Having a Problem with Double Talk

[LLangston]

Ok, I have been battling this for a while now and I am ready to rip my hair out. We are using the Audio Codes MP-114 FXO gateway ver. 5.0, the Polycom Sound Point 501 phones with SIP 2.2 and have just upgraded to the 3CX ver. 5 Enterprise Edition. Before upgrading we were having trouble with Double Talk, that is to say that when in conversation if the other party starts talking while I am still talking I don't hear them. It is as though we are on only half duplex instead of full. Now this only happens on external calls, internal calls work fine. We thought it was getting a little better and then we upgraded and now it seems worse. This is really annoying and poses a lot of problems in a business setting. Because it only happens during external calls I am sure that it something in the configuration of the gateway but I am at my wits end in trying to find where to correct it :? . Has anyone else had this problem and if so how did you correct it. For the record in 3CX the extensions are set to PBX delivers audio but not the gateway. I would appreciate any input on this.

 

[SY]

Hi L. Langston,

PBX doesn't modify audio streams. It just deliver audio content provided by endpoint.

Described problem seems related to "echo cancellation" algorithm implemented by endpoint (phone).

Regards

 

[LLangston]

Perhaps I didn't make the problem clear enough or perhaps I am not understanding you :? . When we call internally, ext. to ext. both parties can talk at the same time and still hear each other, but if the call involves an outside party(i.e. John Doe calls our office from Timbukto or we call a supplier) they can hear me even if we are both talking at the same time but I can not hear them if they start talking while I am talking. I don't believe this has anything to do with how we have 3CX configured but that it is something in how the gateway is configured and I am hoping that maybe someone else out there that is using Audio Codes has had the same problem and found a solution for it.

As for the phones I have not been able to find anywhere in their configuration pages to adjust the echo cancellation.