[Asterisk-Users] Re: Incoming echo cancel

[Andrew Kohlsmith]

On March 11, 2005 04:32 pm, Jon Bebeau wrote:
> the echo suggestions apply only to analog lines.  It's unclear how there
> can be an echo on a T1-PRI (digital) anyway.

Very simple.  Your voice is bouncing off the far-end hybrid circuit.  With the 
delays with the TDM-PCI connection you hear echo instead of the sidetone.

T1/PRI *only* means you don't *generate* echo since there is no 2-to-4-wire 
conversion.  It says nothing about receiving it.

-A.