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What is the vulnerable time in CSMA?
Vulnerable Time: The vulnerable time for CSMA is the propagation time Tp. This is the time needed for a signal to propagate from one end of the medium to the other. When a station sends a frame, and any other station tries to send a frame during this time, a collision will result.
What is the time the transmitting station waits for some time after experiencing collision?
In CSMA / CD protocol, After the occurrence of collision, station waits for some random back off time and then retransmits. This waiting time for which the station waits before retransmitting the data is called as back off time. Back Off Algorithm is used for calculating the back off time.
What is propagation time in CSMA?
CSMA is not suitable for long distance networks like WAN; but works optimally for LAN. If length of packet is bigger, the efficiency of CSMA also increases; but maximum limit for length is 1500 Bytes. Transmission Time >= 2*Propagation Time.
What is CSMA CD explain with flow chart?
The algorithm of CSMA/CD is: When a frame is ready, the transmitting station checks whether the channel is idle or busy. If the channel is busy, the station waits until the channel becomes idle. If the channel is idle, the station starts transmitting and continually monitors the channel to detect collision.
Are there any drawbacks to using CSMA / CD?
A drawback of sharing a medium using CSMA/CD, is that the sharing is not necessarily fair. When each computer connected to the LAN has little data to send, the network exhibits almost equal access time for each NIC. However, if one NIC starts sending an excessive number of frames, it may dominate the LAN.
How does collision detection work in CSMA / CD?
CSMA/CD does not use ‘acknowledgement’ system. It checks for the successful and unsuccessful transmissions through collision signals. During transmission, if collision signal is received by the node, transmission is stopped. The station then transmits a jam signal onto the link and waits for random time interval…
How to calculate success rate in CSMA / CD?
In CSMA/CD, for success, only 1 station should transmit while others shouldn’t. Let p be the probability to transmit data successfully. For max P (success), differentiate with respect to p and equate to zero (to get maxima and minima). Here number of times we need to try (C) = e.
When does the efficiency of CSMA go down?
If distance increases, efficiency of CSMA decreases. CSMA is not suitable for long distance networks like WAN; but works optimally for LAN. If length of packet is bigger, the efficiency of CSMA also increases; but maximum limit for length is 1500 Bytes. Practicing the following questions will help you test your knowledge.