[Asterisk-Users] Echo on a PRI

[steve at daviesfam.org]

On Mon, 19 Jul 2004, David Goldfein wrote:

> Hi,
> I recently set up the following in a production system (2.8 GHZ Xeon, 1 Gig
> Memory, Dell 2650).
> 
> Telco - PRI - Asterisk - T1 - PBX
> 
> I am getting an occasional noticeable echo on some of the phone lines
> (random inbound and outbound).  Everyone I ask keeps telling me that I can't
> be having echo since I am on a PRI, which is a digital circuit.  Ok, so I
> can't be having echo, but I am!  Does anyone have any ideas of what might be
> causing the echo in this situation?  

If you've got any analogue anywhere in the call patch then echo is a
possibility.  Specifically 2-wire analogue.  So if one or both of your
callers are on analogue phones.

Its not usually an issue with your sort of setup though because the Zaptel 
driver has echo cancellation (have you enabled it?) and the overall call 
delay is small.

Steve