Split Mac scenario: WLC’s and AP’s working together.
Real time traffic is handled by the Access Point which includes:
- Beacon Broadcast
- Responding to Probes
- Acknowledges
- RTS/CTS (if used)
- Real time 802.11 traffic
The Controller handles:
- Authentication
- Authorisation
- Dis-association requests
- Coordinates radio policies across multiple Access Points.
- Control Radio Power levels intelligently to cover failures.
CAPWAP – Control and Provisioning of Wireless Access Points
CAPWAP is the protocol used between a WLC and it’s Access Points. There are two streams, a control path and a data path. If a WLC wanted an AP to use a different channel, it would make that instruction using the control path. Client data would be encapsulated in CAPWAP by the AP and sent on to the WLC through the data path. The WLC de-capsulates the CAPWAP packet and then makes a decision on what to do with the packet.