Query on window adjust in SSH server

abhilash abraham abhilashtabraham at gmail.com
Mon Mar 17 15:55:00 EST 2014


      I have a problem regarding window adjust, in the SSH server.

 I was trying to get a file of 400K from a system, via SFTP, which has old
version of openSSH [v2.0 or so] in it. I'm using Windows client, filezilla,
to get thre file. Once it reaches ~12k, the transfer gets halted. On
debugging I could find that it has reached the maximum window size in the
server and the client is never again sending the window adjust message.

    In RFC, I couldn't find anything about handling this situation. Can you
please let me know whether the server has the 'right' to adjust the window
size without the message from client. Or is there any reason for the client
not sending the adjust message[like its not aware of window exhausted in


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