Hi,

For normal scenarios, no specific OS configuration is needed. Just install Java SE 6 SDK and tune the Lightstreamer script files as explained in the comments.

As for the maximum number of concurrent users, this depends on several variables, including the overall throughput you are going to reach, more than the actual number of users. Furthermore, the CPU could become a bottleneck before the RAM, depending on your specific application.

Basically, you should do your own simulations and forecasts to be confident with the capacity planning.