Device Manager Online Help

Configuring IP multicast software forwarding

The IP multicast software forwarding feature enables the CPU to initially forward IP multicast data until a hardware record is created. The CPU forwards the initial packets of a stream it receives and at the same time, creates a corresponding hardware record for any subsequent packets. The advantage to this feature is that it avoids any initial data loss experienced by multicast applications, and is most suited for low bandwidth.

The IP multicast software forwarding is a global system configuration feature that applies to all IP multicast enabled interfaces and protocols. When you enable IP multicast software forwarding, be aware that the hardware is still responsible for forwarding IP multicast traffic. Only initial data traffic is forwarded by the software. Thus, the intention here is not to replace hardware forwarding with software forwarding. By default, the feature is disabled.

Note: To avoid overloading the CPU, Nortel Networks recommends that you do not use the IP multicast software forwarding feature for video multicast applications.

To configure IP multicast software forwarding:

1. From the Device Manager menu bar, choose IP Routing > Multicast.

The Multicast dialog box opens with the Routes tab displayed.

2. Click the Mcast SW Forwarding tab.

The Mcast SW Forwarding tab opens.

3. Click the SWForwardingEnable check box.
4. Click Apply to enable this feature.

The IP multicast software forwarding feature is now enabled.

• Troubleshooting DVMRP
• Viewing multicast route information
• Viewing multicast next hop information
• Viewing and editing multicast interface information
• Configuring multicast static source groups
• Viewing and editing static source groups
• Viewing and editing multicast routes