The controller interfaces and serial interfaces are clean. I would say it's a PRI issue except that it's isolated to a certain set of people an nobody else who uses the same PRI gateway. I won't go into all the details because it's a long story but here is the 10,000 ft view:
The issue is that some inbound callers hear loud beeping in their ear when trying to speak to agents. The agents don't hear the beeping at all, only the callers. The callers only hear the beeping when they speak. If they are silent, no beeping. It only happens to a small fraction of calls and if the agents calls the person back (outbound call), there is never any beeping.
The issue only happens to a specific team of UCCX users. That would point to UCCX except that the only time the issue occurs is once the caller and agent are speaking to each other which means a direct RTP between the agent phone and the PRI gateway. UCCX is essentially out of the loop at that point. I've had UCCX TAC look at debugs of bad calls and they said there was nothing unusual. I've also had the CUCM team look at CUCM logs of the same calls and those didn't yield anything out of the ordinary as far as call control.
That would narrow it down to possibly some kind of switch issue where that team of agents is located (same campus, different VLAN) but nobody else who uses the same switch/VLAN and isn't a UCCX person on that team has the issue so that make a switch.
None of the other UCCX teams have that issue.
It's as if every possible point of failure has something suggesting that it can't be the source of the issue.
Wireshark captures of the agent's phone don't show the beeping, so I don't believe it's being sourced from the agents' phones. Working on getting captures from the gateway to see if the beeping exists before the call hits the interface on the voice gateway. If it shows up there, something is wrong on the network. But if it doesn't I need the PCM captures of a bad call to verify that the gateway isn't producing the beep and sending it out the PRI.
I wish I had a way to SPAN the PRIs themselves to something but we don't have any kind of recording software in place. That way I could see if the beep existed as it leaves the gateway but before it technically hits the telco.
