What's the Internet:"nuts and bolts"view ■Internet:“network of networks” mobile network ·Interconnected ISPs global ISP protocols control sending,receiving of messages e.g.,TCP,IP,HTTP,Skype,802.1I home network ■Internet standards regional ISP RFC:Request for comments IETF:Internet Engineering Task Force institutional network Introduction 1-6
Introduction ▪ Internet: “network of networks” • Interconnected ISPs ▪ protocols control sending, receiving of messages • e.g., TCP, IP, HTTP, Skype, 802.11 ▪ Internet standards • RFC: Request for comments • IETF: Internet Engineering Task Force What’s the Internet: “nuts and bolts” view 1-6 mobile network global ISP regional ISP home network institutional network
What's the Internet:a service view mobile network infrastructure that provides services to applications: global ISP Web,VolP,email,games,e- commerce,social nets,... home provides programming etwork regional ISP interface to apps hooks that allow sending and receiving app programs to"connect"to Internet provides service options, analogous to postal service institutional network Introduction 1-7
What’s the Internet: a service view ▪ infrastructure that provides services to applications: • Web, VoIP, email, games, ecommerce, social nets, … ▪ provides programming interface to apps • hooks that allow sending and receiving app programs to “ connect ” to Internet • provides service options, analogous to postal service Introduction 1-7 mobile network global ISP regional ISP home network institutional network
What's a protocol? human protocols: network protocols: “what's the time?” machines rather than ·“I have a question” humans ■introductions all communication activity in Internet governed by ..specific messages sent protocols ..specific actions taken when messages protocols define format,order of received,or other events messages sent and received among network entities,and actions taken on message transmission,receipt Introduction1-8
Introduction What’s a protocol? human protocols: ▪ “what’s the time?” ▪ “I have a question” ▪ introductions … specific messages sent … specific actions taken when messages received, or other events network protocols: ▪ machines rather than humans ▪ all communication activity in Internet governed by protocols protocols define format, order of messages sent and received among network entities, and actions taken on message transmission, receipt 1-8
What's a protocol? a human protocol and a computer network protocol: Hi TCP connection request Hi TCP connection response Got the time? Get http://www.awicom/kurose-ross +—2:00 <file> time Q:other human protocols? Introduction1-9
Introduction a human protocol and a computer network protocol: Q: other human protocols? Hi Hi Got the time? 2:00 TCP connection response Get http://www.awl.com/kurose-ross <file> time TCP connection request What’s a protocol? 1-9
Chapter I:roadmap 1.I what is the Internet? 1.2 network edge end systems,access networks,links 1.3 network core packet switching,circuit switching,network structure 1.4 delay,loss,throughput in networks 1.5 protocol layers,service models 1.6 networks under attack:security 1.7 history Introduction1-10
Introduction Chapter 1: roadmap 1.1 what is the Internet? 1.2 network edge ▪ end systems, access networks, links 1.3 network core ▪ packet switching, circuit switching, network structure 1.4 delay, loss, throughput in networks 1.5 protocol layers, service models 1.6 networks under attack: security 1.7 history 1-10