zaptel.conf:

loadzone=fi
defaultzone=fi

span=1,1,3,ccs,ami
bchan=1-2
dchan=3

zapata.conf:

[channels]
musiconhold=default
language=fi
switchtype = euroisdn
signalling = bri_cpe
pridialplan=unknown
prilocaldialplan=unknown
echocancel=yes
immediate=no
overlapdial=yes
group = 1
context=from-isdn
channel => 1-2


extension.conf:
...
[from-isdn]
exten => s,1,Wait(1)
exten => s,2,SetCIDName(${CALLERID})
exten => s,3,Goto(inbound-menu,s,1)
exten => ***0,1,Wait(1)
exten => ***0,2,SetCIDName(${CALLERID})
exten => ***0,3,Goto(inbound-menu,s,1)
exten => ***1,1,Wait(1)
exten => ***1,2,SetCIDName(${CALLERID})
exten => ***1,3,Goto(inbound-menu,s,1)
...