zaptel.conf
===========
fxsks=3-4
loadzone=uk
defaultzone=uk

zapata.conf
===========
[channels]
context=toshiba-in
usecallerid=yes
cidsignalling=v23
cidstart=polarity
hidecallerid=no
echocancel=yes
echocancelwhenbridged=yes

signalling=fxs_ks
callerid=asreceived
group=1
channel => 3


signalling=fxs_ks
callerid=asreceived
group=2
channel => 4