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Advanced Information Network

Advanced Information Network. Ashu Marasinghe (9372). Advanced Information Network Course Web and Evaluation. http://kjs.nagaokaut.ac.jp/ashu/AIN/AIN.html Evaluation 20% Class Attendance 40% Midterm Test 40% Final Project.

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Advanced Information Network

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  1. Advanced Information Network Ashu Marasinghe (9372) Introduction

  2. Advanced Information NetworkCourse Web and Evaluation http://kjs.nagaokaut.ac.jp/ashu/AIN/AIN.html • Evaluation20% Class Attendance • 40% Midterm Test40% Final Project Introduction

  3. High school friendship高校での友好関係– Information Network www-personal.umich.edu/~mejn/networks Introduction

  4. Food distribution in the lake- 湖での食物連鎖 www-personal.umich.edu/~mejn/networks Introduction

  5. Yeast proteins--酵母タンパク質- Information Network www-personal.umich.edu/~mejn/networks Introduction

  6. Highway –高速道路-Information Network Introduction

  7. Links of website -ウェブサイトのリンク Information Network www-personal.umich.edu/~mejn/networks Introduction

  8. Internet - Information Network www-personal.umich.edu/~mejn/networks Introduction

  9. USA network traffic – Information Network http://www.soulincode.com/images/usa_network_traffic_map.jpg Introduction

  10. Computer Networking: A Top Down Approach Featuring the Internet, 3rd edition. Jim Kurose, Keith RossAddison-Wesley, July 2004. Introduction

  11. 邦訳版 インターネット技術のすべて：トップダウンアプローチによる実践ネットワーク技法 第２版ジェームズ・F・クロセ(著), キース・W・ロス(著), 岡田 博美(翻訳)出版社:ピアソン・エデュケーション (2003/12/25) ASIN: 4894714949 Introduction

  12. Course Content • Computer Network and Internet • Application Layer • Transport Layer • Network Layer • Link Layer and LAN • Wireless and Mobile network (Optional) • Multimedia Networks (Optional) Introduction

  13. Chapter 1IntroductionComputer Network and Internet 第１章　イントロダクション Introduction

  14. Our goal:目標 get “feel” and terminology 　　概要把握 more depth, detail later in course 　　深い内容は後ほど approach:アプローチ use Internet as example Overview: 概要 what’s the Internetインターネットとは what’s a protocol?プロトコルとは network edgeネットワークエッジ network coreネットワークコア access net, physical mediaアクセス網， 物理媒体 Internet/ISP structureインターネット／ＩＳＰの構造 performance: loss, delay性能評価：ロス，遅延 protocol layers, service modelsプロトコル階層，サービス network modelingネットワークモデリング Chapter 1: Introduction Introduction

  15. Chapter 1: roadmap （内容）　 1.1 What is the Internet?　インターネットとは 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

  16. millions of connected computing devices: 繋がれた多数のコンピュータ機器hosts = end systems running network appsネットワークアプリケーション communication links 通信リンク fiber, copper, radio, satellite transmission rate = bandwidth routers: ルータforward packets (chunks of data) インターネットとは：　概観 router workstation server mobile local ISP regional ISP company network What’s the Internet: “nuts and bolts” view Introduction

  17. “Cool” internet appliances クールなインターネット器具 Web-enabled toaster + weather forecaster IP picture frame http://www.ceiva.com/ World’s smallest web server http://www-ccs.cs.umass.edu/~shri/iPic.html Internet phones Introduction

  18. protocols プロトコル　control sending, receiving of msgs e.g., TCP, IP, HTTP, FTP, PPP Internet: “network of networks”インターネット： “ネットワークのネットワーク” loosely hierarchical public Internet versus private intranet Internet standardsインターネットの標準化 RFC: Request for comments IETF: Internet Engineering Task Force インターネットとは：　概観 What’s the Internet: “nuts and bolts” view router workstation server mobile local ISP regional ISP company network Introduction

  19. communication infrastructure 通信インフラenables distributed applications: Web, email, games, e-commerce, file sharing communication services provided to apps:アプリに提供される通信サービス Connectionless unreliable connection-oriented reliable インターネットとは: サービスの視点から What’s the Internet: a service view Introduction

  20. human protocols: 人間のプロトコル（規約） “what’s the time?” “I have a question” introductions … specific msgs sent … specific actions taken when msgs received, or other events network protocols: ネットワークプロトコル machines rather than humans all communication activity in Internet governed by protocols What’s a protocol? プロトコルとは protocols define format, order of msgs sent and received among network entities, and actions taken on msg transmission, receipt Introduction

  21. a human protocol and a computer network protocol: 　ヒューマンプロトコル　　と　　ネットワークプロトコル TCP connection response Get http://www.awl.com/kurose-ross Got the time? 2:00 <file> time What’s a protocol? プロトコルとは Hi TCP connection request Hi Q: Other human protocols? Introduction

  22. Chapter 1: roadmap 内容 1.1 What is the Internet? 1.2 Network edge　ネットワークエッジ 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

  23. network edge: 　　ネットワークエッジ applications and hosts network core:ネットワークコア routers network of networks access networks, physical media:アクセス網，物理媒体communication links A closer look at network structure: ネットワーク構造：もう少し詳しく Introduction

  24. end systems (hosts):エンドシステム（ホスト） run application programs e.g. Web, email at “edge of network” client/server modelクライアント・サーバ モデル client host requests, receives service from always-on server e.g. Web browser/server; email client/server peer-peer model:ピアトゥーピア（P2P）モデル minimal (or no) use of dedicated servers e.g. Gnutella, KaZaA, Skype The network edge: ネットワークエッジ Introduction

  25. Goal: data transfer between end systems 目標： エンドシステム間のデータ転送 handshaking: setup (prepare for) data transfer ahead of time Hello, hello back human protocol set up “state” in two communicating hosts TCP - Transmission Control Protocol Internet’s connection-oriented service TCP service[RFC 793] TCPサービス reliable, in-order byte-stream data transfer loss: acknowledgements and retransmissions flow control: sender won’t overwhelm receiver congestion control: senders “slow down sending rate” when network congested Network edge: connection-oriented service ネットワークエッジ：コネクション指向型サービス Introduction

  26. Goal: data transfer between end systems 目標： エンドシステム間のデータ転送 same as before! UDP - User Datagram Protocol [RFC 768]: connectionless unreliable data transfer no flow control no congestion control App’s using TCP: TCPを使うアプリケーション HTTP (Web), FTP (file transfer), Telnet (remote login), SMTP (email) App’s using UDP: UDPを使うアプリケーション streaming media, teleconferencing, DNS, Internet telephony Network edge: connectionless service Introduction

  27. Chapter 1: roadmap 1.1 What is the Internet? 1.2 Network edge 1.3 Network core　ネットワークコア 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

  28. mesh of interconnected routers網目状に相互接続されたルータ郡 the fundamental question: how is data transferred through net?根本的な質問： データはネット上でどのように運ばれるのか？ circuit switching:回路交換dedicated circuit per call: telephone net packet-switching:パケット交換data sent thru net in discrete “chunks” The Network Core ネットワークコア Introduction

  29. End-end resources reserved for “call” “呼び出し”に対してエンド間のリソースが予約される link bandwidth, switch capacity dedicated resources: no sharing circuit-like (guaranteed) performance call setup required Network Core: Circuit Switching ネットワークコア：回線交換 Introduction

  30. network resources (e.g., bandwidth) divided into “pieces” ネットワーク資源（例：帯域）を分割 pieces allocated to calls resource piece idle if not used by owning call (no sharing) ネットワークコア：回線交換 Network Core: Circuit Switching • dividing link bandwidth into “pieces” • frequency division • time division Introduction

  31. 回線交換: 周波数分割多重と時分割多重 Example: 4 users FDM- Frequency-division multiplexing frequency time TDM-Time-division multiplexing frequency time Circuit Switching: FDM and TDM Introduction

  32. Numerical example 計算例 • How long does it take to send a file of 640,000 bits from host A to host B over a circuit-switched network?回線交換のネットワークで６４００００ビットのファイルをホストAからホストBまで送るのにどのくらいの時間がかかるか？ • All links are 1.536 Mbps • Each link uses TDM with 24 slots/sec • 500 msec to establish end-to-end circuit Let’s work it out! Introduction

  33. Another numerical exampleもう１つの計算例 • How long does it take to send a file of 640,000 bits from host A to host B over a circuit-switched network?回線交換のネットワークで６４００００ビットのファイルをホストAからホストBまで送るのにどのくらいの時間がかかるか？ • All links are 1.536 Mbps • Each link uses FDM with 24 channels/frequencies • 500 msec to establish end-to-end circuit Let’s work it out! Introduction

  34. each end-end data stream divided into packets それぞれのエンド間のデータストリームはパケットに分割される user A, B packets share network resources each packet uses full link bandwidth resources used as needed ネットワークコア：パケット交換 Bandwidth division into “pieces” Dedicated allocation Resource reservation Network Core: Packet Switching resource contention: リソース競合 • aggregate resource demand can exceed amount available • congestion: packets queue, wait for link use • store and forward: packets move one hop at a time • Node receives complete packet before forwarding Introduction

  35. Sequence of A & B packets does not have fixed pattern, shared on demand  statistical multiplexing. TDM: each host gets same slot in revolving TDM frame. パケット交換：統計多重 D E Packet Switching: Statistical Multiplexing 10 Mb/s Ethernet C A statistical multiplexing 1.5 Mb/s B queue of packets waiting for output link ＡとＢのパケット発生のパターンは異なる 統計多重 Introduction

  36. 1 Mb/s link each user: 100 kb/s when “active” active 10% of time circuit-switching: 10 users packet switching: with 35 users, probability > 10 active less than .0004 Packet switching allows more users to use network! パケット交換　対　回線交換 Packet switching versus circuit switching パケット交換はより多くのユーザのネットワーク利用を可能にする！ N users 1 Mbps link Q: how did we get value 0.0004? Introduction

  37. Great for bursty data resource sharing simpler, no call setup Excessive congestion: packet delay and loss輻輳（ふくそう）： パケットの遅延とロス protocols needed for reliable data transfer, congestion control Q: How to provide circuit-like behavior?　　回線交換のようなサービスをどのように提供するか？ bandwidth guarantees needed for audio/video apps still an unsolved problem (chapter 7) Is packet switching a “slam dunk winner?” パケット交換　対　回線交換 Packet switching versus circuit switching パケット交換は圧倒的な勝者か？ Q: human analogies of reserved resources (circuit switching) versus on-demand allocation (packet-switching)? Introduction

  38. Takes L/R seconds to transmit (push out) packet of L bits on to link or R bps Entire packet must arrive at router before it can be transmitted on next link: store and forward delay = 3L/R (assuming zero propagation delay) Example: L = 7.5 Mbits R = 1.5 Mbps delay = 15 sec パケット交換：蓄積転送 Packet-switching: store-and-forward L R R R more on delay shortly … Introduction

  39. Goal: move packets through routers from source to destination目的：パケットをルータを介して送信ホストから終点ホストまで運ぶ we’ll study several path selection (i.e. routing) algorithms (chapter 4) datagram network:データグラムネットワーク destination address in packet determines next hop routes may change during session analogy: driving, asking directions virtual circuit network:バーチャルサーキットネットワーク each packet carries tag (virtual circuit ID), tag determines next hop fixed path determined at call setup time, remains fixed thru call routers maintainper-call state ルータは呼び出しごとの状態を保持 パケット交換ネットワーク：転送 Packet-switched networks: forwarding Introduction

  40. Packet-switched networks Circuit-switched networks FDM TDM Datagram Networks Networks with VCs Network Taxonomy ネットワークの分類 Telecommunication networks • Datagram network is not either connection-oriented • or connectionless. • Internet provides both connection-oriented (TCP) and • connectionless services (UDP) to apps. Introduction

  41. Chapter 1: roadmap 内容 1.1 What is the Internet? 1.2 Network edge 1.3 Network core 1.4 Network access and physical media　ネットワークアクセス・物理媒体 1.5 Internet structure and ISPs 1.6 Delay & loss in packet-switched networks 1.7 Protocol layers, service models 1.8 History Introduction

  42. Q: How to connect end systems to edge router?エンドシステムをエッジルータにどのように接続するか？ residential access nets institutional access networks (school, company) mobile access networks Keep in mind: 重要 bandwidth (bits per second) of access network? shared or dedicated? アクセスネットワークと物理媒体 Access networks and physical media Introduction

  43. Dialup via modem ダイヤルアップ接続 up to 56Kbps direct access to router (often less) Can’t surf and phone at same time: can’t be “always on”（常時接続） ホームアクセス：ポイント・ツー・ポイントアクセス Residential access: point to point access • ADSL: asymmetric digital subscriber line • up to 1 Mbps upstream (today typically < 256 kbps) • up to 8 Mbps downstream (today typically < 1 Mbps) • FDM: 50 kHz - 1 MHz for downstream 4 kHz - 50 kHz for upstream 0 kHz - 4 kHz for ordinary telephone Introduction

  44. HFC: hybrid fiber coax asymmetric: up to 30Mbps downstream, 2 Mbps upstream network of cable and fiber attaches homes to ISP router homes share access to router deployment: available via cable TV companies Residential access: cable modems ホームアクセス：ケーブルモデム Introduction

  45. ホームアクセス：ケーブルモデム Residential access: cable modems Diagram: http://www.cabledatacomnews.com/cmic/diagram.html Introduction

  46. ケーブルネットワークアーキテクチャ：概要 Cable Network Architecture: Overview Typically 500 to 5,000 homes cable headend home cable distribution network (simplified) Introduction

  47. ケーブルネットワークアーキテクチャ：概要 Cable Network Architecture: Overview cable headend home cable distribution network (simplified) Introduction

  48. ケーブルネットワークアーキテクチャ：概要 server(s) Cable Network Architecture: Overview cable headend home cable distribution network Introduction

  49. ケーブルネットワークアーキテクチャ：概要 C O N T R O L D A T A D A T A V I D E O V I D E O V I D E O V I D E O V I D E O V I D E O 5 6 7 8 9 1 2 3 4 Channels Cable Network Architecture: Overview FDM: cable headend home cable distribution network Introduction

  50. company/univ local area network (LAN) connects end system to edge router Ethernet:イーサネット shared or dedicated link connects end system and router 10 Mbs, 100Mbps, Gigabit Ethernet LANs: chapter 5 企業アクセス： LAN Company access: local area networks Introduction

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