[asterisk-users] Selecting outbound trunk

[Iain Young]

On Tue, Aug 29, 2006 at 02:18:32PM +1000, Devraj Mukherjee wrote:
 
> The simplest way I can think of solving this is using prefixes, so
> someone appends a 0 or 1 and the dialplan puts the call through the
> selected trunk, where 0 being voip and 1 being PSTN.

Whats wrong with something like this :

exten => _91X.,1,Dial(SIP/${EXTEN:2}@${OUTBOUND1})
exten => _92X.,1,Dial(SIP/${EXTEN:2}@${OUTBOUND2})
exten => _93X.,1,Dial(IAX2/iaxprov/${EXTEN:2})

Users would dial 91 to dial outbound on SIP Provider 1, 92 for
outbound on SIP Provider 2, and 93 for outbound on IAX. Personally
I use 9X for automatic routing (along with some sane forced routing,
ie local, emerg calls etc), and am planning on using 8X for manual
forced routing.

> I have figured out how to use a Substring like function to extract the
> number out of the dialed extension. My question is how do I make a
> decision in the dialplan to dynamically select a trunk for the call?
> Is there a SetIf function or an If function by itself?

Checkout the command GotoIf()

Heres an example that I use to in my exten Macro, that does
slightly different things depending on the number range the
extension dialed is from:

[macro-exten]
exten => s,1,GotoIf($[${ARG1:0:1} = 1]?11:21)   ; Did we call a real ext ?
exten => s,11,SetVar(TODIAL=${ARG2}/${ARG1})    ; Yes so we have the ext
exten => s,12,Goto(91)                          ; Jump to Dial() routint
exten => s,21,GotoIf($[${ARG1:0:2} = 20]?31:41) ; Did we call a virt or soft ?
exten => s,31,SetVar(VMBOX=${ARG1})             ; Virt, So vm is the same
exten => s,32,SetVar(TODIAL=${VIRT[${ARG1}]})   ; Grab the list of real exts
exten => s,33,Goto(91)                          ; Jump to the dial routine
exten => s,41,SetVar(VMBOX=20${ARG1:1:1})       ; Soft, So vm is the virt
exten => s,42,SetVar(TODIAL=${ARG2}/${ARG1})    ; But it is a real ext
exten => s,43,Goto(91)
exten => s,91,Dial(${TODIAL},25,Tt)
exten => s,92,GotoIf($[${ARG1:0:1} = 2]?93:94)  ; Do we need to handle vm ?
exten => s,93,GoSub(s-${DIALSTATUS},1)
exten => s,94,Hangup()
exten => s-NOANSWER,1,Voicemail(u${VMBOX})      ; Virtual extensions have
exten => s-BUSY,1,Voicemail(b${VMBOX})          ; VM, so transfer caller
exten => s-CHANUNAVAIL,1,Voicemail(u${VMBOX})   ; Offline, so transfer call

I have a dialplan where 1xx are real extensions, with no voicemail,
20x are virtual extensions, identified with an induvidual, with voicemail, and
2xy are extensions assoiated with the same induvidual as the virtual
number (ie 21x are all linked to 201 etc..)


HTH

Iain