In this simplest form, you would have seperate calling seach spaces for the phones/device and for the line/DN. The line's calling search space ends up being the combination of both, and the entire list of partitions is searched for the best match. If there is a tie, the line's CSS takes precendence.
Create route patterns (take 9.@ for simplicity sake) for each set of gateways and put them into the proper partition. For example 9.@ going out the Montreal PRI would be in the Acme_MontrealPSTN_PT, and 9.@ going out the Toronto PRI would be in the Acme_TorontoPSTN_PT. Then create similar calling search spaces for each group of phones, Acme_MontrealPSTN_CSS for the phones in Montreal and Acme_TorontoPSTN_CSS for the phones in Toronto. This way, when ever anyone on any of these phones dials 9+number, it will go out the approriate gateways.
Now, onto the lines. Basically create route patterns that now block access to the PSTN. So, create a route pattern that has 9.@ with a filter that says "area code exists" and block this pattern (be sure to route this out a route list with no gateways, i.e. the null route list). Put it in a partition that says Acme_NoLongDistance_PT. Now, create your lines calling search spaces as you normally would, using the search space to 'allow' access to your internal extension via partitions and disallowing them to certain PSTN access. Say you have a calling search space called Acme_JuniorSalesMen_CSS and it contains partitions which allow them to call pretty much every phone, but you know they have girlfriends in Vancouver, so you don't want them to dial long distance, no matter where they are - so you add the Acme_NoLongDistance_PT to the Acme_JuniorSalesMen_CSS. Now, where ever they log in, they can make outbound PSTN calls off the correct gateway and will always be restricted from dialing numbers which contain a long distance area code.
Now, this in the simplest form will work, but it is a little more complicated to get it working the way you like it. For example, the route list above will also prevent them from dialing 1-800 numbers as well. To get around this, and basically the template for creating a fully functional alternate PSTN dial plan is to isolate all the types of numbers you would like to restrict by and include those as 'allows' in your Acme_XXXPSTN_PT partitions, that way by restricting certain things, those best matches will still be allowed through. For example, if we had a route pattern 9.@ with filter (areacode=800 or areacode=888) in each of the Acme_MontrealPSTN_PT and Acme_TorontoPSTN_PT partitions, then the salesmen would be able to dial those numbers even though the long distance numbers are blocked.
Another thing to worry about is the 'image' they portray - do you want outbound calls from them to come from one number only, only their home office? Then you have to use the external calling mask on the phone. If you want the number to show the local office they're in, then you have to write the external calling mask in the route patterns or higher levels.
I have created a spreadsheet which I used to deploy my dial plan, I'll see what I can do about posting parts of it to help.
