Someone

[channels]
;;General options
callwaitingcallerid=yes
busydetect=yes
busycount=10
immediate=no
cidsignalling=dtmf
cidstart=polarity
usecallerid=yes
hidecallerid=no
callwaiting=yes
threewaycalling=yes
transfer=yes
echocancel=yes
echocancelwhenbridged=yes
rxgain=0.0
txgain=0.0
;;FXO Modules
Group=1
echocancel=yes
signalling=fxs_ks
context=from-trunk
channel=4