I have opened an office with 1000 clients. There is another office with another 1000 clients. These buildings are geographically separated by 1 mile distance. I want to setup a free voice and video call feature within these two branches provided my client size increases by multiples of 10. And new branch offices will also be opened shortly. So what do i need to setup this network structure. I have a qud core intel processor with linux red hat installed. What more do i need. And how to setup the Asterisk server and give connectivity. I have wireless links between these offices. So through this, both data and voice calls will pass through. So help me setup this network with the requirements. in my private LAN.