We have some site with problematic FTP trasnfers, found that Active FTP was working, Passive FTP was not working. Found IE and FileZilla both have ways to change default behavior. We needed to get FTP working.
Found a note on Nortel's site known issues with specific firmware and passive FTP.
Here is my test file, first line is active, second is passive - the second line was failing. The test downloads a 3 meg file from Microsoft.
I also found this guide:
Active FTP vs. Passive FTP, a Definitive Explanation
curl ftp://anonymous:firstname.lastname@example.org/PSS/Tools/NetMon/netmon2.zip > netmon2-norm.zip
curl --disable-epsv ftp://anonymous:email@example.com/PSS/Tools/NetMon/netmon2.zip > netmon2-disable.zip
After the firmware it worked as expected.