Central - SOF3/redox GitHub Wiki
Central is a process that hosts two servers: a control panel over HTTPS and an internal communications server over TCP/SSL.
Central is an executable written in Go. It is the heart of the network, and it must be always online, or the whole network will be down. But the good news is that Central doesn't need to be exposed to the public, so it is usually not possible to, for example, DDoS the Central, because attackers don't know where your Central is located.