Based on the use of a hierarchical, star-wired cable layout. B. Wiring Closets vs. Hubs Two general strategies for laying out LAN transmission medium - linear and star. Linear strategy attempts to provide the desired topology with the minimum cable, subject to the physical constraints of the building. Star layout uses an individual cable from a concentration point to each subscriber location. Obvious choice for a star topology LAN, but can also be used for the bus and ring LAN topologies.
Wiring closet is the concentration point.
LAN Standards Key to LAN market is availability of a low-cost interface. IEEE 802 committee - has developed standards for the development of local area networks. Needed is a LAN standard that assures volume and also enables equipment from a variety of manufacturers to intercommunicate. The task of communication across LANs needs to be broken up into more manageable subtasks, and no single technical approach will satisfy all requirements. Standards are organized in a 3-layer protocol hierarchy.