2. NETWORKING

3. NETWORKS TELECOMMUNICATIONS Two or more computers communicating Long distance communications

7. LAN Characteristics TOPOLOGY Bus Star Ring Protocol Polling CSMA/CD Token Ring

9. MAJOR FUNCTIONS Make long distance communication seem local Standardize network interface Standardize procedures for sending information Govern error transmission Govern security Govern integrity of data

10. NETWORK COMPONENTS Computers Media Software Network connections Satellites Microwave stations Multiplexer – combines many data streams into a single stream

11. Additional Media Type Electromagnetic waves A type of radio wave Used by satellites Used by portable computers

12. MICROWAVE STATIONS Needs a direct sight line SATELLITES

13. WAN TOPOLOGIES 1. Point to Point 2. Multidrop 3. Mesh 4. Star

14. Point to Point Direct Connection Between Computers

15. Advantage No Waiting Disadvantage Expensive to connect Adding new computer

16. Multidrop Hierarchical Between Concentrator

17. Advantage No Waiting Direct connections Disadvantage May find delays if going outside the predefined connections Adding new computer

18. Star Central Point Time Sharing Host

19. Advantage Centralized control (security) Disadvantage Centralized control (delays)

20. Mesh Individual Routes Needs a router

21. Advantage No Waiting Disadvantage Connections (solutions – servers)

22. Other types of NETWORKS Public access networks (government) VAN – value added network (extra feature – faxes) Private area networks (Sears) Public Data Network (TYMNET)

23. Wide Area Networks Environments

24. PSTN Public Switch Telephone Network

25. TYPES of Lines Private –Direct –Expensive Tie line –Dedicated without the use of the PSTN Exchanges –Foreign/private 800 numbers

26. DDN data digital network Only transmits DIGITAL information

27. PSN packet switching network Sends information in groups called PACKETS

28. ISDN integrated services digital network Sends only digital signals Transmits HIGH VOLUME of data Can use the Internet while using the phone line – use of two phone lines

29. DSL Digital Subscriber Line Translates digital signals to analog Transmits HIGHER VOLUME of data than ISDN Spreads analog signal over a wide range of frequencies