[Asterisk-Users] Echo Cancellation Feature

[Erik Barker]

On Thu, 2004-04-22 at 13:52, Chris Maresca wrote:
> I've got a really cheap analog phone connected to a Sipura SIP adaptor,
> and have zero echo problems...
> 
> Just static problems, but it may be related.
> 
> Chris.
> 
> On Thu, 22 Apr 2004, Brent Franks wrote:
> 
> > > We have three Cisco 7940 SIP phones and 1 POTS phone connected to our
> > *
> > > server with  TDM10B fxs card.  Our * server is connected to the pstn
> > with
> > > 3
> > > X100P cards.  We have similar echo problems but only on our SIP
> > phones.
> > > We do not have any echo problems with the POTS phone.
> > > 
> > > We just purchased a Polycom IP 500 SIP phone to test but I expect
> > similar
> > > echo problems.
> > > 
> > 
> > Don't expect the IP 500's to do anything as you stated, we are using
> > these now and are having the problem I described earlier with these
> > phones.
> > 
> > - B
> > 
> > 

Hmmm, that's bizarre regarding the Sipura Adapters. We too are using
Polycom IP600s as well as Sipura Adapters (SPA2000) and find that the
Sipuras consistently have lower (ms) times than the Polycoms:

asterisk1*CLI> sip show peers

# Polycom IP600
320/320          10.100.xxx.xxx  (D)  255.255.255.255  5060     OK (66 ms)

#Sipura Adapter
306/306          10.100.xxx.xxx  (D)  255.255.255.255  5060     OK (12 ms)

I'm not sure if this has any bearing on the echo problems noted above
but I too am experiencing echo issues with SIP phones. However, I know
that IP600 phones have built-in Echo Suppression as well as Echo
Cancellation which can be enabled/disabled for the
Handset/Headset/Speakerphone in the config files. I'm actually going to
test this tonight as these options are disabled by default.

I would check the docs on the Polycom IP500 as well as they *should*
have similar features as the IP600s (I don't know if this will only
effect SIP -> SIP calls or calls placed through a PBX Zap device as
well; Documentation is sparse on descriptions for these features).

For all the configuration options listed in the ipmid.cfg including
Acoustic Echo Suppression/Cancellation, check out the 'SoundPoint IP SIP
Admin Guide' located at:

http://www.polycom.com/products_services/1,1443,pw-182-3025,00.html

Regards,

-- 
Erik Barker