PLANET IPX-300 - Manual (Page 37)

I think this can be easily be done by using long group number.
Figure 3-45. Call Screen settings-Application 2
The user now needs to dial 77963(as password) to make call by this trunk
C. Group 3 must be close to all traffic, open only to dial extension numbers.
Select All Reject
Choose the extensions that you don’t want it to make calls.
For instance 200
Extension 200 is not able to call out, ONLY able to dial extension numbers.
Figure 3-46. Call Screen settings-Application 3
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