[Asterisk-Users] Echo after upgrade * 1.05 -> 1.06

[Kris Boutilier]

> -----Original Message-----
> From: Remco Barende [mailto:asterisk at barendse.to]
> Sent: Sunday, March 20, 2005 9:13 AM
> To: Asterisk Users Mailing List - Non-Commercial Discussion
> Subject: RE: [Asterisk-Users] Echo after upgrade * 1.05 -> 1.06
> 
> >> The echo is quite slow, I would estimate about half a second
> >> or even more!
> >
> > Wow, that's enormous - However your ears can easily deceive you on this. The
> > only way to know for sure is to record and analyse. Half a second would
> > imply its accoustic coming from the other end. Is it on all calls or only on
> > calls with certain people ? Is it when they call you, you call them or both
> > ?
> 
> It could be deceiving indeed but the echo is slower than 
> usually. I did downgrade to asterisk 1.0.5 and the echo is less but still 
> there. I did not downgrade zaptel as I think it's not related. Or could it 
> be a zaptel timing problem?

Increases and decreases in the time taken for the audio to traverse the entire audio path will manifest themselves as changes in percevability of echo. For example, changing from an entirely uLaw path to a Speex-compressed path will introduce additional non-trivial processing delays (see 'show translation' in console). It's possible to have an echo on a path that is initially perceived as sidetone suddenly become a problem echo because of the introduction of additional delays (ie. longer than the 20ms perceivability threshold).

Perhaps there compiler options have changed or the code has become less efficient somewhere resulting in a greater delay. If you haven't changed your configuration anywhere then try comparing the output of 'show translation' on both versions to verify the codecs are performing similarly.

Kris Boutilier
Information Systems Coordinator
Sunshine Coast Regional District