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Telecommunications & Networking

Telecommunications & Networking. TELECOMMUNICATIONS & NETWORKING. TELECOMMUNICATIONS: Communications (both voice and data) at a distance NETWORKING: Electronic linking of geographically dispersed devices *. THE NEED FOR NETWORKING. SHARING OF TECHNOLOGY RESOURCES SHARING OF DATA

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Telecommunications & Networking

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  1. Telecommunications & Networking

  2. TELECOMMUNICATIONS & NETWORKING • TELECOMMUNICATIONS: Communications (both voice and data) at a distance • NETWORKING: Electronic linking of geographically dispersed devices *

  3. THE NEED FOR NETWORKING • SHARING OF TECHNOLOGY RESOURCES • SHARING OF DATA • DISTRIBUTED DATA PROCESSING AND CLIENT/SERVER SYSTEMS • ENHANCED COMMUNICATIONS, INCLUDING ELECTRONIC DATA INTERCHANGE (EDI) AND ACCESS TO THE INTERNET *

  4. KEY ELEMENTS OF TELECOMMUNICATIONS & NETWORKING • ANALOG SIGNALS: Continuous waveform, passes thru system. Example: voice communications • DIGITAL SIGNALS: Discrete waveform two discrete states (1-bit & 0-bit, on / off pulse). Data communication. Uses modem to translate analog to digital, digital to analog *

  5. MODEM • ABBREVIATION FOR MODULATOR/ DEMODULATOR • DEVICE THAT CONVERTS DATA FROM DIGITAL FORM TO ANALOG FORM TO BE SENT OVER ANALOG TELEPHONE NETWORK (RECONVERTS DATA AFTER IT HAS BEEN TRANSMITTED) *

  6. SPEED OF TRANSMISSION • BANDWIDTH: Difference between highest and lowest frequencies (cycles per second) that can be transmitted on a particular medium; a capacity measure • HERTZ: Cycles per second • BAUD: Signals sent per second • BITS PER SECOND(bps): Common measure *

  7. TYPES OF TRANSMISSION LINES • PRIVATE, OR DEDICATED, LINES • SWITCHED LINES • SIMPLEX TRANSMISSION • HALF-DUPLEX TRANSMISSION • FULL-DUPLEX TRANSMISSION *

  8. TRANSMISSION MEDIA • TWISTED PAIR • COAXIAL CABLE: Baseband and broadband • WIRELESS: Cordless phone, cellular phone, wireless LAN, infrared devices • SATELLITE: Microwave, line of sight • FIBER OPTICS *

  9. ORBITING SATELLITES MICROWAVE TRANSMISSION UPLINK DOWNLINK

  10. NEW SATELLITES • OVER A DOZEN NEW PROJECTS PROPOSED • LOW EARTH ORBIT (LEO) SATELLITES: Only 400 to 1000 miles above the earth, compared to geosynchronous satellites at 22,000 miles above the equator. 1,700 satellites to be launched by 2006 *

  11. NEW SATELLITES • IRIDIUM: 66 satellites offered mobile telephony, paging, and data communications. Bankrupt by 1999. • TELEDESCIC: Will include 288 LEO to provide low-cost, high-speed Internet access, networking, teleconferencing *

  12. TELECOMMUNICATIONS TRANSMISSION SPEEDS • Twisted pair - voice telephone 14.4 kbps -56 kbps • Twisted pair - conditioned 56 kbps - 144 kbps • Twisted pair - LAN 4 mbps - 100 mbps • Coaxial cable - baseband 10 mbps - 2 gbps • Coaxial cable - broadband 10 mbps - 550 mbps • Radio frequency wireless LAN 1 mbps - 11 mbps • Infrared light wireless LAN 4 mbps - 16 mbps • Microwave / Satellite 64 kbps - 100 mbps • Fiber optic cable 100 mbps - 100 gbps *

  13. TOPOLOGY OF NETWORKS • BUS TOPOLOGY • RING TOPOLOGY • STAR TOPOLOGY • TREE, OR HIERARCHICAL, TOPOLOGY • MESH TOPOLOGY • MORE COMPLEX TOPOLOGIES *

  14. NETWORK TYPES • COMPUTER TELECOMMUNICATIONS NETWORK • PRIVATE BRANCH EXCHANGE (PBX) NETWORK • LOCAL AREA NETWORK (LAN) *

  15. NETWORK TYPES • BACKBONE NETWORK • WIDE AREA NETWORK (WAN) • INTERNET *

  16. LOCAL AREA NETWORKS • CONTENTION BUS NETWORK: UsesCSMA/CDprotocol. Example: Ethernet • TOKEN BUS NETWORK: Central to Manufacturing Automation Protocol(MAP) • TOKEN RING NETWORK: Used in LAN; unidirectional data flow *

  17. NEW LAN TECHNOLOGY • FAST ETHERNET: Ethernet operating at speeds up to 100 mbps • FIBER DISTRIBUTED DATA INTERFACE (FDDI): Token ring architecture delivered on a dual ring at speeds up to 100 mbps *

  18. BACKBONE NETWORKS • MIDDLE DISTANCE NETWORKS: Interconnect LANs in a single organization with each other and with the organization’s WAN and Internet • EMPLOY HIGH-END LAN TECHNOLOGY, OFTEN OPERATING AT 100 MBPS OR MORE *

  19. BACKBONE NETWORK TERMINOLOGY • HUB: Simple device connecting one section of a LAN to another • BRIDGE: Connects two LAN segments when the LANs use the same protocols • ROUTER, OR GATEWAY: Connects two or more LANs together. Networks may use different protocols • SWITCH: Connects more than two LANs that use the same protocol into a backbone network *

  20. WIDE AREA NETWORKS • DIRECT DISTANCE DIALING (DDD) • WIDE AREA TELEPHONE SERVICE (WATS) • LEASED LINE: Most common, T-1 lines • SATELLITE: C-Band, KU-Band • VALUE ADDED NETWORK (VAN) • INTEGRATED SERVICES DIGITAL NETWORK (ISDN) *

  21. VALUE ADDED NETWORK (VAN) • DATA-ONLY, PRIVATE, NONREGULATED TELECOMMUNICATIONS NETWORK: Uses packet switching • AN ORGANIZATION MAY CHOOSE TO BUY SERVICES OF A VAN TO IMPLEMENT ITS WIDE AREA NETWORK (WAN) *

  22. PACKET SWITCHING • INFORMATION DIVIDED INTO PACKETS OF SOME FIXED LENGTH, SENT OVER NETWORK SEPARATELY • PERMITS MORE EFFICIENT USE OF THE NETWORK *

  23. INTEGRATED SERVICES DIGITAL NETWORK (ISDN) • EMERGING SET OF INTERNATIONAL STANDARDS • USING PUBLIC TELEPHONE NETWORK • EXTENSIVE NEW TELECOMMUNICATIONS CAPABILITIES • SIMULTANEOUS TRANSMISSION OF VOICE AND DATA OVER SAME LINE TO TELEPHONE USERS WORLDWIDE *

  24. USES OF ISDN • CUSTOMER SERVICE APPLICATION: Customer’s records automatically sent to service representative’s workstation when customer calls in • SOLVES DIAL-IN PROBLEMS INTO CORPORATE NETWORK FOR TELECOMMUTERS, BRANCH OFFICES *

  25. NEW WAN AND LAN TECHNOLOGY ASYNCHRONOUS TRANSFER MODE (ATM): Switching technology employing fast packet switching. Emerging standard for broadband ISDN. Speeds from 1.544 mbps to 622 mbps. Represents the future for both LANs and WANs *

  26. PROTOCOL RULES & PROCEDURES TO GOVERN TRANSMISSION BETWEEN COMPONENTS IN A NETWORK *

  27. NETWORK PROTOCOLS • OPEN SYSTEMS INTERCONNECTION(OSI):Reference model, emerging standard • TRANSMISSION CONTROL PROTOCOL / INTERNET PROTOCOL (TCP/IP):Standard used on the Internet • SYSTEMS NETWORK ARCHITECTURE(SNA):IBM standard • FILE TRANSFER PROTOCOL (FTP): Allows file transfer on Internet *

  28. INTERNET • NETWORK OF NETWORKS THAT USE THE TCP/IP PROTOCOL, WITH GATEWAYS (CONNECTIONS) TO OTHER NETWORKS THAT DO NOT USE TCP/IP • INTERNET APPLICATIONS:e-mail, Usenet newsgroups, listserv, FTP, Gopher, Archie, Veronica, World Wide Web *

  29. CONNECTIONS TO INTERNET • PHONE LINE MODEM • CABLE MODEM • DIGITAL SUBSCRIBER LINE (DSL) • T-1 DATA PHONE LINE • SATELLITE • FIBER OPTICS *

  30. INTRANET • A NETWORK OPERATING WITHIN AN ORGANIZATION EMPLOYING TCP/IP PROTOCOL • ORGANIZATION USES SAME WEB BROWSER, CRAWLER, SERVER SOFTWARE AS IT WOULD ON THE INTERNET, BUT INTRANET IS NOT ACCESSIBLE FROM OUTSIDE THE ORGANIZATION *

  31. CONNECTIVITY MEASURE OF ABILITY OF COMPUTING DEVICES TO PASS & SHARE INFORMATION WITHOUT HUMAN INTERVENTION OPEN SYSTEMS: Software able to function on different computer platforms. Nonproprietary operating systems, applications, protocols *

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