Faculty of Science and Humanitarian studies- Al- Aflaj

1. Faculty of Science and Humanitarian studies- Al-Aflaj Department of computer Science Computer Network Systems

2. Plan

3. Foreword… • People initially bought computers for word processing and games…etc • Recently, the biggest reason to buy a home computer was probably for Internet access. • Consumer electronic devices, such as set-top boxes, game consoles, and clock radios, come with embedded computers and computer networks, especially wireless networks, and home networks are broadly used for entertainment, including listening to, looking at, and creating music, photos, and videos.

4. DEFINITION •  Def1: A couple of computers have some cables connected them, and send data back and forth using electrical signaling over the cable. • Def2: A network is simply a collection of computers or other hardware devices that are connected together, either physically or logically, using special hardware and software, to allow them to exchange information and cooperate.

5. HISTORY Robert Metcalfe wrote a formal memo at Xerox PARC describing Ethernet, commercial services using X.25 were deployed, and later used as an underlying infrastructure for expanding TCP/IP networks  the commercial airline reservation system semi-automatic business research environment (SABRE) Western Electric introduced the first widely used telephone switch that implemented true computer control. Thomas Marill and Lawrence G. Roberts published a paper on an experimental wide area network (WAN) In 1995, the transmission speed capacity for Ethernet increased from 10 Mbit/s to 100 Mbit/s the first four nodes of the ARPANETwereconectedusing 50 kbit/s circuits between 4 university John Murphy of Datapoint Corporation created ARCNET, a token-passing network first used to share storage devices.  Intergalactic Computer Network. was a computer networking concept similar to internet Dartmouth Time Sharing System for distributed users of large computer systems Louis Pouzin developed the Cyclades network networks of computers included the U.S. military radar system (SAGE)  Soviet project to create a nationwide information network years 1972 1969 1950 1976 1965 1973 1959 1963 1960 1964 1965 1995

6. Advantages of networking • It enhances communication and availability of information.  • Instant messaging can now allow users to talk in real time and send files to other people wherever they are in the world. • it allows access to a vast amount of useful information, including traditional reference materials and timely facts, such as news and current events. • Allows File Sharing • Computer networking allows accessibility for the people to share their files easily

7. Advantages of networking • Provides Convenient Resource Sharing • This is very important particularly for those larger companies who are greatly in need to produce huge number of resources to be shared to all the people. • Flexible • Computer networking is known to be very flexible since you are given the chance to explore everything about the software without affecting its functionality. •  It boosts(increase) storage capacity

8. The Disadvantages (Costs) of Networking • Security Difficulties • Since there are already huge number of people who are using computer networking in sharing some of their files and resources, your security would be always at risk • Presence of Computer Viruses and Other Malwares • There are instances that the stored file you have in your storage devices is already destroyed because there are already viruses that corrupt your file

9. The Disadvantages (Costs) of Networking • Lack of Independence • Since computer networking is a process operated through computers, people are already relying more of the works of the computer rather than exerting an effort for their works.

10. Fundamental Network Classifications • PANs (Personal Area Networks): let devices communicate over the range of a person. A common example is a wireless network that connects a computer with its peripherals Bluetooth PAN configuration • Bluetooth networks use the master-slave paradigm. • PANs can also be built with other technologies that communicate over short ranges, such as RFID.

11. Fundamental Network Classifications • LAN (Local Area Networks): A LAN is a privately owned network that operates • within and nearby a single building like a home, office or factory. • LANs are widely used to connect personal computers and consumer electronics to let them share resources (e.g., printers) and exchange information Wireless and wired LANs • The switch is used to relay packets between computers that are attached to it, using the address in each packet to determine which computer to send it to. • Access Point: relays packets between the wireless computers and also between them and the Internet.

12. Fundamental Network Classifications • Wireless LANs : very popular especially in in homes, older office buildings, • cafeterias….etc • Wired LANs use a range of different transmission technologies: • copper wires, optical fiber

13. Fundamental Network Classifications • Metropolitan Area Network (MAN): • A metropolitan area network (MAN) is a network that interconnects users with computer resources in a geographic area or region larger than that covered by even a large local area network (LAN) but smaller than the area covered by a wide area network (WAN). • The term (MAN) is applied to the interconnection of networks in a city into a single larger network .

14. Fundamental Network Classifications • The best-known examples of MANs are the cable television networks available in many cities. • Head end deviceis a central control devicerequired by some MAN networks. It provide a centralizedfunctionssuch us re-modulation, diagnostic control…etc

15. Fundamental Network Classifications • WAN (Wide Area Network) • Spans a large geographical area, often a country or continent. • The largest and most well-known example of a WAN is the Internet. This is a network that connects offices in Perth, Melbourne, and Brisbane in Australia • the subnet consists of two distinct components: transmission lines and switching elements • the routers will usually connect different kinds of networking technology

16. Client and Server computer role in networking • Server : • A server is a physical computer dedicated to run services to serve the needs of other computers. Depending on the service that is running, it could be a file server, database server, home media server, print server, or web server. • Client • Aclient is a computer that connects to and uses the resources of a remote computer, or serve.

17. Computer networking connectivity • Network connectivity describes the extensive process of connecting various parts of a network to one another, for example, through the use of routers, switches and gateways, and how that process works.

18. Computer networking connectivity • USB cable: USB ports can power up certain devices and transfer the data at the same time. The USB standards use A and B connectors to avoid confusion and comparatively the connectivity between the computers through the USB cables doesn't provide the fast speed. The speed also depends on the quality of the cable, operating system, protocols, network devices, CPU and other electronic components.

19. Ethernet Straight & Crossover Cables • The most commonly used method of the connectivity between the LAN computers is through the Ethernet cables.  • Ethernet is a local area network communication standard.

20. Computer networking connectivity • Bluetooth Personal Area Network (PAN) • Fiber Optic Cable: A fiber optic cable is made up of strands of glass fibers, which allows the transmission of data at the speed of light.  • Wireless (Wi-Fi) ad-hoc network: Wireless network communication is possible through the IEEE Wireless 802.11b/g also called Wi-Fi or wireless Ethernet.