what determines the final windows scaling factor? example FTP client initiates a TCP connection and has a 1GIG interface. Window scaling is enabled.
RTT is 76ms
in the original SYN packet it had: MSS is 1460. window size value: 65535,
window scale: 7 (multiply by 128).
SYN-ACK from opposite side: MSS is 1260, window size value: 8192,
window scale: 14 (multiply by 16384).
in final ACK it came to: Window size value: 32768, window size scaling factor: 128, calculated window size: 4194304.
(for the rest of FTP transfer it stayed on this value: 4194304)
so 2 questions regarding initiating side (FTP client): 1)How at the end the window size reduced to 32768 on the initiating side? 2) Why if the interface is set to GIG - it did not use the 14 as window scale ? but used 7?what could have determined that - is it a hard setting on server or did the TCP connection catch some buffer on the network? thanks for any help Nik