asterisk users - Apr 2009 - Sequential Ring Groups?

Hi fellow Asterisk users!

I've got a PRI being used with a bunch of iaxmodems/Hylafax. I
currently have each individual channel of the PRI in its own context
that rings a specific iaxmodem. However, when a fax is complete on
that modem and another call comes into it, the modem is still in a
state of 'settling down' from the last call and I'd like to have it
ring a different channel if possible. So essentially, instead of each
PRI channel with a different context, I'd like to see one context that
simply handles calls to any available IAX peer (iaxmodem). How is this
done? I can certainly use the Dial() app to ring a bunch of extensions
at once but I'd like to have it try the first modem, if busy, then the
second, etc until one is available and answers.

I'm not using FreePBX for this fax server but am using it on my voice
PBX. Looking at the code for the 'firstavailable' ring group strategy
is of no help since its clouded within a whole mess of other functions
within [macro-dial]. Any ideas or pointers? THANKS!

--Marshall

Marshall Henderson wrote:
> Hi fellow Asterisk users!
> 
> I've got a PRI being used with a bunch of iaxmodems/Hylafax. I
> currently have each individual channel of the PRI in its own context
> that rings a specific iaxmodem. However, when a fax is complete on
> that modem and another call comes into it, the modem is still in a
> state of 'settling down' from the last call and I'd like to
have it
> ring a different channel if possible. So essentially, instead of each
> PRI channel with a different context, I'd like to see one context that
> simply handles calls to any available IAX peer (iaxmodem). How is this
> done? I can certainly use the Dial() app to ring a bunch of extensions
> at once but I'd like to have it try the first modem, if busy, then the
> second, etc until one is available and answers.
> 
> I'm not using FreePBX for this fax server but am using it on my voice
> PBX. Looking at the code for the 'firstavailable' ring group
strategy
> is of no help since its clouded within a whole mess of other functions
> within [macro-dial]. Any ideas or pointers? THANKS!
> 
This is how I'm doing it (AEL notation):

context inbound-pri {
   FAXNBRHERE => {
     Dial(IAX2/iaxmodem00/${EXTEN});
     Dial(IAX2/iaxmodem01/${EXTEN});
     Dial(IAX2/iaxmodem02/${EXTEN});
     Dial(IAX2/iaxmodem03/${EXTEN});
     // Et cetera ...
     Busy();
   }
}

Call comes in, starts at the top and if that modem is busy asterisk 
moves on to the next line. If all the modems are busy then a busy 
indication is sent back to the caller.

-Dave

Marshall Henderson wrote:
> However, when a fax is complete on
> that modem and another call comes into it, the modem is still in a
> state of 'settling down' from the last call and I'd like to
have it
> ring a different channel if possible.
iaxmodem stays busy for 5 seconds after going on-hook and for 5 seconds 
after receiving a reset command (ATZ).  In my experience this is plenty 
of time to cover the "settling down" such that you won't need to
even
consider it.  Just do the normal "hunt group" dialplan approach as 
suggested here:

http://iaxmodem.sourceforge.net/faq.php

Thanks,

Lee.