Ring topology is an advantage for a few machine and high speed links, but otherwise use the star top or something like hub and spoke top. The star is prefferable since the pcs don't have to wait for the token to arrive... Supppose you are dl a 600mgs for a movie and the guys next to you is trying to get a email to his provider .... guess what will happen if the dl starts first.

Star also can take advantages of multi bw capacity and ddr depanding upon the links that you are using and can optimize it too.
check out http://www.cisco.com/en/US/products/...0800e955d.html
btw star top is the most common top used