CANOGA PERKINS 9175 Configuration Guide - Manual (Page 140)

CanogaOS Configuration Guide
23-1
23 Configuring MVR
23.1 Overview
Multicast VLAN Registration (MVR) is designed for applications using wide-scale
deployment of multicast traffic across an Ethernet ring-based service provider network
(for example, the broadcast of multiple television channels over a service-provider
network). MVR allows a subscriber on a port to subscribe and unsubscribe to a multicast
stream on the network-wide multicast VLAN. It allows the single multicast VLAN to be
shared in the network while subscribers remain in separate VLANs. MVR provides the
ability to continuously send multicast streams in the multicast VLAN, but to isolate the
streams from the subscriber VLANs for bandwidth and security reasons.
MVR assumes that subscriber ports subscribe and unsubscribe (join and leave) these
multicast streams by sending out IGMP join and leave messages. These messages can
originate from an IGMP version-2-compatible host with an Ethernet connection. Although
MVR operates on the underlying mechanism of IGMP snooping, the two features
operation affect with each other. One can be enabled or disabled with affecting the
behavior of the other feature. If IGMP snooping and MVR are both enabled, MVR reacts
only to join and leave messages from multicast groups configured under MVR. The
switch CPU identifies the MVR IP multicast streams and their associated MAC
addresses in the switch forwarding table, intercepts the IGMP messages, and modifies
the forwarding table to include or remove the subscriber as a receiver of the multicast
stream, and the receivers must be in a different VLAN from the source. This forwarding
behavior selectively allows traffic to cross between different VLANs.
23.1.1 Terminology
MVR
Multicast Vlan Registration
Source vlan
The vlan for receiving multicast traffic for MVR
Source port
The port in the source vlan for sending report or leave to upstream
Receiver port
The port not in source vlan for receiving report or leave for downstream