Mine

[trunkgroups]

[channels]
language=en

busydetect=yes
busycount=5
callwaiting=no
;callwaitingcallerid=yes
threewaycalling=no
transfer=no
cancallforward=yes
callreturn=yes
usecallerid=no
hidecallerid=no
echocancel=yes
echocancelwhenbridged=yes
echotraining=yes
immediate=no
rxgain=7.0
txgain=7.0

group=1

signalling=fxs_ks
context=inc_3800
channel => 4

channel => 3

channel => 2

channel => 1