[Asterisk-Users] Individual call-forwarding on ISDN

[Peter Svensson]

On Wed, 25 Aug 2004, Stefan Neufeind wrote:

> Hi,
> 
> 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.

> 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.

> 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.

> 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.

Peter