[Asterisk-Users] Haven't got a clue ...

[Asterisk]

On how to even search for this "feature" as I have no idea on what it can
be.

I've got a meridian linked to * (by EuroISDN) which is linked to a ISDN30.

I can make calls from the meridian, and receive calls into the meridian.
Great stuff.

However, if someone dials an invalid number, then instead of hearing a
"three tone", the line just drops and goes dead. The console does not really
give any clues (verbose as verbose can be). I've verified that the dialled
number is invalid by calling it with a mobile, and I get the "number is
incorrect".

How do I pass that information back to the callee ?

What I suspect is happening is that the caller uses zap/g4 (the link to the
meridian), * tries to dial on zap/g3 (the link from * to the isdn30), finds
that the number is invalid, drops the channel on zap/g3. Zap/g4 therefore
cannot be connected, and it is dropped as well.

Help!

My (snipped) dialplan is 

[dial-isdn-a]
exten => _0.,1,AgentMonitorOutgoing(n)
exten => _0.,2,CallingPres(0)
exten => _0.,3,SetCIDName(${CALLERIDNAME})
exten => _0.,4,SetCIDNum(555123) ; number changed to protect the guilty!
exten => _0.,5,Dial(Zap/g3/${EXTEN},40)
exten => _0.,6,Hangup()
exten => _118.,1,Dial(Zap/g3/${EXTEN},40)
exten => _118.,2,Hangup()

Julian