![Further ReadingStallings, W. [2003] Data and Computer Communications (7th edition), Prentice Hall, Upper Saddle River NJ, chapter 1Web site for Stallings bookhttp://williamstallings.com/DCC7e.html](https://image.slidesharecdn.com/lect-1-110320110307-phpapp01/85/Lect-1-18-320.jpg)
Lect 1
- 1. Data Communication & NetworkingLecturer: Dr. Hassan YousifLocation: office-97Textbook: Data Communications and Networking, BehrouzForouzan, 4th Edition
- 2. What is Data Communications?Data communications is the exchange of data between two devices via some form of transmission medium.
- 3. It is the subset of business telecommunications that addresses the processes, equipment, facilities, and services used to transport data from devices at one location to devices at other locations
- 4. It involves the transmission of data through conducted or radiated communication mediaWhat is a Network ?interconnected group of computers and communication devicesWhat is Networking ?A process involving the connection of computers, media and networking devices.
- 5. A Communications Model Sourcegenerates data to be transmittedTransmitterConverts data into transmittable signalsTransmission SystemCarries dataReceiverConverts received signal into dataDestinationTakes incoming data
- 6. Simplified Communications Model - Diagram
- 7. Simplified Data Communications Model
- 8. NetworkingPoint to point communication not usually practicalDevices are too far apartLarge set of devices would need impractical number of connectionsSolution is a communications networkWide Area Network (WAN)Local Area Network (LAN)
- 9. Wide Area Networks (WANs)Large geographical areaCrossing public rights of wayRely in part on common carrier circuitsAlternative technologiesCircuit switchingPacket switchingFrame relayAsynchronous Transfer Mode (ATM)
- 10. Circuit SwitchingDedicated communications path established for the duration of the conversatione.g. telephone network
- 11. Packet SwitchingData sent out of sequenceSmall chunks (packets) of data at a timePackets passed from node to node between source and destinationUsed for terminal to computer and computer to computer communications
- 12. Frame RelayPacket switching systems have large overheads to compensate for errorsModern systems are more reliableErrors can be caught in end systemMost overhead for error control is stripped out
- 13. Asynchronous Transfer Mode (ATM)ATMEvolution of frame relayLittle overhead for error controlFixed packet (called cell) lengthAnything from 10Mbps to GbpsConstant data rate using packet switching technique
- 14. Local Area Networks (LANs)Smaller scopeBuilding or small campusUsually owned by same organization as attached devicesData rates much higherUsually broadcast systemsNow some switched systems and ATM are being introduced
- 15. LAN ConfigurationsSwitchedSwitched EthernetMay be single or multiple switchesATM LANFibre ChannelWirelessMobilityEase of installation
- 16. Metropolitan Area NetworksMANMiddle ground between LAN and WANPrivate or public networkHigh speedLarge area
- 18. Further ReadingStallings, W. [2003] Data and Computer Communications (7th edition), Prentice Hall, Upper Saddle River NJ, chapter 1Web site for Stallings bookhttp://williamstallings.com/DCC7e.html