ok so ive just got a dedicated server running on the demo servers. whenever someone comes on the experience the worst lag ever- long as 30 seconds every 10- 15 seconds. my ping , well the max i can get it to is about 20, some servers are runing 500! how do i make it better?

A few things to point out;
A lower ping is better
Lag is usually caused by upload limitations (i.e. you're pushing too many players on to your line)
Lag can also be caused by extreme packet loss, or bad routes

Usually theres little you can do to make your ping better, except close down other stuff using the internet, and using QoS to prioritize the LFS traffic out of any routers