ZyXEL Communications ONU-2024 Series, User Manual

Page: 132 / 268

Chapter 19 Multicast
ONU User’s Guide
132
IGMP Filtering
With the IGMP filtering feature, you can control which IGMP groups a subscriber on a port
can join. This allows you to control the distribution of multicast services (such as content
information distribution) based on service plans and types of subscription.
You can set the ONU to filter the multicast group join reports on a per-port basis by
configuring an IGMP filtering profile and associating the profile to a port.
IGMP Snooping
The ONU can passively snoop on IGMP packets transferred between IP multicast routers/
switches and IP multicast hosts to learn the IP multicast group membership. It checks IGMP
packets passing through it, picks out the group registration information, and configures
multicasting accordingly. IGMP snooping allows the ONU to learn multicast groups without
you having to manually configure them.
The ONU forwards multicast traffic destined for multicast groups (that it has learned from
IGMP snooping or that you have manually configured) to ports that are members of that
group. IGMP snooping generates no additional network traffic, allowing you to significantly
reduce multicast traffic passing through your ONU.
IGMP Snooping and VLANs
The ONU can perform IGMP snooping on up to 16 VLANs. You can configure the ONU to
automatically learn multicast group membership of any VLANs. The ONU then performs
IGMP snooping on the first 16 VLANs that send IGMP packets. This is referred to as auto
mode. Alternatively, you can specify the VLANs that IGMP snooping should be performed
on. This is referred to as fixed
mode. In fixed mode the ONU does not learn multicast group
membership of any VLANs other than those explicitly added as an IGMP snooping VLAN.
19.2 Multicast Status
Click Advanced Applications > Multicast to display the screen as shown. This screen shows
the multicast group information. See Section 19.1 on page 131 for more information on
multicasting.
Figure 62 Advanced Application > Multicast
The following table describes the labels in this screen.
Table 40 Multicast Status
LABEL DESCRIPTION
Index This is the index number of the entry.
VID This field displays the multicast VLAN ID.
Port This field displays the port number that belongs to the multicast group.
Multicast Group This field displays IP multicast group addresses.