[Asterisk-Users] Echo on SIP -- not on analog.

[timebandit001 at gmail.com]

Echo will only happen when you go from digital to analog.

Here is more info on this :
http://www.voip-info.org/wiki-Asterisk+echo+cancellation
http://www.voip-info.org/wiki-Asterisk+echo+analog+lines
http://www.voip-info.org/wiki-Asterisk+Echo+Avoidance

And remember : Google is your friend