/etc/zaptel.conf

span=1,1,0,esf,b8zs
bchan=1-23
dchan=24
loadzone = us
defaultzone=us

/etc/asterisk/zapata.conf

[channels]
switchtype=ni1
signalling=pri_cpe
;pridialplan=local
pridialplan=unknown
;prilocaldialplan=local
prilocaldialplan=unknown
context=incoming
language=en

;echocancel=64
echocancel=yes
echotraining=no
;echocancelwhenbridged=yes
rxgain=0
txgain=0

group=1
channel => 1-23