of the business organization, so ease of installation and support are primary considerations in the choice of network technology. Network administrators today have several alternatives to choose from. Although each network faces different issues, Gigabit Ethernet meets several key criteria for choosing a high-speed networkEasy, straightforward migration to higher performance levels without disruption Low cost of ownership—including both purchase cost and support cost Capability to support new applications and data types One of the most important questions network administrators face is how to get higher bandwidth without disrupting the existing network. Gigabit Ethernet follows the same form and function as its 10 Mbps and 100 Mbps Ethernet precursors, allowing a straightforward migration to higher-speed networking. All three Ethernet speeds use the same IEEE 802.3 frame format, full-duplex operation and flow control methods. In half-duplex mode, Gigabit Ethernet employs the same fundamental CSMA/CD access method to resolve contention for the shared media. Simply stated, Gigabit Ethernet is Ethernet, only faster. Because of the high scalability of Ethernet technology, it is simple to connect existing lower-speed Ethernet devices to Gigabit Ethernet devices using LAN switches or routers to adapt one physical line speed to the other. This evolutionary upgrade path allows Gigabit Ethernet to be seamlessly integrated into existing Ethernet and Fast Ethernet networks. Network administrators today face a myriad of internetworking choices and network design options. They are combining routed and switched networks, and building intranets of increasing scale. Ethernet networks are shared (using repeaters) and switched based on bandwidth and cost requirements. The choice of a high-speed network, however, should not restrict the choice of internetworking or network topology. Gigabit Ethernet can be switched, routed and shared. All of today&...
