User Manual Part 3

AP-51xx Access Point Product Reference Guide
9-4
The access point in client bridge mode attempts to establish up to 3 simultaneous wireless
connections. The second and third connections are established in the background while the system
is running. The first connection needs to be established before the system starts bridging traffic.
The dual-radio model access point affords users better optimization of the mesh networking feature
by allowing the access point to transmit to other access points (in base or client bridge mode) using
one independent radio and transmit with its associated MUs using the second independent radio. A
single-radio access point has its channel utilization and throughput degraded in a mesh network, as
the access point’s single radio must process both mesh network traffic with other access points and
MU traffic with its associated devices.
9.1.2 Spanning Tree Protocol (STP)
The access point performs mesh networking using STP as defined in the 802.1d standard.
Once device association is complete, the client and base bridge exchange Configuration Bridge
Protocol Data Units (BPDUs) to determine the path to the root. STP also determines whether a given
port is a redundant connection or not.
9.1.3 Defining the Mesh Topology
When a user wants to control how the spanning tree determines client bridge connections, they need
to control the mesh configuration. The user must be able to define one node as the root. Assigning a
base bridge the lowest bridge priority defines it as the root.
The access point can manipulate the path cost assigned to a bridge connection based on that
connection’s RSSI. This results in the spanning tree selecting the optimal path for forwarding data
when redundant paths exist. However, this can be overridden using the preferred list. When using the
NOTE The Symbol AP-4131 access point uses a non-standard form of 802.1d
STP, and is therefore not compatible as a base bridge or client bridge
within an access point managed network.
NOTE Symbol recommends using the Mesh STP Configuration screen to
define a base bridge as a root. Only advanced users should use the
Advanced Client Bridge Settings screen’s Preferred List to define the mesh
topology, as omitting a bridge from the preferred list could break
connections within the mesh network.