2.5.4 Inter-Domain Multicast Routing (idmr)

NOTE: This charter is a snapshot of the 45th IETF Meeting in Oslo, Norway. It may now be out-of-date. Last Modified: 06-Jul-99


Tony Ballardie <ABallardie@acm.org>
Bill Fenner <fenner@research.att.com>

Routing Area Director(s):

David Oran <oran@cisco.com>
Rob Coltun <rcoltun@siara.com>

Routing Area Advisor:

Rob Coltun <rcoltun@siara.com>

Mailing Lists:

General Discussion:idmr@cs.ucl.ac.uk
To Subscribe: idmr-request@cs.ucl.ac.uk
Archive: http://www.jnx.com/~pusateri/idmr

Description of Working Group:

Existing inter-domain multicast routing protocols are not scalable to a large internetwork containing very large numbers of active wide-area groups. The purpose of the IDMR Working Group, therefore, is to discuss proposed inter-domain multicast routing protocols, and put forward one (or a hybrid of several) as a Proposed Standard to the IESG.

Several proposals have been made to date, including Core-Based Tree (CBT) multicasting, Core-Based Join (CBJ) multicasting, and Scalable Reverse Path Multicasting (SRPM). Some of the above have yet to be reviewed.

Goals and Milestones:



Post the Core Based Trees architecture as an Internet-Draft.



Meet at IETF. All proposals must be submitted by this date. Discuss all proposals which have been submitted.

Dec 93


Submit the Core Based Trees architecture Internet-Draft to the IESG to be published as an Informational RFC.



Meet at IETF. Discuss security issues with respect to the proposed protocol(s).

Aug 94


Post an Internet-Draft for a single protocol (which may be one of the proposals, or a combination of proposals), and an Internet-Draft serving as a protocol analysis document for that protocol (as required by RFC 1264).

Jan 95


Submit the single protocol to the IESG as a Proposed Standard.

Mar 95


Post an Internet-Draft for an IDMR MIB.

Jul 95


Submit the IDMR MIB Internet-Draft to the IESG as a Proposed Standard.


Request For Comments:







Scalable Multicast Key Distribution



Core Based Trees (CBT) Multicast Routing Architecture



Core Based Trees (CBT version 2) Multicast Routing -- Protocol Specification --



Internet Group Management Protocol, Version 2



Protocol Independent Multicast-Sparse Mode (PIM-SM): Protocol Specification

Current Meeting Report

IDMR met in one session at the Oslo IETF: Tuesday 3:45 - 4:45.
These minutes were reported by Bill Fenner.

The new charter, as discussed in Minneapolis and on the mailing list, was not yet officially active, but the group was run following the new charter. It was basically a status session, trying to determine the status and path of the working group.

What follows is a summary of the protocols, the associated documents, and action items assigned.


v3 Spec - draft-ietf-idmr-dvmrp-v3-08.{txt.ps}
- Status: Almost ready for WG Last Call for Proposed Standard.
- Action Item: Tom Pusateri submits updated version by August 31

v3 Applicability Statement
- Status: Required document for routing protocols to move to Proposed Standard.
- Action Item: Tom Pusateri writes and submits by August 31

MIB - draft-thaler-dvmrp-mib-09.txt
- Status: Needs minor updates; should become WG document.
- Action Item: Dave Thaler submits updated version by August 31

v2 spec - RFC 2236
- Status: time to progress it to Draft Standard. Needs an update to incorporate Erik Nordmark's comments on the IPv6 MLD spec (most of which apply to the IGMPv2 spec as well). Also should mention that the common practice of not reporting any group in 224.0.0/24 is not valid (only is excluded).
- Action Item: Bill Fenner submits updated version by August 31.

MIB - draft-ietf-idmr-igmp-mib-10.txt
- Status: WG approved submission for Proposed Standard, several minor revisions since.
- Action Item: AD's ask IESG to advance to Proposed Standard.

v3 spec - draft-ietf-idmr-igmp-v3-01.txt
- Status: Implementable now; needs minor revisions before submitting for WG last call.
- Action Item: Authors submit version ready for last call by August 31.

v3 router behavior
- Status: A Companion document to the IGMPv3 spec, describing how existing multicast IGP's react to given IGMPv3 membership information.
- Action Item: Cain submits initial draft by September 30.

IGMP Proxying - draft-fenner-igmp-proxy-02.{txt,ps}
- Status: probably ready for WG Last Call.
- Action Item: Working Group and Implementors give feedback to author on completeness of spec.

Multicast Router Discovery
- Status: needs an update, then should be ready for Last Call.
- Action Item: Brad Cain submits updated version by August 31.

Other MIBs

Multicast Routing MIB - draft-ietf-idmr-multicast-routmib-09.txt
- Status: Submitted to the IESG; several minor revisions since; needs more minor revisions.
- Action Item: Dave Thaler submits updated version by August 31.

PIM MIB - draft-ietf-idmr-pim-mib-06.txt
- Status: Submitted to the IESG for consideration as Proposed Standard; several minor revisions since; needs more minor revisions.
- Action Item: Dave Thaler submits updated version by August 31.

Domain-Wide Reports

Discussion: we've needed these for years; nobody has implemented them.
Why not? Is it still worth specifying? The opinions expressed were that Domain-Wide Reports are something that fills a hole in the current architecture, and perhaps the lack of implementation is due to the fact that it's not an RFC yet.

Domain-Wide Reports - draft-ietf-idmr-membership-reports-03.{txt,ps}
- Status: needs update to security before Last Call.
- Action Item: Bill Fenner submits document with updated security considerations by August 31.

Interoperability Rules for Multicast Routing Protocols

Discussion: This spec doesn't mention e.g. MSDP or BGMP; should it? The opinions expressed was that those are charter items for the BGMP and MSDP working groups; this document was meant to cover the protocols currently in use or documented in an RFC.

- Status: Ready for Last Call to publish as Informational RFC.
- Action Item: Bill Fenner sends WG Last Call after IETF.

Multicast Traceroute

- Status: Needs an update for old language in statistics section. Based on discussion in meeting, also needs a more complete discussion of the "Routing Protocol" field and what criteria the IANA are to use when allocating new values.
- Action Items: Feedback from WG on spec. Bill Fenner submits updated spec by August 31.

Other Items

One document that was suggested is a document specifying the use of SAFI 2 and 3 in MBGP, similar to RFC2545 for IPv6. In addition, it was mentioned that SAFI 2 is overloaded for both the M-RIB and the G-RIB and it might be better to specify the use of a different SAFI for the G-RIB. No action items were discussed at the meeting.
- Action Item: Bill Fenner discusses with David Meyer about whether this document belongs in IDMR or MBONED.


None received.