【正文】
所有的子網(wǎng)的地位是平等的 ? 具有開放行。采用 TCP/IP協(xié)議 ? 入網(wǎng)方式靈活多樣。聯(lián)網(wǎng)設(shè)備增加 N倍,效率增加 N2倍 Inter的發(fā)展的規(guī)律 Inter技術(shù) 網(wǎng)絡(luò)帶寬與 CPU性能 2023 1998 1996 All Other IPX TCP/IP Traffic Ratios Source: Gartner 1997 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Inter技術(shù) Relative User Population 8% 17% 39% 27% 7% 2% 13% 18% 23% 23% 16% 7% 14% 17% 12% 15% 28% 14% To Transactional Pages (Red) and Audio/Video Content (Purple) 100% 80% 60% 40% 20% 0% 2023 1998 1996 Source: The Yankee Group, 1996 Inter技術(shù) Simple Video, Multimedia Browsing, PCM Voice IP, PCS, EMail, File Transfer Paging Video Conferencing, MPEG1 NTSC Video Tel, VoIP ISDN, Frame Relay ATM/POS T3/E3 T1/E1 New Modem Wireless WAN Old Modem .004 .0192 .0288 .128 3 155 Mb/s Minimum Bandwidth for Application per User Virtual Reality, Medical Imaging Inter技術(shù) Inter Data/Voice/Video Transport Convergence Inter技術(shù) ? Inter的應(yīng)用 ? 在信息交流方面的應(yīng)用 ? 在教育方面的應(yīng)用 ? 在醫(yī)療方面的應(yīng)用 ? 在政府工作中的應(yīng)用 ? 在商業(yè)領(lǐng)域的應(yīng)用 ? 在娛樂方面的應(yīng)用 Inter技術(shù) Inter技術(shù) Inter提供的服務(wù): ? Everything is digital: voice, video, music, pictures ? Everything is online: bank statement, medical record, books, airline schedule, weather, highway traffic, toaster, refrigerator … ? Everyone is connected: doctor, teacher, broker, mother, son, friends, enemies Inter技術(shù) 當(dāng)前的狀況: ? Electronic merce ? virtual enterprise ? Inter entertainment ? interactive sit ? World as a small village ? munity anized according to interests ? enhanced understanding among diverse groups ? Electronic democracy ? little people can voice their opinions to the whole world ? bridge the gap between information haves and have no’ s ? Electronic terrorism ? hacker can bring the whole world to its knee Inter技術(shù) Inter 的展望: Inter技術(shù) Inter 的特點(diǎn)和結(jié)構(gòu) ? Inter的特點(diǎn) ? 具有公平性??蓳芴?hào)、專線、無(wú)線上網(wǎng) ? 信息資源極為豐富。未聯(lián)網(wǎng)設(shè)備增加 N倍,效率增加 N倍。 ? 安全性差。 帶寬需求呈超高速增長(zhǎng)的趨勢(shì) 邁特卡爾夫定律 :聯(lián)網(wǎng)定律 , 網(wǎng)絡(luò)價(jià)值隨用戶數(shù)平方成正比。 ? 資源分散。 所有電子系統(tǒng)(包括電子通信系統(tǒng),計(jì)算機(jī))都適用 光纖定律 : 超摩爾定律 ,骨干網(wǎng)帶寬 9個(gè)月 翻番, 10年10000倍 。 Backbone ISP ISP Inter技術(shù) Inter 的邏輯結(jié)構(gòu) Inter技術(shù) Inter 的協(xié)議結(jié)構(gòu) OSI Model Inter技術(shù) Inter技