Networks

• Computer networks


  Collection of interconnected devices or nodes that can communicate and share resources with each other

  
• Advantages of networks


  • Communication and collaboration
  • Resource sharing
  • Centralized management
  • Data sharing and backup
  • Scalability
  • Internet access
  • Resource efficiency
• Disadvantages of networks


  • Security risks
  • Reliability and downtime
  • Complexity
  • Initial cost
  • Network congestion
  • Privacy concerns
  • Dependency on infrastructure
• Client-server network model


  Centralized architecture with a central server that stores resources, data, and applications. Clients connect to the server to access these resources.
• Functions of the client-server model

  • Resource sharing
  • Centralized management
  • Client applications
• Peer-to-peer network model


  Decentralized architecture where all devices are equal peers and can act as both clients and servers. No centralized authority.
• Functions of the peer-to-peer model

  • Resource sharing
  • Collaborative applications
• Ad hoc network


  Network formed on-the-fly, often in situations where fixed infrastructure is not available, with dynamic topologies
• Functions of ad hoc networks

  • Self-configuration
  • Data sharing
• Tethering


  Sharing a mobile device's internet connection with other devices, either wired or wirelessly
• Functions of tethering


  • Internet access
  • Temporary network
  • Internet sharing
  • Connectivity on the go
• Advantages of client-server network models

  • Centralized management
  • Scalability
  • Robust performance
  • Specialized functionality
  • Centralized backup and recovery
• Disadvantages of client-server network models

  • Cost and complexity
  • Single point of failure
• Advantages of peer-to-peer network models

  • Decentralization
  • Cost-effectiveness
  • Easy collaboration
  • Flexibility
• Disadvantages of peer-to-peer network models


  • Security risks
  • Performance limitations
  • Resource overuse
• The choice between client-server and peer-to-peer network models depends on the specific needs and goals of the organization or users
• Wi-Fi


  Enables wireless communication between devices using radio waves, allowing devices to connect to a local area network and access the internet without physical cables
• ZigBee


  Low-power protocol designed for low-power devices, with mesh networking capabilities, used in home automation and smart home devices
• Bluetooth


  Short-range communication protocol, with low-power variants like Bluetooth Low Energy, used for wireless connections between devices
• Cellular - GSM communications (3G/4G)

  Provides wide coverage and high-speed data transfer rates, enabling mobile communication, voice calls, text messaging, and internet access on mobile devices
• Infrared


  Requires a direct line of sight between transmitting and receiving devices, commonly used for remote control applications
• Ethernet


  Uses physical cables for data transmission, supporting very high data transfer rates, the primary technology for wired local area networks
• Infrared


  Requires a direct line of sight between the transmitting and receiving devices for communication to occur
• Infrared applications


  • Remote control for TV and other consumer electronics
• Ethernet


  • Uses physical cables, such as twisted-pair copper cables or fiber-optic cables, for data transmission
  • Can support very high data transfer rates, ranging from 10 Mbps (Ethernet) to 1 Gbps (Gigabit Ethernet) and beyond
  • The primary technology used for wired local area networks (LANs) in offices, data centers, and home networks
• Each network communication protocol serves specific needs and is suitable for different scenarios
• The choice of protocol depends on factors such as the type of devices, the desired range, data transfer requirements, and power consumption considerations
• Network standards


  Formal specifications or guidelines that define how network components should operate and interact to achieve interoperability and seamless communication

  
• Network protocols


  Sets of rules and conventions that devices use to communicate and exchange data within a network

  
• Network standards define the guidelines and rules for creating and operating network components, while network protocols specify how devices communicate and exchange data to enable effective networking

  
• Common network protocols


  • Transmission Control Protocol (TCP)
  • Internet Protocol (IP)
  • Hypertext Transfer Protocol (HTTP)
  • File Transfer Protocol (FTP)
  • Simple Mail Transfer Protocol (SMTP)
• Voice Over Internet Protocol (VoIP)


  • A technology that allows voice communication (phone calls) over the internet or IP-based networks
  • Converts analog voice signals into digital data, which can be transmitted over IP networks as packets
  • Facilitates real-time voice transmission between users
  • Uses audio compression algorithms to minimize bandwidth usage while maintaining voice quality
• Session Initiation Protocol (SIP)


  • A signaling protocol used to establish, modify, and terminate real-time communication sessions over IP networks
  • Manages session setup, negotiation, and termination for various communication services, including voice, video, and instant messaging
  • Performs Addressing and Routing using Uniform Resource Identifiers (URIs) to identify users and locate their communication endpoints
• OSI model


  A conceptual framework that standardizes the functions of a telecommunication or computing system into seven distinct layers, each with a specific role and interacting with adjacent layers to enable end-to-end communication

  
• Layers of the OSI model

  • Physical Layer
  • Data Link Layer
  • Network Layer
  • Transport Layer
  • Session Layer
  • Presentation Layer
  • Application Layer

  
• The OSI model serves as a reference model for understanding network communication and developing interoperable networking protocols

  
• TCP/IP model


  • A conceptual framework used for designing and understanding the communication protocols that govern data transmission over the internet and other computer networks
  • It is the foundation of modern networking and the protocol suite used to enable communication between devices connected to the internet

  
• Layers of the TCP/IP model

  • Application Layer
  • Transport Layer
  • Internet Layer
  • Link Layer

  
• The TCP/IP model provides a scalable and flexible framework for implementing internet and network communication

  
• The TCP/IP model defines how data is packaged, transmitted, and delivered across different networks, ensuring interoperability and seamless communication between devices connected to the internet