Hello friends, I am installing an Asterisk central, it works well with internal calls. I connected an analog line and works well. The problem is that when I connect 4 lines to the Asterisk is a busy tone for all internal users and also for those who want to call the central, it happens the most of the time but not always. I have created a trunk for each line that connects to the exchange, four outgoing routes: (internal, local, national and mobile). The incoming route is the default one. I don't know what's the problem. I hope I explained well, I am not very good with my English. :blush: If you know what is the problem and how I can fix it, please contact me.