Experiential Learning of Networking Technologies: Understanding TCP Flow Control
2019
In any TCP-based client-server communication, the application layer is implemented in the application program whereas the transport layer (i.e., TCP protocol) is implemented in the underlying operating system. TCP achieves reliability using acknowledgement packets and retransmitting any packets that are lost in the network, or corrupted, or delayed or delivered out-of-order. In addition, the TCP protocol ensures that the receiver application is not overwhelmed by data from the sender application — only the amount of data that the receiver can consume is transmitted. This is called TCP Flow Control. In this article, we explain the basics of flow control and provide experiential learning exercises to help understand its impact on TCP performance.