I have a customer that used to use the PSTN for there inter-office dialing/forwarding and was then sold an LDK130 with 6xBRI to cut line costs.

Now I find they are all upset because when they fwd the phones to their mobiles (off-net) the caller ID comes up as the Pilot number for their isdn.

I know that I can setup outgoing caller id to be the same as the individual ddi, but is there a way to pass the incomming caller ID back out of the system so the user can look at their mobile and screen calls that way?

Yes. A solution exists, but it depends very much on your local phone line provider. (LEC).
In our country it is referred to as partial rerouting, or CLIP-SA (special arrangement). It gives you the passibility to dial-in to a forwarded number (to e.g. a GSM phone). The receiver of the call will see the diallers correct number and the ISDN lines are routed on the public exchange, so the call does not take 2 lines in the ipLDK.
Excellent solution, but you need to discuss this with your CO line provider...(before you promise your costumer anything).

///doktor

As I suspected you have to do the diversion in the exchange not in the Aria.

The reason I wanted the extension to be fwd off-net as opposed to exchange forwarding, is so transferred calls as well as CO calls go to mobile.

Incidentaly they wanted B/N fwd off-net, as you know this cannot be done. So to solve it I set B/N fwd to a group with an overflow timer of 1sec to a speed bin. This works quite well.

I am glad I am not the one that sold the system and made the promises, unfortunately I still had to deal with the upset customer as I was the only tec on site.