Types Of Mvr Ports; Mvr Modes; How Mvr Works; Figure 66 Mvr Network Example - ZyXEL Communications ONU-2024 Series User Manual

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Chapter 19 Multicast

19.6.1 Types of MVR Ports

In MVR, a source port is a port on the ONU that can send and receive multicast traffic in a

multicast VLAN while a receiver port can only receive multicast traffic. Once configured, the

ONU maintains a forwarding table that matches the multicast stream to the associated

multicast group.

You can set your ONU to operate in either dynamic or compatible mode.

In dynamic mode, the ONU 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 ONU 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

ONU. Multiple subscriber devices can connect through a port configured as the receiver on the

ONU.

When the subscriber selects a television channel, computer A sends an IGMP report to the

ONU to join the appropriate multicast group. If the IGMP report matches one of the

configured MVR multicast group addresses on the ONU, an entry is created in the forwarding

table on the ONU. 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 ONU to leave the multicast group. The ONU sends a query to VLAN 1 on the

receiver port (in this case, an uplink port on the ONU). 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 ONU removes the receiver

port from the forwarding table.

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ONU User's Guide

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