[Asterisk-Users] Individual call-forwarding on ISDN

[Stefan Neufeind]

On Wed, 25 Aug 2004 at 13:12:51, Peter Svensson wrote:

> On Wed, 25 Aug 2004, Stefan Neufeind wrote:
> 
> > I'm looking forward to install an asterisk-server to perform ISDN-to-SIP-
> > bridging. But for the times when I'm not available via SIP I also need
> > call-forwarding-features. Afaik it is possible to directly forward a call
> > on ISDN instead of opening a second ISDN-channel additional to the
> > incoming-ISDN-channel and forward the call "by hand", right?
> > 
> > What if I need features like "ring for 3 seconds, if not reachable divert
> > call to a different number" or something. Is that possible with Asterisk?
> > Is it possible without using an additional channel?
> 
> With the channel drivers from http://www.junghanns.net/asterisk/ you can 
> use isdn call deflection. I am unsure which hardware is supported by this 
> channel.

Will have a look/try. Thank you!

> > Can I detect if the phone I'm trying to redirect to is maybe unavailable
> > and itself wants to redirect me (unavailable mobile phone, which would
> > redirect the call again - e.g. to the voice-mail)?
> 
> Probably. I think all the isdn channels give you the isdn cause code in a 
> variable after a failed dial or a hangup.

Do I really have a failed dial? Asterisk would dial my mobile - and that would 
recirect to it's voicemail-box. But what I intend to do is detect the 
additional redirect and cancel the try to reach my mobile phone (and instead 
divert to another phone from Asterisk directly). Is that possible? I'm quite 
sure that I can detect a failed dial - but this is about detecting (and 
avoiding) another redirect.

> > Can I give the caller a message like "please stay tuned" while Asterisk 
> > searches for me?
> 
> Well, kindof. You can play a message before you attempt to dial the 
> outgoing leg. You can play the message without answering the line if you 
> are on isdn (the reverce audio path is opened before the call is answered. 
> I do not think the Dial app allows playing anything but ringtones while 
> you wait.

Really? Didn't know that - cool. So the caller is not yet charged but you can 
play out something for him while waiting? How can I set up something like that?
When I play something to the caller, I can dial in background (and not have the 
caller hear ring-tones), can't I?

> > Can I try multiple destination-phonenumbers at once? E.g. ring three phones
> > - if I pickup one, divert incoming call to that destination.
> 
> Do you want to dial first and, if that person answers, push the loop to 
> your pstn provider thus freeing two b channels? That may be more tricky. 
> I am not sure if that is possible or not. It may even depend on your 
> operator.

Kind of, yes. Otherwise I'd need e.g. one channel for incoming caller, three 
for outgoing (trying) calls. And if the outgoing call is active I'd 
interconnect the caller with the outgoing call and free the other two 
additional, not needed lines, right? That would mean I need four channels and 
would occupy two channels during the call though I don't need that after having 
connected the two call-participants.


Regards,
 Stefan