Networking devices are hardware components used to connect computers or other electronic devices together so they can share files or resources.
Router
Function: Connects multiple networks (e.g., home network to the Internet).Works on: Network Layer (Layer 3 of OSI Model).Assigns: IP addresses using DHCP.Example Use: Wi-Fi router at home connects multiple devices to the internet.
Switch
Function: Connects multiple devices within a Local Area Network (LAN) .Works on: Data Link Layer (Layer 2).Smarter than a hub – Sends data only to the intended device (MAC-based).Example: Office network switch connects computers and printers.
Hub
Function: Basic device to connect multiple devices in a network.Works on: Physical Layer (Layer 1).Broadcasts data to all devices regardless of the destination.Not intelligent , less secure, rarely used now.
Modem (Modulator-Demodulator)
Function: Converts digital signals to analog and vice versa.Use: Enables internet connectivity via telephone or cable lines.Example: BSNL modem or fiber modem.
Access Point (AP)
Function: Allows wireless devices to connect to a wired network.Used in: Expanding Wi-Fi coverage in large areas (offices, cafes, schools).
Bridge
Function: Connects two LAN segments and filters traffic.Works on: Data Link Layer.Reduces traffic and avoids collisions.
Gateway
Function: Acts as a translator between two different network protocols.Works on: All layers of the OSI model.Used to connect: LAN to external networks like the internet.
A protocol is a set of rules that define how data is transmitted and received over a network.
Protocol Full Form Purpose HTTP HyperText Transfer Protocol Used for accessing web pages. HTTPS HTTP Secure Secure version of HTTP. FTP File Transfer Protocol Transfers files between computers. TCP/IP Transmission Control Protocol/Internet Protocol Fundamental protocol suite for the internet. IP Internet Protocol Assigns addresses and routes data. SMTP Simple Mail Transfer Protocol Sends emails. POP3 Post Office Protocol v3 Retrieves emails from server (downloads and deletes). IMAP Internet Message Access Protocol Retrieves emails (keeps emails on server). DHCP Dynamic Host Configuration Protocol Automatically assigns IP addresses. DNS Domain Name System Translates domain names (like google.com) into IP addresses.
Protocol Use Data Stored On Server? SMTP Sending emails No POP3 Receiving emails No (downloads & deletes) IMAP Receiving emails Yes (remains on server)
Feature TCP UDP Full Form Transmission Control Protocol User Datagram Protocol Connection Connection-oriented Connectionless Reliability Reliable Not reliable Speed Slower Faster Use Case Emails, Web browsing Video streaming, VoIP
IP address is a unique identifier for a device on a network.
Two Versions:
IPv4 (e.g., 192.168.0.1) – 32-bitIPv6 (e.g., 2001:db8::ff00:42:8329) – 128-bit
Layer Function 7. Application User interface 6. Presentation Data translation & encryption 5. Session Session management 4. Transport End-to-end communication 3. Network IP addressing & routing 2. Data Link MAC addressing 1. Physical Transmission media (cables, signals)
Most devices & protocols in networking operate on these layers.
Device OSI Layer Function Hub Physical Broadcasts data Switch Data Link Forwards data to specific devices Router Network Routes data between networks Modem Physical/Data Link Connects to the Internet Gateway All Layers Protocol translation Access Point Data Link Wireless LAN connectivity
