Nortel 6220 User Manual page 106

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A higher value may result in longer partitions after the Spanning Tree
reconfigures.
Port Priority-- Normally the Bridge Port priority in Spanning Tree
topologies is imposed by the Root Bridge and the applicable values of
the Path Cost to the Root Bridge.
When concurrent bridge ports of a single bridge unit are connected in a
loop, this parameter enables you to influence which port should be
included in the Spanning Tree.
Valid Values:
Default:
A lower value makes a port more likely to become selected in the
Spanning Tree than the concurrent one that has a higher numerical value.
A higher value makes a port less likely to be selected in the Spanning
Tree than a port with a lower numerical value.
Path Cost-- The Path Cost value is used to determine the preferred data
paths between bridges throughout the network and the root bridge.
The Root Bridge transmits BPDU messages throughout the Local Area
Network. When a bridge unit receives a BPDU message at one of its
ports, it will add the value in the Path Cost field for that port to the value
in the Root Path Cost Field of the BPDU message before forwarding the
message again. This will help the other bridges to determine the Total
Path Cost to the Root Bridge via this port.
Valid Values:
Default:
A lower Path Cost value would typically be used for ports to LAN
segments closer to the Root Bridge.
A higher Path Cost value would typically be used for ports to LAN
segments that are the "leafs" of the Spanning Tree.
For example, when using the Secure Data Mode Station as an access
point for wireless stations to the Ethernet, a high Path Cost for the
wireless interface will minimize unnecessary use of the bandwidth for
the wireless medium (recommended value 255).
When using Secure Data Mode Stations in a wireless point-to-point link
to interconnect two LAN segments, a low Path Cost for the wireless
interface will prioritize this link as compared to other physical links, such
as a leased line or low-bandwidth connections.
WLAN Cable Access Point 6220 CSU NTPM99CA Rel 2.0 Issue 5 Dec 2005
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