[asterisk-dev] Adding Octastic Soft-Echo to external SIP adapters

[Vazir]

On 7 May 2007 20:57, Andrew Kohlsmith wrote:
> Echo is not generated by VOIP.  VOIP is known as a 4-wire
> system.  Transmit and receive paths are along totally
> separate (albeit logical) paths.

True, But in my case 90% calls are PSTN <-> VOIP <-> PSTN so 
it could be echo coming from other side AFTER VOIP-PSTN 
conversion... and some cases shows that it's so - that if I 
switch off echo cancelling I can hear my echo in ~1 second 
time difference.