Phillipe,
Perhaps you can point me in the right direction, I currently install NEC DSX & Samsung OfficeServ 7200/7400 series phone systems in the DFW area. My boss is wanting to start installing Asterisk machines but is disappointed in the fact that there are still some features lacking in FreePBX vs. a proprietary PBX such as those mentioned above, one of the biggies is whats known as “Class of Service.” I am more than willing to remedy this myself, but would like to build it as a module for FreePBX, could you point me in the right direction on how to properly build a module for your system?
Class of Service is basically this -
you set up different “Classes” and in each you can specify what feature codes are allowed, what toll restrictions are in place (if any) and so forth, you then assign each individual extension to be in one of those classes. So for instance, the Bosses extension could be in Class of Service 1, where he is allowed access to ALL features available on the system, as well as no toll restrictions, you could then assign the employee’s extensions Class of Service 2, where perhaps they can use all features except for barge in and say chanspy, and then assign the lobby phone Class of Service 3, which would restrict the phone from dialing page groups, using intercom, accessing voicemail, and can only call local numbers. You see where this is heading? 
This evening I coded a small function in php to recognize Asterisk style dial plan patterns and decide if the number dialed matches, I have never done pattern matching before, so this was the hurdle for me to get past. Now that I have that figured out, the rest should be fairly simple for me as I have worked with PHP/MySQL for a while now, so designing the database tables, etc, should be no problem for me. I just need to know how to put all of this together in such a way that it would be easy for the FreePBX community to install it to their system and put it into production use without alot of headaches. I realize that you can already restrict toll calls using pin sets, but a lot of our customers would rather not have the hassle of dialing a code to call LD and just restrict it on a per extension basis. This could also be further designed to allow for multi-tenant systems where Company A doesn’t want their employees to be able to dial Company B’s extensions and vice versa…
Hope I’ve made clear what I am looking to do and what input I need from you
Hope to hear from you soon!
-Andy
Andrew Miffleton
Telecommunications Technician
DFW Business Telephones
1260 Shiloh Rd.
Plano, TX 75074
(972)424-4242 x455