User manual

24: Multicasting using PIM and IGMP interfaces
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24 Multicasting using PIM and IGMP interfaces
IP multicast is a bandwidth-conserving technology that reduces traffic by
simultaneously delivering a single stream of information to potentially thousands
of corporate recipients. Applications that take advantage of multicast include
video conferencing and corporate communications.
IP multicast delivers application source traffic to multiple receivers without
burdening the source or the receivers while using a minimum of network
bandwidth.
PIM (Protocol Independent Multicast) and IGMP (Internet Group Management
Protocol) are protocols used to create multicasting networks within a regular IP
network.
A multicast group is an arbitrary group of receivers that expresses an interest in
receiving a particular data stream. The receivers (the designated multicast
group) are interested in receiving a data stream from the source. They indicate
this by sending an Internet Group Management Protocol (IGMP) host report to
their closest router in the network. The routers are then responsible for
delivering the data from the source to the receivers. The routers use Protocol
Independent Multicast (PIM) between themselves to dynamically create a
multicast distribution tree. The data stream will then be delivered only to the
network segments that are in the path between the source and the receivers.
To summarize: PIM is used between routers while IGMP is used between a
receiver and its router only. As a result, PIM must be enabled on all the
interfaces on the route from the multicast source to the multicast client while
IGMP must be enabled on the interface to the multicast client only.
24.1 Configuring PIM and IGMP via the web interface
To configure PIM through the web interface, in the top menu, select Network ->
PIM. The PIM page appears.
Figure 70: The PIM page
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© Virtual Access 2015
GW1000 Series User Manual
Issue: 2.4 Page 159 of 255