Useful info dump: STUN (session traversal utilities for nat) servers are available on the internet.
Current implementations of STUN use UDP, TCP is still under development. RUDP (Reliable UDP) is a plan 9 protocol that extends UDP. It provides some of the reliability features of TCP. There's a java implementation of RUDP with a BSD license. SSL over RUDP can provide integrity and authenticity. STUN can be used to provide UDP connections to services behind firewalls. Clients can currently use publicly available services from the internet. STUN doesn't provide a total solution for nat traversal. TURN provides internet relays for occasions when stun doesn't work. STUN and TURN servers can be found on the internet using DNS-SRV. I plan to develop SocketFactory's that open (when possible) and maintain network connections through firewalls that can be used by existing jeri Endpoint implementations. Implementing SocketAddress properly will take some time, especially to determine immutable object identity. Choosing the right java STUN TURN implementation seems to be the issue at present. The STUN code I've seen so far is designed for voip and the best isn't apache license compatible (platform requirement, can't distribute), to add the RUDP layer might require some code donation to an upstream library. Any suggestions, ideas or assistance is welcome. Cheers, Peter.
