when we have set this up here in the uk if you make a call from the phone it will send the ddi of that phone or whatever you have set it to send but if you do a call forward ext then it has only ever showed the ddi of the main number of the isdn2 or 30. when we asked tosh about this they said as the call never really hits the phonei its just the proccessor card turning a call around it will only ever show the main ddi of the lines