We've settled on ARS standards that have worked very well for us. I can look at a phone and know exactaly what restrictions it has as well as a route and know exactaly who is allowed to use it without tracing anything back.
A Brief explanation:
We set up CORs (NA Dialing plan) that look like this:
11 - Local calls only
12 - Intra lata
13 - State wide
14 - North America
15 - International + 900 calls
Then for routes:
11 - Local calls Trunk Group A
12 - Intra lata Trunk Group A
13 - Statewide Trunk Group A
14 - NA Trunk Group A
15 - Internat Trunk Gruup A
21- Local calls Trunk Group B
22 - Intra lata Trunk Group B
23 - Statewide Trunk Group B
24 - NA Trunk Group B
25 - Internat Trunk Gruup B
31 - Local calls Trunk Group C
32 - Intra lata Trunk Group C
etc and etc and etc
This is of course just the frame work and can be expanded and modifed from there but it has worked extreamly well and is easy to explain to a customer.
911 creates some special considerations. A long time ago I wrote an article that got picked up all over the internet.
You can find it here:
http://workplace-communication-tips.blogspot.com/2008/06/911-misdials-programming-your-pbx-to.htmlRalph