ZyXEL MI-7248 User Guide - Page 152

Types of MVR Ports, MVR Modes, How MVR Works

Page 152 highlights

Chapter 27 Multicast Figure 61 MVR Network Example 27.6.1 Types of MVR Ports In MVR, a source port is a port on the switch that can send and receive multicast traffic in a multicast VLAN while a receiver port can only receive multicast traffic. Once configured, the switch maintains a forwarding table that matches the multicast stream to the associated multicast group. 27.6.2 MVR Modes You can set your switch to operate in either dynamic or compatible mode. In dynamic mode, the switch sends IGMP leave and join reports to the other multicast devices (such as multicast routers or servers) in the multicast VLAN. This allows the multicast devices to update the multicast forwarding table to forward or not forward multicast traffic to the receiver ports. In compatible mode, the switch does not send any IGMP reports. In this case, you must manually configure the forwarding settings on the multicast devices in the multicast VLAN. 27.6.3 How MVR Works The following figure shows a multicast television example where a subscriber device (such as a computer) in VLAN 1 receives multicast traffic from the streaming media server, S, via the switch. Multiple subscriber devices can connect through a port configured as the receiver on the switch. When the subscriber selects a television channel, computer A sends an IGMP report to the switch to join the appropriate multicast group. If the IGMP report matches one of the configured MVR multicast group addresses on the switch, an entry is created in the forwarding table on the switch. This maps the subscriber VLAN to the list of forwarding destinations for the specified multicast traffic. When the subscriber changes the channel or turns off the computer, an IGMP leave message is sent to the switch to leave the multicast group. The switch sends a query to VLAN 1 on the receiver port (in this case, a DSL port on the switch). If there is another subscriber device connected to this port in the same subscriber VLAN, the receiving port will still be on the list of forwarding destination for the multicast traffic. Otherwise, the switch removes the receiver port from the forwarding table. 152 MS-7206 User's Guide

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Chapter 27 Multicast
MS-7206 User’s Guide
152
Figure 61
MVR Network Example
27.6.1
Types of MVR Ports
In MVR, a source port is a port on the switch that can send and receive multicast traffic in a
multicast VLAN while a receiver port can only receive multicast traffic. Once configured, the
switch maintains a forwarding table that matches the multicast stream to the associated
multicast group.
27.6.2
MVR Modes
You can set your switch to operate in either dynamic or compatible mode.
In dynamic mode, the switch sends IGMP leave and join reports to the other multicast devices
(such as multicast routers or servers) in the multicast VLAN. This allows the multicast devices
to update the multicast forwarding table to forward or not forward multicast traffic to the
receiver ports.
In compatible mode, the switch does not send any IGMP reports. In this case, you must
manually configure the forwarding settings on the multicast devices in the multicast VLAN.
27.6.3
How MVR Works
The following figure shows a multicast television example where a subscriber device (such as
a computer) in VLAN 1 receives multicast traffic from the streaming media server,
S
, via the
switch. Multiple subscriber devices can connect through a port configured as the receiver on
the switch.
When the subscriber selects a television channel, computer
A
sends an IGMP report to the
switch to join the appropriate multicast group. If the IGMP report matches one of the
configured MVR multicast group addresses on the switch, an entry is created in the forwarding
table on the switch. This maps the subscriber VLAN to the list of forwarding destinations for
the specified multicast traffic.
When the subscriber changes the channel or turns off the computer, an IGMP leave message is
sent to the switch
to leave the multicast group. The switch sends a query to VLAN 1 on the
receiver port (in this case, a DSL port on the switch). If there is another subscriber device
connected to this port in the same subscriber VLAN, the receiving port will still be on the list
of forwarding destination for the multicast traffic. Otherwise, the switch removes the receiver
port from the forwarding table.