Pim-Sm, Pim-Ssm, And Pim-Bidir - Cisco XR12000 Series Configuration Manual

Implementing Multicast Routing on Cisco IOS XR Software

PIM-SM, PIM-SSM, and PIM-BIDIR

This image shows IGMP/MLD and PIM-SM operating in a multicast environment.
Figure 1: Multicast Routing Protocols
PIM-SM, PIM-SSM, and PIM-BIDIR
Protocl Independent Multicast (PIM) is a multicast routing protocol used to create multicast distribution trees,
which are used to forward multicast data packets. PIM is an efficient IP routing protocol that is "independent"
of a routing table, unlike other multicast protocols such as Multicast Open Shortest Path First (MOSPF) or
Distance Vector Multicast Routing Protocol (DVMRP).
Cisco IOS XR Software supports Protocol Independent Multicast in sparse mode (PIM-SM), Protocol
Independent Multicast in Source-Specific Multicast (PIM-SSM), and Protocol Independent Multicast in
Bi-directional mode (BIDIR), permitting these modes to operate on your router at the same time.
PIM-SM and PIM-SSM supports one-to-many applications by greatly simplifying the protocol mechanics for
deployment ease. Bidir PIM helps deploy emerging communication and financial applications that rely on a
many-to-many applications model. BIDIR PIM enables these applications by allowing them to easily scale
to a very large number of groups and sources by eliminating the maintenance of source state.
PIM-SM Operations
PIM in sparse mode operation is used in a multicast network when relatively few routers are involved in each
multicast and these routers do not forward multicast packets for a group, unless there is an explicit request
for the traffic.
For more information about PIM-SM, see the PIM-Sparse Mode, on page 11.
Cisco IOS XR Multicast Configuration Guide for the Cisco XR12000 Series Router, Release 5.1.x
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