[HELP] having echo using Asterisk 1.2

hi all! i’ve tried all the echo cancellers in zconfig.h and all compiled well, zaptel and asterisk. but still when i’m calling to pstn am having a voice feedback. very undesirable. anyone who’ve configured this echo problem already, need a little help. :smile:

It could be all sorts of things… Where is the echo coming from?
It could be your phone, your cpu (of the * server), can you give some details on those?