Ch1 - EEE 459 C m om unication Ne tworks S pring 2007 Prof M Re in issle C hapte 1 r I ntroduction Te xtbook C pute Ne om r tworking A Top Down Approach

Introduction 1-1 EEE 459 Communication Networks Spring 2007 Prof. M. Reisslein Chapter 1 Introduction Textbook: Computer Networking: A Top Down Approach Featuring the Internet, 3 rd edition. Jim Kurose, Keith Ross Addison-Wesley.

Introduction 1-2 Chapter 1: Introduction Our goal:  get “feel” and terminology  moredepth, detail later in course  approach: ❍ useInternet as example Overview:  what’s theInternet  what’s a protocol?  network edge  network core  access net, physical media  Internet/ISP structure  performance: loss, delay  protocol layers, servicemodels  network modeling

Introduction 1-3 Chapter 1: roadmap 1.1 What is theInternet? 1.2 Network edge 1.3 Network core 1.4 Network access and physical media 1.5 Internet structureand ISPs 1.6 Delay & loss in packet-switched networks 1.7 Protocol layers, servicemodels 1.8 History

Introduction 1-4 What’s the Internet: “nuts and bolts” view  millions of connected computing devices: hosts = end systems  running network apps  communication links ❍ fiber, copper, radio, satellite ❍ transmission rate = bandwidth  routers: forward packets (chunks of data) local ISP company network regional ISP router workstation server mobile

Introduction 1-5 What’s the Internet: “nuts and bolts” view  protocols control sending, receiving of msgs ❍ e.g., TCP, IP, HTTP, FTP, PPP  Internet: “network of networks” ❍ loosely hierarchical ❍ public Internet versus private intranet  Internet standards ❍ RFC: Request for comments ❍ IETF: Internet Engineering Task Force local ISP company network regional ISP router workstation server mobile

Introduction 1-6 What’s the Internet: a service view  communication infrastructure enables distributed applications: ❍ Web, email, games, e-commerce, file sharing  communication services provided to apps: ❍ Connectionless unreliable ❍ connection-oriented reliable

Introduction 1-7 What’s a protocol? human protocols:  “what’s thetime?”  “I havea 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

Introduction 1-8 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 <file> time

Introduction 1-9 Chapter 1: roadmap 1.1 What is theInternet? 1.2 Network edge 1.3 Network core 1.4 Network access and physical media 1.5 Internet structureand ISPs 1.6 Delay & loss in packet-switched networks 1.7 Protocol layers, servicemodels 1.8 History

Introduction 1-10 A closer look at network structure:  network edge: applications and hosts  network core: ❍ routers ❍ network of networks  access networks, physical media: communication links