JJ

Network Protocols and Communication

2 min read

Data Communication

Exchange of data between two nodes through a link, or transmission medium.

  1. Simplex: One direction only, such as a keyboard
  2. Half Duplex: Bidirectional, but one direction at a time, such as a walkie-talkie
  3. Full Duplex: Such as a telephone line

Protocols

  • Source or sender
  • Destination or receiver
  • Channel or media

Elements of a Protocol

  • Message encoding: Converts data into a signal
  • Message formatting and encapsulation: Uses an agreed format and encapsulates the message to identify the sender
  • Message timing: Uses flow control so that the data can be received
  • Message size: A long message must be broken down
  • Message delivery option: Unicast, multicast, or broadcast

message encoder -> transmitter -> transmission medium -> receiver -> decoder -> destination

The transmission medium can have different forms, such as cable or air.

Peer-to-Peer Network

  • No centralized administration
  • All peers are equal
  • Simple sharing applications

Client-Server Network

  • Central administration
  • Request Response Network
  • Scalable
  • Server may be overloaded

Components of a Computer Network

  • Nodes
    • End nodes are end devices, such as computers and network printers
    • Intermediary nodes include switches, Wireless Access Points, Routers, Firewalls, and Cell Towers
  • Media
    • Wired medium is guided medium
    • Wireless medium is unguided medium
  • Services
    • File sharing
    • Email
    • Storage services
    • Online games

Local Area Network

  • A computer network that interconnects computers within a limited area, such as a residence, school, laboratory, university campus, or office building
  • Wired LAN, such as Ethernet, uses a Hub or Switch
  • Wireless LAN uses Wi-Fi

Metropolitan Area Network

A computer network that interconnects users with computer resources in a geographic region the size of a metropolitan area, or city.

Wide Area Network

  • Some people refer to this as the Internet
  • A telecommunications network that extends over a large geographical area
  • End devices and intermediary devices

The Internet

The "wide wide area network" contains many LANs and WANs.

Storage Area Network

Cloud Computing

On-demand availability of computer system resources, especially data storage and computing power, without direct active management by the user.

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