uest and the other computers (i.e., the cli- ents) request services from the server. There are a number of benefits associated with creating these internal LAN infrastructures. First, they allow very timely access to data. Knowledge is a com- Figure 6.1 An example of a shared-medium LAN LAN Basics petitive edge, and the faster you have access to the newest and latest information, the better off you will be in servicing customers and developing products. Second, LANs allow standardization of applications. Over time, departments acquire differ- ent computing platforms, depending on the cycles between centralized and decen- tralized management. Instead of having to go through the labor hours and cost porting applications to reside in different platforms, you can use LANs to enable sharing of an application over the common data highway, resulting in savings and convenience. Third, because of the resource sharing, these internal LAN infrastruc- tures provide great cost reductions. One of the simplest yet greatest benefits of hav- ing a LAN is the ability to share devices, such as printers and scanners. Finally, they promote speedy and functional communication within an organization. LAN Components Typically, a LAN is made up of several key elements: Network nodes-A network node is not a specific device; it is a single, addressable entity. It is an element to which a communications line inter- faces. These interfaces can exist on a personal computer, a multiplexer, a modem, and SO on. In the context of a LAN, a unique address is associated with each network interface card (NIC). Therefore, a server with many MAC addresses is considered to have multiple nodes. NICs-A NIC, sometimes referred to as a network adapter card, fits inside a computer and connects it to the underlying physical transport. Today the NIC is often built into the computer and is not a separate adapter card, making it a LAN interface device. Transmission system-The transmission system (which can be either wired or wireless media) performs the actual c