[asterisk-users] Modification of Caller ID based on context

[Matthew Brothers]

> Hi,
> 
> I have been looking for an example of accomplishing this, but 
> I've been unable to locate something similar to what I'm trying 
> to do.
> 
> Here's the scenario:
> 
> Users caller ID is set to their internal extension (200-250). 
> This is set in sip.conf for each user. Each user has a local DID 
> as well (hosted through Vitelity, for example (555)111-2222). The
>  problem is that this extension was being passed to the outside 
> world. I currently have a SetCallerID command changing the 
> CallerID to our main office number, but some users want their DID
>  sent, not the general number.
> 
> The problem is that if their caller ID is set to their DID, when 
> users hit redial on their phones internally they dial out and 
> back in. I corrected this by putting each DID in extensions.conf 
> under their three digit extension, but that seems a bit like a 
> kludge obviously.
> 
> I'm looking for a method of sending the internal three digit 
> extension only when a user is dialing another user internally, 
> otherwise it will send their DID. Is their a method to do this in
>  the dial plan? Anyone have an example of how to accomplish this?
> 
> 
> Thanks in advance.


Mike,

I have a similar setup (I even use Vitel) and the easiest and
cleanest method that I have found to accomplish this is with the
AstDB. You can simply create a cross-reference of DIDs and Internal
extensions similar to extdid/200 => 5551112222 ... extdid/250 =>
5551112272 in the AstDB. Then you can change your outgoing dialplan
to change the caller id based upon this cross reference. Example:


exten => NXXNXXXXXX,n,Set(outgoingCID=<MAINNUMBER>)

exten => NXXNXXXXXX,n,
GotoIf($[ ${DB_EXISTS(extdid/${CALLERID(num)})} = 0 ]?makecall)

exten => NXXNXXXXXX,n,
Set(outgoingCID=${DB(extdid/${CALLERID(num)})})

exten => NXXNXXXXXX,n(makecall),Set(CALLERID(num)=${outgoingCID})

...

You could even simplify your incoming context by cross-referencing
in the other direction. That is didext/5551112222 => 200 ...
didext/5551112272 => 250.

exten => NXXNXXXXXX,n,
Goto(internal-extensions,${DB(didext/${EXTEN})},1)

OR you could do something similar with LOCAL channels or with a Dial
command.

-Matthew