Snom secondary (outside) dialtone


I have a Snom 300 and need to find out how to generate a secondary dial tone (i.e. after a user has pressed 9 for an outside line).

I have managed to get this working (sort of) with DISA answering after a 9, but then the Snom doesn’t display any of the dialled digits.

Has anybody got a solution for this? I tried calling Snom but they couldnt understand what I was after.