Unit1

🔌 Network Device: Bridge A Bridge is a networking device that operates at Layer 2 (Data Link Layer) of the OSI model. It is used to connect two or more network segments within a local area network (LAN), helping to filter traffic and reduce collisions. 🔹 What is a Bridge? A Bridge is a device used to divide large networks into smaller segments. It helps in controlling traffic between segments, increasing the efficiency of network communications. Unlike a hub or a switch, which broadcasts data to all devices, a bridge forwards data only to the segment where the destination device is located, improving network performance. ...

🔌 Network Device: Router A Router is a networking device that operates at Layer 3 (Network Layer) of the OSI model and is responsible for routing data packets between different networks. It uses IP addresses to determine the best path for data transmission. 🔹 What is a Router? A Router connects different networks together and manages traffic between them. For example, it connects a local area network (LAN) to the internet (a wide area network, WAN) and forwards data packets between them. Routers also assign local IP addresses to devices within a network. ...

🔌 Network Device: Switch A Switch is a networking device that operates primarily at Layer 2 (Data Link Layer) of the OSI model, though some switches can also function at Layer 3 (Network Layer). 🔹 What is a Switch? A Switch is an intelligent device used in LANs to connect multiple devices (like computers, printers, and servers). It uses MAC addresses to forward data only to the intended recipient, making communication more efficient compared to hubs. ...

Layered Network Protocol Architectures: OSI and TCP/IP Protocol architectures organize communication tasks into layers. Each layer handles a specific function, ensuring modularity, easier troubleshooting, and interoperability. 🔹 What is a Protocol Stack? A protocol stack is a collection of network protocols layered to work together. Each layer performs a specific function and interacts with layers directly above and below. 🔹 OSI Model (Open Systems Interconnection) The OSI model is a theoretical model developed by ISO to standardize networking. ...

Introduction to Computer Networking Concepts Computer networking connects computing devices to enable data sharing and communication. This foundation supports services like the internet, file sharing, and cloud computing. 🔹 Purposes of Digital Communication and Computer Networks Resource Sharing: Access shared printers, files, storage. Communication: Email, chat, video conferencing. Remote Access: Control systems across locations. Centralized Data: Easier management and backups. Efficiency: Distributed workloads and services. 🔹 Types of Digital Communication and Computer Networks Network Coverage Area Example PAN Personal range (~10 meters) Bluetooth headset LAN Building or campus Home/office Wi-Fi MAN Citywide University networks WAN Country or global Internet 🖼️ Textual Diagram - Network Scale PAN < LAN < MAN < WAN 🔹 Network Components End Devices: Users’ computers, phones. Network Devices: Switch: Connects devices in a LAN (uses MAC address). Router: Connects different networks (uses IP). Modem: Converts digital ↔ analog for ISP. Hub: Broadcasts data to all ports (no intelligence). Bridge: Connects LAN segments, filters by MAC. Repeater: Regenerates weak signals. Access Point: Provides Wi-Fi access. Network Interface Card (NIC): Hardware to connect devices to a network. Transceivers: Send and receive signals over media. Transmission Media: Wired: Ethernet (Cat6), Fiber. Wireless: Wi-Fi, 4G/5G, Bluetooth. 🖼️ Textual Diagram - Basic LAN Setup [PC]---+ | [PC]---+--[SWITCH]---[ROUTER]---[INTERNET] | [Printer] 🔹 Communication Modes Mode Description Example Simplex One-way only Keyboard to PC Half Duplex Two-way, one at a time Walkie-talkies Full Duplex Two-way, simultaneous Phone calls 🖼️ Textual Diagram - Duplex Modes Simplex: A ---> B Half-Duplex: A <--> B (one at a time) Full-Duplex: A <===> B (simultaneous) 🔹 Transmission Types Unicast: One-to-one Broadcast: One-to-all Multicast: One-to-selected Anycast: One-to-nearest 🖼️ Textual Diagram - Broadcast vs Unicast Unicast: [Sender] ---> [Receiver] Broadcast: [Sender] ---> [All Devices on Network] Multicast: [Sender] ---> [Group of Devices] Anycast: [Sender] ---> [Nearest Suitable Receiver] 🔹 Communication Models Peer-to-Peer (P2P): ...

🖧 Network Device: Network Interface Card (NIC) A Network Interface Card (NIC) is a hardware component that allows a computer or device to connect to a network. It operates at both the Physical Layer (Layer 1) and Data Link Layer (Layer 2) of the OSI model. 🔹 What is a NIC? A NIC is an internal hardware component (or sometimes external) that provides the physical interface for a device to connect to a network. It contains the necessary circuitry to communicate using Ethernet, Wi-Fi, or other networking standards. ...