人科計(jì)算機(jī)網(wǎng)絡(luò)的發(fā)展過程

2第1 OSITCP/IP31

/server

WirelessAdhoc 1 52090 6。7是20世紀(jì)60年代美蘇 60年代初， ARPA(AdvancedResearchProjectAgency)提傳統(tǒng)的電路交換(circuitswitching)的電信網(wǎng)有一8 9X.25各種的網(wǎng)絡(luò)體系結(jié)構(gòu)：SNA(系統(tǒng)網(wǎng)絡(luò)架構(gòu),是IBM針結(jié)構(gòu),是由數(shù)字設(shè)備公司DEC設(shè)計(jì)的網(wǎng)絡(luò)結(jié)構(gòu))InternetARPANETLAN建成NSFNET，InternetWeb技術(shù)在Internet/Intranet 一方面，通信網(wǎng)絡(luò)為計(jì)算機(jī)之間的數(shù)據(jù)傳遞和 另一方面，數(shù)字計(jì)算技術(shù)的發(fā)展?jié)B透到通信技(主要是超大規(guī)模集成電路VLSI-VeryLargeScaleIntegratedcircuit技術(shù))上取得的輝煌成就。 5 N

ABAB

BCDCD

B :電路交鏈路帶寬, :電路交(e.g帶寬例如

400 分組分組分組據(jù)數(shù)分組據(jù)數(shù)據(jù)數(shù)據(jù)據(jù)數(shù)據(jù)數(shù)用這樣的轉(zhuǎn)發(fā)方式，最后分組就能到達(dá)分組據(jù)數(shù)分組據(jù)數(shù)據(jù)數(shù)據(jù)據(jù)數(shù)據(jù)數(shù)10 B

1.5

45 一種是，提供并接受預(yù)訂服務(wù) 賢進(jìn)樓 分組交換: DB H2HH2H6AH1H1H5C

最后到達(dá)目的主機(jī)H1H1向H5EAC 1Mb/s10

N

Mbps35個(gè)用戶同時(shí)激活小于 (虛電路ID), 1D23B123H111234H5A34124C 2040

報(bào)文報(bào)文 t

在電路交換中，已分配給線未用的帶寬只能浪費(fèi)分組交換是轉(zhuǎn)發(fā)的，會(huì)增加傳輸延時(shí)；電路交換 終 是有部分的，這是因?yàn)榫W(wǎng)絡(luò)的演進(jìn)是逐第一個(gè)分組交換網(wǎng)ARPANET個(gè)1983TCP/IP標(biāo)準(zhǔn)協(xié)議 1983~1984Internet1990ARPANET1991年， 199345Mb/s（T3速率）。

的ISP網(wǎng)絡(luò)所代替。1994年開始創(chuàng)建了4個(gè)網(wǎng)絡(luò)接入點(diǎn)NAP(NetworkAccessPoint4

ISP

網(wǎng)絡(luò)接入點(diǎn)地區(qū)本地backboneprovidersNBP)e.g.BBN/GTE,Sprint,AT&T,IBM,UUNet 點(diǎn)(NetworkAccessPoint,NAP

regionalNBPNBP本地ISP

Internet5000了4年時(shí)間

效率差別。網(wǎng)中每部的效率是1:1,電視網(wǎng)中每臺(tái)Data(Still)Overtaking00Source:MCI(VintToday’sEverythingisdigital:voice, music,picturesEverythingison-line:bankstatement,medicalrecord,books,airlineschedule,weather,highwaytraffic,toaster,refrigerator…Everyoneisconnected:doctor,teacher,broker,mother,son,friends,WhatisElectronicvirtualInternet WorldasasmallcommunityorganizedaccordingtoenhancedunderstandingamongdiverseElectroniclittlepeoplecanvoicetheiropinionstowhole

ordInternetPhysical

Enterprise/ISPaccess,–T1/T3,DS-1DS-–OC-3,OC-–ATMvs.SONET,vs.

Campus–Ethernet,InternetServicePointofPresenceNetworkAccessPoint 互聯(lián)網(wǎng) 互聯(lián)網(wǎng) 互聯(lián)網(wǎng)3WAN(WideAreaLAN(LocalAreaMAN(MetropolitanAreaAN(Access……(public(private4計(jì)算機(jī)網(wǎng)絡(luò)的主要性能指標(biāo):或b/s(bit/s)。kb/s（103Mb/s（106Gb/s（109Tb/s（1012請(qǐng)注意：在計(jì)算機(jī)界，K2101024M=220,G=230,T=240。1101101011每秒每秒10640.254時(shí)延(delay發(fā)送時(shí)延（傳輸時(shí)延） 時(shí)延(delay

信道長(zhǎng)度（米信號(hào)在信道上 時(shí)延(delay 時(shí)延(delay 從結(jié)點(diǎn)AB結(jié)點(diǎn)

101100

結(jié)點(diǎn) 時(shí)延帶RTTRound-TripTime)5OSIOSIOSIOSIOSITCP/IP 或約定即網(wǎng)絡(luò)協(xié)議(networkprotocol)，簡(jiǎn)稱

M HnHt HlHn

HnHt HlHn

TCP/IP是四層的體系結(jié)構(gòu)：應(yīng)用層、 因此往往采取折中的辦法，即綜合OSI和系結(jié)構(gòu)。ftp,smtp,tcp,ipppp,

計(jì)算機(jī)12計(jì)算機(jī)154321

計(jì)算機(jī)254321計(jì)算機(jī)12計(jì)算機(jī)5443322

應(yīng)用層PDU再傳送

計(jì)算機(jī)25432111計(jì)算機(jī)12計(jì)算機(jī)154321

IP（或分組

計(jì)算機(jī)254321計(jì)算機(jī)12計(jì)算機(jī)154321

計(jì)算機(jī)254321計(jì)算機(jī)12計(jì)算機(jī)544332211

計(jì)算機(jī)254321計(jì)算機(jī)12計(jì)算機(jī)154321

計(jì)算機(jī)254321 計(jì)算機(jī)12計(jì)算機(jī)154321

計(jì)算機(jī)254321計(jì)算機(jī)12計(jì)算機(jī)154321

計(jì)算機(jī)254321計(jì)算機(jī)12計(jì)算機(jī)5443322

1 1

計(jì)算機(jī)254321計(jì)算機(jī)12計(jì)算機(jī)5443322

計(jì)算機(jī)25432111計(jì)算機(jī)12計(jì)算機(jī)154321

計(jì)算機(jī)254321計(jì)算機(jī)12計(jì)算機(jī)154321

嘿嘿！我收到了AP1

計(jì)算機(jī)254321計(jì)算機(jī)12計(jì)算機(jī)

計(jì)算機(jī)54

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23 231 101001101001011計(jì)算機(jī)12計(jì)算機(jī)15432

計(jì)算機(jī)25432 10100110100101比特流 計(jì)算機(jī)12計(jì)算機(jī)154

2323

計(jì)算機(jī)54432111計(jì)算機(jī)12計(jì)算機(jī)154321

計(jì)算機(jī)544332211計(jì)算機(jī)12計(jì)算機(jī)

計(jì)算機(jī)5 55444333322221111計(jì)算機(jī)12計(jì)算機(jī)154321

PDU

計(jì)算機(jī)544332211計(jì)算機(jī)12計(jì)算機(jī)154321

嘿嘿！我收到了AP1

計(jì)算機(jī)254321 點(diǎn)SAP(ServiceAccess n1