LWAP
Cisco introduced Lightweight Access Points (LWAP) that use the concept of
“split MAC,” which separates the real-time communication and management
functions. An LWAP controls beaconing, buffering, and encryption and uses
a controller for 802.1x, Extensible Authentication Protocol (EAP), key
management, and bridging functions.
In the LWAP scenario, QoS is handled at the controller. QoS is marked at
Layer 2 using 802.11e. 802.11e, like 802.1p, will not pass through a router,
so it has to be converted to DSCP if used end-to-end in a large network.
Similarly, .1p and DSCP fields must be mapped back to WMM when traffic
goes to the client.
Controllers host profiles that describe traffic handling. At the controller, an
administrator can specify:
■ Average and burst “best-effort” data rate
■ Average and burst “real-time” data rate
■ Maximum RF usage (set to 100%)
■ Queue depth, which is the number of packets that will be in the queu if
the line is busy
■ WMM-to-802.1p mapping
Furthermore, the controller may be set up to ignore, allow, or require
802.11e.