I set my ip ins the DSP to 127.0.0.1 and the password to the same ones I used in the SHOUTcast server config.
If you are using a router, you might have to turn port forwarding on. (SHOUTcast needs ports 8000 and 8001)
This site gives you step by step instructions if you are using a router.
I hope this helps you with your problem.