FTP-to-FTP compare and/or synkronizing

[sune]

Is it possible to compare two FTP-folders?

My hosts do not support FXP (site-to-site transfer),
so I look for comparing two folders, on each FTP-server, and hopefully also synkronize (by combined local down- and upload, as the site-to-site is not allowed).
But I don't see how to setup a second FTP-connection instead of "local files"...?

PS. The wanted feature is to avoid downloading all from Server-A and compare/syncronize from there, to Server-B, and having all files locally - it is 1-2 GB files, maybe more...