Cabling
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Supported in Link Aggregation
Avid ISIS 7500 | 7000 supports 10-Gb link aggregation (between the ISS and the Avid
Production Network switch) and Hi-Gig link aggregation (between two IXS). Avid ISIS software
supports the link aggregation standard clause 43 of 802.3-2005 (also known as 802.3ad).
Number of Groups Supported
A link aggregation group refers to a number of links that combine together to form a single link
aggregation. The number of link aggregation groups supported in Avid ISIS 7500 | 7000 is five.
Number of Members Supported
A link aggregation group can have a maximum of eight members. This means no more than eight
10-Gb links can be combined into one link aggregation group per VLAN. The minimum number
of link aggregation members in a group is 2.
For performance reasons, Avid recommends that you maintain an even number of link
aggregation members. So for an eight engine stack, you can have a link aggregation group with
two, four, and six members. For a ten or twelve engine stack, there can be two, four, six, and
eight members in a link aggregation group.
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If a member is already part of a link aggregation group, it cannot be part of another link
aggregation group. You also cannot create a link aggregation group with a single member.
Load Balancing
The software balances the load across multiple 10-Gb aggregated links based on source and
destination IP addresses.
Failover
If a 10-Gb trunk link fails, the software load balances the traffic among the remaining trunk
links. For example in a four-way 10-Gb trunk if a single 10-Gb link fails, the traffic is load
balanced among the remaining three links. This also means that the average traffic distribution
increases from 25% with the four links, to 33% in the three links. Therefore, it is strongly
advised that network planners setup the trunks to handle the additional load if a link or a set of
links should fail in a trunk configuration. The traffic automatically re-balances the load when a
trunk link returns.
Warning messages are sent to ISIS Management Console notifying you that a 10-Gb aggregation
link status has changed. Switch diagnostics also provides errors when you have a failed link in a
trunk.
