Advanced Topics

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Class-of-Service (CoS) Support
The OmniStack® 8008 provides two transmit queues on each port, with a Weighted
Fair Queuing scheme. This function can be used to provide independent priorities
for various types of data such as real-time video or voice, and best-effort data.
Priority assignment to a packet in the OmniStack® 8008 can be accomplished in any
of the following ways:
• Priority can be explicitly assigned by end stations which have applications that
require a higher priority than best-effort. This switch utilizes the IEEE 802.1p and
802.1Q tag structure to decide priority assignments for the received packets.
• A port may be manually configured as high priority. In this case, when any other
port receives traffic from a high-priority port, that traffic is automatically placed in
the high-priority output queue.
Port Trunks
Ports can be combined into an aggregate link to increase the bandwidth of a network
connection or ensure fault recovery. You can group ports into trunks that consist of
two, three or four ports, creating an aggregate bandwidth of up to 8 Gbps. Besides
balancing the load across each port in the trunk, the a dditional ports provide
redundancy by taking over the load if another port in the trunk should fail.
When using port trunks, remember that:
• Before removing a port trunk via the configuration menu, you must disable all the
ports in the trunk or remove all the network cables. Otherwise, a loop may be
created.
• To disable a single link within a port trunk, you should first remove the network
cable, and then disable both ends of the link via the configuration menu. This
allows the traffic passing across that link to be automatically distributed to the other
links in the trunk, without losing any significant amount of traffic.
SNMP Management Software
SNMP (Simple Network Management Protocol) is a commun ication protocol
designed specifically for managing devices or other elements on a network. N etwork
equipment commonly managed with SNMP includes hubs, switches, bridges,
routers and host computers. SNMP is typically used to configure these devices for
proper operation in a network environment, as well as monitor them to evaluate
performance and detect potential problems.