Avaya 8800 Planning And Engineering, Network Design page 173

3. Do not configure multicast routing on edge switch interfaces that do not contain multicast
senders or receivers. By following this rule, you:
• Provide secured control over multicast traffic that enters or exits the interface.
• Reduce the load on the switch, as well as the number of routes. This improves overall
performance and scalability.
4. Avoid initializing many (several hundred) multicast streams simultaneously. Initial stream
setup is a resource-intensive task, and initializing a large number may slow down the setup
time. In some cases, this can result in some stream loss.
5. Whenever possible, do not connect IP multicast sources and receivers by using VLANs that
interconnect switches (see the following figure). In some cases, this can result in excessive
hardware record use. By placing the source on the interconnected VLAN, traffic takes two
paths to the destination, depending on the RPF checks and the shortest path to the source.
For example, if a receiver is placed on VLAN 1 on switch S1 and another receiver is placed
on VLAN 2 on this switch, traffic can be received from two different paths to the two
receivers. This results in the use of two forwarding records. When the source on switch S2 is
placed on a different VLAN than VLAN 3, traffic takes a single path to switch S1 where the
receivers are located.
Figure 77: IP multicast sources and receivers on interconnected VLANs
6. Use default timer values for PIM and DVMRP. When timers are decreased for faster
convergence, they usually adversely affect scalability because control messages are sent
more frequently. If faster network convergence is required, configure the timers with the
same values on all switches in the network. Also, in most cases, you must perform baseline
testing to achieve optimal values for timers versus required convergence times and
scalability. For more information, see
7. For faster convergence, configure the Bootstrap and Rendezvous Point routers on a
circuitless IP. For more information, see
8. For faster convergence, Avaya recommends using a static Rendezvous Point (RP) router.
June 2016
DVMRP timer tuning
Circuitless IP for PIM-SM
Planning and Engineering — Network Design
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General multicast considerations
on page 192.
on page 205.
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