Cisco Systems 78-11741-02 Configuring Source Specific Multicast, SSM Components Overview, IPC-459

Configuring Source Specific Multicast

This chapter describes how to configure Source Specific Multicast (SSM). For a complete description of the SSM commands in this chapter, refer to the “IP Multicast Routing Commands” chapter of the Cisco IOS IP Command Reference, Volume 3 of 3: Multicast. To locate documentation of other commands that appear in this chapter, use the command reference master index, or search online.

The Source Specific Multicast feature is an extension of IP multicast where datagram traffic is forwarded to receivers from only those multicast sources to which the receivers have explicitly joined. For multicast groups configured for SSM, only source-specific multicast distribution trees (no shared trees) are created.

To identify the hardware platform or software image information associated with a feature, use the Feature Navigator on Cisco.com to search for information about the feature or refer to the software release notes for a specific release. For more information, see the “Identifying Supported Platforms” section in the “Using Cisco IOS Software” chapter.

SSM Components Overview

SSM is a datagram delivery model that best supports one-to-many applications, also known as broadcast applications. SSM is a core networking technology for the Cisco implementation of IP multicast solutions targeted for audio and video broadcast application environments. This chapter discusses the following Cisco IOS components that support the implementation of SSM:

•Protocol Independent Multicast source specific mode (PIM-SSM)

•Internet Group Management Protocol Version 3 (IGMPv3)

•Internet Group Management Protocol Version 3 lite (IGMP v3lite)

•URL Rendezvous Directory (URD)

PIM-SSM is the routing protocol that supports the implementation of SSM and is derived from PIM sparse mode (PIM-SM). IGMP is the Internet Engineering Task Force (IETF) standards track protocol used for hosts to signal multicast group membership to routers. Version 3 of this protocol supports source filtering, which is required for SSM. To run SSM with IGMPv3, SSM must be supported in the Cisco IOS router, the host where the application is running, and the application itself. IGMP v3lite and URD are two Cisco-developed transition solutions that enable the immediate development and deployment of SSM services, without the need to wait for the availability of full IGMPv3 support in host operating systems and SSM receiver applications. IGMP v3lite is a solution for application developers that allows immediate development of SSM receiver applications switching to IGMPv3 as soon as it becomes available. URD is a solution for content providers and content aggregators that enables them to

Cisco IOS IP Configuration Guide

IPC-459