Phone Call Time Delay Issues

[renegade34g]

We recently moved from Windstream to ATT IP Flex and are experiencing time delays in the phone calls. By this I mean when I'm talking to a person over the phone, it might take 1-4 seconds for the other person to hear my voice. It doesn't happen always and it doesn't happen immediately in the phone call. Users stated that it seems the longer you are on the call, the higher chance you will experience phone delay. I have updated my firmware on my PBX and phone units. Is there anything in the Adtran that might shed light on this? Currently the ATT phone line is set as the primary timing source and the Atlas as the secondary.

[Anonymous]

I can't think of anything in the ATLAS to cause a delay in the audio.

I'm afraid there is nothing in the ATLAS to monitor audio through it. If you have an older T1/PRI module, it may have "monitor jacks" where it may be possible to listen to the audio transmitted and received on T1. Other than that, all you can do in the ATLAS is look to see if there are any errors on the physical interfaces.

The EVENT LOG can monitor the calls through the ATLAS, but do not monitor the actual audio through it.

I don't know what the connection to your equipment is, or what the connection to AT&T is, but you may be able to place a call that hits the ATLAS and is routed back to another device and see if you have any audio delays when the call only goes through the ATLAS (without going out to AT&T). You may even be able to have the call go to AT&T and immediately be routed back to the ATLAS and see if there is any delay there.

Hope this helps,

Patrick

[jayh · Accepted solution]

The problem isn't in the Atlas. It's with AT&T's IP service. This is caused by "buffer bloat" and an oversubscribed link with no or misconfigured QoS. Voice packets are being buffered because a link in the AT&T IP network doesn't have sufficient capacity to handle both the voice traffic and other traffic. Complain to AT&T about excess latency on voice calls due to buffer bloat. You'll probably need to escalate a few levels above the first-line techs, good luck.

[renegade34g]

Thank you very much jayh. I sent the information you suggested and escalated it with ATT. After 4 tickets they said they were going to do "router software upgrade". I haven't heard any users complain but they also don't tell me everything all the time. Again, thanks so much for the vital information! I'm not a phone guru so I was at the mercy of Tier 1 ATT support...