Network Types and Topologies

• A network is a collection of interconnected devices, enabling communication and resource sharing

Network Types

• Personal Area Network (PAN): Connects devices within an individual's immediate range, typically using technologies like Bluetooth
• Local Area Network (LAN): Connects devices within a limited area such as a home, school, or office
• Wireless Local Area Network (WLAN): A LAN that uses wireless communication.
• Metropolitan Area Network (MAN): Covers a larger area than a LAN, such as a city
• Wide Area Network (WAN): Spans a large geographical area, such as a country or the globe, connecting multiple LANs and MANs

Network Topologies

• Bus topology: All devices are connected to a central cable, called the bus
  • Simple but a break in the bus cable can disrupt the entire network
• Star topology: All devices connect to a central hub or switch
  • A failure in one device does not affect the rest of the network, but failure of the central hub can bring down the entire network
• Ring topology: Each device is connected to two other devices, forming a ring
  • Data travels in one direction, and a break in the ring can disrupt the network
• Mesh topology: Each device is connected to many other devices
  • Highly redundant, but complex and expensive to implement
• Tree topology: Combines characteristics of linear bus and star topologies; groups of star-configured networks are connected to a linear bus backbone

Network Devices

• Hub: A simple device that connects multiple devices in a LAN, forwarding all received data to all connected ports
• Switch: An intelligent device that forwards data only to the intended recipient based on MAC addresses
• Router: Connects different networks, forwarding data based on IP addresses
• Modem: Modulates and demodulates signals to transmit data over telephone lines or other communication channels
• Wireless Access Point (WAP): Allows devices to connect to a network wirelessly, typically a Wi-Fi network
• Firewall: A security device that monitors and controls network traffic, blocking unauthorized access while permitting legitimate communications
• Bridge: Connects two LANs together, forwarding traffic based on MAC addresses

Communication Protocols

• TCP/IP (Transmission Control Protocol/Internet Protocol): A suite of protocols that governs communication over the Internet, including IP addressing, routing, and data transmission
• HTTP (Hypertext Transfer Protocol): Used for transmitting web pages and other content over the Internet
• HTTPS (HTTP Secure): A secure version of HTTP that uses encryption to protect data in transit
• FTP (File Transfer Protocol): Used for transferring files between computers on a network
• SMTP (Simple Mail Transfer Protocol): Used for sending email messages
• DNS (Domain Name System): Translates domain names into IP addresses
• DHCP (Dynamic Host Configuration Protocol): Automatically assigns IP addresses to devices on a network
• SSH (Secure Shell): Provides a secure, encrypted connection to a remote computer
• TLS/SSL (Transport Layer Security/Secure Sockets Layer): Protocols that provide encryption and authentication for secure communication over a network

Network Addressing

• IP Address (Internet Protocol Address): A unique numerical identifier assigned to each device on a network
  • IPv4: Uses 32-bit addresses
  • IPv6: Uses 128-bit addresses
• MAC Address (Media Access Control Address): A unique hardware address assigned to a network interface card (NIC) by the manufacturer

Network Models

• OSI Model (Open Systems Interconnection Model): A conceptual model that standardizes the communication functions of a telecommunication or computing system
  • 7 Layers: Application, Presentation, Session, Transport, Network, Data Link, Physical
• TCP/IP Model: A simplified model with four layers: Application, Transport, Internet, and Network Access

Network Security

• Firewalls: Hardware or software that controls network access based on predefined rules
• Intrusion Detection Systems (IDS): Monitor network traffic for suspicious activity and generate alerts
• Intrusion Prevention Systems (IPS): Actively block or prevent malicious activity on a network
• Virtual Private Networks (VPN): Create a secure, encrypted connection over a public network
• Encryption: Protecting data by converting it into an unreadable format
• Authentication: Verifying the identity of users or devices attempting to access a network
• Access Control Lists (ACL): Rules that specify which users or devices are allowed to access certain network resources

Wireless Technologies

• Wi-Fi (Wireless Fidelity): A popular wireless networking technology based on the IEEE 802.11 standards
• Bluetooth: A short-range wireless technology used for connecting devices such as headphones, keyboards, and mice
• Cellular Networks: Mobile networks that provide wireless communication over a wide area
  • 4G LTE (Long-Term Evolution): A high-speed cellular technology
  • 5G: The latest generation of cellular technology, offering even faster speeds and lower latency

Cloud Networking

• Virtual Networks: Software-defined networks that allow for the creation of isolated network environments in the cloud
• Software-Defined Networking (SDN): A network architecture that allows network administrators to manage network services through abstraction of lower-level functionality
• Network Functions Virtualization (NFV): Virtualizing network functions that were traditionally carried out by hardware, such as firewalls and routers

Network Performance

• Bandwidth: The amount of data that can be transmitted over a network connection in a given amount of time
• Latency: The delay between sending and receiving data over a network
• Throughput: The actual rate of data transfer over a network
• Packet Loss: The percentage of data packets that are lost during transmission
• Jitter: The variation in latency over time

Network Management

• Network Monitoring: Continuously monitoring network performance and health
• Configuration Management: Managing network device configurations
• Performance Tuning: Optimizing network performance by adjusting various parameters
• Troubleshooting: Diagnosing and resolving network issues

Emerging Trends

• Internet of Things (IoT): The growing network of interconnected devices, such as appliances, vehicles, and sensors
• Edge Computing: Processing data closer to the edge of the network, reducing latency and bandwidth usage
• Artificial Intelligence (AI) in Networking: Using AI to automate network management, improve security, and optimize performance