L1 - Computer Networks Review.pptx
- 1. Basic Concepts of Computer Networks – A Review
- 2. Agenda • Definitions and Applications of Computer Networks • Components of a Computer Network • Network Benefits • Disadvantages • Network classification -Geography -Resource Sharing modes • Server Types
- 3. Definitions and Applications of Computer Networks A computer network is defined as the interconnection of two or more computers. It is intended to facilitate the computers to communicate and share available resources. Applications: i. Sharing of resources such as printers ii. Sharing of expensive software and databases iii. Facilitating communication between PCs iv. User exchange of data and information v. Sharing information over wide geographic areas
- 4. Components Two or more computers Communication media (wired/wireless) A network interface card (NIC) on each PC Navigation devices (switches, routers, etc) Special software known as operation system (OS)
- 5. Benefits The fundamental purpose of a network is to ensure seamless connectivity between nodes and to facilitate dependable resource sharing. Thus, they afford the following benefits I. Hardware sharing- printers, modems, fax machines, etc. II. Sharing software resources reduces the cost of software installation, saves space oh hard disks III. Increased speed in business processes IV. Reduced operational cost V. Improved Security VI. Centralised software management VII.Enhances resource availability
- 6. Demerits I. High cost of specialised installations II. Entails round the clock administrative tasks III. Single point of failure challenges IV. Faulty devices
- 7. Classification - Geography Network PAN LAN WAN MAN
- 8. Local Area Network Primarily designed to operate within a limited confined area such as an office, factory of group of closely located buildings. Facilitates easy exchange of information and resources Characterised with different types of topologies like star, mesh, bus.. Usually privately owned
- 9. Wide Area Network (WAN) When a network spans over a large geographic area or when the computers that require connectivity are located in distant premises, it becomes infeasible to run it as a LAN. A WAN is required for this. WANs link two or more LANS and they span wide geographic areas. The communication between the nodes is done using various technologies like telephone leased lines, satellite links, VPNs, etc.
- 10. Personal Area Network (PAN) Organised around an individual or a group Generally comprises a PC, cell phone, tablet, PDA, etc. PAN enables communication between these devices Construction can be wired or wireless (Bluetooth for example)
- 11. Metropolitan Area Network(MAN) A type of WAN network typically confined within a city. Can be a single network such as Cable TV, or a measure of connecting a number of LANs on a large network
- 12. Summary Characteristics of LAN, wan & MAN
- 13. Network Classification – Resource Sharing Mode Network Peer toPeer Client Server
- 14. Peer To Peer Each computer is responsible to maintain its resources and making them available to requesting peers. The individual computer are responsible for setting up and maintaining the security protocols for the hosted resources. Each PC is responsible for requesting and accessing needed resources from the peered connectivity. It is useful for small business enterprises of up to 10 users, for example. No central control system
- 15. Advantages & Disadvantages Advantages Disadvantages 1. Uses inexpensive computer and related devices and software 1. Less secure 2. Easier to administer 2. No central storage location leading to challenges in maintaining data integrity, slow searches for needed files, etc. 3. Does not require specialised NOS 3. Additional pressure on limited computing resources and might affect overall performance of the network. 4. High redundancy 4. Poor scalability 5. Easier to setup and low cost 5. High chances of data loss, except if terminal PCs have localised backup drives.
- 16. Client / Server Network Certain computers act as servers and others as clients. Available network resources such as files, directories, applications and shared devices are centrally managed and hosted for clients access. Most widely deployed network relationship type in small and large enterprises
- 17. Advantages & Disadvantages Advantages Disadvantages 1. Very Secure 1. Requires professional administration 2. Better performance because of specialised servers to handle specific tasks 2. More hardware & Software intensive 2. Better performance because of specialised servers to handle specific tasks. 3. Expensive 3. Very reliable 4. Single point of failure 4. Provides for scalability
- 18. Infographic
- 19. Popularly Deployed Servers in Networks Based on Purpose