Connection between two firewalled computers?

[IniX]

Is it possible to do this? I want to establish a connection between two computers, but I can't portforward any ports on either of the routers, so can't do direct client->server connection. Is there any method that exists so that they can connect to each other?

I was thinking there might be a service available that hosts a main server, where two clients can connect to that server then transfer data between each other, but I haven't found anywhere that does this.

[hoxsiew]

Is it possible to do this? I want to establish a connection between two computers, but I can't portforward any ports on either of the routers, so can't do direct client->server connection. Is there any method that exists so that they can connect to each other?

They wouldn't be very good firewalls if they allowed this behavior.

I was thinking there might be a service available that hosts a main server, where two clients can connect to that server then transfer data between each other, but I haven't found anywhere that does this.

This is the only way I know of. You need a third party to act as a proxy. Instant messengers and such take this approach. I don't know of any generic servers that allow this arbitrarily though.