[asterisk-dev] Queries regarding Echo Cancellation in Zaptel-1.2.6

[Chan Kwang Mien]

Hi Leo,

Actually, my intention was to create echo so that I could verify that
the echo cancellation of zaptel-1.2.6 is working.

Best Regards,
Kwang Mien

> Chan Kwang Mien wrote:
> 
> >IP Phone A <------> Asterisk IP PBX <---> Analog Phone B
> >
> >In my tests, echos were generated by IP Phone A when I turned on the
> >speaker. As was pointed out, zaptel could not cancel these echos because
> >the echo was not received at the zaptel interface, rather on the SIP
> >interface. 
> >
> >I have a question : 
> >
> >Does it mean that the SIP interface has to cancel the echo from IP Phone
> >A ? 
> >
> >This should be a real problem since it is possible that echo could be
> >generated by IP Phones when they are in the handsfree mode (Speaker
> >mode) or echo could be generated from an old IP Phone. 
> >  
> >
> This is acoustic echo. Have you tried adjusting the phone's mic/speaker 
> level? It's a very common problem with lousy handsfree. Echo 
> cancellation has to be done at the problem phone's end.
> 
> Cheers.
> 
> Leo
> Datvoiz Singapore Pte Ltd
> 
>