ZAPATA: 

[trunkgroups]

[channels]
language = es
context = from-pstn
switchtype = national
signalling = fxs_ks
rxwink = 300
usecallerid = yes
hidecallerid = no
callwaiting = yes
usecallingpres = yes
callwaitingcallerid = yes
threewaycalling = yes
transfer = yes
canpark = yes
cancallforward = yes
callreturn = yes
echocancel = yes
echocancelwhenbridged = yes
echotraining = 800
rxgain = 1.0
txgain = 2.0
group = 0
callgroup = 1
pickupgroup = 1
immediate = no
busydetect = yes
busycount = 5
faxdetect = incoming
channel = 1