From Windows Server 2003, I'm uploading a file (~50MB) every day at 4:00am to my hosting space in the cloud. I'm doing it by calling "ftp -s:" in a batch file that a Scheduled Task runs.
I did what Edward suggested in the post below and watched Process Monitor while uploading: FTP Transfer Very Slow When Windows Firewall Enabled
When Windows Firewall is on, alg.exe and ftp.exe are involved at the beginning, and do quite a lot of what appears to be handshaking. Then finally only ftp.exe gets going with the send, and each event (each line in Process Monitor) appears about once a second, and has a size of 65535. The upload takes about 10 minutes.
When Windows Firewall is off, alg.exe never shows up. ftp.exe seems to start sending almost immediately, after the first 3 events/lines or so. Then the events/lines in Process Monitor appear very fast and also have a size of 65535. The upload takes about 1 min 20 secs.
Also thought I'd add that I tried this same thing using copy/paste in Windows Explorer. With firewall on or off, the upload takes about 10 minutes. The events/lines in Process Monitor appear pretty fast, but all of them only have a size of 4096.
Any ideas how to get the faster upload speed with Windows Firewall on?