[Asterisk-Users] SIP device rings once on busy before giving busy tone with dialplan

[Linus Surguy]

> > > exten => _00.,1,AbsoluteTimeout(3600)
> > > exten => _00.,2,Dial(${TRUNK1}/${EXTEN:2},45,r)
> > > exten => _00.,3,Answer
> > > exten => _00.,4,Hangup
> >
> > I can't help with presenting busy to the SIP devices, but if you have
the
> > above on any sort of PSTN gateway you are going to annoy the PSTN
users - as
> > if the number selected is busy or otherwise unavailable you will still
> > 'Answer' the PSTN call, causing the person calling to pay whatever call
> > establishment charges/minimum charges appropriate to their tariff.

> Thanks for pointing that out.
>
> Luckily Asterisk has a 'billed seconds' field in the cdr which is 0 when a
> number is unavailable or busy despite showing the call as 'answered'.
>
> A view could be taken that 0 length billed seconds calls need not be
> billed with a minimum connection charge... perhaps.
> Not ideal though.

Thats not quite the point, I was saying that if instead of this being SIP ->
Asterisk, this was PSTN -> Asterisk then you would have cost the caller real
money, as their telco, BT, AT&T or whoever would have charged the caller as
a result of your 'Answer'. Asterisk's own billing records are not relevant
to this.

Linus