[asterisk-dev] design question: handling incoming ETSI partial rerouting request

[Tony Mountifield]

In article <48564347.509 at pernau.at>,
Klaus Darilion <klaus.mailinglists at pernau.at> wrote:
> Hi!
> 
> I wonder how I could implement the handling of incoming ETSI Partial 
> Rerouting in Asterisk. What should happen in chan_zap/app_dial if this 
> is received?
> 
> Should it be handled automatically or manually? I would prefer manually 
> - so that in the dialplan I can decide to handle the redirection or not. 
> E.g. by setting a certain DIALSTATUS and having the redirected number in 
>   another variable:
> 
> Implementation:
>   - chan_zap receives incoming rerouting request (on an outgoing channel)
>   - chan_zap sends a CONTROL frame which indicates redirection
>   - app_dial receives the redirection CONTROL frame on
>     the outgoing channel and sets DIALSTATUS to REDIRECTED and also sets
>     variable which contains the number of the new target, e.g. rdnis (is
>     this the correct one?)
>   - then in the dialplan I can decide how to handle this, e.g. forward
>     upstream using zapCD (bristuff) or make a new call using Dial()
> 
> exten => _0X.,1,Dial(Zap/12345);
> exten => _0X.,2,GotoIf($["${DIALSTATUS}" = "REDIRECTED"]?103:3);
> exten => _0X.,3,Hangup;
> exten => _0X.,103,zapCD(CALLERID(rdnis));
> 
> Any comments on this? Would a patch for this be accepted?

You should also consider how it would be handled for calls started from
a call file or the Manager API, when they specify Zap/xx/nnnnnnnn as
the Channel parameter. In that case, there is no incoming channel that
originated the call, so nowhere for DIALSTATUS to be set, nor for any
dialplan decisions to be made about how to handle the redirect.

Cheers
Tony
-- 
Tony Mountifield
Work: tony at softins.co.uk - http://www.softins.co.uk
Play: tony at mountifield.org - http://tony.mountifield.org