Getting dead air calls in cisco Jabber

[chandru_bbc]

We are using both Cisco Jabber and UCCX for our contact center. We got a few users reporting they get randomly the calls with dead air. All the customer support calls were getting routed through UCCX to the Jabber. All agents takes calls through Jabber.

I have done audio drivers update, switched the internet provider, tried with Cisco VPN and Zscaler and did with reinstallation of the Cisco Jabber profiles. Still the users reporting dead air in the calls. Checked with cisco tac and they told its a network related issue and asked us to check the network connectivity. If thats the case then all users should impacted. May I know what are the things to be checked network related?

Can any one of guide me?-

-Chandru

[Brad Magnani]

What version of Jabber are you running?  There's a known Jabber bug on 14.1.0 for the symptoms you're stating, which may be what you're hitting: 

Jabber audio drops during active calls
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwb35237

Symptom: Jabber Windows 14.1.0. Calls are established and audio will drop to one-way and periodically return, then drop out again. Issue is intermittent and a hold/resume brings the audio back two-way. The network is 100% stable with no drops, the audio processing issue is internal to Jabber after receiving audio on the wire. Network captures and local Jabber raw audio captures show it's a Jabber audio processing issue.
Conditions: Jabber Windows 14.1.0
Workaround:
Further Problem Description: Fixed. Applies to Jabber Windows/Mac/JVDI 14.1(1) and Jabber Android 14.1(2)

[lyndon_s87]

To confirm, the dead air, is the person calling into UCCX able to hear the agent on Jabber? Or is there no audio in either direction?

Something that would be worth checking is your firewall(s). You could be hitting the bug Brad suggested, but also would be worth checking your firewalls to ensure that SIP ALG isn't causing you problems (recommend to disable it for voice as if can cause reliability issues), and that you're not seeing any denies/drops for RTP in either direction.

[Elliot Dierksen]

Also Jabber supports some codecs that most ITSP's do not. I would suggest making sure you have CDR and CMR enabled on all CM nodes. Then check the CDR/CMR info when a problem call occurs. If you get notified quickly enough, you can check the CM logs or SIP traces.

[chandru_bbc]

The agent is not able to hear the external customer voice. Its a dead air. If the agent press Hold and resume, then the agent is able to hear external customer voice, without any issue. We are using Jabber 14.1.5.57909. So I am not hitting the Bug as per your Brad right? Also I took packet capture traces and not seeing any RTP traffic in that. Since its a randomly occurring not able to identify the issue.