Chapter1-Introduction.pdf

Introduction Chapter 1 Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Uses of Computer Networks Business Applications...

Introduction Chapter 1 Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Uses of Computer Networks Business Applications Company LANs, Resource Sharing, VPNs, Web Applications, client-server model, email, VoIP, e-commerce Home Applications Internet, client-server and p2p, messanging, social media, IPTV, smart home, Mobile Users Connectivity, hotspot, Cellular, SMS, GPS, m-commerce, RFID, NFC, Sensor network, wearables Social Issues and Applications Network neutrality Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Business Applications (1) A network with two clients and one server Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Business Applications (2) The client-server model involves requests and replies Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Home Applications (1) In a peer-to-peer system there are no fixed clients and servers. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Home Applications (2) Some forms of e-commerce Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Mobile Users Combinations of wireless networks and mobile computing Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Social Issues Network neutrality - communications that are not differentiated by their content or source or who is providing the content Digital Millennium Copyright Act - automated systems that search peer-to-peer networks and fire off warnings to network operators and users who are suspected of infringing copyright Profiling users – People privacy Phishing Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Network Hardware (1) Personal area networks Local area networks Metropolitan area networks Wide are networks The internet Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Network Hardware (1) Transmission Technology Broadcast link and point-to-point links Delivery Models Unicast Multicast Broadcast Anycast Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Network Hardware (2) Classification of interconnected processors by scale. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Personal Area Network Bluetooth PAN configuration Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Local Area Networks Wireless and wired LANs. (a) 802.11. (b) Switched Ethernet. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Metropolitan Area Networks A metropolitan area network based on cable TV. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Wide Area Networks (1) WAN that connects three branch offices in Australia Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Wide Area Networks (2) WAN using a virtual private network. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Wide Area Networks (3) WAN using an ISP network. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Wide Area Networks (3) Key Terms Packet Packet switching Routing Datagram Virtual Circuit Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Network Software Protocol hierarchies Design issues for the layers Connection-oriented versus connectionless service Service primitives Relationship of services to protocols Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Protocol Hierarchies (1) Layers, protocols, and interfaces. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Protocol Hierarchies (2) The philosopher-translator-secretary architecture Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Protocol Hierarchies (3) Example information flow supporting virtual communication in layer 5. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Connection-Oriented Versus Connectionless Service Six different types of service. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Service Primitives (1) Six service primitives that provide a simple connection-oriented service Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Service Primitives (2) A simple client-server interaction using acknowledged datagrams. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 The Relationship of Services to Protocols The relationship between a service and a protocol. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Reference Models OSI reference model TCP/IP reference model Model used for this text Comparison of OSI and TCP/IP Critique of OSI model and protocols Critique of TCP/IP model Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  The OSI Reference Model Principles for the seven layers Layers created for different abstractions Each layer performs well-defined function Function of layer chosen with definition of international standard protocols in mind Minimize information flow across interfaces between boundaries Number of layers optimum Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  The OSI Reference Model The OSI reference model Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  OSI Reference Model Layers Physical layer Data link layer Network layer Transport layer Session layer Presentation layer Application layer Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 The TCP/IP Reference Model Layers Link layer Internet layer Transport layer Application layer Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 The TCP/IP Reference Model (1) The TCP/IP reference model Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  The TCP/IP Reference Model (2) The TCP/IP reference model with some protocols we will study Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  The Model Used in this Book The reference model used in this book. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Comparison of the OSI and TCP/IP Reference Models Concepts central to OSI model Services Interfaces Protocols Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 Critique of the OSI Model and Protocols Bad timing. Bad technology. Bad implementations. Bad politics. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Example Networks Internet ARPANET NSFNET Third-generation mobile phone networks Wireless LANs: 802.11 RFID and sensor networks Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  The ARPANET (1) a) Structure of the telephone system. b) Baran’s proposed distributed switching system. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  The ARPANET (2) The original ARPANET design Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  The ARPANET (3) Growth of the ARPANET. December 1969. July 1970. March 1971. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  The ARPANET (4) Growth of the ARPANET. April 1972. September 1972. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  NSFNET The NSFNET backbone in 1988. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Architecture of the Internet Overview of the Internet architecture Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Third-Generation Mobile Phone Networks (1) Cellular design of mobile phone networks Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Third-Generation Mobile Phone Networks (2) Architecture of the UMTS 3G mobile phone network. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Third-Generation Mobile Phone Networks (3) Mobile phone handover (a) before, (b) after. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Wireless LANs: 802.11 (1) a) Wireless network with an access point. b) Ad hoc network. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Wireless LANs: 802.11 (2) Multipath fading Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Wireless LANs: 802.11 (3) The range of a single radio may not cover the entire system. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  RFID and Sensor Networks (1) RFID used to network everyday objects. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  RFID and Sensor Networks (2) Multihop topology of a sensor network Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Network Standardization Who’s Who in telecommunications Who’s Who in international standards Who’s Who in internet standards Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 Who’s Who in International Standards (1) The 802 working groups. The important ones are marked with *. The ones marked with  are hibernating. The one marked with † gave up and disbanded itself. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011 Who’s Who in International Standards (2) The 802 working groups. The important ones are marked with *. The ones marked with  are hibernating. The one marked with † gave up and disbanded itself. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Metric Units (1) The principal metric prefixes Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  Metric Units (2) The principal metric prefixes Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011  End Chapter 1 Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011