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Types of Network,OSI Model

 

                Types of Network

Ø  A LAN is a network that connects computers within a limited area like a home, school, or office.

Ø  It typically uses Ethernet or Wi-Fi for connectivity.

Ø  LANs allow sharing of resources such as files, printers, and internet connections.

Ø  It is usually high-speed and provides a secure connection within the localized area.

Ø  A WAN spans a large geographic area, often connecting multiple LANs.

Ø  The internet is the largest example of a WAN.

Ø  WANs use long-distance communication links like satellite, leased lines, or public networks.

Ø  They are slower than LANs and often involve higher costs due to the distance and technology used.

 

Ø  A MAN covers a larger area than a LAN but is smaller than a WAN, usually a city or a campus.

Ø  It is often used by organizations to connect different branches or buildings.

Ø  MANs typically use high-speed fiber-optic cables for connectivity.

Ø  They provide faster data transfer compared to WANs but are more expensive than LANs.

 

Ø  A VPN creates a secure, encrypted connection over a public network like the internet.

Ø  It is commonly used for secure remote access to a private network.

Ø  VPNs protect data privacy and prevent unauthorized access.

They are used by businesses to ensure secure communication and by individuals to access restricted content.


Wireless Network

Ø  A wireless network connects devices using radio waves instead of cables.

Ø  Wi-Fi is the most common form of a wireless network.

Ø  It allows for flexible, mobile connectivity within a certain range.

Ø  Wireless     networks    are     convenient but may       have    security vulnerabilities if not properly protected.

 

Q.           Discuss Data Communication Protocols. Ans   Data Communication Protocols

Different communication protocols define how data is transmitted and received over a network. Examples are:

TCP/IP (Transmission Control Protocol/Internet Protocol)

Ø  TCP/IP is the foundational protocol suite for the internet, responsible for data packet transmission and routing.

Ø  TCP ensures reliable data delivery, while IP handles addressing and routing to ensure data reaches the correct destination.

HTTP (Hyper Text Transfer Protocol)

Ø  HTTP is the protocol used for transmitting web pages over the internet.

Ø  It operates on the application layer, enabling communication between web browsers and servers.

FTP (File Transfer Protocol)

Ø  FTP is used for transferring files between a client and a server over a network.

Ø  It allows users to upload, download, and manage files on remote servers.

SMTP (Simple Mail Transfer Protocol)

Ø  SMTP is the protocol used for sending emails from clients to servers and between servers.

Ø  It operates at the application layer, ensuring the proper delivery of email messages




          OSI Model

Layer 7 – Application Layer

Interfaces directly with end-user applications, providing services like email, file transfer, and web browsing.

Layer 6 – Presentation Layer

Translates data between the application and network formats, handling encryption, compression, and translation.

Layer 5 – Session Layer

Establishes, manages, and terminates sessions or connections between applications

Layer 4 – Transport Layer

Provides reliable data transfer, error correction, and flow control between end-to-end systems (e.g., TCP, UDP).

Layer 3 – Network Layer

Manages data routing, addressing, and packet forwarding between different networks, using IP addresses.

Layer 2 – Data Link Layer

Ensures error-free data transfer between adjacent nodes and handles MAC addressing and framing.

Layer 1 – Physical Layer



Handles the physical connection between devices, including cables, switches, and transmission of raw data bits.

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