ZyXEL Communications ZyXEL Dimension ES-3124 - Manual (Page 173)

Dimension ES-3124 Ethernet Switch
Multicast 22-7
22.5.3 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.
Figure 22-5 MVR Multicast Television Example
22.6 General MVR Configuration
Use the MVR screen to create multicast VLANs and select the receiver port(s) and a source port for each multicast
VLAN. Click Advanced Applications and Multicast in the navigation panel. Click the Multicast Setting link and
then the MVR link to display the screen as shown next.
You can create up to three multicast VLANs and up to 256 multicast rules on the switch.
Your switch automatically creates a static VLAN (with the same VID) when you create a multicast
VLAN in this screen.