first of all, you have to respect the thread that Sofouenne has put it and be serious about your answer, this is not a general forum or for hangout forum , its a professional forum, so let's be serious here. We have a technical situation on work and we need to implement this method (exemple of usage : a director dont want to be disturbed by a specific internal user, so he want to block a specific extension for calling him ,and let the rest can call him normally). The DND solution is not usefull because if we have 1000 users , so to block one extension , i have to put 999 extentions number on the exception list , this is not realistic. So please if there is one experience on IPO in Tek-Tips forum, let us know about the best solution.