[asterisk-users] Sending back a ring signal, SIP 180 i think.

[Mark Ackroyd]

Guys,

I am trying to set up a SIP to PSTN gateway, and I have a client sending in
SIP traffic, once on the asterisk machine, I do something like this.

[outbound-sip]
exten => _XXX.,1,NoOP(${CDR(accountcode)})
exten => _XXX.,2,Dial(ZAP/g1/${CDR(accountcode)}${EXTEN})

This works, except that the client wants to bill only when the call is
finally connected on the zap line, and to his SIP equipment he needs to see
a 180 or 183 SIP signal back until the call on the zap line is connected. 

I am a bit stuck at this point :-(.   Anyone know how I can do this?

Thanks,
Mark