Echo in voip-only sytem

Asterisk Asterisk Support
1

We have a reliable 10Mbps fiber connection and are using bandwidth.com sip trunking. We have two groups of users:

Group 1 uses polycom hardphones. They never report echo or other phone quality problems.

Group 2 is on an auto-dialer. They use Plantronics H261N USB headsets and spend their days in MeetMe conferences (it’s how the dialer patches calls through to them). Sometimes they report echo that is very faint and not bothersome, and other times it’s noticeable and annoying. The one guy I spoke to said it would last for the duration of the call and be gone on the next one. It might happen a couple of times per day to any one particular user. The echo they hear is always their own voice and I can’t hear the echo in recordings I am making of the calls.

It is possible that people on headsets are just on the phone more often, but we have a could of polycom users that are basically on the phones all day, and they report no problems.

Anyway, I can’t figure out a solution to the problem. It seems like the endpoint echo-cancellation of the softphones isn’t great. I’m not sure what the solution could be. I really don’t think the microphones are picking up sound from the headsets. We’ve also just begun replacing older headsets with these high-end plantronics ones, but the problem occurs in both types. Does anyone have any ideas? Thanks.

2

you could try switching to app_conference to see if the problem goes away. I replaced MeetMe in our platform because of horrible echo problems. I got the feeling that if you were using the ztdummy/dahdidummy as the timing device it wasn’t super reliable.

3

We’re actually using a Sangoma USB VoiceTime for the timing signal, and not the default ztdummy.

I’ve always wondered about MeetMe conferences and their effect on call quality. It’s hard to test because you can’t predict when it will be bad. I know that once in a while everyone will get kicked from the conference at the same time. I can’t just switch to app_Conference() thuogh because the auto-dialer is programmed for MeetMe.

I just installed a program called Solicall on the station of one of the users that complains the most about echo. It’s supposed to do noise cancellation and echo cancellation. Apparently you can install a different version of it directly on the pbx as well. This is the free version though and they claim the one you pay for has better algorithms. We’ll see see how it performs tomorrow I guess…

4

MeetMe and Conference are actually quite compatible. Generally you need little more than a replacement in your dialplan.

Are you using Manager Events to make decisions?

5

No idea. I didn’t code the dialer (it’s vicidial if that means anything to you). I’d have to look at the agi scripts. Why out of curiosity?

6

I was wondering about the Manager Events because that is one thing that is slightly different between MeetMe and Conference.

You should be able to basically do a find/replace in the Vicidial code to make the switch to Conference.