HP ProCurve 6200yl Multicast And Routing Manual page 99

PIM-SM (Sparse Mode)
Terminology
Designated Router (DR): Within a given VLAN or network, the router
elected to forward a multicast flow from its IP source (in the VLAN or
network) to the appropriate rendezvous point (either an RP or static-RP) in
the PIM-SM domain.
Edge Router: Any router directly connected to a host or other endpoint in
the network.
Flow: Multicast traffic having one source and one multicast group address
(destination). This traffic may reach many hosts in different subnets, depend­
ing on which hosts have issued joins for the same multicast group.
Multicast Source: A single device originating multicast traffic for other
devices (receivers).
Prune: To eliminate branches of a multicast tree that have no hosts sending
joins to request or maintain membership in that particular multicast group.
Rendezvous Point (RP): A router that is either elected from a pool of
eligible C-RPs (dynamic RPs) or statically configured (static RP) to support
the distribution of traffic for one or more multicast groups and/or ranges of
multicast groups. The RP for a given multicast group receives that group's
traffic from a DR on the VLAN receiving the traffic from a multicast traffic
source. The RP then forwards the traffic to downstream edge or intermediate
PIM-SM routers in the path(s) to the requesting hosts (end points). (See also
Candidate Rendezvous Point, page 4-6).
Rendezvous Point Tree (RPT): The path extending from the DR through
any intermediate PIM-SM routers leading to the PIM-SM edge router(s) for the
multicast receiver(s) requesting the traffic for a particular multicast group.
(Refer to "Rendezvous-Point Tree (RPT)" on page 4-9.)
Reverse Path Forwarding (RPF): This is a methodology that uses the uni­
cast routing table created by IP protocols such as RIP and OSPF to determine
the source address of a packet. PIM uses RPF to set up distribution trees for
multicast traffic.
Router: In the context of this chapter, a router is any ProCurve switch model
covered by this guide and configured with IP routing enabled.
Routing Switch: See Router, above.
RP: See Rendezvous Point, above.
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