Agent and customer cannot hear one another

[Ryan]

Recently we have had a spike ~5% of total daily call volume where agents cannot hear the customers voice and the customer cannot hear the agent.

Customer calls 800 number
Parked in PBX voice treatment port for GVP ivr application
Leaves GVP port to be parked on avaya vdn and routed to URS backend strategy for for skills based routing

Customer waits in queue and URS selects a target agent. The call is successfully delivered (event ringing and establised) to the agents phone, the agent and customer hear ringing, the agent answers the call but they cannot hear each other. The customer is disconnected and hears a fast busy. The issue appears to be random and increases with call volume.

We compared a good log to a bad log and they are the same...

Specs
Avaya S8700 CM 3.1
TDM phones
AES 4.1 using DLG
Genesys GVP 7.6
Genesys 7.6 framework

Any ideas?

[cavagnaro]

I'd check GVP configuration and behaviour, is it IPCS or VCS? In-Front or Behind the PBX?
Have you tracked some call with the problem reported since it started on the PBX?

[Ryan]

It is VCS, behind the switch configuration.
The GVP Port answers and IVR plays and releases the call.  So I was thinking it was not an issue with GVP. The issue where the call and customer cannot hear happens after the call is routed to the agents from an avaya VDN route point.  This happens on a few calls per day.

tserver targets an agent and sends the route request to the PBX via DLG (Avaya AES). 

The avaya techs are not seeing any issues in their logs either....but it seems like the voice path is not connecting.

Any other thoughts?

[cavagnaro]

Can't it be the case that you are calling home phones and they hangup but the public pstn doesn't send the disconnect signal and therefore you have phantom calls...?? can you determine the type of phone calls or is it indistinct?

[Ryan]

We called the customers and they said they heard ringing and then were disconnected

[cavagnaro]

Ringing? Sounds like they are overflowing somewhere, what I would do is as you have already identified some customers check TServer logs for that ConnectionID and follow the whole call among all servers related and check where they are breaking apart.