One-Way Audio Call Issues

[Meyer2338]

Hello there,

I apologize if I miss anything specific, as I am only reaching out in hopes of discovering the cause of an issue that is affecting myself and thousands of others across different locations, and there hasn't been any solution yet.

I work at a holding company that owns 11 different banks with a total of over 120 different branch locations. We work at the parent company that everything in a way flows from, and all talk/transfer/and what not occurs over a cisco unity call system. We have different transfers set up for each bank (ex: bank 9 would be 109-****), and when a banker contacts us through the automated help line (101-****, option 2), there are so many times when I start talking at the beginning and the banker says a word or two then the call is silent and I cannot hear the banker at all for 5-10 seconds, but the banker can hear me if I were to chime in during that silence (saying we're having that phone issue hold up until I can hear you). Then the rest of the call usually flows smoothly, except sometimes it may happen again a time or two.

When a customer calls a branch phone # and the bankers are busy, that call then gets rerouted to myself and others to help with at the parent company. Some go through just fine for different banks (especially if they call our direct line in my department), and others the issue happens sporadically throughout the call to where we can hear the customer just fine, yet the customer cannot hear us for 5-10 seconds and says the phone is super choppy and laggy and we're "breaking up." The banker issue is whatever, but this is just what annoys the heck out of me and is why I'm trying to find a solution myself, as this is a major issue that doesn't seem to be getting the care it should. When we call the customer back on our phone then the call/connection is perfectly fine and the customer can hear us perfectly. 

So I know that's a lot right there, but I am desperate for a solution. I have a feeling there is something wrong in between bankers dialing the number for the automated set of options that can lead to different departments, and when they press 2 for us it causes that initial delay once they speak. As for the customers, I feel it's more when they call an individual branch# and they don't answer and then it reroutes to us as for when it occurs in that scenario. 

Would any of you please have some advice or recommendations as to what could be causing this?

I would truly appreciate any and all help.

[Jaime Valencia]

Unless you use MTP/TRP, the backend servers only handle the signaling for the call, audio never goes through them.

RTP flows directly between endpoints, and most one way audio or no audio issues are network issues, routing, FW, ACL, etc.

You'd need to make sure that EVERY phone in your network can send the RTP directly to any other phone in your network. When you transfer a call, you're changing the RTP connection between endpoints, so your network needs to be able to send the packets the proper way after a transfer. 

Audio issues (choppy,robotic) sometimes can be related to the phone FW, but you'd need to take a sniffer to confirm the audio actually comes alright, but it can also be a bottle neck in your network causing the packets to not arrive at the proper time.

You'd need to analyze some sniffer traces, and analyze your network to find out where the problem is. You might have asymmetric routing, some routing might be lacking in your network, or an ACL/FW might be blocking RTP.