Computer Networks Zili Zhang(张自力) Faculty of Computer and Information Science Southwest China Normal University Introduction 1-1
Introduction 1-1 Computer Networks Zili Zhang(张自力) Faculty of Computer and Information Science Southwest China Normal University
Chapter Computer Networks and the Internet Computer Networking The powerPoint slides are based on the material A Top Down Approach provided by Featuring the Internet, J. f Kurose and K.W. ross 2nd edition Jim Kurose, Keith Ross Addison-Wesley, July 2002 Introduction 1-7
Introduction 1-7 Chapter 1 Computer Networks and the Internet Computer Networking: A Top Down Approach Featuring the Internet, 2nd edition. Jim Kurose, Keith Ross Addison-Wesley, July 2002. The PowerPoint Slides are based on the material provided by J.F Kurose and K.W. Ross
Chapter 1: Introduction Our goal: Overview: 口 get context, 口 What's the internet overview, feel"of o what's a protocol? networ King 口 network edge 口 more depth, detai 口 network core later in course a access net, physical media 口 approach a Internet/IsP structure descriptive m use internet as a performance: loss, delat example a protocol layers, service models u history Introduction 1-8
Introduction 1-8 Chapter 1: Introduction Our goal: q get context, overview, “feel” of networking q more depth, detail later in course q approach: m descriptive m use Internet as example Overview: q what’s the Internet q what’s a protocol? q network edge q network core q access net, physical media q Internet/ISP structure q performance: loss, delay q protocol layers, service models q history
Chapter 1: roadmap 1.1 What is the Internet? 1.2 Network edge 1.3 Network core 1.4 Network access and physical media 1.5 Internet structure and isps 1.6 delay loss in packet-switched networks 1. 7 Protocol layers, service models 1. 8 History Introduction 1-9
Introduction 1-9 Chapter 1: roadmap 1.1 What is the Internet? 1.2 Network edge 1.3 Network core 1.4 Network access and physical media 1.5 Internet structure and ISPs 1.6 Delay & loss in packet-switched networks 1.7 Protocol layers, service models 1.8 History
What's the Internet: "nuts and bolts"view O millions of connected router computing devices: hosts workstation end-systems server mobile PCs workstations servers 丹IsP m PDAs phones, toasters running network apps ●●● 口 communication links regionalISM wn fiber copper radio satellite m transmission rate= bandwidth o routers: forward packets company (chunks of data) network Introduction 1-1
Introduction 1-10 What’s the Internet: “nuts and bolts” view q millions of connected computing devices: hosts, end-systems m PCs workstations, servers m PDAs phones, toasters running network apps q communication links m fiber, copper, radio, satellite m transmission rate = bandwidth q routers: forward packets (chunks of data) local ISP company network regional ISP router workstation server mobile
Cool"internet appliances IP picture frame http://ww.ceiva.com/ Veb-enabled toaster +weather forecaster Worlds smallest web server http://www-ccs.cs.umass.edU/-ShrI/ipic.html Introduction 1-1
Introduction 1-11 “Cool” internet appliances World’s smallest web server http://www-ccs.cs.umass.edu/~shri/iPic.html IP picture frame http://www.ceiva.com/ Web-enabled toaster+weather forecaster
What's the Internet: "nuts and bolts"view protocols control sending router workstation receiving of msgs server m e.g., Tcp Ip Http Ftp ppP mobile D Internet: network of 叫lIsP networks loosely hierarchica ●●● m public Internet versus regional/TSP private intranet 口 Internet standards m RFC: Request for comments m IETF: Internet Engineering Task Force company y 9 network Introduction 1-12
Introduction 1-12 What’s the Internet: “nuts and bolts” view q protocols control sending, receiving of msgs m e.g., TCP, IP, HTTP, FTP, PPP q Internet: “network of networks” m loosely hierarchical m public Internet versus private intranet q Internet standards m RFC: Request for comments m IETF: Internet Engineering Task Force local ISP company network regional ISP router workstation server mobile
What's the Internet: a service view 口 communication infrastructure enables distributed applications 國 mm Web, email, games,e commerce database ●●●■ voting, file (MP3)sharing a communication services provided to apps w connectionless m connection-oriented 口 cyberspace[ Gibson] a consensual hallucination experienced daily by billions of operators, in every nation Introduction 1-13
Introduction 1-13 What’s the Internet: a service view q communication infrastructure enables distributed applications: m Web, email, games, e- commerce, database., voting, file (MP3) sharing q communication services provided to apps: m connectionless m connection-oriented q cyberspace [Gibson]: “ a consensual hallucination experienced daily by billions of operators, in every nation,
What's a protocol? human protocols network protocols: 口" what's the time? 口 machines rather than 口" i have a question" humans 口 introductions 口 all communication activity in Internet specific msgs sent governed by protocols specific actions taken protocols define format, when msgs received order of msgs sent and or other events received among network entities. and actions taken on msg transmission, receipt Introduction 1-14
Introduction 1-14 What’s a protocol? human protocols: q “ what’s the time?” q “I have a question” q introductions … specific msgs sent … specific actions taken when msgs received, or other events network protocols: q machines rather than humans q all communication activity in Internet governed by protocols protocols define format, order of msgs sent and received among network entities, and actions taken on msg transmission, receipt
What's a protocol? a human protocol and a computer network protocol TCP connection req TCP connection Got the response time? Gethttp://www.awl.com/kurose-ross 2:00 file fime Q: Other human protocols? Introduction 1-15
Introduction 1-15 What’s a protocol? a human protocol and a computer network protocol: Q: Other human protocols? Hi Hi Got the time? 2:00 TCP connection req TCP connection response Get http://www.awl.com/kurose-ross time