/etc/zaptel.conf
span=2,0,2,d4,ami
fxoks=1-4
e&m=5-28
loadzone = us
defaultzone=us

/etc/asterisk/zapata.conf
signalling=em
switchtype=national
echocancel=yes
echocancelwhenbridged=yes
echotraining=400
callerid=asreceived
group=2
context=from-trunk
channel => 5-28
signalling=fxo_ks
echocancel=yes
echocancelwhenbridged=yes
echotraining=400
callerid=asreceived
group=1
context=from-internal
channel => 1-4