Java socket performance bottleneck: where?

Question

I recently started the development of an application making intensive usage of networking. A first attempt was made using RMI and for a couple of reasons, we switched over

Answer 1

Found it:

Instead of:

out = new ObjectOutputStream(kkSocket.getOutputStream());

You should use:

out = new ObjectOutputStream(new BufferedOutputStream(kkSocket.getOutputStream()));

And

out.flush();

when sending a message.

...makes a huge difference ...though I don't know exactly why.