The main difference between congestion control and flow control is that congestion control prevents the traffic of the entire network, while the flow control prevents sending packets from the sender to a receiver at a high rate.
A computer network is a collection of devices that are connected together to exchange data and resources. There is a lot of devices in a single network. Overall, it is necessary to control the congestion and flow of a network to maintain its proper functionality.
Key Areas Covered
1. What is Congestion Control
-Definition, Functionality
2. What is Flow Control
–Definition, Functionality
3. Difference Between Congestion Control and Flow Control
-Comparison of key differences
Key Terms
Congestion Control, Flow Control
What is Congestion Control
Congestion control refers to the traffic that occurs in a network. In other words, it refers to many packets in the network. Congestion reduces the performance of the network. Therefore, the time to deliver the packet to the receiver becomes higher. There can also be stations that can cause packet losses. Congestion control is the mechanism that helps to control the traffic in the network. It reduces the rate of packets in a way that the devices can handle. In other words, it prevents the sender from sending many packets, which makes it difficult for the other devices to process.
There are three main congestion control methods. Firstly, in provisioning, the network is capable of handling the traffic. Secondly, in traffic-aware routing, routers work according to the traffic pattern. Moreover, in admission control, the new connections to the network are refused that causes congestion to the network.
What is Flow Control
Flow control is the process of managing the rate of data transmission between two nodes. If the sender is fast, then the receiver might not be able to obtain and process that data. It can occur due to heavy traffic load and minimum process power in the receiver. Flow control helps to avoid that kind of situation. It allows the sender to control the transmission speed without overwhelming the data from the transmitting node. Likewise, this mechanism allows the sender to transmit information at a faster rate than the receiver and obtain data and process them.
Two types of flow control mechanisms are open-loop flow control and closed-loop flow control. The open-loop flow control mechanism has no feedback between the receiver and the transmitter. It is a simple mechanism. Furthermore, the allocation of resource can be a prior reservation or hop to hop type. Moreover, the closed-loop flow control mechanism refers to the capability of the network to report pending network congestion back to the transmitter.
Difference Between Congestion Control and Flow Control
Definition
Congestion control is the process of modulating the traffic entry into a telecommunications network to avoid congestive collapse resulting from over subscription. In contrast, flow control is the process of managing the rate of data transmission between two nodes to prevent a fast sender from overwhelming a slow receiver.
Layers
Network layer and transport layer handle congestion control while the data link layer and transport layer handle flow control.
Functionality
Moreover, congestion control prevents senders from overwhelming the network, whereas flow control prevents the sender from overwhelming the receiver.
Technique
In congestion control, the transport layer transmits the data to the network slowly, whereas, in the flow control, the sender transmits the data slowly to the receiver.
Conclusion
In brief, congestion control and flow control are two ways of maintaining the proper functionality of the network. The main difference between congestion control and flow control is that congestion control prevents the traffic of the entire network, while the flow control prevents sending packets from the sender to a receiver at a high rate.
References:
1.“Flow Control (Data).” Wikipedia, Wikimedia Foundation, 29 July 2019, Available here.
2.“Network Congestion.” Wikipedia, Wikimedia Foundation, 23 July 2019, Available here.
Image Courtesy:
1.”A sample network diagram” By SilverStartalk – Made using Dia (CC BY 2.5) via Commons Wikimedia
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