|RWIN||RWIN (TCP Receive Window) is a buffer that determines how much data the receiving computer is prepared to get at one time.
The sending side will only send data up to the size of the RWIN, and wait for acknowledgement before sending additional packets.
A RWIN value that's too large will result in greater loss of data if a packet is lost or damaged. A too small RWIN will be very slow, as each packet will have to be acknowledged before the next packet is sent.
RWIN is one of the most important parameters in tweaking any TCP/IP connection.