Inter-Domain Multicast Routing (idmr)

NOTE: This charter is a snapshot of that in effect at the time of the 38th IETF Meeting in Memphis, Tennessee. It may now be out-of-date.


Tony Ballardie <>
Bill Fenner <>

Routing Area Director(s): 

Joel Halpern <>

Mailing Lists: 

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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 that 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.


· Protocol Independent Multicast-Sparse Mode (PIM-SM): Motivation and Architecture 

· Internet Group Management Protocol MIB 

· IP Multicast Routing MIB 

· Protocol Independent Multicast MIB 

· Core Based Trees (CBT) Multicast -- Protocol Specification -- 

· Core Based Trees (CBT) Multicast Routing Architecture 

· Internet Group Management Protocol, Version 2 

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

· A "traceroute" facility for IP Multicast. 

· Protocol Independent Multicast-Dense Mode (PIM-DM): Protocol Specification 

· Distance Vector Multicast Routing Protocol 

· Core Based Tree (CBT) Multicast Border Router Specification for Connecting a CBT Stub Region to a DVMRP Backbone

Request For Comments:





Scalable Multicast Key Distribution

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