*quoted from their site*
Q: I am planning a cabling installation in a large building. How can we keep all of the cable runs within the distance limitation of 295 feet?
A:This question may require an entire article to properly cover. Basically, you should strategically divide the building into sections. Pick a central location (equipment closet) for each section that allows all of the cable runs in that section to fall within 295 feet. Now choose a main equipment location. You now need to plan a backbone cable from the main equipment room to connect each switch/hub in each closet to the main switch. If the distance of the closet to the main equipment room is within 295 feet, you may run a UTP backbone to that closet. However, if the run is over 295 feet, a fiber optic backbone is required. A fiber optic backbone is also necessary if you need higher speeds to transmit a lot of data from many locations. Be sure to use switch ports to link to the main switch to assure that data can effectively be transmitted without having to share bandwidth. If only a few runs fall over the 295 feet, and you dont need higher bandwidth in the backbone, you may want to consider using media converters.