Network Topologies and Wireless Networking

Definition: The arrangement of different elements (links, nodes) in a computer network.
Types:
- Bus Topology: Single central cable; all devices connected to it. Simple but can be inefficient.
- Star Topology: All devices connected to a central hub/switch. Easy to manage but a single point of failure.
- Ring Topology: Each device connected in a circular fashion. Data travels in one direction. Failure of one device can disrupt the network.
- Mesh Topology: Each device connected to multiple others. Highly reliable but complex and costly.
- Hybrid Topology: Combines two or more topologies. Flexible and scalable.

Definition: Use of wireless data connections for networking.
Key Technologies:
- Wi-Fi: Wireless networking technology based on IEEE 802.11 standards.
- Bluetooth: Short-range wireless technology for data exchange over short distances.
- Cellular Networks: Use of radio waves for mobile communication (e.g., 4G, 5G).
Advantages: Mobility, ease of installation, and scalability.
Challenges: Signal interference, security vulnerabilities, and limited range.

Purpose: Protect data integrity, confidentiality, and availability.
Types:
- Authentication: Verifying the identity of users/devices (e.g., passwords, biometric systems).
- Encryption: Scrambling data to prevent unauthorized access (e.g., AES, RSA).
- Firewalls: Monitoring and controlling network traffic based on security rules.
- Intrusion Detection Systems (IDS): Monitoring for suspicious activities.
- VPN (Virtual Private Network): Secure remote access to a network.

Definition: Rules and conventions for communication in a network.
Common Protocols:
- TCP/IP: Fundamental suite for internet communication.
- HTTP/HTTPS: Protocols for web data transfer; HTTPS includes encryption.
- FTP: File Transfer Protocol for transferring files.
- SMTP/IMAP/POP3: Email transmission and retrieval protocols.
Standards Organizations:
- IEEE: Sets standards for networking protocols (e.g., 802.3 for Ethernet).
- IETF: Develops and promotes internet standards.

Definition: The design and structure of a network.
Types:
- Client-Server Model: Centralized architecture where servers provide resources to clients.
- Peer-to-Peer Model: Decentralized model where each device can act as both a client and server.
Layers:
- Physical Layer: Hardware and transmission media.
- Data Link Layer: Node-to-node data transfer and error detection.
- Network Layer: Routing and forwarding data packets.
- Transport Layer: End-to-end communication and data integrity.
- Application Layer: Interfaces for end-user applications.

Arrangement of elements (links, nodes) in a computer network.
Bus Topology:
- Involves a single central cable.
- All devices connect to the cable, which simplifies structure but may lead to inefficiencies.
Star Topology:
- Each device connects to a central hub or switch.
- Facilitates easier management but represents a single point of failure.
Ring Topology:
- Devices connect in a circular layout, with data traveling in one direction.
- A failure of any device can disrupt the entire network.
Mesh Topology:
- Every device connects to multiple others, enhancing reliability.
- Complexity and cost are greater than other topologies.
Hybrid Topology:
- Combines two or more topological structures.
- Provides flexibility and scalability to network design.

Involves wireless data connections for networking purposes.
Wi-Fi:
- Based on IEEE 802.11 standards, widely used for wireless internet access.
Bluetooth:
- Short-range technology for data exchanges between devices at close proximity.
Cellular Networks:
- Utilizes radio waves for mobile communication implementations like 4G and 5G.
Advantages:
- Offers mobility, ease of installation, and scalability compared to wired networks.
Challenges:
- Signal interference, potential security weaknesses, and constrained range.

Aim to safeguard data integrity, confidentiality, and availability.
Authentication:
- Confirms the identity of users or devices through methods such as passwords and biometrics.
Encryption:
- Protects sensitive data by scrambling it, using techniques like AES and RSA.
Firewalls:
- Monitor and filter network traffic based on defined security rules.
Intrusion Detection Systems (IDS):
- Continuously watch for suspicious activities within the network.
VPN (Virtual Private Network):
- Allows secure remote access to a private network over the internet.

Set of rules and conventions for communication within a network.
Common Protocols:
- TCP/IP: Essential suite enabling communications over the internet.
- HTTP/HTTPS: Protocols for web data transfer, with HTTPS including security through encryption.
- FTP: Offers a standardized way to transfer files over a network.
- SMTP/IMAP/POP3: Specific protocols for email transmission and retrieval.
Standards Organizations:
- IEEE: Establishes standards for various networking protocols, notably 802.3 for Ethernet.
- IETF: Focuses on developing and promoting Internet standards.

Refers to the overall design and structure of a network.
Types:
- Client-Server Model: Servers deliver resources to clients, constituting a centralized architecture.
- Peer-to-Peer Model: Each device functions as both client and server in a decentralized setting.
Layers of Network Architecture:
- Physical Layer: Deals with hardware elements and transmission media.
- Data Link Layer: Responsible for node-to-node data transfer and error detection processes.
- Network Layer: Handles routing and forwarding of data packets across networks.
- Transport Layer: Ensures end-to-end data communication and integrity.
- Application Layer: Provides interfaces for end-user applications to interact with the network.