Networking Flashcards
Network Categories
PAN
LAN
MAN
WAN - Combination of two or more MAN and LAN.s
Network Topologies
Bus
Ring
Star
Mesh
Hybrid
Best Network topology
Hybrid
Reasons: Fault tolerant
Cons: Expensive to set up
Types of data Transmission mediums
- Analog Signal: using infinite levels of intensity over a period of time. Hence, resulting in a continuous waveform
- Digital Signal: using binary digits (which has a finite number of possibilities
Analogue Transmission Cons
- Susceptible to electromagnetic interference
- Susceptible to distortion
Components of data transmission
- Sender
- Receiver
- Data
- Channel (medium)
- Protocol
Transmission modes
- Simplex
- Half duplex
- Full duplex
Methods of transmission
i. Serial (Synchronous & Asynchronous)
ii. Parallel
Multiplexing
Process of combining multiple signals or data streams into a single signal or transmission medium
Types of multiplexing
- Time Division Multiplexing (TDM)
- Frequency Division Multiplexing (FDM)
- Wave Division Multiplexing
- Statistical Time Division Multiplexing ( STDM)
Circuit Switching and Packet Switching
Circuit switching is an older method that was used in traditional telephone networks. In circuit switching, a dedicated physical circuit is established between the sender and the receiver for the duration of the communication session. This circuit is reserved exclusively for the use of that communication session, even if there is no data being transmitted. This means that the resources of the network are tied up for the duration of the session, even if there are periods of inactivity. Circuit switching is ideal for applications that require a continuous and dedicated connection, such as voice calls.
Packet switching, on the other hand, is a newer method of transmitting data that is used in modern computer networks, including the Internet. In packet switching, data is divided into small packets that are sent individually from the source to the destination. Each packet is sent independently and can take a different route to the destination. This means that the network resources are shared among many users and applications, and packets from different sources can be interleaved on the same transmission medium. Packet switching is ideal for applications that require bursty data transmission, such as file transfers and web browsing.
In summary, circuit switching is a method of establishing a dedicated connection between two points, while packet switching is a method of transmitting data in small, independent packets over a shared network.
What is distortion
Distortion in network media occurs when the original signal is altered or degraded during transmission over a network medium. Distortion can occur due to several factors, including attenuation, noise, interference, and delay.
Attenuation
Attenuation is the loss of signal strength as it travels over a network medium. The signal strength reduces as the distance between the transmitting and receiving devices increases. Attenuation is more significant in wired networks, such as copper or fiber optic cables, than in wireless networks.
Types of Network Media
Wired and Unwired Networks
OR
Bounded Media:
1. Twisted Pair (Shielded and Unshielded)
2. Coaxial
3. Fiber Optic
Unbounded Media
Sources of Distortion (4)
- Attenuation: Decrease in Amplitude of signals as they travel along transmission Media.
- Limited Bandwidth:
- Noise and Crosstalk
- Delay Distortion