asterisk users - Sep 2003 - How to prevent echo ?

Hi all,

i have following scenario:

	 ____________* 1____
______________* 2______
	|                   |                                                   |
|
	analog/Zap --> IAX2 ----> DSL ---> INTERNET ---> Backbone/100Mbit
---->
IAX2 ---> Zap/pri(E400P) ----> PSTN

And, if i make a call from *1 over *2 to PSTN, i can hear an echo in my
analog phone,
even though "echocancel" and echocancelwhenbridged" is on
"yes" on both
sides.

Can somebody explain me what i'am doing wrong ?


Thanks,

Thomas.

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