1 / 23

Data Communication Systems and Networks

Data Communication Systems and Networks. CSCI 465 Martin van Bommel Lecture 1. Data & Information. What is data? Elements that can be represented by a finite set of symbols, such as digits or alphabets What is information? a tangible, measurable thing a subjective construction.

tjack
Download Presentation

Data Communication Systems and Networks

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Data Communication Systemsand Networks CSCI 465 Martin van Bommel Lecture 1

  2. Data & Information • What is data? • Elements that can be represented by a finite set of symbols, such as digits or alphabets • What is information? • a tangible, measurable thing • a subjective construction

  3. What Is Communication? • Symbolic • Representational • “The map is not the territory.” • Communication is only as good as the representation • Examples • spoken language, gestures, actions, icons

  4. Human Communication vs. Data Communication • Human communication is richer, less predictable • Words vary in meaning with context • Many factors influence meaning and perception of message • Data communication is more precise • Exact replication of information • Computers do not interpret, they simply relay

  5. Telecommunication • Uses electricity to transmit messages • Speed of electricity dramatically extends reach • Sound waves: ~670 mph • Electricity: ~186,000 (speed of light) • Bandwidth= information-carrying capacity of a channel

  6. Data Communication • Adding storage overcomes time constraints • Store-and-forward communication • E-mail • voice mail • facsimile • file transfer • WWW

  7. Information and Communication • Companies depend on generation and movement of information • Communications technology fundamental • Enables reshaping of corporations • Communication technology driving change • Allows geographical dispersal • Becomes management nightmare

  8. Information Communication • Voice communications - telephone • PSTN and PBX • Data communications - text and numbers • Image communications - fax and beyond • Video communications - videoconferencing

  9. Data Communications, Data Networks, and the Internet “The fundamental problem of communication is that of reproducing at one point either exactly or approximately a message selected at another point” The Mathematical Theory of Communication by Claude Shannon

  10. Changes in Networking Technology • Emergence of high-speed LANs • Centralized servers, distributed workgroups • High-speed local backbones • Corporate WAN needs • Data intensive applications spread across wide geographical areas • Digital electronics • Much higher bandwidth required for video/image

  11. Three Layer Modelfor Enterprise Communication • Applications • Seen by end users • Voice, email, IM, image, video, collaborations • Enterprise services • Design, maintenance, and support of apps • Capacity management and QoS provisions • Infrastructure • Communication links, LANs, WANs, Internet access

  12. Convergence of Communication Facilities - Benefits • Efficiency • Better use of existing resources • Centralized capacity planning, asset management, and policy management • Effectiveness • Flexibility, mobility, enhanced connectivity • Rapid standardized service deployment • Transformation • Enterprise-wide adoption of global standards

  13. Communications Model

  14. Communication Tasks

  15. Data Communications Model

  16. Transmission Lines • The basic building block of any communications facility is the transmission line. • The business manager is concerned with a facility providing the required capacity, with acceptable reliability, at minimum cost. • However, the use of compression, multiplexing, load sharing, and other line features can significantly affect the end choice

  17. Transmission Media • Convert electronic signal to transmit over some medium • Twisted-pair, coaxial cable, optical fiber cable, terrestrial and satellite microwave (wireless) Fiber optic transmissions Wireless transmissions

  18. Data Transmission • Communication techniques • analog vs digital, synchronous vs asynchronous • modulation, flow control, interfaces • error detection and correction • Multiplexing and compression

  19. Networks • LAN - Local Area Network • single building or cluster of buildings • ethernet, token ring, star, wireless • WAN - Wide Area Network • city-to-city, country-to-country • telephone, ISDN, ATM, etc. • Wireless Network • radio, microwave, satellite

  20. Internet • Internet evolved from ARPANET • Developed to solve the dilemma of communicating across arbitrary, multiple, packet-switched network • TCP/IP provides the foundation

  21. Internet – Key Elements

  22. Internet Architecture

  23. Network Configuration

More Related