[asterisk-users] RDNIS question

[Julian Lyndon-Smith]

Perhaps I've got the whole concept wrong, but here goes:

Using 1.4, when someone from the outside dials my direct line (123456), 
I want it to call my extension at work (SIP/456), my extension in my 
home office (vpn connection to corporate lan, SIP/678) and my mobile 
(654321). So my dialplan is thus:

exten => 123456,1,Dial(SIP/456&SIP/678&Zap/G3c/07803654321,30)
exten => 123456,n(VMNoAnswer),Voicemail(${EXTEN}|su)
exten => 123456,n,Hangup()

this works well, with one exception: when I take the call on the mobile, 
the callerid info is the number of my switchboard. I presume that this 
is because I am dialling out from the switch board.

Enter RDNIS. I added an extra line to the dialplan

exten => 123456,1,Set(CALLERID(rdnis)=${CALLERID(number)})
exten => 123456,n,Dial(SIP/456&SIP/678&Zap/G3c/07803654321,30)
exten => 123456,n(VMNoAnswer),Voicemail(${EXTEN}|su)
exten => 123456,n,Hangup()

However, I get exactly the same result (callerid of the switchboard, not 
  the original caller). And yes, I did a reload ;)

Any help would be appreciated.

Julian