User's Guide

Wireless Array
290 Configuring the Wireless Array
• for compatibility with ordinary operation, i.e., there is no
optimization or modification of multicast traffic.
• if you have an application where many subscribers need to see
the multicast—a large enough number that it would be less
efficient to convert to unicast and better just to send out multicast
even though it must be sent out at the speed of the slowest
connected station.
An example of a situation that might benefit from the use of this
mode is ghosting all the laptops in a classroom using multicast. One
multicast stream at, say, 6 Mbps is probably more efficient than thirty
unicast streams.
The next three options convert multicast to unicast. Packets are sent
directly to the stations at the best possible data rates. This approach
significantly improves the quality of the voice and video multicast
streams.
• Convert to unicast and send unicast packets to all stations. This
may be useful in link-local multicast situations.
• Convert to unicast, snoop IGMP, and only send to stations
subscribed (send as multicast if no subscription). This option is
useful when you need to stream voice or video multicast traffic to all
stations, but some stations are capable of subscribing to multicast
groups while other stations are not. The stations that do not subscribe
will not benefit from conversion to unicast; their video or voice
quality may be compromised.
• Convert to unicast, snoop IGMP, and only send to stations
subscribed (don't send packet if no subscription). This option is
useful in well controlled environments when you need to stream
voice or video multicast traffic only to stations that are capable of
subscribing to multicast groups and there is no need for the rest of the
stations to receive the data stream.
20. Multicast Exclude: This is a list of multicast IP addresses that will not be
subject to multicast-to-unicast conversion. This list is useful on networks
where applications such as those using multicast Domain Name System