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CPET 355 Data Communications and Networking Paul I-Hai Lin, Professor Electrical and Computer Engineering Technology Purdue University, Fort Wayne Campus Jan. 7, 2004 Prof. Paul Lin 1 Data Communication Data: • Refers to: Information, Facts, Concepts, Instructions • Represented by: binary information units (bits: 0, 1) • Consists of: text, numbers, pictures, sound, or video Jan. 7, 2004 Prof. Paul Lin 2 Data Communication (continue) Data Communication • Exchange of data between devices via some form of transmission medium Jan. 7, 2004 Prof. Paul Lin 3 Data Communication (continue) Three Fundamental Characteristics • How to Delivery: source, destination, transmission signal, encoding, media, interfacing, multiplexing • Accuracy of Delivery: reliable and error free • Timeliness: efficient, real-time Jan. 7, 2004 Prof. Paul Lin 4 A Communication Model Message, Sender, Medium, Receiver, and Protocol Message • Text, numbers, pictures, sound, video, or a combination of these messages Sender • Computer, workstation, server, telephone handset, video camera, etc Jan. 7, 2004 Prof. Paul Lin 5 A Communications Model (continue) Medium • Twisted pair wire, coaxial cable, fiberoptic cable, laser, radio waves, microwaves Receiver • Computer, workstation, server, etc Protocol • A set of rules that govern data communications (HTTP, TCP/IP, PPP, etc ) Jan. 7, 2004 Prof. Paul Lin 6 Communications Tasks Message Formatting Encryption, or Encoding (Security) Addressing Routing Synchronization Flow Control Jan. 7, 2004 Prof. Paul Lin 7 Communications Tasks (continue) Exchange Management Error Detection and Correction Recovery Network Management Jan. 7, 2004 Prof. Paul Lin 8 Overview of Computer Networks Introduction Uses of Computer Networks Network Hardware Network Software Reference Models and Standards Example Networks Jan. 7, 2004 Prof. Paul Lin 9 Introduction Computer Network • A collection of autonomous computers interconnected by a single technology Internet • A network of networks World Wide Web • A distributed system that runs on the top of the Internet Jan. 7, 2004 Prof. Paul Lin 10 Introduction Distributed System • A collection of independent computers appears to its user as a single coherent system • A software system built on the top of a network Middleware • A software sit on the top of the OS for implementing distribution systems Jan. 7, 2004 Prof. Paul Lin 11 Definition of a Network A set of nodes (hosts) connected by media links for resource sharing, communications, etc A Node: computer, server, printer, etc A Link: communication channel Resources: printer, files, programs, database, etc Jan. 7, 2004 Prof. Paul Lin 12 Networking Distributed Processing • use network connected computers Loosely connected computer networks • LANs, WANs, WWW Jan. 7, 2004 Prof. Paul Lin 13 Uses of Computer Networks Business/Enterprise Applications • E-Commerce, E-Business • Manufacturing Applications Home Applications Mobile Users Educational Applications Jan. 7, 2004 Prof. Paul Lin 14 Business/Enterprise Applications Resource Sharing • Physical resources: printers, scanners, CD burners, etc • Information sharing (client-server model): customer records, inventories, account info, etc Communication and Information Services • email, videoconferencing, etc E-Commerce E-Business Jan. 7, 2004 Prof. Paul Lin 15 Business/Enterprise Applications (continue) Enterprise Resource Planning Marketing, Sales, and Customer Services Supply Chain Management Manufacturing (CAD/CAM), robotics, industrial control, measurement, monitoring Jan. 7, 2004 Prof. Paul Lin 16 Home Applications Access to remote information Peer-to-peer communication • Chat room, Instant messaging, Home appliances and security Interactive entertainment • Video games, video on demands, Internet radio E-commerce Jan. 7, 2004 Prof. Paul Lin 17 Mobile Users Personal Digital Assistance (PDAs) Global Positioning System (GPS) Notebook Computers, Pocket PC, Tablet PC Cell phone Mobile Wireless Networks – trucks, taxis, delivery vehicles, etc Utility meter reading Military users Jan. 7, 2004 Prof. Paul Lin 18 Network Hardware Connection Technology • Broadcast links • Point-to-point links Scale • Personal area networks • Local area networks (wired, wireless) • Metropolitan area networks (wired, wireless) • Wide area networks • The Internet Jan. 7, 2004 Prof. Paul Lin 19 Network Criteria Performance • No of users • Types of transmission medium • Hardware • Software Reliability Scalability Security Jan. 7, 2004 Prof. Paul Lin 20 Local Area Networks Scale • Room – 10m • Building – 100m • Campus – 1km Connection Technology • Ethernet bus (wired, wireless) • IBM Token ring Data rate: • 10 Mbps, 100 Mbps, Giga bps Jan. 7, 2004 Prof. Paul Lin 21 Metropolitan Area Networks Scale • City Connection Technology • TV network • Microwave, RF, antenna • High-speed wireless IEEE 802.16 Jan. 7, 2004 Prof. Paul Lin 22 Wide Area Networks Scale • A country or continent Connection Technology • Subnets • Routers Transmission • Store-and-forward or packet-switched • Satellite systems • Routing algorithm (shortest path, etc) Jan. 7, 2004 Prof. Paul Lin 23 Wireless Networks System interconnection • Bluetooth – connecting digital cameras, headsets, scanners, etc Wireless LANs (access point + antenna) • IEEE 802.11a • IEEE 802.11b • IEEE 802.11g Wireless WANs Jan. 7, 2004 Prof. Paul Lin 24 Home Networks Computers Entertainment equipments • TV/DVD, camcorder, camera, stereo, MP3 Telecommunications • telephone, mobile phone, intercom, fax Home appliances • microwave, refrigerator, clock, furnace, lights, heating and air conditioning Telemetry and Remote Monitoring Jan. 7, 2004 Prof. Paul Lin 25 Intrernetworks Gateway • A computer with appropriate software for connecting incompatible networks Internetworks • A network of distinct networks Jan. 7, 2004 Prof. Paul Lin 26 Network Software Protocols Stacks of layers Five-layer protocol • TCP/IP protocol suite (FTP, TELNET, http, etc) Seven-layer protocol: OSI (Open Systems Interconnect) reference model Jan. 7, 2004 Prof. Paul Lin 27 Network Software (continue) TCP/IP Five-Layer Protocol • Application Layer - FTP, TELNET, SMTP, DNS, HTTP, etc) • Transport Layer – TCP, UDP • Internet Layer – IP • Data Link Layer • Physical Layer Jan. 7, 2004 Prof. Paul Lin 28 Network Software (continue) OSI Seven-Layer Protocol • Application • Presentation • Session • Transport • Network • Data Link • Physical Jan. 7, 2004 Prof. Paul Lin 29 Example Networks ARPANET • ARPANET • Advanced Research Project Agency NET • A Small network started in the mid1960s for connecting mainframe computers • In 1969, four nodes are connected by media links and IMP (interface message processor); UCLA, UCSB, Stanford Research Institute, and University of Utah Jan. 7, 2004 Prof. Paul Lin 30 Example Networks (continue) TCP/IP-based Network • 1973-1983 • Become official protocol for the ARPANET MILNET: military users ARPANET: non-military users Jan. 7, 2004 Prof. Paul Lin 31 Example Networks (continue) CSNET: networks for universities and companies that connected through TCP/IP, and Telnet; sponsored by the National Science Foundation, 1981-1986 NSFNET: a backbone that connected 5 supercomputer centers by a T1 (1.544 Mbps) line; 1990 - 1995 Jan. 7, 2004 Prof. Paul Lin 32 Example Networks (continue) Internet (Wide Area Networks) • E-mail • World wide web • News • Remote login • File transfer • Entertainment Jan. 7, 2004 Prof. Paul Lin 33 Example Networks (continue) Architecture of the Internet • POP (point-of-presence) • Regional ISP • Backbone • NAP (network access point) • Routers • Corporate LAN • Server farm Jan. 7, 2004 Prof. Paul Lin 34 Example Networks (continue) Connection-Oriented Networks (WAN) • X.25 Public data network, deployed in 1970s • Frame Relay Deployed in 1980s, replaced X.25 networks • ATM (Asynchronous Transfer Mode) Designed in the early 1990s For solving telecomm and networking problems Jan. 7, 2004 Prof. Paul Lin 35 Example Networks (continue) Ethernet (LAN) • Designed and implemented at Xerox Palo Alto Research Center, 1976 • Bob Metcalfe and David Boggs • Xerox Ethernet failed to commercialized • Metcalfe formed 3Com to sell Ethernet adapters Jan. 7, 2004 Prof. Paul Lin 36 Example Networks (continue) LAN Standards • IEEE 802.3 DIX standard by DEC, Intel, and Xerox, 1978, 10 Mbps Ethernet DIX standard become IEEE 802.3 in 1983 • IEEE 802.4 Token bus (GM) • IEEE 802.5 Jan. 7, 2004 Token ring (IBM) Prof. Paul Lin 37 Example Networks (continue) Wireless LAN Standards • Design considerations Privacy, Security, Battery Life, Human Safety With a base station (access point) Ad Hoc Networking (wireless peer communicate with each other directly) • IEEE 802.11 Jan. 7, 2004 Prof. Paul Lin 38 Example Networks (continue) Wireless LAN Standards (1999-) • IEEE 802.11a Up to 54 Mbps • IEEE 802.11b Up to 11 Mbps • IEEE 802.11g Jan. 7, 2004 Up to 54 Mbps Prof. Paul Lin 39 Example Networks (continue) Wireless LAN Standards (1999-) • IEEE 802.15 Bluetooth 10-meter distance • IEEE 802.16 Jan. 7, 2004 Broadband Wireless WAN Prof. Paul Lin 40