1. Networking Basics Introducing Basic Network Concepts “In the beginning, there were no networks. Life was bad.” —MIKE MEYERS Mohammad Ferdous(ehsan) “safi” EHSANSAFI2005@GAMIL.COM ITCK Information Technology Center Of Kabul University Date: 24 / Sep / 2016

2. In this Lecture, you will learn : Understanding The Differences Between Internet Connections Basic Administration Network Architectures  Client/Server Network  Peer-to-Peer Network Networking Topologies (Physical & Logical) Network Operating System What is a Network Protocol?

3. Page 1 of 20 Modem : A combined device for modulation and demodulation, for example, between the digital data of a computer and the analog signal of a telephone line. Cable Modem : A type of modem that connects a computer or local network to broadband Internet service through the same cable that supplies cable television service. Cable Internet connection is a form of broadband access. Through use of a cable modem, users can access the Internet over cable TV lines. Cable modems can provide extremely fast access to the Internet. The Differences Between Internet Connections

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5. Page 3 of 20 Fiber : Fiber optic (or "optical fiber") refers to the medium and the technology associated with the transmission of information as light impulses along a glass or plastic wire or fiber. Fiber optic wire carries much more information than conventional copper wire and is far less subject to electromagnetic interference. Fiber Optic Cable : A fiber optic cable consists of a bundle of glass threads, each of which is capable of transmitting messages modulated onto light waves. Fiber optics has several advantages over traditional metal communications lines: Fiber optic cables have a much greater bandwidth than metal cables. The Differences Between Internet Connections

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7. Page 5 of 20 Wireless : Using radio Signals, microwaves, etc Frequency. (as opposed to wires or cables) to broadcast and transmit signals. One of the greatest advantages of wireless Internet connections is the “always-on” connection that can be accessed from any location that falls within network coverage. Wireless connections are made possible through the use of a modem, which picks up Internet signals and sends them to other devices. The Differences Between Internet Connections

8. Page 6 of 20 The Differences Between Internet Connections Satellite : An artificial body placed in orbit around the earth or moon or another planet in order to collect information or for communication. Satellite Internet Connection : In a two-way satellite Internet connection, the upstream data is usually sent at a slower speed than the downstream data arrives. Thus, the connection is asymmetric. A dish antenna, measuring about two feet high by three feet wide by three feet deep, transmits and receives signals.

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10. Page 6 of 20 The Differences Between Internet Connections DSL : DSL, which stands for Digital Subscriber Line, uses existing 2-wire copper telephone line connected to one’s home so service is delivered at the same time as landline telephone service. Customers can still place calls while surfing the Internet.

11. Page 1 of 20 Broadband over power lines (BPL) Is a method of power line communication (PLC) that allows relatively high-speed digital data transmission over the public electric power distribution wiring. Broadband : This high-speed Internet connection is provided through either cable or telephone companies. One of the fastest options available, broadband Internet uses multiple data channels to send large quantities of information. The term broadband is shorthand for broad bandwidth. Broadband Internet connections such as DSL and cable are considered high-bandwidth connections. Although many DSL connections can be considered broadband, not all broadband connections are DSL The Differences Between Internet Connections

12. Page 1 of 20 Client-server architecture (client/server) Is a network architecture in which each computer or process on the network is either a client or a server. Servers are powerful computers or processes dedicated to managing disk drives (file servers), printers (print servers), or network traffic (network servers ). Basic Administration Network Architectures

13. Page 1 of 20 Peer-to-peer architecture (P2P architecture) Is a commonly used computer networking architecture in which each workstation,or node, has the same capabilities and responsibilities. It is often compared and contrasted to the classic client/server architecture, in which some computers are dedicated to serving others. Basic Administration Network Architectures

14. Page 1 of 20 Network topology : Is the arrangement of the various elements (links, nodes, etc.) of a computer network. Essentially, it is the topological structure of a network and may be depicted physically or logically. Networking Topologies (Physical & Logical) Physical Topology : The physical layout of devices on a network. Every LAN has atopology, or the way that the devices on a network are arranged and how they communicate with each other. The way that the workstations are connected to the network through the actual cables that transmit data -- the physical structure of the network -- is called the physical topology. LANtopology workstations Logical Topology : Logical topology is the way that the signals act on the network media, or the way that the data passes through the network from one device to the next without regard to the physical interconnection of the devices.

15. Page 1 of 20 Physical Topologies :

16. Page 1 of 20 Logical Topology :

17. Page 1 of 20 What is a Network Operating System : A network operating system (NOS) is a computer operating system that is designed primarily to support workstation, personal computer, and, in some instances, older terminal that are connected on a local area network (LAN).

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19. Protocol : The official procedure or system of rules governing affairs of state or diplomatic occasions. Network Protocol : Network protocols are formal standards and policies comprised of rules, procedures and formats that define communication between two or more devices over a network. Network protocols govern the end-to-end processes of timely, secure and managed data or network communication. What is a Network Protocol :

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21. References : Lammle, T. (2007). Cisco Certified Network Associate. Study Guide. 6 th Ed. Wiley Publishing: Indianapolis, Indiana. Warner, K. (2003). Cisco Networking Academy Program. Companion Guide. 3 rd Ed. Ciscopress: Cisco Systems Inc. More resources are available at:  https://www.techopedia.com/definition/25597/computer-network https://www.tutorialspoint.com/ https:/ www.searchnetworking.techtarget.com/definition https://www.omnisecu.com/cisco-certified.../unicast-multicast- broadcast.php