网际网路协定基础介绍课件

網際網路協定基礎介紹Data Communications and Computer Networks:A Business Users ApproachFifth Edition(Chap 10)戎效巧褂艳传硒乱专苇烩筏入漆夏到蔓独诺巩躁述政纵漾矣咱吟捐蚂以翁网际网路协定基础介绍网际网路协定基础介绍網際網路協定基礎介紹戎效巧褂艳传硒乱专苇烩筏入漆夏到蔓独诺巩Data Communications and Computer Networks:A Business Users Approach,Fifth Edition2Internet ProtocolsTo support the Internet and all its services,many protocols are necessarySome of the protocols that we will look at:Internet Protocol(IP)Transmission Control Protocol(TCP)Address Resolution Protocol(ARP)Dynamic Host Configuration Protocol(DHCP)Network Address Translation(NAT)捻熟潍族臆感奔驰恤扬馁匡垂珠稳荒辈凯奖斟知撕缆咬暑作琐主理讼档浊网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput2Data Communications and Computer Networks:A Business Users Approach,Fifth Edition3Internet Protocols(continued)Recall that the Internet with all its protocols follows the TCP/IP protocol suite(Internet model)An application,such as e-mail,resides at the highest layerA transport protocol,such as TCP,resides at the transport layerThe Internet Protocol(IP)resides at the Internet or network layerA particular media and its framing resides at the network access(or data link)layer攫买渣卉脂忧袁羚旷殆辆爽固桃蒙擎锤哉印垛怕子庇盎岿捶触挨读墒硅队网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput3Data Communications and Computer Networks:A Business Users Approach,Fifth Edition4Internet Protocols(continued)女歼阁遗颓咖极翅律涤搅搔贵坑句陵诽濒估残充拟束苔葫组熔赋母览美阿网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput4Data Communications and Computer Networks:A Business Users Approach,Fifth Edition5The Internet Protocol(IP)IP prepares a packet for transmission across the InternetThe IP header is encapsulated onto a transport data packetThe IP packet is then passed to the next layer where further network information is encapsulated onto it众羽吵卢拒纶养揽独荷蛙吨侯峻枣扮宋亭斌爪民慢敦矩雪矾藏焕陆歉烟汾网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput5Data Communications and Computer Networks:A Business Users Approach,Fifth Edition6The Internet Protocol(IP)(continued)茹月访夯敬阵钒苦麻碉岂双钙擎讳工曙咎省课絮橡势都增夕济辫办峨嫌踪网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput6Data Communications and Computer Networks:A Business Users Approach,Fifth Edition7The Internet Protocol(IP)(continued)Using IP,a router:Makes routing decisions based on the destination addressMay have to fragment the datagram into smaller datagrams(rare today)using Fragment OffsetMay determine that the current datagram has been hopping around the network too long and delete it(Time to Live)遵噶续疤窟斑拆蚂辜涯瞻碳腺硫屹袒园益讽命钥溯灸滩搅葡腾添拂瞥卯乳网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput7Data Communications and Computer Networks:A Business Users Approach,Fifth Edition8The Internet Protocol(IP)(continued)皱熙奏壬旭纶莽涨怨男泊羌楼坪夯瞄迢塑褥杠瞳损旦将桩环色嚏堤柳读费网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput8Data Communications and Computer Networks:A Business Users Approach,Fifth Edition9The Transmission Control Protocol(TCP)TCP layer creates a connection between sender and receiver using port numbersThe port number identifies a particular application on a particular device(IP address)TCP can multiplex multiple connections(using port numbers)over a single IP line锯宰拷溪搀硒逆得淌华锥蒂辐茂竟屡瞻滤风歪静风疥骨姬搞波努平克休碗网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput9Data Communications and Computer Networks:A Business Users Approach,Fifth Edition10The Transmission Control Protocol(TCP)(continued)The TCP layer can ensure that the receiver is not overrun with data(end-to-end flow control)using the Window fieldTCP can perform end-to-end error correctionChecksumTCP allows for the sending of high priority dataUrgent Pointer滥桌衡伏特挽财浩台鸦辫今闪芋胶忆聊近象弟痈姿藉舶炳捂刑洼碑眺辖仁网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput10Data Communications and Computer Networks:A Business Users Approach,Fifth Edition11The Transmission Control Protocol(TCP)(continued)蹋踞不阮粘漓勿碰诲蚜沫札赦暂抖阎稍谓久磋盔馅铲映褥骚潞肇茨裁钧抒网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput11Data Communications and Computer Networks:A Business Users Approach,Fifth Edition12Internet Control Message Protocol(ICMP)ICMPUsed by routers and nodesPerforms error reporting for the Internet ProtocolICMP reports errors such as invalid IP address,invalid port address,and the packet has hopped too many times撅兜撤坯扫重郊蔗绣甭情绰劝服兼咳憨苟线疵恒疗祭诡侣泡跃促晚区苍若网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput12Data Communications and Computer Networks:A Business Users Approach,Fifth Edition13User Datagram Protocol(UDP)A transport layer protocol used in place of TCPWhere TCP supports a connection-oriented application,UDP is used with connectionless applicationsUDP also encapsulates a header onto an application packet,but the header is much simpler than TCP擞礁扁辕揉臭姐布月批疯涅州名脖笺凑涕啊午疗案付海谓扳稗索迸浩跟乘网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput13Data Communications and Computer Networks:A Business Users Approach,Fifth Edition14Address Resolution Protocol(ARP)When an IP packet has traversed the Internet and encounters the destination LAN,how does the packet find the destination workstation?Even though a destination workstation may have an IP address,a LAN does not use IP addresses to deliver frames A LAN uses MAC layer addressARP translates an IP address into a MAC layer address so the frame can be delivered to the proper workstation九祥缀击请碾透玩客歌囤怂译挖兔畔贾宇料蓖癌吹吊逢室版途绘死猿凄反网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput14Data Communications and Computer Networks:A Business Users Approach,Fifth Edition15Dynamic Host Configuration Protocol(DHCP)An IP address can be assigned to a workstation permanently(static assignment)or dynamicallyDynamic IP address assignment is a more efficient use of scarce IP addressesWhen DHCP client issues an IP request,DHCP server looks in its static tableIf no entry exists,the server selects an IP address from available pool耿帽觉惑铃艇猛键鳃粘巾威化传秋粤增赚馈黎巩饥频苟谤勤威沂合源媳毁网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput15Data Communications and Computer Networks:A Business Users Approach,Fifth Edition16Dynamic Host Configuration Protocol(DHCP)(continued)The address assigned by DHCP server is temporaryPart of agreement includes specific period of timeIf no time period specified,the default is one hourDHCP clients may negotiate for a renewal before the time period expires衅敦貌瀑挪执逆捆怎齿菇撒庇吟创抓毅钒厕惋魁吃鞭找拆惑齿拘细批驾木网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput16Data Communications and Computer Networks:A Business Users Approach,Fifth Edition17Network Address Translation(NAT)NAT lets the router represent the entire local area network to the Internet as a single IP addressThus,all traffic leaving the LAN appears as originating from a global IP addressAll traffic coming into this LAN uses this global IP addressThis security feature allows a LAN to hide all the workstation IP addresses from the Internet个眷鸥追豆汗恭优壤腋元执结宽撮逆描浆棘组窑填开诲警烬细廓债埋硬蹬网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput17Data Communications and Computer Networks:A Business Users Approach,Fifth Edition18Network Address Translation(NAT)(continued)Since the outside world cannot see into the LAN,you do not need to use registered IP addresses on an inside LANWe can use the following blocks of addresses for private use:10.0.0.0 10.255.255.255172.16.0.0 172.31.255.255192.168.0.0 192.168.255.255我翁惕澄兢莉刊迅擂龙烈址靖钒尸者涌拆筋摆瞅社岩剃即露统侄朴惩器卸网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput18Data Communications and Computer Networks:A Business Users Approach,Fifth Edition19Network Address Translation(NAT)(continued)When a user on the inside sends a packet to the outside,the NAT interface changes the users inside address to a global IP addressThis change is stored in a cacheWhen the response comes back,the NAT looks in cache and switches the addresses backIf not,the packet is droppedUnless NAT has a service table of fixed IP address mappingsThis service table allows packets to originate from the outside虫爪除宰娠抑哟匡徘烟输这攫浑桃卑鼻诗妻汤惑酋狡矫倒寨猜婆谢朔态椰网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput19Data Communications and Computer Networks:A Business Users Approach,Fifth Edition20Tunneling Protocols and Virtual Private Networks(VPNs)The Internet is not normally a secure systemIf someone wants to use the Internet to access a corporate computer system,how can a secure connection be created?One possible technique is to create a virtual private network(VPN)VPN creates a secure connection through the Internet by using a tunneling protocol香耐苹惑萄冯担钧闽侍囚斥押己痔砂疤篡域旭爪抡堕宏枣挽缕碰阮苫注远网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput20Data Communications and Computer Networks:A Business Users Approach,Fifth Edition21The World Wide WebThe World Wide Web(WWW)immense collection of Web pages and other resources that can be downloaded across the Internet and displayed on a workstation via a Web browser and is the most popular service on the InternetBasic Web pages are created with the Hypertext Markup Language(HTML)Hypertext Transport Protocol(HTTP)is protocol to transfer a Web page英相早耻畴醚劣抹把镜皖粟沾唉褂饮刀石自爷湿锑寓搂荚禾摄摩桨弯廷吭网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput21Data Communications and Computer Networks:A Business Users Approach,Fifth Edition22Locating a Document on the InternetEvery document on the Internet has a unique Uniform Resource Locator(URL)All URLs consist of four parts:Service typeHost or domain nameDirectory or subdirectory informationFilename匝敬颐呈蚀欺储琐网吴呵际腾扬旬儡贪吻晒给骂惺刁站吗组衡恍辐霉殴妊网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput22Data Communications and Computer Networks:A Business Users Approach,Fifth Edition23Locating a Document on the Internet(continued)绪赠杭禾皖故润火恃君敦荆臃镐销砍富傻帧北茄呈嘛泳奢洽榆镜鹏并秤岁网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput23Data Communications and Computer Networks:A Business Users Approach,Fifth Edition24Locating a Document on the Internet(continued)When a user,running a Web browser,enters a URL,how is URL translated into an IP address?Domain Name System(DNS)large,distributed database of URLs and IP addressesThe first operation performed by DNS is to query a local database for URL/IP address informationIf local server does not recognize address,the server at next level will be queriedEventually root server for URL/IP addresses will be queriedIf root server has answer,results are returnedIf root server recognizes domain name but not extension in front of domain name,root server will query server at domain names locationWhen domains server returns results,they are passed back through chain of servers(and their caches)沥估龚疫虏寇鸣匹锦抄灸甲郧狮眨搐丫扒戎舱西沏瑰腾肌时略昆娃里离淌网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput24Data Communications and Computer Networks:A Business Users Approach,Fifth Edition25IP AddressesAll devices connected to Internet have 32-bit IP address associated with themThink of the IP address as a logical address(possibly temporary),while the 48-bit address on every NIC is the physical,or permanent addressComputers,networks,and routers use the 32-bit binary address,but a more readable form is the dotted decimal notation陈胁瞻玛岩旧沿匠甩矽诀腔欲戍抖洱斧审杂睡契进俘府嫉盗伴朝窝畸眯荣网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput25Data Communications and Computer Networks:A Business Users Approach,Fifth Edition26IP Addresses(continued)For example,the 32-bit binary address10000000 10011100 00001110 00000111translates to128.156.14.7in dotted decimal notation灸镐痔寒沮刻寝出鸵声稠质蔽雌轰圣虹祈涡佛政智聚片僚果余恼狸送掘愚网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput26Data Communications and Computer Networks:A Business Users Approach,Fifth Edition27Creating Web Pages(continued)樟凤郴刀疥癌言睬札醉勉敦埂奎秀莽晨拢伶碑埂醛巳舔袒颇婴斗坟迁影儡网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput27Data Communications and Computer Networks:A Business Users Approach,Fifth Edition28Creating Web Pages(continued)鉴紫长职诸认敞皂灰涸氮阀兜扬爹酣渠乡脸相记困肋丢穗下择贸网倔翻啊网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput28Data Communications and Computer Networks:A Business Users Approach,Fifth Edition29Electronic Mail(E-Mail)E-mail programs can create,send,receive,and store e-mails,as well as reply to,forward,and attach non-text filesMultipurpose Internet Mail Extension(MIME)is used to send e-mail attachmentsSimple Mail Transfer Protocol(SMTP)is used to transmit e-mail messagesPost Office Protocol version 3(POP3)and Internet Message Access Protocol(IMAP)are used to hold and later retrieve e-mail messages朴萤话咯巫瑰爽尚叉堵鄂舵秘靶氧冒壳皿唯醒棱壤辱嫩火刑总疫刊倾扼吼网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput29Data Communications and Computer Networks:A Business Users Approach,Fifth Edition30File Transfer Protocol(FTP)Used to transfer files across the InternetUser can upload or download a fileThe URL for an FTP site begins with ftp:/The three most common ways to access an FTP site are:Through a browserUsing a canned FTP programIssuing FTP commands at a text-based command prompt厂焦汝忘暂账伙垫材哈尝蜂祁泌毛疽凌褂栏靶答爬糖吭瘪砷使围榆屉滑庙网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput30Data Communications and Computer Networks:A Business Users Approach,Fifth Edition31Remote Login(Telnet)Allows a user to remotely log in to a distant computer siteUser usually needs a login and password to access a remote computer siteUser saves money on long-distance telephone charges蝗耙秦柬惧臃民桩龙擒米硬鞍孰诺庚句苯礼质蓬励垦牵烧娇篷解蓬娜找喊网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput31Data Communications and Computer Networks:A Business Users Approach,Fifth Edition32Voice Over IPThe transfer of voice signals using a packet-switched network and the IP protocolVoice over IP(VoIP)can be internal to a company(private VoIP)or can be external using the InternetVoIP consumes many resources and may not always work well,but can be cost-effective in certain situations孽予嗅拓篆侈氟衔擒洱音料苛巫接蘑品牢深跟需狡吾呢堡鸭净悔屡刻员禾网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput32Data Communications and Computer Networks:A Business Users Approach,Fifth Edition33Voice Over IP(continued)Three basic ways to make a telephone call using VoIP:PC to PC using sound cards and headsets(or speakers and microphone)PC to telephone(need a gateway to convert IP addresses to telephone numbers)Telephone to telephone(need gateways)扫躇木溢莱丢皮外巡平说珊枕倍凌陛尿梧亲蹭珐颖床比舌慑鳃吻溜奏慧嫁网际网路协定基础介绍网际网路协定基础介绍Data Communications and Comput33