CUCM 6.1.4 - Troubleshooting CRM - Absolute Silence

[AdamMuzzatti]

Hey Everyone,

I have an issue being reported by only a few users across multiple sites.   They indicate they here dead silence during their calls both external and internally.   I have played the users the absolute silence example files and they indicate that is what they here.  Line cut out for fractions of a second and it is not consistent.  I have an example of a call and pulled the CDR/CMR record and I can see that only in the CMR portion of the call that there is "numberpacketslost" 1822 which is roughly 1% of the total packets sent.   This user reported the problem on their end only and the caller did not experience this loss.  I have done a pile of searching but can't find anything concrete on how to look at this.  Current monitoring of WAN links at each site show no saturation either.

All sites have a Cisco gateway (MGCP) and the Pub/Sub(6.1) are centralized at the DC with are connected via LANX (layer2).

Thank you for any input you may have.

[Manish Gogna]

Hi Adam,

If the dead air is experienced throughout the call it can be tracked by callmanager traces to see if there is a signaling issue. However if the issue is intermittently seen between the calls then this will most likely require the packet captures to be enabled on some of the switchports where the phones are connected and where the issue is most frequently seen. There are also options of triggered capture as explained in the following link which allow the user to dial a trigger code when the issue is actually experienced for an external call

http://www.cisco.com/c/en/us/support/docs/voice/h323/116078-technologies-technote-commandreference-00.html#anc12

Identifying the phone models , locations with highest frequency of the issue, getting a detailed network topology involving signaling and RTP flow and checking the switches/routers involved for any packet drops / interface errors will help in taking the issue towards a resolution.

Manish