I'd like to use a server between two machines (with no static IP). The only IP known to me is the server's IP address. I'd like to build/use a system that listens to 2 different ports within the server and whatever is received from localhost:portA is sent to localhost:portB and vise versa. Consequently, both machines (with java apps) can communicate through the server in the middle.
Please what is the best solution to do this. I'm working on linux system and I thought of using an SSH java API (hudson / ganymed-ssh-2) to build a port forwarding server application.
Some issue: 1) determining the size of the data transmitted to buffer read or not to forward it to the other port. 2)The speed of reading/writing bytes.
If you can use ssh protocol you can tunnel local or remote ports (this need support on server side). You can also think about an OpenSSH VPN (take a look on ssh -w option, this will create a real VPN (TUN/TAP device is required). ).