CUCM 11.5 Internal only calls

[mmoss80]

Is there a simple way to block external calls from a single device or extension? All of our phones have the ability to call out, but they've asked for one to be internal only and I'm not sure how to do so without creating new partitions, pools, CCS etc which seems like more work that should be needed.

[Nithin Eluvathingal]

What are the CSS configured on your system.

most commonly we all create a CSS internal  which has no access to outside. if we assign  CSS internal to the line/phone thats enough to block the outside access. 

if you share the existing CSS and partition configurations we will be able to  guide you. 

[Jaime Valencia]

If you do not have your system configured as Nithin says, which is extremely common (have a CSS for internal only, local, national, international, restricted, etc.) then all you'd really need to do, is to create a new CSS for internal only and add the internal partition(s), I don't see why you'd need to create any new partitions, device pools, etc. for this purpose unless you have specific requirements to do so.