1. Basic Communications Overview of communication technology.

2. Communications Electronically exchanging data or information. zVoice interactive communication zData large volume batch transmissions zImage encoded graphics zVideo streaming media

3. Telecommunications History zPre 1984 Local and long distance monopoly z1984 AT&T settlement Intense long distance competition z1996 Telecommunications Act Local access competition

4. Digital Standard Telephone System Analog Network Analog Digital Modem Switch Digital Switch Network

5. Telephone Changes zRapidly decreasing long distance rates zValue added telephone services zCellular access zFlat rate long distance? zData and voice convergence.

6. Issue: Access zDedicated lines zStandard voice zIntegrated Services Digital Network zDigital Subscriber Lines zCable Modem zWireless

7. Voice vs. Data Voice zDelay Sensitive zConstant bit rate zNot error sensitive zGrowth stable (video ??) Data z Delay insensitive z Variable bit rate z Error sensitive z Demand growing

8. Data Networks NIC LAN Public TELCO WAN POP Switch Router Campus or Metropolitan Area

9. Application Presentation Session Transport Network Data Link Physical ©”A Guide to Networking Essentials”, 1998, Course Technology. OSI Reference Model Program Functions Wide Area Network Functions LAN Functions Connection Functions

10. Packet Structure Header(s) Data PayloadTrailer

11. LAN Operating Protocols (layer 2) zEthernet open standard, cheap, most common zToken Ring IBM proprietary, high quality, expensive zOthers

12. Network Interface Cards zBuild, send out and accept frames zUsually a daughter board on PC zMust match LAN and CPU zRequire drivers to operate

13. Network Interface Cards (NIC)

14. Ethernet Carrier Sense Multiple Access/Collision Detection Header BodyTrailer Listen before transmit Contention access Retransmit on collision

15. Network Routing Protocols for internetworking.

16. Two major types zPacket switching (or datagram) yUsually layers 3 and 4 zCircuit switching yUsually layers 1 and/or 2

17. Packet switching or Datagram Protocols zBest effort zFrames take individual routes zPacket assembly devices needed zError Control zTraffic Management yBuffering yDiscard

18. Datagram Logic (IP) Packet n Packet 1Packet 2 3 2 1 3 1 2 3 2 1 PAD

19. IP zBest Effort zAddressing zVariable packet lengths (1500 bytes or less) zIPv4 vs IPv6 zFrame and Header

20. TCP and UDP Transmission Control Protocol zConnection oriented Assures that packets arrive in order and that they are correct. User Datagram Protocol z Connectionless Sends packets out without confirming that they arrive

21. Ethernet/TCP/IP Header Structure

22. Circuit Protocols zAll packets take the same route zNo packet assembly device to reorder packets zNormally layer 2 connection zMay be permanent or switched zAllow guaranteed service quality levels zMay be used to carry datagram protocols

23. Circuit Logic Source Destination Setup Message & ACK’s Teardown

24. 3 2 1 3 1 2 Inter- networking

25. Technologies Common WAN technologies.

26. ISDN Circuit Switched Data and Voice Service

27. Digital Subscriber Lines DSL uses packet switching technology that operates independent of the voice telephone system, allowing the telephone companies to provide the service and not lock up circuits for long calls.

28. WAN Costs zCircuit Charges zCommitted Bandwidth zPeak Bandwidth zDiscard Priority zLatency

29. Representative Prices per MB of traffic (Qwest, Dec. 98) zFrame Relay Non-discard eligible4 cents Discard eligible3 cents zATM Constant bit rate2 cents Variable bit rate (real-time)1.2 cents Variable bit rate (non real-time).75 cents Available bit rate.55 cents Unspecified bit rate.4 cents

30. Representative Prices per port (Qwest, Dec. 98) z56 Kb Frame Relay$190 zT-1 Frame Relay$1,595 zT-3 Frame Relay$3,190

31. Client/Server Architecture An architecture in which the client (personal computer or workstation) is the requesting machine and the server is the supplying machine, both of which are connected via a network.

32. Client/Server Architectures SERVER PROCESSING CLIENT PROCESSING CENTRALIZEDSTAND-ALONE FAT SERVER FAT CLIENT

33. Client/Server zScalability zInteroperability zUser buy-in zIncreased cost zMulti-tier

34. One Tier System

35. Two Tier Client/Server

36. Three Tier Client/Server

37. Application Issues zInteroperability (e.g. ODBC) zOS support zMulti-threaded or single threaded zNetwork impact (e.g. chattiness) zQoS demands zDelivery: centralized, clien/server, web

38. Application Management zStandards ySupported yAccepted yProhibited zVersion Control and Distribution zLicense Management zVirus detection and inoculation