This my answer:
1) In what context do you use the Captive Portal of Zeroshell?
In the office and some of my clients
2) What are the hardware (CPU, RAM and disk) do you use?
RAM: 1 GB
Disk: 4 GB
3) What release of Zeroshell do you use?
4) Did you enable the protection against DoS (Denial of Service)? if the answer is yes, please specify the protection level (Low, Medium or High).
Yes in Medium Level
5) What is the total number of users that you manage with the captive Portal?
6) What was the peak of concurrent users connected?
7) At the peak of concurrent users connected, did you notice unacceptable delays in the captive portal authentication?