I'm trying to understand what happens to the TCP Congestion Window (Cwnd) if the transfer rate is limited by the Receive Window (Rwnd). I know that the transfer rate is the minimum of Rwnd and Cwnd. I also know that Cwnd increases for each ACK received. Suppose the receive buffer is very small, so Rwnd always stays very low, but all the packets are received and ACKed. Does this mean that Cwnd just keeps increasing forever? Is there some limit to it?
Tcp – Does TCP Cwnd keep increasing if transfer is limited by Rwnd
protocol-theorytcp
Best Answer
It depends to which mechanism you are using, and yes the Cwnd keep increasing till your first packet drop happens, you can read more about slow start and other mechanism in the links below.