Problem with outbound caller id

Hi everybody
I am using Asterisk and freepbx, I have an E1 card on my server and pri connection from one of the provider. I had 100 numbers assigned from the provider, and i mapped to the extensions. Now i am able to call to the particular numbers of SIP phones from the mobiles, but when i call from SIP phones to the mobiles the numbers are not getting displayed and only the base numbers is getting displayed on mobiles from all the SIP phones.

 How can i configure to get the numbers alloted to the SIP Phones to be displayed on the mobiles or landlines on the outer network(outbound calls).

Please tell me on the GUI method also.

Have you enabled this with your network operator - whoever provides the E1 line for you. With Telewest / Virgin Media in the UK, there are 4 callerid modes, and we needed option 3 for it to work like you want.