Echo on Local calls with PRI

[euser4life]

Echo on Local calls with PRI (RESOLVED)

Hi Guys I've got an install that is having problems with local calls. The person in the office will call a local number and they can hear themselves echo back. Next they can call a long distance number and the call is crystal clear.

Before we were having issues with the POTS lines so we switched to a PRI but now with local calls sounding this way we don't seem to be much better off.

We are using a Rhino PCI express (r1t1-ec) with hardware echo cancellation. I've been on the phone with Rhino, but they did not have much to offer. Would I be better off dropping rhino and getting a sangoma pri card? We used Rhino on our other installs but this is a first as far as PRI issues go.

Everything looks good from dahdi_test, no interrupt issues, etc... I've tried reducing my tx gain down but it doesn't seem to be taking. Looking for anyone that has experienced these symptoms with local calls and a PRI

I've also reached out to the CLEC but get the typical "Everything looks good on our side"

Using Asterisk 1.4.39.2 and Dahdi 2.4.0

 

[jmullinix]

Is it always the local number and is it always the same few local numbers with other numbers working well. If toll calls are working great and local calls are having the problem, I don't think the problem is in the PBX.

One of the toughest echo's to get rid of is acoustic echo originating from the remote phone. The sidetone on the remote phone is loud enough that the mic element is picking it up. This was common with old Grandstream phones. See if you can duplicate the problem and if you can, ask the person on the other end to turn down their earpiece volume a notch or two. That might just fix it.

 

[euser4life]

We've had several PRI installs and never experienced this type of behavior. We are using Aastra phones with tx gain and sidetone reduced. We have also tried a few Yealink sets for testing and still have the same issues.

The strange part is that the PRI is through Centurylink (CLEC for our area) and calls that go to other local Centurylink customers sound perfect (as well as long distance). The calls that always have echo are the ones that go out to local numbers that belong to the ILEC (AT&T).

I was fortunate enough to get the Centurylink CO techs interested and they have been working with me this afternoon. They are still researching, but at least they are not jumping on the "It's not our problem" train.

 

[Linetux]

I have a PBX w/a Sangoma card on a Century Link PRI in Florida... not that it's apples-to-apples, but I'd be willing to help you out with some test calls or something if you'd like.

 

[valer77]

Are there any results from yesterday's research ?

 

[euser4life]

We had a tech come out and connected up directly to the smart jack with his test set and made some test calls. Even on his set you could tell a noticeable difference (not quite as bad but the tech noticed it as well). He then went down to the CO and moved us over to some different equipment and tried making some calls again. Same as before: Local calls to Centurylink customer's and long distance calls sound fantastic, but calls to local AT&T customers sound horrible (everything I say being echo'd back in my ear).

The AT&T techs had left for the evening so they could not work with them, but promised they would get back with me today. (Fingers crossed)

 

[euser4life]

Resolved

So just for closure....... After troubleshooting for a week the problem ended up being the echo cancellation on the Rhino Card itself

I changed it out with another card and instantly the echo was gone.......

Here is what tipped me off.... In examining the dmesg output relevant to the card I saw:

R1T1: 1 DSP 1: G168 DSP Port Config failed res = 3 error = -138654224


After I submitted this info to James at Rhino he went back and checked and found that the last batch of cards they made all had this defect. So if you recently purchased a R1T1-ec you may want to check the dmesg output.

I hope this helps someone (as it nearly drove me nuts).