Tools to artificially increase IP (TCP) latency on Linux OS?

I'm looking for a (Linux) tool to allow me to simulate high latency IP communication between two machines.

Machines A and B are on the same LAN (<1ms latency).

Goal: My Java app, ma开发者_Go百科chine A, should experience high latency (~500ms) when talking TCP with a service on machine B.

Comments:

1. I'm looking for fine grained control over the individual IP packet latency (controlling just the overall bandwidth doesn't cut it).
2. I would rather not slow down the entire network, just the communication between machines: A+B.
3. I mainly care about Linux and I rather use a freeware tool, though a Windows/commercial tool might also do. I Googled, but found nothing.

This looks like It'll do what you want: http://www.linuxpoweruser.com/?p=41