Forum

I've now gotten feedback on this issue. The changes were done by the customer so I can only report what they have observed.
Intial tests with removing the lower rates and turning on SSID in beacons did not give the desired effect. There were also tests done with upgrading to new available firmware on both the APs and the handsets. That had a negative efect on the voice quality and was rolled back.
The handset was operating on 802.11a which used 18 different channels. Limiting the channels to 8 solved the problem. So apparently the Cisco handset cannot effectively roam across 18 channels - even if the documentation claims so.