PCF or just DCF in Cisco AP ?

[mkoch]

Hi !

I was reading the IEEE 802.11 spec and now i'm wondering if the Cisco APs do PCF (Point Co-ordination Function) or just use DCF (Distributed Co-ordination function)

I was unable to find anything in the Docs or on the AP interface...

Thanks for any input

Michael

[jorge_lopez]

Hello Michael. I have the same doubt as you. After searching in several sites I think I have one answer that may be right (but not sure :( ). You can set up a RTS packet size treshold. I thhink DCF is based on RTS/CTS, so PCF will be used when packets are smaller than the treshold, and DCF when are bigger. Using a tresshold of 2400 disables de DCF function. I'm not sure, so if anyone has more accurate information, please, tell us

[bmcmurdo]

PCF is not implemented on Cisco APs. PCF is not generally thought to be a very effective/useful QoS technique

The radio Access Point (and radio firmware) are "PCF aware" meaning if they

detect a PCF coordinator they will "play nice" in that area and back off a

little so it can do it's best effort.

IEEE 102.11e working group is currently working on a QoS standard but that has not yet been ratified.