Someone

[channels]
language=en

signalling=fxs_ks
usecallerid=yes
hidecallerid=no
callwaiting=yes
;restrictcid=no
usecallingpres=yes
callwaitingcallerid=yes
threewaycalling=yes
transfer=yes
cancallforward=no
callreturn=yes
echocancel=yes
echocancelwhenbridged=yes
echotraining=yes
;
rxgain=0.0
txgain=0.0
group=1
callgroup=1
pickupgroup=1

immediate=yes
musiconhold=default
busydetect=yes
;
callprogress=no
channel => 1-12