UDP DatagramSocket Port 3658 Not Connecting

Question

Hey, I've created a server and client for an online space game I'm creating. I have all important stuff being sent on TCP, and all movement on UDP. I test it on my lan network, and it works wonderfully.I got 3658 port forwarded for both UDP and TCP. TCP and UDP works for the person hosting the server, though only TCP works for people across the internet.
Any suggestions on how to fix this?
-Gandolf

Answer 1

(1) I've never used Flush before, why flush? Is it similar to print line to send the data?See [BufferedOutputStream.flush()|http://java.sun.com/javase/6/docs/api/java/io/BufferedOutputStream.html#flush()]. It flushes your buffers. If you're using a BufferedOutputStream or any stream or writer that buffers you should be calling flush() at the end of every every transaction.
(2) How do you turn off the algorithm[Socket.setTcpDoDelay()|http://java.sun.com/javase/6/docs/api/java/net/Socket.html#setTcpNoDelay(boolean)]. As I mentioned above, TCP can delay packets for up to 200ms, with the aim of coalescing them into larger packets, which is normally a really good idea, because the TCP packet overhead is 40 bytes, so sending single bytes around gets expensive. In this case turning it off will help your timing.
(4) WIll this give me as good results as UDP in a speed test?Again, you don't have any UDP results to compare to, do you?
(5) Are there any down sides?It's a space/time tradeoff. As mentioned above, normally the Nagle algorithm is left alone as it optimizes space on the network, at a very slight time cost which you only see in highly interactive applications like this. The X Window System is another example..