1 Telecommunications, the Internet, Intranets, and Extranets CSC101 SECTIONS 01 & 02

2 Telecommunication Systems Telecommunication Medium is anything that carries an electronic signal and interfaces between a sending device and a receiving device.

3 Media Types Twisted-pair wire cable (Telephone) Coaxial cable (Cable and Telephone) Fiber-optic cable (Higher Speed, Smaller) Microwave transmission (No cable, High spd) Cellular transmission (Mobile users) Infrared transmission (Unobstructed line of sight, Move and reinstalled)

4 Wiring and Cabling Types

5 Telecommunication Devices

6 DSL versus Cable Modems

7 Compare Line and Service Types

8 Computer Network The communications media, devices, and software needed to connect two or more computer systems and/or devices

9 Data Processing Strategies Centralized Processing: all processing occurs in a single location or facility Decentralized Processing: processing devices are placed at various remote locations Distributed Processing: computers are placed at remote locations and connected via telecommunication devices

10 Terminal-to-Host Connection

11 File Server Connection

12 Client/Server Connection

13 Client/Server Advantages Reduce cost (potential) Improve performance Increase security Disadvantages Increase Cost of managing network Loss of control Administration can be difficult Complex systems (Internal and External users)

14 Local Area Network (LAN)

15 Wide Area Network (WAN)

16 Home Computer Network

17 Terminology NOS (Network Operating System) Allows all computers on the Network to communicate with each other NMS (Network Management Software) Allows the network administrator to scan for viruses and manage users facilities Communication Protocols Rules and standards that make communication possible

18 The Internet ARPANET – Advanced Research Project Agency, Now is called DARPA UCAID – University Corporation for Advanced Internet Development Internet add hoc linkage of many networks

19 Internet Protocols Internet Protocol (IP): standard that enables traffic to be routed from one network to another as needed Transport Control Protocol (TCP): rules that computers on a network use to establish and break connections Uniform Resource Locater (URL): an assigned address on the Internet for each computer Backbone High-speed, long distance links

20 U.S. Top-Level Domains

21 Accessing the Internet SLIP LAN AOL ISP

22 Internet Service Providers

23 Internet Services Voice Mail, Electronic Mail, and Instant Messaging Telecommuting, Videoconferencing, and Internet Phone Service Electronic Data Interchange (EDI) Public Network and Specialized Services Distance Learning

24 Internet Services (con’t.) On-line Music, Radio, and Video Telnet, FTP, and Content Streaming Chat Rooms

25 Videoconferencing

26 Electronic Data Interchange

27 Public Network Services

28 The World Wide Web (WWW) An Internet service compromising tens of thousands of independently owned computers that work together as one.

29 Interesting Web Sites

30 Interesting Web Sites Monster.com Askme.com WebMD

31 Hypertext Markup Language (HTML)

32 Search Engines

33 Intranets and Extranets Intranet An internal corporate network built using Internet and World Wide Web standards and products; used by the employees of the organization to access corporate information. Extranet A network that links selected resources of the intranet of a company with its customers, suppliers, or other business partners; based on Web technologies.

34 Internet, Intranet, and Extranet

35 Virtual Private Network Tunneling – encapsulating IP’s to send over the Internet. Firewall – sits between the intranet and the outside internet

36 Net Issues Management Issues Managed at the local level IAB Internet Activities Board (TCP/IP) Service Bottlenecks Corporate intranet traffic is growing faster then internet traffic Recapturing missing packets Privacy and Security (Next Lecture)

37 Cryptography