1. EEC4113 Data Communication & Multimedia System Chapter 1: Introduction by Muhazam Mustapha, September 2011

2. Learning Outcome By the end of this chapter, students are expected to have some surface overview of models, networking, protocol architecture & standards related to data communication

3. Chapter Content Communications model Data communication networking Protocol architecture –OSI –TCP/IP Standards

4. Communications Model CO1

5. Data Communication Tasks Communications model Data communication networking Protocol architecture –OSI –TCP/IP Standards Address Routing Recovery Message formatting Security Network management Fundamental purpose of communications system: Exchange of data between two parties CO1

6. Data Communications Networking CO1

7. Data Communication Networking Point to point communication not usually practical Devices are far apart Large set of devices would need impractical number of connections Solution is a communications network: –Wide Area Network (WAN) –Local Area Network (LAN) CO1

8. Wide Area Network (WAN) Large geographical area Crossing public rights of way Rely in part on common carrier circuits Used technologies –Circuit switching –Packet switching –Frame relay –Asynchronous Transfer Mode (ATM) CO1

9. WAN Technologies Circuit Switching –Dedicated communications path established for the duration of the conversation e.g. telephone network Packet switching –Data sent out of sequence –Small chunks (packets) of data at a time –Packets passed from node to node between source and destination –Used for terminal-to-computer and computer- to-computer communications CO1

10. WAN Technologies Frame Relay –Packet switching systems have large overheads to compensate errors –Modern systems are more reliable –Errors can be caught in end system –Most overhead for error control is stripped out Asynchronous Transfer Mode (ATM) –Evolution of frame relay –Little overhead for error control –Fixed packet (called cell) length –Anything from 10Mbps to Gbps –Constant data rate using packet switching technique CO1

11. Local Area Network (LAN) Smaller scope –Single or a cluster of building Usually owned by same organization Data rates much higher than WAN CO1

12. LAN Configurations Switched –Switched Ethernet May be single or multiple switches –ATM LAN –Fiber Channel Wireless –Mobility –Ease of installation CO1

13. Metropolitan Area Networks (MAN) Middle ground between LAN and WAN High speed Cover larger area than LAN –City –Town Private or public network CO1

14. Networking Configuration Client Service Provider Phone line, DSL Internet Client ATM Network LAN Ethernet switches Local Servers CO1

15. Standardized Protocol Architecture for Data Communications CO1

16. Standardized Protocol Architecture Required for devices to communicate Vendors have more marketable products Customers can insist on standards based equipment Two standards –OSI Reference model –TCP/IP protocol suite Also: –Internetwork Packet eXchange/Sequenced Packet eXchange (IPX/SPX) –NetBIOS Enhanced User Interface (NetBEUI) –AppleTalk –IBM Systems Network Architecture (SNA) CO1

17. OSI CO1

18. OSI Reference Model Open System Interconnection (OSI) reference model Designed by International Organization for Standardization (ISO) A seven-layer model Never seriously implemented as a protocol stack A theoretical model designed to show how a protocol stack should be implemented CO1

19. OSI Reference Model ApplicationLayer 7 PresentationLayer 6 SessionLayer 5 TransportLayer 4 NetworkLayer 3 Data LinkLayer 2 PhysicalLayer 1 CO1

20. OSI Reference Model ApplicationLayer 7 PresentationLayer 6 SessionLayer 5 TransportLayer 4 NetworkLayer 3 Data LinkLayer 2 PhysicalLayer 1 -Basically communication softwares -Provide the human interface to the communication system CO1

21. OSI Reference Model ApplicationLayer 7 PresentationLayer 6 SessionLayer 5 TransportLayer 4 NetworkLayer 3 Data LinkLayer 2 PhysicalLayer 1 -Standardizes data representation -Decouples application from data CO1

22. OSI Reference Model ApplicationLayer 7 PresentationLayer 6 SessionLayer 5 TransportLayer 4 NetworkLayer 3 Data LinkLayer 2 PhysicalLayer 1 -Sessions data structure -Creates, maintains, destroy sessions -Network security CO1

23. OSI Reference Model ApplicationLayer 7 PresentationLayer 6 SessionLayer 5 TransportLayer 4 NetworkLayer 3 Data LinkLayer 2 PhysicalLayer 1 -Low Level Communication APIs -Creates, maintains, destroy connection to network devices -Routing technology CO1

24. OSI Reference Model ApplicationLayer 7 PresentationLayer 6 SessionLayer 5 TransportLayer 4 NetworkLayer 3 Data LinkLayer 2 PhysicalLayer 1 -Bit level manipulation -Communication hardware device driver -Error detection, recovery, transparent flow CO1

25. OSI Reference Model ApplicationLayer 7 PresentationLayer 6 SessionLayer 5 TransportLayer 4 NetworkLayer 3 Data LinkLayer 2 PhysicalLayer 1 -Communication hardwares: modems, network cards -Embedded machine code on the communication hardware -Conversion of data to signals: NRZ, Manchester coding CO1

26. OSI Reference Model ApplicationLayer 7 PresentationLayer 6 SessionLayer 5 TransportLayer 4 NetworkLayer 3 Data LinkLayer 2 PhysicalLayer 1 -Actual connectors -Cables, optical fibers, telephone line CO1

27. OSI Environment Application Presentation Session Transport Network Data Link Physical Application Presentation Session Transport Network Data Link Physical Headers being attached at each layer Headers being stripped off at each layer Data Connectors, switchers Data CO1

28. TCP/IP CO1

29. TCP/IP Model Transmission Control Protocol / Internet Protocol Result of protocol research & development conducted on the experimental packet-switched network, ARPANET, funded by Defense Advanced Research Projects Agency (DARPA) Generally referred to as the TCP/IP protocol suite Consists of a large collection of protocols that have been issued as internet standards by the Internet Architecture Board (IAB) Most widely used interoperable network protocol architecture CO1

30. TCP/IP Model ApplicationLayer 5 TransportLayer 4 InternetLayer 3 Network AccessLayer 2 PhysicalLayer 1 CO1

31. OSI vs TCP/IP Application Presentation Session Transport Network Data Link Physical Application Transport Network Access Internet Physical Communication Softwares & Device Drivers Communication Hardwares & Embedded Code Connectors CO1

32. TCP/IP Layers Application Transport Internet Network Access Physical -Communicating softwares -Make use of many protocols available: FTP, HTTP, SMTP, POP, etc -Control data (standardized), data structure, and sessions CO1

33. TCP/IP Layers Application Transport Internet Network Access Physical -Low Level Communication APIs -Creates, maintains, destroy connection to network devices -Application transparent communication -Device driver CO1

34. TCP/IP Layers Application Transport Internet Network Access Physical -Routing functions at communication hardware -Internet Protocol and IP address CO1

35. TCP/IP Layers Application Transport Internet Network Access Physical -Embedded Code on Communication hardwares: modems, network cards -Conversion of data to signals: NRZ, Manchester coding -Bit level manipulation -Error detection, recovery, transparent flow CO1

36. TCP/IP Layers Application Transport Internet Network Access Physical -Actual connectors -Cables, optical fibers, telephone line CO1

37. Operations of TCP/IP For successful communication, two levels of addressing are needed Each host on a subnetwork must have a unique global internet address: IP address Each process with a host must have an address that is unique within the host to allow TCP to deliver data to proper process: ports CO1

38. Operations of TCP/IP Application Transport Network Access Internet Physical Application Transport Internet Physical Headers being attached at each layer except at physical layer Headers being stripped off at each layer except at physical layer Connectors, switchers Network Access Data CO1