voip:~# cat /etc/asterisk/zapata.conf 
[channels]
language=de
nationalprefix=00
internationalprefix=000
context=versatel
switchtype=euroisdn
signalling=pri_cpe
callerid=asreceived
hidecallerid=no
callwaiting=yes
usecallingpres=yes
callwaitingcallerid=yes
threewaycalling=yes
transfer=yes
canpark=yes
cancallforward=yes
callreturn=yes
;pridialplan=unknown ;; REQUIRED TO FIX Cause 28 ERROR
pridialplan=unknown
prilocaldialplan=unknown


group=1
channel => 1-15,17-31