Allied Telesis AT-S29 - Manual (Page 53)

AT-S29 Management Software User’s Guide
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The RJ-45 ports used for each trunk must all be on the same internal
switch chip. The port groups permitted include:
❑ Group 1: 1, 2, 3, 4 and 13, 14, 15, 16
❑ Group 2: 5, 6, 7, 8 and 17, 18, 19, 20
❑ Group 3: 9, 10, 11, 12 and 21, 22, 23, 24
The 100Base-FX fiber optic ports used for one side of a trunk must all be
on the same module. However, the 1000Base-SX and 1000Base-LX ports
used for one side of a trunk may be on any switch in the stack, or both on
the same switch if used as a standalone switch.
For example, when using Gigabit ports to form a trunk within a stack, the
Gigabit ports will all be at Port 25. In this case, you could specify a trunk
group consisting of:
(Unit1-Port25, Unit2-Port25, Unit3-Port25, Unit4-Port25)
or two trunks consisting of:
(Unit1-Port25, Unit2-Port25) and (Unit3-Port25, Unit4-Port25)
IGMP Multicast
Filtering
Multicasting is used to support real-time applications such as video
conferencing or streaming audio. A multicast server does not have to
establish a separate connection with each client. It merely broadcasts its
services to the network, and any hosts which want to receive the
multicast register with their local multicast switch/router. Although this
approach reduces the network overhead required by a multicast server,
the broadcast traffic must be carefully pruned at every multicast
server/router it passed through to ensure that traffic is only passed on
the hosts which subscribe to this service.
This switch uses IGMP (Internet Group Management Protocol) to query
for any attached hosts who want to receive a specific multicast service.
The switch looks up the IP Multicast Group used for this service and adds
any port which received a similar request to that group. It then
propagates the service request on to any neighboring multicast
switch/router to ensure that it will continue to receive the multicast
service.