behaviors) to better support dense meshed
   network topologies, such as are commonly used in data centers.

The Link-State Routing (LSR) Working Group will coordinate with other working
groups, such as RTGWG, SPRING, MPLS, TEAS, PCE, V6OPS, and 6MAN, to understand
the need for extensions and to confirm that the planned work meets the needs
and is compatible with IS-IS and/or OSPF from functional, architectural and
performance point of views.  LSR-WG will coordinate with CCAMP, TEAS, and BIER
on their extensions to the LSR IGPs as applicable to LSR protocol operation and
scale.  LSR-WG should coordinate with other WGs as needed.