Echo on IP to IP and IP to PSTN calls from 7940's

[paul.higgsboyo]

Ive got a problem on a site with echo. The customer is telling me that they are getting echo on internal (IP to IP) and external calls (external destinations to the PSTN and to a Philips system via a second gateway). Has anyone come across this before and is there a fix?

CCM is ver 3.3.3

Phoneloads are P00305000400

Gateways are both c2600-is-mz.122-15.T14.bin

[dgahm]

Are the echo cancellers enabled and set for max coverage on the gateway voice ports?

You probably will need to upgrade your IOS to get the enhanced 64ms tail capture echo cancellers. If you have enough memory IP Voice 12.4.3a has been good in 2620XMs. You need 122-15ZJ or 12.3T minimum for the enhanced cancellers.

As for IP phone to IP phone echo, you may have a bad phone, but I have only seen one instance of that in 3 years. If the canceller is bad in a phone, the party on the other end will hear the echo.

[msolak]

seems to be phoneload issue such as CSCee67437. a new phoneload should fix your issue. for echo on tail-circuit you may upgrade your ios to a version with enhanced echo canceller.

greetings

mehmet

[Randall White]

Echo from IP phone to IP phone is supposed to be impossible. I have heard of it happening in 2 instances:

1. Audio feedback from a handset or headset. Try turning down the volume and see if it gets better.

2. Having a hub on the same VLAN/subnet. This may be a VoIP urban legend, but I have heard this from more than one experienced engineer.

Randy

[paul.higgsboyo]

Thanks all for you advise. I will try your recommendations out and let you know the outcome.