1 topic: living with a computer plan: Understanding of personal computer. Basic devices of a personal computer Additional devices of the personal computer

18 SUBJECT NETWORK WORKS A network is a connection between two or more devices. An example of this is voluntary. For example, it is possible to transfer data from one computer to another or to play multiplayer or team games. The network is also the basis for 2 people to talk on the phone. In short, the concept of networking lies in the communication of any device with other devices.

NETWORK COMPONENTS

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• 1. Device:
• a) Last devices (computer, phone, printer, fax, etc.);
• b) Intermediate devices (router, switch, hub, etc.);
• 2. Tool (connection method):
• a) copper (med) cable:
• 1) symmetrical - parallel cables;
• 2) coaxial;
• b) Optical cable:
• 1) single-mode - used on the highway;
• 2) multi-mode - used in the local network;
• c) Wireless communication (wi-fi, bluetooth, etc.);\3. Service - Services provided by the network (audio/video call, data transfer, etc.)
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NETWORK TYPES

• 1. PAN (Personal Area Network) – there can be a maximum of 8 participants and the radius coverage is up to 30 meters.
• 2. LAN (Local Area Network) – from 10 to 100 users can exist and the radius coverage is up to 100 meters.
• 3. CAN (Campus Area Network) - connects several LAN networks to itself. A large and multi-segment LAN is created.
• 4. MAN (Metropolitan Area Network) - a network covering the city. 1000
• 5. It covers a distance of 1000 meters and has 1000 users.
• 6. WAN (Wide Area Network) is a global computer network. It unites millions of subscribers (Internet).
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OSI and TCP/IP

• OSI and TCP/IP
• For the network to work, we need the OSI model and the TCP/IP protocol stack. The OSI (Open System Interconnection) model consists of 7 steps, and each step has its own signature when creating a packet (a type of data transfer). That is, in this case, if the information, before leaving a device, starts from the 7th level and goes down to the lower level, it becomes a packet and is transmitted. After the second computer receives it, it goes up from step 1 and displays the information. In this case, if there is an error at some point, the packet will be re-requested or the request will be canceled (these concepts are relative and the data exchange is not carried out exactly as stated). 7 steps of the OSI model: