[Asterisk-Users] How to ensure that software echo cancellation ison?

[Don Murray]

Problem solved.

this zapata.conf works (i.e echo is gone, echo cancellation is detected 
on "zap show channel"):
context=from-pstn
switchtype = national
signalling = pri_cpe
echocancel=yes
echotraining=500
echocancelwhenbridged=yes
faxdetect=incoming
group = 0
channel => 1-8

this zapata.conf has echo cancellation not work:
context=from-pstn
switchtype = national
signalling = pri_cpe
group = 0
channel => 1-8
echocancel=yes
echotraining=500
echocancelwhenbridged=yes

And if I add "faxdetect=incoming" as the last line in that one, asterisk 
doesn't even start.  I get the "Ouch" message and asterisk crashes.

Lesson learned: the order in which lines appear in zapata.conf does matter.
Questions to be asked:  is that expected behavior? is it documented 
somewhere?

Thanks,
Don