HTTP Tunneling

• When an RMI client (stub, even registry stub) tries to contact a server, it will try:

1. Contact directly using JRMP.
2. Make direct HTTP connection to server, encapsulate method call in HTTP request.
3. Assume firewall is proxy server, ask it to forward the request to appropriate port on server. Firewall forwards request as HTTP request.
4. Connect to port 80 on server machine and send request to URL beginning with /cgi-bin/java-rmi.cgi. Hope request gets forwarded to proper port on server machine.
5. Connect to port 80 of firewall machine and send request to URL beginning with /cgi-bin/java-rmi.cgi. Hope request gets forwarded to server.