香港科技大学：《计算机网络 Computer Networks》课程教学资源（PPT课件）Chapter 1 Introduction of computer networking

COMP 561:Computer Networks Qian Zhang Fd2008 HKUST

Introduction 1-1 COMP 561: “Computer Networks” Qian Zhang Fall 2008 HKUST

Chapter 1 oInpulcr Networking Introduction A note on the use of these ppt slides James F Kuse. Keith W Ross The notes used in this course are substantially based on powerpoint slides developed and Computer Networking copyrighted by J.F. Kurose and K.W. Ross, 2007 A Top Down Approach 4th edition Jim Kurose. Keith ross Addison-Wesley, July 2007 Introductio 1-6

Introduction 1-6 Chapter 1 Introduction Computer Networking: A Top Down Approach , 4th edition. Jim Kurose, Keith Ross Addison-Wesley, July 2007. A note on the use of these ppt slides: The notes used in this course are substantially based on powerpoint slides developed and copyrighted by J.F. Kurose and K.W. Ross, 2007

Chapter 1: Introduction ur god Overview: 口Get"feel"and 口 What's the Internet? terminology 口 More depth, detai 口 What's a protocol? later in course a Network edge; hosts,access Approach net, physical media ☆凵 se Internet as a Network core: packet/circuit example switching, Internet structure a Performance: loss, delay throughput 口 Security a Protocol layers, service models 口 Histo Introductio

Introduction 1-7 Chapter 1: Introduction Our goal: ❑ Get “feel” and terminology ❑ More depth, detail later in course ❑ Approach: ❖ use Internet as example Overview: ❑ What’s the Internet? ❑ What’s a protocol? ❑ Network edge; hosts, access net, physical media ❑ Network core: packet/circuit switching, Internet structure ❑ Performance: loss, delay, throughput ❑ Security ❑ Protocol layers, service models ❑ History

Chapter 1: roadmap 1.1 What is the Internet? 1.2 Network edge O End systems, access networks, links 1.3 Network core a Circuit switching, packet switching, network structure 1.4 Delay, loss and throughput in packet-switched networks 1.5 Protocol layers, service models 1.6 Networks under attack: securi 1.7 History Introduction 1-8

Introduction 1-8 Chapter 1: roadmap 1.1 What is the Internet? 1.2 Network edge ❑ End systems, access networks, links 1.3 Network core ❑ Circuit switching, packet switching, network structure 1.4 Delay, loss and throughput in packet-switched networks 1.5 Protocol layers, service models 1.6 Networks under attack: security 1.7 History

What's the Internet: nuts and bolts"view C口 Millions of connected Mobile network computing devices Global isp wireless hosts end systems apOp g Running network cellular handheld apps Home network O Communication links Relgiona) ISP access 令Fber, copper, points radio, satellite Institutional network wired links Transmission rate bandwidth 画越 口 Routers: forward packets(chunks of data) Introductio 1-9

Introduction 1-9 What’s the Internet: “nuts and bolts” view ❑ Millions of connected computing devices: hosts = end systems ❖ Running network apps Home network Institutional network Mobile network Global ISP Regional ISP router PC server wireless laptop cellular handheld wired links access points ❑ Communication links ❖ Fiber, copper, radio, satellite ❖ Transmission rate = bandwidth ❑ Routers: forward packets (chunks of data)

What's the Internet: "nuts and bolts"view Protocols control sending Mobile network receiving of msgs Global isp D e.g., Tcp, Ip, Http, Skype Ethernet 口 nternet:" network of Home network Regional IsP networks Loosely hierarchical x Public internet versus Institutional network private intranet 口 Internet standards o RFC: Request for comments 画越 ETF: Internet Engineering Task force Introduction 1-10

Introduction 1-10 What’s the Internet: “nuts and bolts” view ❑ Protocols control sending, receiving of msgs ❖ E.g., TCP, IP, HTTP, Skype, Ethernet ❑ Internet: “network of networks” ❖ Loosely hierarchical ❖ Public Internet versus private intranet ❑ Internet standards ❖ RFC: Request for comments ❖ IETF: Internet Engineering Task Force Home network Institutional network Mobile network Global ISP Regional ISP

What's the Internet: A Service View 口 Communication infrastructure enables distributed applications .o Web, VoIP, email, games e-commerce, file sharing O Communication services provided to apps e Reliable data delivery from source to destination 4 o"Best effort"unreliable) data delivery Introduction 1-11

Introduction 1-11 What’s the Internet: A Service View ❑ Communication infrastructure enables distributed applications: ❖ Web, VoIP, email, games, e-commerce, file sharing ❑ Communication services provided to apps: ❖ Reliable data delivery from source to destination ❖ “Best effort” (unreliable) data delivery

What's a protocol? Human protocols: Network protocols: aWhat'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 msas received order of msgs sent and or other events received among network entities. and actions taken on msg transmission, receipt Introductio 1-12

Introduction 1-12 What’s a Protocol? Human protocols: ❑ “What’s the time?” ❑ “I have a question” ❑ Introductions … specific msgs sent … specific actions taken when msgs received, or other events Network protocols: ❑ Machines rather than humans ❑ 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 requesT TCP connection Got the response time? http://www.awl.com/kurose-ross 2:00 fime file Q: Other human protocols? Introduction 1-13

Introduction 1-13 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 request TCP connection response Get http://www.awl.com/kurose-ross time

Chapter 1: Roadmap 1.1 What is the Internet? 1.2 Network edge O End systems, access networks, links 1.3 Network core a Circuit switching packet switching, network structure 1.4 Delay, loss and throughput in packet-switched networks 1.5 Protocol layers, service models 1.6 Networks under attack: securi 1.7 History Introduction 1-14

Introduction 1-14 Chapter 1: Roadmap 1.1 What is the Internet? 1.2 Network edge ❑ End systems, access networks, links 1.3 Network core ❑ Circuit switching, packet switching, network structure 1.4 Delay, loss and throughput in packet-switched networks 1.5 Protocol layers, service models 1.6 Networks under attack: security 1.7 History