计算机网络双语Andrew-STanenbaum第五版CNchapter1.pptx

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,2019/11/15,#,COMPUTER NETWORKS,TEACHER:HUAN,introduction,Chapter One,第,一,章,1,Uses of computer networks,2,Network hardware,3,Network software,4,Reference models,1 Uses of computer networks,Business applicatictions,Resource sharing(VPN),E-mail,Desktop sharing,E-commerce,Home applications,Twitter,Youtube,Facebook,Ubiquitous computing,Social issues,Sharing problems,Piracy,Privacy,Law problems,Mobile users,Smart phone,GPS,M-commerce,Wearable computer,Chapter two,第,二,章,1,Uses of computer networks,2,Network hardware,3,Network software,4,Reference models,2.1 Network hardware-transmission technology,Point-to-point,Point-to-point links connect individual pairs of machines,broadcast,On a broadcast network,the communication channel is shared by all the machines on the network,2.2 Network hardware-scale,2.2.1 Network hardware-scale,PAN,Personal Area Networks,2.2.2 Network hardware-scale,lAN,Local Area Networks,2.2.3 Network hardware-scale,mAN,Metropolitan Area Networks,2.2.4 Network hardware-scale,wAN,Wide Area Networks,Chapter three,第,三,章,1,Uses of computer networks,2,Network hardware,3,Network software,4,Reference models,3 Network software,Layer,Protocol,service,Connect-oriented service,Connectless service,Network architecture,3.1 Network software-layer,layer,To reduce their design complexity,most networks are organized as,a stack of layers,or,levels,each one built upon the one below it.,The purpose of each layer is to offer certain services to the higher layers while shielding those layers from the details of how the offered services are actually implemented.,3.2 Network software-protocol,protocol,A,protocol,is an agreement between the communicating parties on how communication is to proceed.,As an analogy,when a woman is introduced to a man,she may choose to stick out her hand.He,in turn,may decide to either shake it or kiss it,depending,for example,on whethershe is an American lawyer at a business meeting or a European princess at a formal ball.Violating the protocol will make communication more difficult,if not completely impossible.,3.3 Network software-interface,interface,Interface,is a connection point which exchange of informationbetween the adjacent layers.,The interface defines which primitive operations and,services,the lower layer makes available to the upper one.,3.4 Network software-service,service,A,service,is a set of operations that a layer provides to the layer above it.,A service relates to an interface between,two layers,with the lower layer being the service provider and the upper layer,being the service user.,Layers can offer two different types of service to the layers above them:,connection-,oriented,and,connectionless,.,3 Network software,3.4 Network software-network architecture,network architecture,A set of layers and protocols is called a,network architecture,.,Dutch,Chapter four,第,四,章,1,Uses of computer networks,2,Network hardware,3,Network software,4,Reference models,4 Reference models,OSI,TCP/IP,Used in This Book,Although the protocols associated with the OSI model are not used any more,the model itself is actually quite general and still valid,and the features discussed at each layer are still very important.,The TCP/IP model has the opposite properties:the model itself is not of much use but the protocols are widely used.,Since computer scientists like to have their cake and eat it,too,we will use the hybrid model of Fig.1-23 as the framework for this book.,4.1 Reference models-OSI,4.1 Reference models-OSI,4.2 Reference models-TCP/IP,4.3 Reference models-,Used in This Book,目前在计算机网络领域有影响的标准化组织：,1,、国际电信联盟（,ITU),2,、国际标准化组织（,ISO,）,3,、电子工业协会（,EIA,）,4,、电气与电子工程师协会（,IEEE,）,5,、,ATM,论坛,see,you,next,time,