Cisco 8831 audio issues - calling party unable to hear - called party fine

[Stuart Morrissey]

Info

Call Manager	11.5.1.11900-26
Phone	Cisco 8831
Firmware	10-3-1SR3-5

Hi 

I've had an issue I haven't been able to pin point for a while with 8831's and audio. The issue is, a user makes a call on the 8831 (landline/mobile/conference bridges) and periodically audio issues will arise. The calling party is unable to hear anyone on the other end, yet the called party can hear the people on the other side without any problems. It just seems to be that the 8831 fails to transmit anything from the mic.

I haven't spanned anything to get an RTP stream but looking at the admin logs on the phone, the phone is transmitting and receiving packets. Things like latency and jitter are all within normal ranges including what's reported on CDR.

As far as I can tell it's related to up-time potentially ? regardless, restarting the phone will solve the problem instantly.

Has anyone any thoughts on what direction to look ?

Thanks in advance.

[hitzeg · Accepted solution]

There was a full duplex/half duplex audio issue the the 8831s. We had it also. Firmware upgrade fixes it. Bug report is: https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvh12266/?rfs=iqvred

[Stuart Morrissey]

Thanks Hitzeg,

Although the symptoms weren't an exact match. After upgrading the firmware we haven't had a repeat of the issue so that solves that one.

Regards
Stuart.