We are having a very difficult time addressing a voice quality issue with the 7920 wireless phones. When there is no traffic on the ap to which the phone is connected other than the traffic produced as a result of the phone being connected to the ap, the phone works fine. When there is other traffic on the ap, even a very, very small amount, the phone begins cutting in and out.
If you look at the lcd on the phone during one of these cutout periods, the signal strength appears to drop to zero even though other devices in the same area as the phone continue to report a strong signal from the ap.
When a wireless sniffer is used alongside the phone to capture traffic between the phone and its associated ap, it shows that the phone stops sending ack's back to the ap. In response, the ap retransmits and then retransmits more at lower speeds until it finally gives up. Once it has given up, it begins sending RTS packets. Only after it has sent several RTS packets does the phone begin functioning again. I have been able to capture this occurence several times with a sniffer. Each time, there is very little traffic other than the phone traffic itself.
Is anyone else experiencing similar problems? Any thoughts on how to resolve? Thank you.