cho một tập hợp các bộ định tuyến, với các liên kết kết nối các bộ định tuyến, một thuật toán định tuyến tìm thấy một con đường "tốt" từ nguồn tới đích. Thông thường, một con đường "tốt" là một trong đó có "chi phí thấp nhất", nhưng chúng ta sẽ thấy rằng trong thực tế | LAN addresses and ARP Return to Table Of Contents Copyright James F. Kurose and Keith W. Ross 1996-2000 . All rights reserved. file D Downloads Livros computaẹão Computer 20Approach 20Featurmg 20the 20Internet 8 of 8 20 11 2004 15 52 36 Ethernet Ethernet Ethernet has pretty much taken over the LAN market. As recently as the 1980s and the early 1990s Ethernet faced many challenges from other LAN technologies including token ring FDDI and ATM. Some of these other technologies succeeded at capturing a part of the market share for a few years. But since its invention in the mid-1970 Ethernet has continued to evolve and grow and has held on to its dominant market share. Today Ethernet is by far the most prevalent LAN technology and is likely to remain so for the foreseeable future. One might say that Ethernet has been to local area networking what the Internet has been to global networking There are many reasons for Ethernet s success. First Ethernet was the first widely-deployed high-speed LAN. Because it was deployed early network administrators became intimately familiar with Ethernet -its wonders and its quirks -- and were reluctant to switch over to other LAN technologies when they came on the scene. Second token ring FDDI and ATM are more complex and expensive than Ethernet which further discouraged network administrators from switching over. Third the most compelling reason to switch to another LAN technology such as FDDI or ATM was usually the higher data rate of the new technology however Ethernet always fought back producing versions that operated at equal data rates or higher. Switched Ethernet was also introduced in the early 1990s which further increased its effective data rates. Finally because Ethernet has been so popular Ethernet hardware in particular network interface cards has become a commodity and is remarkably cheap. This low cost is also due o the fact that Ethernet s multiple access protocol CSMA CD is totally .
