LESSON 5 TO 8

• Node


  A physical device within a network of other tools that's able to send, receive, or forward information. A personal computer is the most common node.
• NIC


  A network interface card, a hardware component without which a computer cannot be connected over a network. It is a circuit board installed in a computer that provides a dedicated network connection.
• Access Point


  Operates on the second OSI layer, the data link layer, and can either act as a bridge that connects a standard wireless network to wireless devices or as a router that transmits data to another access point.
• Hub


  Links various networking devices. Amplifies signals that deteriorate over cables after long distances. Hubs do not process or address packets; they only send data packets to all connected devices.
• Bridge


  Links two or more hosts or network segments. Performs bridge processing and transfer of frames between the various bridge links. Can transmit the data or block the crossing by looking at the devices' MAC addresses connected to each line.
• Switch


  Has a smarter job than hubs in general. Improves the capacity of the network. Keeps limited information on routing nodes in the internal network and provides links to systems such as hubs or routers.
• Router


  Allows packets to be transmitted to their destinations by monitoring the sea of networking devices interconnected with different network topologies. Stores data on the networks to which they are connected.
• Modem


  Converts digital signals into analog signals of various frequencies and transmits them to a modem at the receiver location, allowing digital signals to be transmitted through analog phone lines.
• Transmission Media


  A communication channel that carries the information from the sender to the receiver. Data is transmitted through the electromagnetic signals.
• Main functionality of transmission media

  To carry the information in the form of bits through LAN (Local Area Network)
• Transmission media


  A physical path between transmitter and receiver in data communication
• Factors to consider for designing transmission media

  • Bandwidth
  • Transmission impairment
  • Interference
• Bandwidth


  All the factors are remaining constant, the greater the bandwidth of a medium, the higher the data transmission rate of a signal
• Transmission impairment


  When the received signal is not identical to the transmitted one due to the transmission impairment. The quality of the signals will get destroyed due to transmission impairment.
• Interference


  An interference is defined as the process of disrupting a signal when it travels over a communication medium on the addition of some unwanted signal.
• Attenuation


  Loss of energy, i.e., the strength of the signal decreases with increasing the distance which causes the loss of energy
• Distortion


  Change in the shape of the signal. Each frequency component has its own propagation speed, so they reach at a different time which leads to the delay distortion
• Noise


  Unwanted signal added to the data when travelled over a transmission medium
• Classification of Transmission Media

  • Guided Media or Wired Media
  • Unguided Transmission
• Guided Media or Wired Media


  Physical medium through which the signals are transmitted, also known as Bounded media
• Twisted pair


  Physical media made up of a pair of cables twisted with each other
• Types of Twisted Pair

  • Unshielded Twisted Pair
  • Shielded Twisted Pair
• Unshielded Twisted Pair


  Widely used in telecommunication, has different categories based on supported speeds
• Unshielded Twisted Pair


  • Cheap
  • Easy installation
  • Can be used for high-speed LAN
• Unshielded Twisted Pair


  • Can only be used for shorter distances because of attenuation
• Shielded Twisted Pair


  Cable that contains the mesh surrounding the wire that allows the higher transmission rate
• Shielded Twisted Pair


  • Cost is not very high and not very low
  • Easy installation
  • Higher capacity compared to UTP
  • Higher attenuation
• Shielded Twisted Pair


  • More expensive compared to UTP and coaxial cable
  • Higher attenuation rate
• Coaxial cable


  Commonly used transmission media, contains two conductors parallel to each other
• Coaxial cable


  • Has higher frequency compared to Twisted pair cable
  • Inner conductor is made of copper, outer conductor is copper mesh, middle core is non-conductive cover
• Types of Coaxial cable

  • Baseband transmission
  • Broadband transmission
• Coaxial cable


  • Data can be transmitted at high speed
  • Better shielding compared to twisted pair cable
  • Provides higher bandwidth
• Coaxial cable


  • More expensive compared to twisted pair cable
  • If any fault occurs, causes failure in the entire network
• Fiber optic cable


  Cable that uses pulses of light for communication, holds optical fibers coated in plastic
• Basic elements of Fiber optic cable

  • Core
  • Cladding
  • Jacket
• Fiber optic cable vs copper

  • Greater Bandwidth
  • Faster speed
  • Longer distances
  • Better reliability
  • Thinner and Sturdier
• Unguided Transmission


  Transmits electromagnetic waves without using any physical medium, also known as wireless transmission
• Types of Networking Connectors

  • Connectors for Unshielded Twisted Cable (UTP)
  • Connectors for Shielded Twisted Pair (STP)
  • Connectors for Coaxial Cable
  • Connectors for Fiber Optic Cable
  • Other Connectors
• RJ45


  Most common network connector used in networking with 8 pin modular connector, used to connect computers and networking devices in a LAN
• UTP Coupler


  Used to connect UTP network cables