Cables to Go TE100-S55 manual At The Bridge Level

STA operates at two levels, the Switch and the Port level. In addition, STA uses several timers to periodically ensure the integrity of switches/bridges and their ports in a network.

The following paragraphs introduce the key information and terminology needed to understand the STA parameters. Please note that the word “bridge” now refers to TE100-S55.

AT THE BRIDGE LEVEL

Root Bridge: A network must first establish a starting point from which all data forwarding path values are calculated, compared, and determined. The Root Bridge is the unit with the lowest Bridge Identifier1 (Bridge Priority + MAC address).

Bridge Priority: This is a user changeable parameter. This parameter enables all bridges in the network to establish a Root Bridge. A change to the Bridge Priority may cause the network to re-establish a new Root Bridge. A high Bridge Priority increases the chance for a bridge to be selected as the Root Bridge (the smaller the number, the higher the priority).

Root Path Cost: From each bridge, Root Path Cost is the total Path Cost of reaching the Root Bridge from a Designated Bridge. A Root Bridge has Root Path Cost of 0.

Designated Bridge: From each LAN segment, the bridge that has the lowest Root Path Cost to the Root Bridge becomes the Designated Bridge. It forwards data packets for that LAN segment. In case all bridges on a segment have the same Root Path Cost, the bridge with the lowest Bridge Identifier becomes the Designated Bridge.

1The bridge MAC address is only used to decide the Root Bridge when there are 2 or more bridges with the same Bridge Priority.

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