Networks and Networking Chapter 6 Copyright Prentice-Hall, Inc. 2001
Get Wired!! Surfing Online Books Monthly Technology Update
What is it all about? Computer networks simply enhance the efficiency and effectiveness of interactions between people, whether they are knowledge workers or Internet surfers.
Becoming digitally compatible!! Digital Convergence DVDs Telephones Televisions Computers Newspapers College courses Textbooks on CD-ROM Banking/Finance Becoming digitally compatible!!
Connectivity Seeking ways to interface, or connect, a diverse set of hardware, software, and databases.
Cooperative Processing E-commerce (electronic commerce) Intercompany Networking Electronic Data Interchange (EDI) Intranets Extranets
Data Communications Data Communications = Telecommunications Special hardware transmits the digital information between computers
Data Communications Hardware Modem Digital to Analog to Digital Internal & External Fax Modems Network Interface Cards (NIC) Special Function Communications Devices Routers (backbone hardware)
Data Communications Messaging Message is distributed among: Host or Server computer - in control Front-end Processor - establishes handshake Multiplexor - collects data from multiple devices and sends it along Network Address
Communications Protocols Rules that govern the way data are transmitted Communication between networks using incompatible protocols (use of routers) Serendipitous Surfing: Government
Data Communications Channel The medium through which digital information must pass to get from one location in a computer network to the next. Also called the Line, Link or Pipe Transmission Media
Transmission Media Wires & Wireless Media Channel Capacity (Bandwidth) Bits per Second (BPS) vs. Baud Types: Twisted-Pair Wire Coaxial Cable Fiber Optic Cable High-Speed Wireless Transmission Media
Twisted-Pair Wire Carries data as electrical signals POTS (plain old telephone service) 56 K bps ISDN - Line & Modem 128 K bps ADSL - Line & Modem 1.5 to 9 M bps Downstream rate Upstream rate Will compete with cable Transmission Media
Coaxial Cable Carries data as electrical signals Hundreds of times faster than POTS 100 times faster than ISDN Need a cable modem
Fiber Optic Cable Carries data as laser-generated pulses of light Foundation transmission medium for Internet backbone Better for data security Courtesy of International Business Machines Corporation
High-Speed Wireless Carries data via microwave or radio signals Geosynchronous Orbit Satellites Wireless Transceivers
Common Carriers AT&T, MCI, Sprint, etc. Private Line (or Leased Line) Switched Line (or Dial-Up Line)
Is it time to GO yet?
Network Topologies Network Topology is a description of the possible physical connections within a network. It is a configuration of hardware and it shows which pairs of nodes can communicate. Networks
Network Topologies Ring Star Bus Networks
Client/Server Computing Centralized Computing Trend to Decentralizing & Downsizing Server Computer Client Computer Proxy Server Computer Front-end Applications Back-end Applications
Network Line Control Communications Protocols (TCP/IP) Two Classifications: Asynchronous Transmission (low speed) Synchronous Transmission (high speed)
Metropolitan Area Network Types of Networks Wide Area Network WAN Metropolitan Area Network MAN Local Net LAN Tiny Area Network TAN
Sharing Resources on a LAN Applications software Links to mainframes Communications capabilities I/O devices Storage devices Add-on boards
Local Area Networks LAN Access Methods LAN Servers Token Access Method Ethernet LAN Servers File Server Print Server Communications Server
LAN Software Operating Systems Applications Software Peer to Peer LANs LANs with dedicated servers Applications Software Shared software Groupware Networks on the Fly
End of Chapter 6 Interactive Study Guide Copyright Prentice-Hall, Inc. 2001