摘要: 傳輸控制協(xié)議和IP協(xié)議被DOD工程研究部策劃用于連接不同廠商設(shè)計(jì)的網(wǎng)絡(luò)而形成網(wǎng)絡(luò)的網(wǎng)絡(luò)("英特網(wǎng)")。因?yàn)樗ㄟ^許多的客戶端/服務(wù)器系統(tǒng)實(shí)現(xiàn)了一些每個人都需要的基本服務(wù)( 文件移動, 電子郵件, 遠(yuǎn)程登陸) , 所以它最初就取得了成功。在一個小的部門中幾臺計(jì)算機(jī)就能在局域網(wǎng)中使用TCP/IP協(xié)議(或其他協(xié)議) 。IP組件提供部門網(wǎng)絡(luò)到企業(yè)網(wǎng)絡(luò)的路由，然后到地方網(wǎng)絡(luò)的路由，最后到全球網(wǎng)絡(luò)的路由。在戰(zhàn)場上一個通信網(wǎng)絡(luò)因?yàn)槭艿綋p
害是不會自動恢復(fù)的，因此DOD設(shè)計(jì)的TCP/IP協(xié)議是非常健壯的而且能從任何節(jié)點(diǎn)錯誤或電話線錯誤中自動恢復(fù)過來。這種設(shè)計(jì)使得構(gòu)建非常大的網(wǎng)絡(luò)也不需要什么中央處理單元。然而，正是因?yàn)檫@個自動恢復(fù)技術(shù)使得網(wǎng)絡(luò)在篅@ひ歡問奔潯淶貌豢燒鋃蝦筒徽貳：推淥ㄐ判橐謊琓CP/IP協(xié)議也是由層組成的：
basic services that everyone needs (file transfer, electronic mail, remote logon) across a very large number of client and server systems. Several computers in a small department can use TCP/IP (along with other protocols) on a single LAN. The IP component provides routing from the department to the enterprise network, then to regional networks, and finally to the global Internet. On the battlefield a communications network will sustain damage, so the DOD designed TCP/IP to be robust and automatically recover from any node or phone line failure. This design allows the construction of very large networks with less central management. However, because of the automatic recovery, network problems can go undiagnosed and uncorrected for long periods of time.