I get poor performance when sftp'ing a file to a server on a SunOS 5.10 system, with Sun_SSH_1.1.4. The same client performs much better to a linux system at the same site.
From a TCPdump, it appears that the Solaris server is throttling the thruput. After proceeding normally for a while, the server sends a duplicate ack, then a return data packet. This data packet seems to cause my client to stop sending.
After the server receives the ack for that reverse data packet, the server acks all outstanding packets, and sends another data packet. On receipt of that second data packet, my client resumes sending.
This process is repeated regularly, resulting in poor performance.
Any clues on what is going on, or how to speed this up?