MSM7xx Controllers Configuration Guide v6.4.0

19 Local mesh
Key concepts
The local mesh feature enables you to create wireless links between two or more APs. These links
provide a wireless bridge that interconnects the networks connected to the Ethernet port on each
AP.
The local mesh feature replaces the need for Ethernet cabling between APs, making it easy to
extend your network in hard-to-wire locations or in outdoor areas.
Key local mesh features include:
• Automatic link establishment: Nodes automatically establish wireless links to create a
full-connected network. A dynamic network identifier (local mesh group ID) restricts connectivity
to groups of nodes, enabling distinct groups to be created with nodes in the same physical
area.
• Provides fall-back operation to recover from node failure. In a properly designed
implementation, redundant paths can be provided. If a node fails, the mesh will automatically
reconfigure itself to maintain connectivity.
• Maintains network integrity when using DFS channels. In accordance with the 802.11h
standard, dynamic frequency selection (DFS) detects the presence of certain radar devices on
a channel and automatically switches the network node to another channel if such signals are
detected. 802.11h is intended to resolve interference issues with military radar systems and
medical devices.
NOTE: Depending on the radio regulations of some countries, DFS channels are only available
on the 802.11a/n bands, which are the preferred band for local mesh backhaul. If more than
one node detects radar simultaneously and must switch channels, each node does not necessarily
switch to the same channel, and the network might never reconverge. To avoid this problem, local
mesh detects a change in channel and provides a means to reconnect on other channels by scanning
on multiple channels. See “Operating channel” (page 386).
Simultaneous AP and local mesh support
APs can be configured to support both access point and local mesh functionality whether they have
a single radio, or multiple radios.
Single radio APs
A single radio can be configured to simultaneously support wireless users and one or more local
mesh links. Although this offers flexibility it does have the following limitations:
• The total available bandwidth on the radio is shared between all local mesh links and wireless
users. This can result in reduced throughput if lots of traffic is being sent by both wireless users
and the local mesh links. You can use the QoS feature to prioritize traffic.
• It limits you to using the same radio options for both wireless clients and local meshes.
Multiple radio APs
On APs with more than one radio, one radio can be dedicated to support wireless users and
another to provide local mesh links. Each radio can be configured optimally according to its
application.
Controlled APs
Controlled APs can be managed over local mesh links.
384 Local mesh