Cisco 7925 wireless IP phone one way audio

[zzbronski]

We have several of these 7925 wireless IP phones and when we converted our lines to SIP the issue started. Whenever a call is answered on one of these wireless phones it is one way audio. Same call answered on a desk phone is fine.

[shh5455]

One way audio is almost always caused by a mismatch in power levels between the AP and the phone.  Can you verify the phone is close to the AP it is associated to?

[zzbronski]

Yes we are testing this with the phone and the AP within 3 feet of each other. Call from a external number has one way audio but an internal call works fine.

[shh5455]

Can you test with another phone and AP?  Sounds like it would have to do with the SIP messaging since you said that's what changed.  We would probably need to look at the SIP messaging between the devices.  Which way is the audio being lost?

[zzbronski]

We have tried 3 different wireless phones on two different AP's with different SSID's and same issue occurrs on all of them. The called party can hear the caller but not the other way. So one way audio to the called party, nothing in the direction of the calling party which is external.

Could this be DTMF-relay mismatch on the SIP Cube dial peer? We had a similar issue with this and adding sip-kpml to the dtmf-relay rtp-nte fixed the issue. But we only applied it to the dial peers pointing to Call Manager.

[Leo Laohoo]

We have several of these 7925 wireless IP phones and when we converted our lines to SIP the issue started. 

What system is this?  792X phones do NOT support SIP.