[Asterisk-Users] SIP Transfers (Possibly reinvite)

[Chris Shaw]

----- Original Message -----
From: "Christopher Jacob" <chris at jacob-solutions.com>
To: <asterisk-users at lists.digium.com>
Sent: Tuesday, August 10, 2004 3:57 PM
Subject: [Asterisk-Users] SIP Transfers (Possibly reinvite)


> Hey Folks,
>
> Is it possible to transfer an incoming call back out without a "trombone"
> effect.
>
> For instance;
>
> Caller dials my broadvoice # --> Asterisk Answers and plays a menu --> the
> caller selects an option --> asterisk transfers the call to my cell phone
> via broadvoice and removes itself from the equation so I end up with...
>
> Caller --> Broadvoice --> Cell Phone
>
> Vs.
>
> Caller --> Broadvoice --> Asterisk --> Cell Phone
>
>
> Any ideas on how this could work? I'm thinking it's something to do with
> reinvite.
>
> Thanks
>
> Chris

Unless you also have a PSTN connection (you didn't mention one) you will
actually be doing something more like this:

PSTN -> BroadVoice -> Asterisk -> BroadVoice -> Cellphone

Not sure if re-invite really applies here... Basically what reinvite does is
it uses the SDP information passed from a sip proxy to connect an IP phone
that is connected to * directly to the calling party (in this case, the
BroadWorks server), removing * from the equation... What you want to do is
invite the broadvoice server back on itself which would create a loop and I
don't think that will work...

If you have enough bandwidth, the diagram shown above would work like a
3-way call with * as the initiator and your cellphone as the 2nd leg... If
you don't have the bandwidth, the other option would be to get an X100P card
and have * dial your cellphone through POTS when someone dials that
extension... This would remove you from a pure VoIP setup which is probably
not what you want...

    -Chris