Data Communications and Networking

• Data Communications

  • Refers to the exchange of data between a source and a receiver via a transmission medium.
• DTE - Data Terminal Equipment
• DCE - Data Communications Equipment
• Computer Network

  • Is a group of computers that use a set of common communication protocols over digital interconnections for the purpose of sharing resources.
• Classifications of Computer Networks: LAN (Local Area Network), WAN (Wide Area Network), MAN (Metropolitan Area Network)
• • Local Area Network (LAN) group of computers linked electronically to form a common work environment. It facilitates sharing of applications and data.
• • Wide Area Network (WAN) geographically dispersed telecommunication network covering multiple buildings, often across the world.
• • Metropolitan Area Network (MAN) intermediate form of network in terms of geography.
• Network Topologies

  • The physical and/or electrical configuration of cabling and connections comprising a network – the shape of the system.
• • Bus devices are connected to a common table (straight line) Ex. hotspot.
• • Ring devices are connected to a common cable which loops from machine to machine (circle). Pag may putol na connection, putol na lahat
• • Star device has its own cable run connecting the device to a common hub or concentrator.
• • Tree star of stars network. Each device is connected to its own port on a concentrator in the same manner as in a star. Combination of two stars.
• • Mesh consists of a network where every device on the network is physically connected to every other device on the network.
• • Hybrid consists of a combination from two or more topologies to form a complex network Ex. www.
• Network Hardware

  • Includes all computers, peripherals and other equipment needed to perform communication and processing within the network.
• • File Server most powerful computer in the network.
• • Workstations computers connected to the network which uses the resources to the file server.
• • Network Interface Card provides physical connection between the network and the computer workstations.
• • Hub or concentrator device that provides a central connection point for cables in the network.
• 1. Repeater - used to extend local area networks.
• • Bridges device that segments a large network.
• • Routers translates information from one network to another. (find fastest route)
• Network Operating System

  • Basic software that contains basic functionalities required for building an effective network.
  • Basic Functions

  1. Data Sharing
  2. Printing SHaring
  3. Security Management
• • Configuration Management collection and management of information on current network resources as well as on changes in network configuration.
• • Fault Management monitoring system errors to perform automated recovery processes.
• • Security Management monitoring the state of access on the network.
• • Performance Management monitoring response time and traffic load to manage and maintain the performance of the network.
• • Service Charge Management monitoring and analyzing of information indicating the use of network resources.
• Internet

  • Global computer network providing a variety of ICT facilities.
  • Interconnected network
• Internet Protocol Service provides transport of Internet Protocol (IP) packets. IP is the primary protocol in the suite which is used for communicating data across a packet-switched internetwork. 
• File transfer protocol (FTP) is a way to download, upload, and transfer files from one location to another on the Internet and between computer systems.
• Hypertext Transfer Protocol (HTTP) is an application protocol for distributed, collaborative, hypermedia information systems that allows users to communicate data on the World Wide Web.
• Uniform Resource Locator. A URL is nothing more than the address of a given unique resource on the Web.
• An Internet Protocol (IP) address is the unique identifying number assigned to every device connected to the internet.
• Domain Name System (DNS), translates human readable domain names (for example, www.amazon.com) to machine readable IP addresses (for example, 192.0. 2.44).
• Tim Berners-Lee, a British scientist, invented the World Wide Web (WWW) in 1989
• Parts: www.pup.edu.ph

  • www - server name
  • pup - name of organization
  • edu - type of organization
  • ph - country specifier
• Domain Suffixes

  • .gov - government
  • .org - nonprofit organizations
  • .mil - military
  • .edu - education
  • .com - commercial
  • .biz - business
  • .net - networking
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