ZyXEL Communications MES3500-24F 用户手册

Chapter 24 Multicast

MES3500-24/24F User’s Guide

The following figure shows a network example. The subscriber VLAN (1, 2 and 3) information is 
hidden from the streaming media server, S. In addition, the multicast VLAN information is only 
visible to the Switch and S. 

MVR Network Example 

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.

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. 

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, an uplink port on the Switch). If there is another subscriber device connected to this