2002 Sharing Information and Resources Through Networks

2002 TELECOMMUNICATIONS Communicating Information Via Electronic Means Over Some Distance Next Office Next Continent *

2002 Atlanta Chicago MIS Accounting

2002 PROTOCOL Rules & Procedures To Govern Transmission Between Components In A Network -TCP/IP -OSI

2002 ANALOG SIGNAL Continuous Waveform Passes Through System Voice Communications *

2002 DIGITAL SIGNAL Discrete Waveform Two Discrete States: –1-bit & 0-bit –On / Off Pulse Data Communication *

2002 Modems Convert Digital data (computers) to Analog signal(voice) –Internal/ External

2002 Multiplexer / Concentrator Combines signals from several terminals to be carried over one communications channel High-speed line Frequency Time

2002 COMMUNICATION CHANNELS Means By Which Data Are Transmitted: Twisted Pair (Copper Wires) Coaxial Cable: (Insulated Copper Wires) Fiber-optic Cable Wireless

2002 COMMUNICATIONS CHANNELS TRANSMISSION SPEED: Bits per Second (BPS) or Baud BANDWIDTH: Capacity of Channel; Difference between Highest & Lowest Frequencies –Baseband (voice) - single transmission only –Broadband - divides channel by time or frequency for several transmissions at once

2002 Twisted Pair UTP - Unshielded Twisted Pair –Cat 3 ~ 10Mbps, Cat 5 ~ 100Mbps Copper Wire; electrical signal Baseband Analog or Digital signal Crosstalk Low cost, easy to install

2002 Coaxial Cable Shielded Copper Wire; electrical signal Faster, less noise Baseband and Broadband Not flexible More noise resistant *

2002 FIBER OPTICS Super Clear Glass or Plastic Fiber Strands Laser generates light signal Difficult to tap Up To Ten Billion Bits Per Second Full Duplex, Broadband * SIGNALLASERCABLEPHOTODETECTORSIGNAL

2002 Wireless Transmission Microwave Satellite Cellular and PCS Infrared Light

2002 Radio Waves Line of sight Antenna to Antenna Save $ because don’t run cable Interference or Security concerns Good if mobile 1-10 MBPS WAP – Wireless Application Protocol

2002 SPEEDS & COST OF MEDIA MEDIUM MEDIUM SPEED SPEED COST COST TWISTED PAIR TWISTED PAIR 300 BPS - 10 MBPS 300 BPS - 10 MBPSLOW MICROWAVE MICROWAVE 256 KBPS MBPS 256 KBPS MBPS SATELLITE SATELLITE 256 KBPS MBPS 256 KBPS MBPS COAXIAL CABLE COAXIAL CABLE 56 KBPS MBPS 56 KBPS MBPS FIBER OPTICS FIBER OPTICS 56 KBPS - 10 GBPS 56 KBPS - 10 GBPSHIGH BPS: BITS PER SECOND BPS: BITS PER SECOND KBPS: KILOBITS PER SECOND KBPS: KILOBITS PER SECOND MBPS: MEGABITS PER SECOND MBPS: MEGABITS PER SECOND GBPS: GIGABITS PER SECOND GBPS: GIGABITS PER SECOND

2002 Client/Server Networks Server - Stores Programs, Data; Determines Access to Network … for many users. Client - Desktop interface –Fat client - client has power on desktop to run programs (PC) –Thin Client - all deployed from server Less $ to support Always current One interface, Training easier

2002 Computer Networks Arts & Sciences LAN Russ LAN Rike LAN LAN L1 L2 L3 L4 Lake Campus LANs WAN Internet WSU Backbone

2002 NETWORK TOPOLOGIES HOST HOST USER USER STAR

2002 NETWORK TOPOLOGIES BUS USER USER S erver Printer Printer USER USER

2002 NETWORK TOPOLOGIES USER USER RING

2002 LOCAL NETWORKS LOCAL AREA NETWORK (LAN): –Limited Distance (less than 2000 foot radius) –Can Share Expensive Hardware & Software Printers Office Products *

2002 Local Area Networks Server based NetworkPeer-to-peer Network SERVERSERVER PC Client

2002 Metropolitan Area Network Often called a MAN Within a Local Dialing Area Often within a city Uses a Common Carrier’s Lines Often divisions of same company that are not in close proximity to set up a LAN

2002 Spread over a large geographical area Common Carrier –Pay for usage and share ‘lines’ –Telephone Lines –Fiber Optic Cables –Microwaves –Satellites Wide Area Networks

2002 Wide Area Network - Connection Switched or Dial-up –Temporary connection Dedicated or Leased Lines –2 locations (private) –High volume user –Always available Value Added Network –3rd party leased lines

2002 VALUE-ADDED NETWORK (VAN) Private; Multipath; Data Only 3rd Party Managed Used By Several Organizations Subscription Basis –Fee + Usage *

2002 PACKET SWITCHING Breaks Data Blocks Into Small Packets (E.G.: 128 Bytes) Packets Routed By Most Economical Means Reassembled At Destination Used on Value Added Networks *

2002 Wide Area Networks Sending Data on the Internet Destination Computer ISPISP Router Packets User’s PC Packets

2002 Uses of Telecommunications Telecommuting Electronic Mail On-Line Information Services Teleconferencing Facsimile Transmissions Electronic Data Interchange AOL CompuServe MSN

2002 Electronic Data Interchange Computer to Computer exchange of business transactions –Orders –Bills Save $ and time Eliminate errors by entered only once EFT - Electronic Funds Transfer

2002 Group Writing & Commenting Electronic Mail Distribution Scheduling Meetings Shared Files & Databases Electronic Meetings * GroupWare

2002 Teleconferencing Electronic meetings Less travel More can attend Less cost Videoconference Computer conference

2002 Wide Area Networks ISP Link to the Internet ISPISP Parent’s PC Regional Network Internet Backbone College LAN Student’s PC

2002 Connection Options Cable - 4/10 Mbps, ~$40 /mo ( digital) –Ethernet Card and Cable Modem+ ($ ) DSL - 8 Mbps, ~$ /mo ( digital) –DSL Hub + Ethernet Card, Dedicated(3) T-1 Line -1.5 Mbps,~$1,000s, Dedicated, Digital –(T-2~6.3Mbps; T-3~44Mbps; T-4~275Mbps) ISDN Kbps, $56-82 /mo –Digital Service Unit+ ($ ), Dial-up Phone-line modem - 56Kbps, ~$20 /mo –Modem < $50, Dial-up, Analog

2002 The Internet Server address Domain name address A Network of Networks User name Server address

2002 The World Wide Web Client/Server network Browser –Netscape –Internet Explorer Hypertext markup language - HTML

2002 The World Wide Web Web pages Web site Multimedia files URLs

2002 The World Wide Web Default HTML file (Home) Electronic commerce Intranets Extranets

2002 INTRANET Internal Network WWW Technology Firewall: Security System to Prevent Invasion of Private Networks Need Password Overcomes Computer Platform Differences Often Installed On Existing Network Infrastructure *

2002 EXTRANET Private Internet Accessible To Select Outsiders - Need Password Link Organization To Important Clients Business Partners Top Executives & Board Members *

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