This greatly simplified installing and moving computers on LANs because of the lighter weight and flexibility of UTP cabling. Ethernet is an asynchronous protocol. Asynchronous protocols do not specify a specific start and stop time for each packet of data. All devices connected to the net- work attempt to send whenever they're ready. Data Centers and IP Private Branch Exchanges Ethernet's simplicity makes it straightforward to connect equipment to networks. All that's required are computers with Ethernet interfaces (ports) for an Ethernet cable and Ethernet software to link devices to switches in wiring closets. Because of the uncertainty of traffic volume at any given point in time, Ethernet networks are often configured to run at no more than half of their capacity. Using TCP/IP as a Linking Protocol Whereas Ethernet is a way for individual packets to access LANs and for computers to retrieve packets from local networks, TCP/IP is used to tie LANs together and to route packets between networks as well as to and from the Internet. As the need arose to tie LANs together for e-mail and file sharing, compatibility between LANs from different manufacturers became a problem. The TCP/IP suite of protocols became popular choice for overcoming these incompatibilities and for managing the flow of information on LANs. Routers were developed to send data between individual LANs, and between LANs and the Internet. Routers send packets to individual networks based on their IP address. IP addresses are assigned to individual networks and servers that run software applications. Fibre Channel in Storage Area Networks Fibre Channel is a group of open protocols approved by the American National Stan- dards Institute (ANSI). The protocol was designed for the heavy traffic generated in data-intensive networks such as SANs. It is a point-to-point protocol, wherein data is transferred directly from one point (a computer) to another point (perhaps disk stor- age). Because of its capability to transfer large amounts of data at high sp