Communication and networks Part 1
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The lecture by Mr. Rajasekar Ramalingam covers key aspects of communication and networks, including types of networks such as LAN, MAN, and WAN, as well as network architectures like client-server and peer-to-peer. It also discusses network topologies including bus, ring, and star, highlighting their advantages and disadvantages. Additionally, communication standards and protocols such as Ethernet and Bluetooth are explained, detailing how they facilitate device communication.
Communication and networks Part 1
- 1. Communication & Networks Part - 1 MR. RAJASEKAR RAMALINGAM LECTURER – DEPARTMENT OF INFORMATION TECHNOLOGY, COLLEGE OF APPLIED SCIENCES – SUR, SULTANATE OF OMAN.
- 2. In this lecture… Computers in communications Advantages of using networks Network scale Network architecture Network topology Ethernet and Bluetooth 2
- 3. Computer communications Home Office School Café Wireless hotspot Anywhere! 3
- 4. Communicating Sender Medium Wired Wireless Receiver More than talk More than text 4
- 5. Networks "Collection of computers and devices connected together using communication devices and transmission media“ Any device connected to a network (wired or wireless) is called a node The next slide has a diagram from the text showing advantages of using networks 5
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- 7. Network Scale LAN Local Area Network An office, a floor, a university MAN Metropolitan Area Network City-wide Often connects LANS London Fire Service WAN Wide Area Network Country, Region, World 7
- 8. Network Architecture Client-Server One or more servers Controls & coordinates access to network resources Hardware, software, data - "The Boss" Provides centralised, shared storage For software For data Uses network operating system May be specialised e.g. file server, print server Clients use network resources The worker's PCs Each computer is "equal" Every computer can share data and/or hardware Every computer is both a "server" and a "client" About 10 computers is the sensible limit Simple, easy, cheap Internet P2P A file sharing network Users connect direct to each other's hard disks and exchange files directly 8
- 9. Client-Server 9 In this example the server is also a print server
- 10. P2P 10 Network operating system and application software on each computer
- 11. Network topology The layout of the network Bus network Nodes connected to a single central cable (the bus) Inexpensive, easy to install Easy to connect/disconnect nodes without disruption Problems if the bus fails! 11
- 12. Ring network Cable forms a closed loop Data moves in one direction around the loop, from one node to the next If a node fails, nodes after that won't work 12
- 13. Star network All nodes connected to a central device Uses a hub Easy to install and maintain Easy to connect/disconnect nodes If the hub fails… 13
- 14. Hub 14 Small (4 ports) to large (24+ port)
- 15. Most networks use a mixture of topologies 15
- 16. Topology summary Advantage Disadvantage Bus Easy to add/remove nodes Node failure doesn't disrupt network If bus fails, network is disabled Ring Larger distance than bus topography More difficult to install Node failure disables all subsequent nodes Adding/removing a node disrupts network Star Easy to install and maintain Easy to add/remove nodes If hub fails, network is disabled 16
- 17. Communication standards Allow different devices to "talk" to each other Example - PC, Apple, mobile phone Allow different networks to "talk" to each other Example - LAN, WAN, wired and wireless A standard that outlines how network devices communicate is called a protocol The language that is used to communicate Examples include TCP/IP (in OMINT103), Ethernet and Bluetooth 17
- 18. Ethernet A networking standard Based on bus topology, but also used for star Specifies physical configuration Cabling, network cards, nodes etc Popular - inexpensive, relatively easy to maintain Often uses cable as transmission media 18
- 19. Bluetooth A network protocol Defines how Bluetooth devices use short-range radio devices to transmit data Speeds up to 2 Mbps Over distances of up to 10m Devices require a built-in Bluetooth chip, or a plug-in Bluetooth adapter Examples - wireless mouse, sync PC and mobile phone, phone and headset. 19