usecallerid=no
callwaiting=no
usecallingpres=no
callwaitingcallerid=no
threewaycalling=yes
transfer=yes
canpark=no
cancallforward=no
callreturn=no
echocancel=no
echocancelwhenbridged=no
relaxdtmf=yes
busydetect=yes
busycount=6
callprogress=yes
ringtimeout=4400
signaling=fxs_ks
context=outgoing
group=1
channel => 1-12
signalling=fxo_ks
context=incoming
group=2
channel => 13-16