[Asterisk-Dev] Sending ISDN q.931 messages to Zap span?

[John Todd]

At 10:20 PM +0100 on 11/20/04, Peter Svensson wrote:
>On Sat, 20 Nov 2004, John Todd wrote:
>
>>  PS: I _swear_ I saw a patch or something in the bugtracker recently
>>  about the ability to send messages back to Zap spans without
>>  answering them, with particular ISDN response codes.  However, I
>>  can't find documentation or notes on this.  I'm looking for something
>>  like "Hangup(28)" where "28" is from
>>  ./asterisk/include/asterisk/causes.h.  This could apply to pretty
>>  much any channel type, since we've mapped Q.931 codes in that file.
>>  I know I had a method in mind for hanging up calls before they were
>>  even answered, but doing it with specific rejection codes... but I'm
>>  darned if I can find those notes.
>
>Would that be the PRI_CAUSE variable?
>
>http://www.voip-info.org/tiki-index.php?page=Asterisk%20variable%20PRI_CAUSE
>
>Peter

Yes, that's it.  I originally thought it was a variable passed to the 
channel, but I didn't see it in the README.variables file, so I just 
assumed that my memory was playing tricks on me.  Sorry to clutter 
the list with that question; I should have dug through the Wiki more 
diligently.

Though the more I think about it, the more I like "Hangup()" 
including the value.  This way it becomes more generic across channel 
types, so long as we're using Q.931 as the signalling template. 
(Note: this may not work, since SIP hangup codes don't equal Q.931 
codes in all circumstances, and there is even an RFC on this topic: 
http://www.ietf.org/rfc/rfc3398.txt)  Perhaps sticking with 
channel-specific variables is a reasonable idea...

PS: Getting "Hangup" to send user-specifiable SIP 302 redirect 
messages would be pretty cool, too, and would simplify certain 
problems with scaling SIP platforms where a signalling server is 
abstracted from gateways completely.

JT