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

Document Type Expired Internet-Draft (pim WG)
Authors Deborah Estrin  , Van Jacobson  , Dino Farinacci  , Liming Wei  , Steve Deering , Mark Handley  , Dave Thaler  , Ching-Gung Liu  , Puneet Sharma  , Ahmed Helmy 
Last updated 1999-12-01 (latest revision 1999-10-04)
Stream Internet Engineering Task Force (IETF)
Expired & archived
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Stream WG state WG Document
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IESG IESG state Expired
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


This document describes a protocol for efficiently routing to multicast groups that may span wide-area (and inter-domain) internets. We refer to the approach as Protocol Independent Multicast--Sparse Mode (PIM-SM) because it is not dependent on any particular unicast routing protocol, and because it is designed to support sparse groups as defined in [1][2]. This document describes the protocol details. For the motivation behind the design and a description of the architecture, see [1][2]. Section 2 summarizes PIM-SM operation. It describes the protocol from a network perspective, in particular, how the participating routers interact to create and maintain the multicast distribution tree. Section 3 describes PIM-SM operations from the perspective of a single router implementing the protocol; this section constitutes the main body of the protocol specification. It is organized according to PIM-SM message type; for each message type we describe its contents, its generation, and its processing.


Deborah Estrin (
Van Jacobson (
Dino Farinacci (
Liming Wei (
Steve Deering (
Mark Handley (
Dave Thaler (
Ching-Gung Liu (
Puneet Sharma (
Ahmed Helmy (

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)