asterisk users - Apr 2004 - Cisco 7940G/7960G SIP phones local echo on * box.

Our new * server with Cisco SIP phones is now working pretty well.  But we 
still have one problem that has not been resolved.

The Cisco SIP phones have a consistent echo.  It sounds like about a 500ms 
delay.  This echo is not heard from the POTS side.  It is heard when 
calling another SIP extension in our office.  We are running 6.3 firmware 
on the phones.

Any suggestions would be appreciated.

Many thanks,

Tom

On Sun, 2004-04-11 at 13:01, Tom wrote:
> Our new * server with Cisco SIP phones is now working pretty well.  But we 
> still have one problem that has not been resolved.
> 
> The Cisco SIP phones have a consistent echo.  It sounds like about a 500ms 
> delay.  This echo is not heard from the POTS side.  It is heard when 
> calling another SIP extension in our office.  We are running 6.3 firmware 
> on the phones.
> 
> Any suggestions would be appreciated.
> 
> Many thanks,
> 
> Tom
> 
Does the echo have any pings associated with it?  I'm running 7960
(firmware 6.3) and it works great with the exception of echo, which has
a noise similar to a sonar ping associated with it.  It does not occur
all the time, and is independent of whether I make the call using IAX2
(through Voice Pulse Connect) or ZAP (PSTN).  I do have echo
cancellation on and have not adjusted rx/tx gain. I tried adjusting it
once with the effect, so reverted it back to what the default was.  I've
tried just about every tweak in the sip.conf, SIPDefault.cnf and
SIP<mac>.cnf files I've been able to come across.  I am running a
single
X100P and a TDM400P (with three modules installed).  I will be upgrading
to a T100P and Adtran TA750 this week.

Mitch Sharp