S6. Describe the differences between flow and congestion control? Flashcards
What are flow and congestion control?
Mechanisms for effectively managing data transmission and ensuring efficient network communications
What is flow control?
A technique used to prevent the sender from overwhelming the receiver by sending too much data too quickly.
What happens without flow control?
The receiver buffer may be overflowed leading to packet loss
At what layer in the network stack is flow control implemented?
The transport layer
How is flow control implemented?
Through the sliding window protocol in TCP
How does the sliding window protocol work in TCP?
The sliding window protocol involves the receiver advertising a window size that indicates the amount of data that it is able to accept. The sender can’t send data surpassing the advertised window size without first obtaining an acknowledgment from the receiver. This way, balance is maintained between the sender’s data rate and the receiver’s processing capacity, preventing packet loss and delays.
What is congestion control?
Mechanism used to prevent congestion on the network
What is congestion?
Congestion occurs when the total data traffic exceeds the network’s capacity.
How does congestion control work?
Congestion control mechanisms monitor the state of the network and adjust the rate of data transmission to avoid or alleviate congestion.
What congestion control mechanisms does TCP use?
In TCP, congestion control is implemented through algorithms like Slow Start, Congestion Avoidance, Fast Retransmit, and Fast Recovery. These algorithms dynamically adjust the size of the congestion window (which determines how much data the sender can transmit before receiving an ACK) based on network conditions.
Is slow start a flow control or congestion control mechanism? How does it work?
Slow Start is a congestion control algorithm used in TCP. It increases the TCP congestion window size exponentially until packet loss is detected, a potential sign of congestion, at which point it instead increases the window size linearly to alleviate congestion.
What is the difference between flow and congestion control?
Flow control ensures the sender does not overwhelm the receiver, while congestion control prevents network congestion by controlling the rate of data transmission based on network feedback, ensuring that the overall network remains stable and efficient.
