1. N ETWORKS, TYPE, CONNECTIVITY, TOPOLOGY, OSI MODEL, NETWORKING MEDIA, TRANSMISSION, SOFTWARE SUPPORT, NETWORK HARDWARE - BRIDGE, HUB, ROUTERS, SWITCH, MODEM ETC. Week 9 Mr. Mohammed Rahmath

2. N ETWORK Network: A network is a group of two or more computer systems linked together. There are many types of computer networks, including: Mr. Mohammed Rahmath

3. T YPES OF NETWOKS local-area networks (LANs) wide-area networks (WANs) campus-area networks (CANs) metropolitan-area networks (MANs) home-area networks (HANs) Mr. Mohammed Rahmath

4. LOCAL - AREA NETWORKS (LAN S ) The computers are geographically close together (that is, in the same building). Mr. Mohammed Rahmath

5. WIDE - AREA NETWORKS (WAN S ) The computers are farther apart and are connected by telephone lines or radio waves. Mr. Mohammed Rahmath

6. CAMPUS - AREA NETWORKS (CAN S ) The computers are within a limited geographic area, such as a campus or military base. Mr. Mohammed Rahmath

7. METROPOLITAN - AREA NETWORKS (MAN S ) A data network designed for a town or city. Mr. Mohammed Rahmath

8. HOME - AREA NETWORKS (HAN S ) A network contained within a user's home that connects a person's digital devices. Mr. Mohammed Rahmath

9. P ROTOCOL AND A RCHITECTURE protocol : The protocol defines a common set of rules and signals that computers on the network use to communicate. architecture : Networks can be broadly classified as using either a peer-to-peer or client/server architecture. Mr. Mohammed Rahmath

10. C ONNECTIVITY Connectivity: the ability to link to and communicate with other computer systems, electronic devices, software, or the Internet. Mr. Mohammed Rahmath

11. T OPOLOGY Definition : A network topology describes the arrangement of systems on a computer network. It defines how the computers, or nodes, within the network are arranged and connected to each other. 1. Star Topology 2. Ring Topology 3. Bus Topology 4. Mesh Topology Mr. Mohammed Rahmath

12. S TAR T OPOLOGY All the nodes are connected to center device. Mr. Mohammed Rahmath

13. R ING T OPOLOGY Devices are connected to each other in ring form. Mr. Mohammed Rahmath

14. B US T OPOLOGY All computers are connected to common communication channel. Mr. Mohammed Rahmath

15. M ESH T OPOLOGY All computers are interconnected. Mr. Mohammed Rahmath

16. OSI MODEL The OSI, or Open System Interconnection, model defines a networking framework to implement protocols in seven layers. 1. Application layer 2. Presentation layer 3. Session layer 4. Transport layer 5. Network layer 6. Data Link layer 7. Physical layer Mr. Mohammed Rahmath

17. OSI MODEL DIAGRAM Mr. Mohammed Rahmath

18. N ETWORK AND T RANSMISSION MEDIA : Network Media: it is sometimes referred to as networked media) refers to digital media mainly used in computer networks such as the Internet. Transmission media: The means through which data is transformed from one place to another is called transmission or communication media. There are two categories of transmission media used in computer communications. 1. BOUNDED/GUIDED MEDIA 2. UNBOUNDED/UNGUIDED MEDIA Mr. Mohammed Rahmath

19. T YPES OF T RANSMISSION M EDIA Guided Media : 1. Unshielded Twisted Pair (UTP) 2. Shielded Twisted Pair 3. Coaxial Cable 4. Optical Fibre Unguided Media : 1. Radio Transmission 2. Microwave 3. Satellite Communication Mr. Mohammed Rahmath

20. S OFTWARE SUPPORT Definition : After-sales service provided by a software publisher or vendor in solving software conflicts and usability problems, and in supplying updates and patches for bugs and security holes in the program. Mr. Mohammed Rahmath

21. N ETWORKING HARDWARE Networking hardware typically refers to equipment facilitating the use of a computer network. Examples: bridge, hub, routers, switch, modem etc…… Mr. Mohammed Rahmath

22. B RIDGE A bridge device filters data traffic at a network boundary. Bridges reduce the amount of traffic on a LAN by dividing it into two segments. Mr. Mohammed Rahmath

23. HUB HUB - is a device for connecting multiple twisted pair or fiber optic Ethernet devices together and thus making them act as a single network segment. Mr. Mohammed Rahmath

24. R OUTERS Routers are small physical devices that join multiple networks together. Mr. Mohammed Rahmath

25. S WITCH A network switch is a small hardware device that joins multiple computers together within one local area network (LAN). Mr. Mohammed Rahmath

26. M ODEM Definition : a combined device for modulation and demodulation, for example, between the digital data of a computer and the analogue signal of a telephone line. Mr. Mohammed Rahmath

27. S ESSION 9 E ND Mr. Mohammed Rahmath