Introduction to Congestion Control
Explore the concept of congestion in computer networks, its causes at the transport layer, and how protocols like TCP implement congestion control to maintain efficient data transmission. Learn about bandwidth allocation principles, the challenges of traffic bursts, and the effects of transmission rate thresholds on network delay and performance.
What Is Congestion?
When more packets than the network has bandwidth for are sent through, some of them start getting dropped and others get delayed. This phenomenon leads to an overall drop in performance and is called congestion.
This is analogous to vehicle traffic congestion when too many vehicles drive on the same road at the same time. This slows the overall traffic down.
How Do We Fix It?
Congestion physically occurs at the network layer (i.e. in routers), however it’s mainly caused by the transport layer sending too much data at once. That means it will have to be dealt with or ‘controlled’ at the transport layer as well.
Note: Congestion control also occurs in the network layer, but ...