Technology Briefing

1. 4 COIS11011 WEEK 5 TechnologyBriefing Networking Information Systems Today: Managing in the Digital World

2. Learning Objectives Information Systems Today: Managing in the Digital World

3. Learning Objectives Information Systems Today: Managing in the Digital World

4. Evolution of Computer Networking • Computer networking • Sharing of information or services • Comparable to human communication Information Systems Today: Managing in the Digital World

5. Messages, Senders, and Receivers • Components of communication: • Senders and receivers with something to share • A transmission medium to send the message • Protocols (rules) dictating communication Information Systems Today: Managing in the Digital World

6. Coding, Sending, Decoding Information Systems Today: Managing in the Digital World

7. Computer Networks • Computer communication • Bits are sent • Any type of information can be transmitted • Documents, art, music, film, information • Digitizing • Conversion of analog into digital information Information Systems Today: Managing in the Digital World

8. Bandwidth Requirements • Voice • Telephone: 64 KBps • Compact Disc: 1.41 MBps • Data • Single screen of text: 14.4 KB • Publication-quality photograph: 230.4 MB • Video • Video telephony: 9.3 MBps • HDTV: 1.33 GBps Information Systems Today: Managing in the Digital World

9. Centralized Computing • 1940s – 1970s (mainframe era) • Central computer (mainframe) • Processing and storage of data • Terminal • Local input/output device • Not a true network – no information sharing Information Systems Today: Managing in the Digital World

10. Distributed Computing • 1980s • Driver: Introduction of PCs • Separate computers work on subsets of tasks • Results are pooled via network Information Systems Today: Managing in the Digital World

11. Collaborative Computing • 1990s • Synergistic form of distributed computing • Two or more computers working on a common processing task • Computers collaborate to keep employee records current Information Systems Today: Managing in the Digital World

12. Collaborative Computing • Collaborative functionality in IM platforms • Collaborative components in office automation applications Information Systems Today: Managing in the Digital World

13. Computing Networks Today • All types are still present • (centralized, distributed, collaborative) • Usually combined into a network • Networks classified by size, distance covered and structure: • Private branch exchange • Local area network • Wide area network • Metropolitan area network • Personal area network Information Systems Today: Managing in the Digital World

14. Private Branch Exchange (pbx) • Telephone system serving a particular location • Connects phones and computers • Connects PBX to outside network • Limited bandwidth Information Systems Today: Managing in the Digital World

15. Local Area Network • Spans relatively small area – typically within a building. • Computers share: • Information • Peripheral devices • Usually one type of cable used • Wireless Local Area Network (WLAN) Information Systems Today: Managing in the Digital World

16. Wide Area Network • Spans large areas up to global in scope • Usually connects multiple LANs • Different hardware and transmission media used • Used by multinational companies • Information transmitted across cities and countries • 4 specific types of WAN Information Systems Today: Managing in the Digital World

17. Global and Enterprise Networks • Global networks • Span multiple countries • E.g., The Internet • Enterprise networks • Connect disparate networks of a single organization Information Systems Today: Managing in the Digital World

18. Value-Added and Metropolitan Area Networks • Value-added networks • Medium speed WANs • Third party managed • Shared by multiple organizations • Added value: • network management, e-mail, EDI, security • Metropolitan area networks • Limited geographic scope – citywide area • Combine LAN and fiber-optic technologies Information Systems Today: Managing in the Digital World

19. Personal Area Networks • Exchange data between computing devices • Short range radio communication – 10 meters • E.g., networking of PCs, peripheral devices, mobile phones, portable stereos, etc. • Enabling Technology: Bluetooth Information Systems Today: Managing in the Digital World

20. Learning Objectives Information Systems Today: Managing in the Digital World

21. Networking Fundamentals • Three different roles: • Clients • Servers • Peers Information Systems Today: Managing in the Digital World

22. Clients • Request services • Workstations or PCs • Software applications • Usually one user per client Information Systems Today: Managing in the Digital World

23. Servers • Dedicated purpose • Usually have: • More advanced microprocessors • More memory • Larger cache • Many users access its services Information Systems Today: Managing in the Digital World

24. Peers • May request and provide services • Peer-to-peer networks • Equivalent capabilities and responsibilities • Not common in Australian businesses • Usually found in small offices and homes • Popular for file sharing • E.g., BitTorrent, KaZaA • Used as distribution channel • Warner Brothers Information Systems Today: Managing in the Digital World

25. Network Services • File services • Store, retrieve and move data files • Print services • Control and manage access to printers Information Systems Today: Managing in the Digital World

26. Network Services (II) • Message services • Store, access and deliver data • Communication between users and applications • Application Services • Run software for network clients • Enable computers to share processing power • Client/server computing Information Systems Today: Managing in the Digital World

27. Network Operating System (NOS) • System software controlling the network • Enables computers to communicate • Two parts: • Network server • Coordinates: user accounts, information access, security, resource sharing • Workstation • Runs on top of the local OS • Sometimes integrated into the OS • Example: Novell NetWare, Microsoft Windows Server Information Systems Today: Managing in the Digital World

28. Transmission Media • Physical pathways for sending data • Message sending: • Computers send electromagnetic waves • Waves altered by semiconductors to become 0s or 1s – known as bits • Bits are transmitted • Two types: • Cable media • Wireless media Information Systems Today: Managing in the Digital World

29. Bandwidth • Transmission capacity of a computer or a communications channel • Measured in megabits per second (Mbps) • Example: • IS Today textbook: 2 million characters (16 million bits) • 1.6 seconds at 10 Mbps • 0.16 seconds at 100 Mbps • Nearly 5 minutes using 56 Kbps modem Information Systems Today: Managing in the Digital World

30. Attenuation • Power of an electric signal weakens with distance • How far can a signal travel with the same properties and meaning? • Electromagnetic interference (EMI) • Interference by fluorescent light, weather or other electronic signals Information Systems Today: Managing in the Digital World

31. Cable Media: Twisted Pair Cable • Two or more insulated pairs of cable • Unshielded (UTP) • Telephone wire • Rated according to quality: Cat 5, Cat 6 • Cheap and easy to install • Up to 1 Gbps at distance up to 100 meters • Rapid attenuation – sensitive to EMI and eavesdropping • Used in network installations • Shielded (STP) • Less prone to EMI and eavesdropping • More expensive and harder to install • 500 Mbps up to 100 meters • Used to support networks running at 16 Mbps Information Systems Today: Managing in the Digital World

32. Twisted Pair Cable a) Several twisted pairs b) Sample network installation Information Systems Today: Managing in the Digital World

33. Coaxial Cable • Components • Solid inner copper conductor • Plastic insulation • Outer braided copper or foil shield • Variety of thicknesses • Thinnet – less costly than TP but not commonly used • Thicknet – more costly than TP • Used for cable television and networks operating at 10-100 Mbps Information Systems Today: Managing in the Digital World

34. Fiber-Optic Cable • Components: • Light-conducting glass or plastic • Cladding (glass) • Tough outer sheath • Transmission: • Pulses of light • Immune to EMI and eavesdropping • Low attenuation • 100 Mbps to more than 2 Gbps • 2 to 25 kilometers • Used for high-speed backbones Information Systems Today: Managing in the Digital World

35. Cable Media Key Benefits and Drawbacks of Different Cable Media Information Systems Today: Managing in the Digital World

36. Wireless Media:Infrared Line of Sight • High frequency light waves • Distance of up to 24.4 meters • Attenuation, EMI and eavesdropping problems • Relatively inexpensive • Two types: • Point-to-point • Strict line of sight • Up to 16 Mbps at 1 meter • E.g., TV remote • Broadcast • Devices don’t need to be directly in front of each other • Less than 1 Mbps Information Systems Today: Managing in the Digital World

37. Wireless Media: High Frequency Radio • Ideal for mobile transmission • Expensive due to cost of antenna towers • Complex installation • Susceptible to EMI and eavesdropping • Attenuation not a problem • Distance between nodes 12.2 – 40 kilometers • Rate up to several hundred Mbps • E.g., cellular phones and wireless networks Information Systems Today: Managing in the Digital World

38. Cellular Network • Coverage area divided into cells • Low-powered radio antenna/receiver • Cells controlled by a central computer • Unique frequency assigned for duration of phone call • Mostly digital today • Less static • Data transmission capability • Wider reception range Information Systems Today: Managing in the Digital World

39. WLANs or Wi-Fi • 802.11 family of standards • Transmission speed up to 540 Mbps (802.11n) • Easy installation • Connection of computers within a building/home Boeing wireless classroom at Washington State University Information Systems Today: Managing in the Digital World

40. Wireless Media: Microwave • High frequency radio • Terrestrial microwave • Line-of-sight • Transmission up to 274 Mbps • EMI and eavesdropping problems • Cross inaccessible terrain • Cost depends on distance • Alternative when cabling too expensive Information Systems Today: Managing in the Digital World

41. Microwave (II): Satellite Microwave • Relay station transfers signals between antennae on earth and satellites in the orbit • Propagation delay • Satellites orbit 400-22,300 miles above earth • Typically 1-10 Mbps, up to 90 Mbps • Prone to attenuation • Susceptible to EMI and eavesdropping Information Systems Today: Managing in the Digital World

42. Microwave (III): Satellite Microwave • GPS (Global Positioning System) • 24 satellites • Receivers pick up signals from at least 4 satellites • GPS receivers triangulate position using time stamps • Accuracy: 10 square centimeters Information Systems Today: Managing in the Digital World

43. Wireless Media Key Benefits and Drawbacks of Different Wireless Media Information Systems Today: Managing in the Digital World

44. 5 • Technology Briefing • The Internet and the World Wide Web Information Systems Today: Managing in the Digital World

45. Learning Objectives Information Systems Today: Managing in the Digital World

46. How Did the Internet Get Started? • Internet – derived from internetworking • 1960s – U.S. Defense Advanced Research Project (DARPA) • ARPANET – WAN that linked universities and research centers • 1986 – U.S. National Science Foundation • NSFNET – became major component of the Internet • Other networks ultimately connected • BITNET, CSNET, NSINET, ESNET, NORDUNET Information Systems Today: Managing in the Digital World

47. Packet-Switching Technology • Problem: Concurrent data transmission • One wire and several users • Solution: Turn-taking • Messages divided into packets and sent • Packets travel independently • Reassembled by receiver • Header contains address of source and destination Information Systems Today: Managing in the Digital World

48. TCP/IP • Protocol of the Internet • TCP (Transmission Control Protocol) • Breaks information into packets • Manages transfer of packets between computers • IP (Internet Protocol) • Defines how the packet must be formed • Contains destination address Information Systems Today: Managing in the Digital World

49. IP Datagram • Data packet that conforms to the IP specifications • Relies on IP address • Unique address assigned to computers and routers • TCP helps IP deliver packets: • Checks for lost datagrams • Puts received datagrams in correct order • Discards duplicate datagrams Information Systems Today: Managing in the Digital World

50. Connecting Independent Networks • Routers interconnect independent networks • Fundamental building blocks of the Internet • Router: • Special-purpose computer • Job is to: • Interconnect networks • Forward data packets Information Systems Today: Managing in the Digital World