Configuring Mvr; Using Mvr In A Multicast Television Application - Cisco WS-C2950-24 Configuration Manual

Chapter 6 Configuring the System

Configuring MVR

Using MVR in a Multicast Television Application

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Multicast VLAN Registration (MVR) is designed for applications using
wide-scale deployment of multicast traffic (for example, broadcast of multiple
television channels) across an Ethernet ring-based 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.
This 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 Internet Group Management Protocol
(IGMP) join and leave messages. These messages can originate from an IGMP
version-2-compatible set-top box with an Ethernet connection or from a PC
capable of generating IGMP version-2 messages. The switch CPU identifies 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. This forwarding
behavior selectively allows traffic to cross between the two VLANs.
Because MVR does not support IGMP dynamic joins, the user or administrator
must configure static multicast addresses on the router.
In a multicast television application, a PC or a television with a set-top box can
receive the multicast stream. Multiple set-top boxes or PCs can be connected to
one subscriber port. (See
box or the PC. When a subscriber selects a channel, the set-top box or PC sends
an IGMP report to the access layer switch (S1 switch) to join the appropriate
multicast. If the IGMP report matches one of the configured multicast MAC
addresses, the switch CPU modifies the hardware address table to include this
receiver port and VLAN as a forwarding destination of the specified multicast
stream when it is received from the multicast VLAN over the source port.
When a subscriber changes channels or turns off the television, the set-top box
sends an IGMP leave message for the multicast stream. The switch CPU sends an
IGMP group-specific query through the receiver port VLAN. If there is another
Catalyst 2900 Series XL and Catalyst 3500 Series XL Software Configuration Guide
Figure 6-10.) DHCP assigns an IP address to the set-top
Configuring MVR
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