We have configured zentyal as our gateway. but the internet speed is shared equally among all the machines. even when no machine is downloading anything. what i mean by this is if i have 10 machines and a 10MBPS line, each machine is maximum getting 1MBPS download speed, even when other machines are down.
i came to this conclusion, by checking the download speeds by directly connecting to my ISP and connecting to my ISP through zentyal.
By default does not share the load. we can distribute the load using traffic shaping. The problem in my case was my network was not good. i replaced it and everything works like charm