A method of maintaining a peer-to-peer relay network includes sending a maintenance message from a peer computer system to each of one or more connected peer computer systems connected to the peer computer system and evaluating any responses received from the one or more connected peer computer systems. The connection between the peer computer system and a connected peer computer system is closed when the response from that connected peer computer system is not acceptable. Each peer computer system is connected to a number of other peer computer systems that is less than or equal to a connection limit and each peer computer system is configured to relay data to peer computer systems connected to that peer computer system according to a set of one or more relay rules.