Serverless Internet-Wide Chatting Client?

Does anyone know of the logic behind a se开发者_JS百科rver-less chat client that would be able to interconnect not LAN-wide but internet-wide? It doesn't need to be able to detect other users world wide, it just needs to obtain some kind of unique identification to be able to connect to a user, like an IP or a unique ID of some sort.

To start, you need some information from somewhere. You can't just turn it on and start chatting without knowing where everyone is. You might have one node that is online all the time and knows a few other nodes. The other nodes would know other nodes and those would know more, etc. It is debatable whether or not you would call that static node a "server" or not. It could just be your friend's node, or a publicly available IP. Once you are up and running, you wont need the start node anymore.

In this type of system, you would need to query your neighbors if you want some sort of identification besides IP address. An IP address has its own drawbacks as well, because you might have two people behind a router at a home DSL connection. Unique ID's would require a recursive query across the whole mesh to find out if your ID is unique.

In this type of system, you would only need to know a limited subset of people in order to chat with anyone, as you can query everyone around you (and the query happens recursively) for the location of that person. An artificial limit on the number of people stored on the local node might be implemented with a Least Recently Used algorithm, kind of like a CPU cache.