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Chapter 4 Telecommunications and the Internet Dr. Hassan Ismail 1 Chapter 4 Objectives • Understand the role of telecommunications in organizations • Understand the evolution of computer networks • Understand the Internet and how it works • Understand basic Internet services • Understand the use of the World Wide Web 2 The Role of Telecommunications and Networks in Organizations • Definitions – Telecommunications – the transmission of all forms of information, including digital data, voice, fax, sound, and video, from one location to another over some type of network – Network – a group of computers and associated peripheral devices connected by a communication channel capable of sharing information and other resources (e.g., like a printer) between users – Bandwidth – the carrying capacity of telecommunications networks 3 The Role of Telecommunications and Networks in Organizations • Interpersonal Communication Applications – E-mail and Groupware – Voice mail & Facsimile (fax) – Teleconferencing, Data conferencing and Videoconferencing – Common business applications: • Distance learning, • E-learning • E-commerce • E-business • Telemedicine 4 Electronic Mail and Groupware • E-mail: Eliminates telephone tag and costly long-distance telephone charges • Groupware: Enables work groups at different locations to participate in discussion forums and work on shared documents and projects 5 Voice Mail and Fax • Voice mail: Digitizes spoken message and transmits it over a network • Fax: Digitizes and transmits documents over telephone lines 6 Teleconferencing, data conferencing, and videoconferencing • Teleconferencing: Ability to confer with a group of people simultaneously • Data conferencing: Two or more users can edit and modify data files simultaneously • Videoconferencing: Participants are able to see each other over video screens 7 Common business applications • Distance learning: Education or training delivered • E-learning: Instruction delivered online using the • E-Commerce: buying or selling online online using • E-business: use the internet technology to support business. • Telemedicine: exchange of medical information from one location to another via a computer network. over a distance to individuals in one or more locations Internet or private networks the Internet or private networks 8 Network Topologies • Star network • Ring network • Bus network 9 Bus Topology 10 Ring Topology 11 Star topology 12 Evolution of Computer Networking • Sharing Information – Senders and receivers that have something to share – Transmission media: cable to send the message – Rules or protocols: dictating communication between senders and receivers. 13 Evolution of Computer Networking • Computer Networks: 1) Digitizing => 2) Modem 14 Evolution of Computer Networking • Centralized Computing: large centralized computer called mainframe were used to process and store data Mainframe 15 Evolution of Computer Networking Distributed Computing: multiple types of computers are networked together to share information and services 16 Evolution of Computer Networking Collaborative Computing: two or more networked computers are used to accomplish a common processing task. (1) (2) (3) 1. Requests record to change 3. Returns changed record 2. Returns requested record 17 Evolution of Computer Networking •Types of Networks – – – – Private Branch Exchange (PBX) Local Area Network (LAN) Wide Area Network (WAN) Personal Area Networks (PANs): 18 Evolution of Computer Networking • Types of Networks – Private Branch Exchange (PBX): • Central switching system • Handle firm’s voice and digital communications 19 Evolution of Computer Networking Local Area Network (LAN): – Telecommunication network – Require its own dedicated channels – Encompass a limited distance – Gateway, router, Network Operating System (NOS) 20 Wide Area Networks (WANs) • Telecommunication network • Span large geographical distance • Consist of variety of cable, satellite, and microwave technologies • Switched lines, dedicated lines 21 …WAN types • Global Networks: spans multiple countries and may include several organizations • Enterprise Networks: WAN connecting networks of single organization • Value-Added Networks (VANs): private, third-party managed networks (lease communication lines rather than investing in dedicated network equipment). • Metropolitan Area Networks (MANs): network for city-wide area 22 Wide Area Networks (WANs) • Telecommunication network • Span large geographical distance • Consist of variety of cable, satellite, and microwave technologies • Switched lines, dedicated lines 23 Personal Area Networks (PAN) emerging technology uses wireless communication to exchange data through short-range radio communication for short-distance (exp: Bluetooth) 24 The Internet •How did the Internet Get Started? – ARPANET • U.S. Defense • Advanced Research Projects Agency (ARPA) – NSFNET • National Science Foundation 25 The Internet • Internet Technologies – Packet-Switching Technology – TCP/IP • Transmission Control Protocol/Internet Protocol • IP Datagram – Connecting Independent Networks • Routers • Backbone Network 26 Packet switching 27 The Internet • Web Domain Names and Addresses – Uniform Resource Locator (URL) – Common domain extensions • .edu .org .mil .com .net • .ca .th .no (country codes) – IP Addresses 28 The Internet • Who Manages the Internet? – Domain Name System (DNS) – a system used to associate Internet host names with their Internet IP addresses – The Internet Registry – provides central maintenance of the DNS root database, used to associated Internet hostnames with their IP addresses. 29 The Internet • Who Manages the Internet? – Internet Corporation for Assigned Names and Numbers (ICANN) – a non-profit corporation manages IP addresses, domain names, and root server system management – InterNIC Registration Service – assigns Internet addresses 30 The Internet • How Do You connect to the Internet? – Internet Service Providers (ISPs): which will give you username and password to access to the internet. – Network Access Points (NAPs): within which ISPs can connect to one another. – Internet backbone: which is the collection of main network connections and telecommunications lines comprising the Internet. 31 The Internet • How Fast Is Your Connection? – – – – – – – Plain Old Telephone Service (POTS) Integrated Services Digital Network (ISDN) Digital Subsciber Line (DSL) Cable Modems Satellite Connections T1 Lines Asynchronous Transfer Mode (ATM) 32 The Internet •Security in the Internet Age – Encryption – Firewalls – Authentication 33 The Internet • State of the Internet • What are people doing on the Internet? – E-mail – What next for the Internet? • Internet2 • Abilene network backbone 34 35 The Internet • Internet Tools (see table in page 119) – – – – – – – E-mail Telnet File transfer Listserv Usenet Archie WAIS – Gopher – Voice over IP 36 World Wide Web • • • • • • • Web browser Hypertext Hyperlinks Hypertext Markup Language (HTML) Web servers Hypertext Transfer Protocol (HTTP) Uniform Resource Locator (URL) 37 World Wide Web • World Wide Web Architecture • World Wide Web Applications – – – – Electronic brochure Online ordering Electronic marketplaces Online customer service 38