How to prevent certain extensions from dialing certain other extensions?

Seems like a simple situation but I cant think of how to do this. There are a bunch of extensions, some are in the 1XXX range and some are in the 3XXX range. There are some paging groups, 3993-3999. The idea is that the 1XXX phones should NOT be able to dial those paging groups. Any thoughts?

PBX Firmware: 6.12.65-31

I’m fine with updating to 10.13.66-8 if that will help.

The easiest way is to get the “Class of Service” module (it is one of the commercial modules). You can define groups and assign to these groups which paging extensions are allowed. Then you assign the COS to the respective users:

Thanks for that. On the surface it looks like what I want. Will try it out shortly.

that worked perfectly