asterisk users - Aug 2004 - Handling invalid extensions

Hi, I was wondering how other people might handle this situation.  We have a
10 channel fractional E1 and have so far only allocated about 25 numbers out
of a 100 number block (9500 - 9599).  If an external caller dials an invalid
extension then we would like for them to be put through to our main number.
In order to make for a short and simple extensions.conf we have defined our
incoming context along the lines of:

exten => _123495XX,1,Dial(SIP/${EXTEN:4},16,tr)
exten => _123495XX,2,Voicemail,u${EXTEN:4}
exten => _123495XX,102,Voicemail,b${EXTEN:4}

In order to accomodate invalid extensions we did this:
exten => _123495XX,1,Dial(SIP/${EXTEN:4},16,tr)
exten => _123495XX,2,Voicemail,u${EXTEN:4}
exten => _123495XX,102,GotoIf($[${DIALSTATUS} = CHANUNAVAIL]?104)
exten => _123495XX,103,Voicemail,b${EXTEN:4}
exten => _123495XX,104,Dial(SIP/9500,20,tr)
exten => _123495XX,105,Voicemail,u9500
exten => _123495XX,205,Voicemail,b9500

When I was trying to research this I pretty much found no information apart
from an example using GotoIf in the 's' extension which wouldn't
have been
compatible with our pattern matching anyway (exten => s,1,Blah vs exten =>
_123495XX,1,Blah).  The 'i' documentation in the wiki is less than
helpful
and if I read it correctly it is really only for the occasion where an
extension cannot be matched.  The way it is defined above we will always get
a match, we will fail when there is no corresponding SIP extension defined
(priority + 101) and that is where the GotoIf($[${DIALSTATUS}..) comes in.
Is there any other way that we should be 'supposed' to do this
functionality?

Craig

> Is there any other way that we should be 'supposed' to do this
> functionality?
I would probably do something like this:

[macro-siphandset]
exten => s,1,Dial(SIP/${ARG1},16,tr)
exten => s,2,Voicemail(u${ARG1})
exten => s,102,Voicemail(b${ARG1})
; do whatever you want your normal SIP handsets to do here

[extensions]
exten => 950X,Macro(siphandset,${EXTEN})
exten => 951X,Macro(siphandset,${EXTEN})
exten => 9521,Macro(siphandset,${EXTEN})
exten => 9537,Macro(siphandset,${EXTEN})
exten => 9543,Macro(siphandset,${EXTEN})
; ...
; define patterns matching all assigned extensions

[inbound]
; Attempt to connect to extensions/xxxx
exten => _123495XX,1,Dial(Local/${EXTEN:4}@extensions)

; Didn't work? Connect to 9500
exten => _123495XX,2,Goto(extensions,9500,1)

Hope this helps.

--Will Glynn
Freedom Healthcare Group

Hrm:
> [extensions]
> exten => 950X,Macro(siphandset,${EXTEN})
> exten => 951X,Macro(siphandset,${EXTEN})
> exten => 9521,Macro(siphandset,${EXTEN})
> exten => 9537,Macro(siphandset,${EXTEN})
> exten => 9543,Macro(siphandset,${EXTEN})
> ; ...
> ; define patterns matching all assigned extensions
> 
> [inbound]
> ; Attempt to connect to extensions/xxxx
> exten => _123495XX,1,Dial(Local/${EXTEN:4}@extensions)
> 
> ; Didn't work? Connect to 9500
> exten => _123495XX,2,Goto(extensions,9500,1)
I guess that's a bit silly, now isn't it? :-)
Let's try that again:

[extensions]
exten => 9500,...
; ...
; all phones here

; No patterns matched?
exten => i,Goto(9500,1)

[inbound]
; Unconditionally hand off to [extensions] context
exten => _123495XX,Goto(extensions,${EXTEN:4},1)

--Will Glynn
Freedom Healthcare Group