Slow FTP upload speed
Posted: Wed May 12, 2010 10:49 pm
Hello,
we're planning to use jFileUpload and jDiskExplorer in ftp mode on our website, but the upload speed of the applet is slow compared to standard ftp-clients. We need to transfer huge files to our webserver so upload speed is very important for us.
I did some test uploads with jFileUpload and jDiskExplorer and the maximum upload speed I get is about 200-250 KB/s. When I do the upload with Filezilla or DOS command line I get about 1MB/s which is approx. the bandwidth of our internet line. Downloading a file with jDiskExplorer works fine and is as fast as Filezilla (~2MB/s). I tried this on different machines (PC and Mac) and with different internet connections but the upload speed was never higher than 250Kb/s.
So I tried to find out what's the problem and analysed the TCP packet flow with Wireshark. I found out that JFileUpload hardly ever sends FTP-Data packets with the maximum packet size, while Filezilla always sends with maximum segment size of 1460 bytes. Both TCP connections (from JFileUpload and Filezilla) are esablished with a maximum segment size of 1460 bytes. Also the TCP window size is 4x smaller with JFileUpload than with Filezilla. It seems that JFileUpload is not using the TCP conection at maximum efficiency.
Is it possible, that there are internal transfer buffers too small or something like that?
We would really like to buy your tools but as I've mentioned above, upload speed is very important for us. Do you have any suggestions?
Thanks,
Bernhard
we're planning to use jFileUpload and jDiskExplorer in ftp mode on our website, but the upload speed of the applet is slow compared to standard ftp-clients. We need to transfer huge files to our webserver so upload speed is very important for us.
I did some test uploads with jFileUpload and jDiskExplorer and the maximum upload speed I get is about 200-250 KB/s. When I do the upload with Filezilla or DOS command line I get about 1MB/s which is approx. the bandwidth of our internet line. Downloading a file with jDiskExplorer works fine and is as fast as Filezilla (~2MB/s). I tried this on different machines (PC and Mac) and with different internet connections but the upload speed was never higher than 250Kb/s.
So I tried to find out what's the problem and analysed the TCP packet flow with Wireshark. I found out that JFileUpload hardly ever sends FTP-Data packets with the maximum packet size, while Filezilla always sends with maximum segment size of 1460 bytes. Both TCP connections (from JFileUpload and Filezilla) are esablished with a maximum segment size of 1460 bytes. Also the TCP window size is 4x smaller with JFileUpload than with Filezilla. It seems that JFileUpload is not using the TCP conection at maximum efficiency.
Is it possible, that there are internal transfer buffers too small or something like that?
We would really like to buy your tools but as I've mentioned above, upload speed is very important for us. Do you have any suggestions?
Thanks,
Bernhard