Something

[root@voip /usr/local/etc/asterisk]# less zapata.conf
[channels]
language=en
context=default
signalling=fxs_ks

usecallerind=yes
hidecallerid=no
callwaiting=yes
restrictcid=no
usercallingpres=yes
threewaycalling=yes
transfer=yes
cancallforward=yes
callreturn=yes

rxgain=0.0
txgain=0.0

group=1

immediate=no
busydetect=yes
musiconhold=default

channel => 1