UCCX long distance call one way audio

[HappyBob]

Our state recently expanded upon area codes, and we are now required to outbound dial using 10 digits. Since this change, calls coming into UCCX that would have previously been considered long distance are now experiencing one way audio. Local calls are working without issue. We are currently in between voice engineers, so the issue has been handed to our networking group. We suspect the area code change and a dial-peer or voice translation are the culprit. It does not appear to be an issue with routing or QoS. Both CUCM and UCCX are on our campus network. 

[Roger Kallberg]

You’d need to look at the path the two call cases takes and compare them to see if you can identify the cause of the issue. One way audio is almost always caused by issues with traffic not reaching the two parties in the call. Ie network or firewall related.

[Jonathan Schulenberg]

I’d start with a PCAP of the first IP hop within your control. Assuming this is a modern SIP trunk with an Ethernet handoff from the provider, capture that PE/CE router handoff interface. Do you see audio in both directions for that specific call (be careful to match SDP offer/answer to UDP ports of the RTP streams)? If audio isn’t arriving from the provide it’s a carrier trouble ticket.

[HappyBob]

I can certainly get a PCAP, but the issue is only happening on calls to the UCCX trigger. 

[bill.king1]

So a long distance call inbound to 2125551234 that goes to UCCX has one way audio, but a long distance call inbound to 2127771234 to a phone on UCM doesn't have the issue?
Does the UCCX one way audio issue happen only when agent and caller are connected, or is it one way even while hearing UCCX prompts?
Lastly, what about outbound, same scenario, if agent calls that customer long distance from UCM, does it happen?
This should at least let you isolate the issue.

[Mohamed H. Abdelmotaleb]

Mostly you need to check the media path between the UCCX and the internal IP address of the  voice gateway or CUBE, what you can do run PCAP on the CUBE and you can run PCAP on UCCX like CUCM login to CLI run command "utils network capture" then collect the PCAP file from the RTMT tool, then you can verify if the RTP packets reach to UCCX or not.