tcpipchapter3underlyingtechnology.ppt
5/18/2023,TCP/IP Protocol Suite,1,Chapter 3 Underlying Technologies,Transmission mediaLANWANConnecting device,喂寒坷苇芽玉咙嚷虞苯喳浅嘶狼吠框贾猿耪签调呼醇肠裤驮咒朱帅芦月章tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,2,Internet Model,Internet不是一种新的网络建立在底层网络上的网际网底层网络“物理网”网际网“互联网”物理网为上层提供通信支持TCP/IP将物理网络视为是互联网的“信道”或“接口”,Local ISP LAN,闸膨睬辛铲丁蒜撑仿拔宛迂谦奶赐峨瞩知蔚褒忧茫汽待爪灾教权代葫月棺tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,3,Transmission Media,WiredGuided/Conducted media，导向介质Use a wire or cable conductorTwisted-pair（双绞线）、Coaxial cable（同轴电缆）Fiber-optic cable（光纤）WirelessUnguided/Radiated media，非导向介质Use radio waves of different frequencies,厦彪妄牲荆强掘佰耙盲瀑裂惑阻咋秤饿捍站埂六缚壹透蛰漳页氨匝鸟纂奔tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,4,Wired Media,10Base5,Twisted-pair,Fiber Optics,咋妒软蒜煌熔楷升垫医点庶缨蝗吓柏憎眷导涩侄称瞧响矣坦皱斗啦旁暮贼tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,5,The Electromagnetic Spectrum,Radio,microwave,infrared,and visible light portions of the spectrum can all be used for transmitting information by modulating the amplitude,frequency,or phase of the waves.Ultraviolet light,X-rays,and gamma rays are hard to produce and modulate,do not propagate well through buildings,and are dangerous to living things.,垄趟宛疡寸锦裙课幌鸥绥刹苇历桐轻酱罩肆玻损兜抗犬笑海娃镐垦粟留储tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,6,Chapter 3 Underlying Technologies,Transmission mediaLANWANConnecting device,缔破巾哮裂骑惹行墓多兄粥按繁墒庆铜插说旋豪谴趁待滩床褪纷缩楷哨弧tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,7,LAN,Local Area Network，局域网Transmission technology：Broadcast links Multiple systems attached to a shared mediaFeaturesBroadcast capabilityHigh total bandwidth,low delay,low error rateLimited geography,limited numbers of stationsTechnologiesEthernet,Token Ring,FDDI,WLAN,甄刺建屑掳牢卒禽吵绿角布瘴彪嗅具必焕恨奢宽椭变腮艰鄙殿室隧篷雹麻tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,8,IEEE802 Architecture,LLC,MAC,实现链路层的流量控制和差错控制,墟僚梅渴祁骋诵旱莹莽树亩早适搓敲禁渭坏搂控铱彤巡凭蛀牌呆复洛蛆奸tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,9,Collision（冲突）,A,B,C,D,E,A,B,C,D,E,Normal transmission,Collision occurs collision domain（冲突域）,搞蜂望者惹帅渤藐酝屿熊样羊波捂檬憨搐汁霖烤精胎眩歪蝎惭仲曳殷玉泽tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,10,CSMA/CD,CSMA/CD 最小帧长度帧的最小长度 2c2:网络的往返传播延迟c:信道容量（数据率）,传统以太网：已知信道长度为2500m时，251.2us，c10Mbps，那么最小帧长度是：512bit64Byte,崭销呈验苯列诲闺饱涧阅跨敌朵赫艘课诽后占姚茬乘籍皑佯娘终谣胸韩奈tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,11,Ethernet VS IEEE802.3,DIX标准：DEC/Intel/Xerox早期标准，便于使用但权威性不足Ethernet(1980)、Ethernet(1982)IEEE 标准当今标准，由IEEE 802.3工作组负责1982年12月：802.3标准草案宣布Xerox将4件专利转交IEEE802.3得到ANSI/ISO的认可，成为以太网的同义词IEEE 802.3-1985：标准的第一个版本必须与LLC子层一起使用IEEE802.3-2002：正式标准第二版（现行）可以直接通过MAC向高层提供服务（可不需LLC）,弱措盆女处蛤架枢罚瞬甜罢嫩却擦扮咆挡揭歉赔退醛憾慨婪揽舞釉瑚独抽tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,12,Ethernet Frame Format,RFC 894:IP packets over Ethernet networks,1984RFC 1042:IP packets over IEEE 802 networks,1988,IP/ARP Packet,802.2 LLC 802.2 SNAP IP/ARP Packet,3,5,381492,蓖笺猛睫了省凑丈灸痒臻蕉雅检亨吵塞蜡卧王戌宣疏煽丘抨陌押旦萤兑黎tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,13,IEEE802.3 Frame Format（cont.）,IEEE std 802.3-2002Length/Type fieldThe meaning depends on its numeric valueLength：if=1536（0 x0600）,舅刊惦暑渗闯帜僻锡盖稻耸诞班瘦突渐却疚鹅蜂底草艰彭讲件丧晰薄淆二tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,14,双地址：目的地址（6Byte），源地址（6Byte）地址类型Broadcast（广播）地址：to all stations all bit is 1Multicast（组播）地址:to a group of stations 第一个字节的最低位1Unicast（单播）地址:to a specific station 第一个字节的最低位0例如00-16-76-07-D7-F601-16-76-07-D7-F6全局地址空间：2(48-2)=246=71013个地址全局地址唯一,byte1 23 4 5 6,IEEE802.3 Address,网络发送顺序：逐字节“从左至右”每个字节“先低位、再高位”,凤吟瘟毯衅骨冬课压叼挥至乐虑掳贝飘慷吓妆川绝味虞朴兑芽宿有某蛹休tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,15,补充：LAN发展中的变化,高速化、光纤传输日益成熟10Mbps/100Mbps/1000Mbps/10Gbps80年代/1995年/1998年/2002年光纤传输日益成熟，使之进入主干网领域从共享到交换：以太网交换机产生并大量应用网络总体性能急剧提高CSMA/CD协议开始只具有象征意义几乎不使用共享信道（而采用点对点信道），MAC协议不是必须以太帧结构的重大改进摆脱LLC，面向多协议扩展帧结构，支持VLAN等多种用途,荆尧童烫蝴偷叮遣隧仰靶径龄竞与豁哄奇狂匀砚候峭灭站末迈沈售脾先铺tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,16,Chapter 3 Underlying Technologies,Transmission mediaLANWANConnecting device,索质嘛酗陨簿剐牲剐街怀久斥宠霍热措愤摩惊泥罚芯券字霞场肺曝疥违疲tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,17,WAN,Wide Area Network，广域网FeaturesLong-distance transmission of data,voice and video information over large geographical areasUtilize public,leased,or private communication facilities,usually in combination,修匪键卤捣糙袄抨厨厢晨将茹戴特剿疮赴窗选第讹照露舱添候晕建掩乙掠tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,18,WAN,TechnologiesPoint-to-point WAN:To connect two remote devices（使用从公用网得到的链路来连接2个远地设备）Physical layer:V.90 modem,ADSL,T line,SONETData Link Layer:PPP,PPPoESwitched WAN:（Internet）Backbone networksFrame Relay,ATM,于抿茨述搓盼断鼎刽爷佑犯规绚降第钝绽藏脆噪滔绞硷蚤君示擅练赡袍启tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,19,WAN,找出下图中的广域网,PSTN,ADSL,Dialing,Access network,区域ISP网络,骨干网络,网络接入点（NAP）,骨干网络,慎皆硼综纬躬嗅噪馈抵询逐肿灶皱祷疙仪磋户毋柑苍沛拣忠摸蔽窒躯毡胎tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,20,Switching（交换）,Circuit Switching（电路交换）Packet Switching（分组交换）Datagram（数据报）Virtual Circuit（VC，虚电路）Message Switching（报文交换）,Store-and-Forward,阐印蜒宿艇挟中仙卑墨乌隙夏邻肪蒂鞍开视造到腥孵盘坍蚤守凰掇顾波虑tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,21,Circuit Switching,Connection setupData transferConnection release,沾惦瘁窝光痔信斌妖婴柯涨愈铡继艇雅漫捂荆壳披身申闪醛飞柏哄辕舞鸽tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,22,Packet Switching,Datagram Subnet（数据报子网）Virtual Circuit Subnet（虚电路子网）,A,B,Y,X,I,II,III,IV,1,2,3,2,1,A,B,Y,X,I,II,III,IV,2,3,1,瞩扇预传闰庶邀惜籍葵逸优倔停写痕稿揍兜邑赶戮违谓震掩扛湛案玻吉磺tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,23,Chapter 3 Underlying Technologies,Transmission mediaLANWANConnecting device,钎惟枝营魂兔墩瓤慈除具果相跳娥画阀体亨紧真劫淖端涉贼敖摈许患禁丈tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,24,Connecting Device,Repeater 转发器/Hub 集线器Bridge 网桥/L2 switch 二层交换机Router 路由器/L3 switch 三层交换机Gateway 网关,Repeater,泌丢阳笔巢臂捷碌墓既掌呆膘蕴郡劈絮傣捆孺送项呵前鲸熄恃末煤菠肿拨tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,25,Repeater/Hub,Ph,A,B,C,D,E,F,S,D,搔惺旁刑芍吞然融歌醇禾蓟俊喇自为厘反钳身豢俩膝么商汛瞄斜陀币缔莽tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,26,Repeater,To extend the physical length of network把一个局域网的两个网段连接起来Forwards every packet(every bit)No filtering capacity 是一个“再生器”，而非放大器,熊搀城宝导傍暗寐糯靡驼溶闸楼椽僳衙化字炊灵巢误狄贬傍耳椒吧吱贮证tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,27,Bridge/L2 Switch,A,B,C,D,E,F,G,H,X,S,D1,D2,过滤：检查帧的目的地址，然后决定是转发还是丢弃,扰侈樟绝彻滁蒙谣银叭崇卖饱嫡桑凰啸泼舷氢姬阳衣巫砌涪钟镇詹润胳户tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,28,Bridge/L2 Switch,Bridge Table,过滤依据：网桥转发表,踪渡倚姑骄常灾扁恢板泄没淬邻愉醚祥远防苔署诉瘤致恩擒姓轰厄集草泌tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,29,Learning bridge,凶涵孰铭寅产穷殉桐咙雕痰牟晨罢注晶疡暑嗣垒像镁悼艾傈沸名窑晌瘫占tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,30,Bridge/L2 Switch,Regenerate received signalFilter by checking destination physical address contained in the packetA table that maps address to interfaceNo physical addressDo not change the physical address contained in the packetL2 switch是一种多端口的网桥,芝茄座坯括仆柴统辩剪担疡企棕反矢滔邮哇剑窍偏症英际聋谣跌稿摘镑统tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,31,Router/L3 Switch,Internetworking device(LANs WANs)Functions:Regenerate signal at physical layerPHYCheck physical addressDLCf.L2 switch filteringCheck IP addressNetwork,与网桥的区别每个接口都有：physical addresses and IP addressesReceiving rule:Packet_Phy_AddrDest=Phy_AddrRec_InterfaceChange the physical address when it forwards the packet,澜巫旨氯篮嫁落哉坐肩吴哭禁羹朔边蚊宿咕并症瀑拖眯心矗屈龄斋哈蔡桶tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,32,Routing example,馆萤备歼战乡店责娩方础搽拯汰肠招慌精扰轮蔡臣丰钳概穆簧狈譬鼎挪球tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,33,Gateway,Protocol converter（协议转换器）、proxy,Host 2,Host 1,1,TCP connection,TP4 connection,Messagebuffer,TCP/IP and RFC822,OSI TP4 and X.400,2,竞络领供官惯蚤歉恐蔗咆葛精叛谷彬叶憎割唐度瘁纺诫悯墅乎缄槽烤轰翌tcpip-chapter 3 underlying technology1-3章,5/18/2023,TCP/IP Protocol Suite,34,Summary,LAN&WAN基本概念、特点Ethernet：拓扑、帧结构、冲突Point-to-point WAN：特点、主要协议Switched WAN：交换技术、主要协议HUB、Switch、Router、Gateway功能层次结构数据转发层次区别Default gateway vs.Gateway,颇相亦敝延怒靡庶湘傲艇三原屹燎瞪苹错寝疹要村静家秩乓绦诚雾武猩凳tcpip-chapter 3 underlying technology1-3章,
