Comment 5 for bug 622566

I've coded a simple cached FTP transport on top of standard FTP transport in bzrlib, the plugin is available at lp:~bialix/+junk/kftp
and you need to use kftp://host/path URL instead of ftp://host/path.
It works good and indeed reduce the tme for pull and even push. I know it's ad-hoc, but it's better than nothing at all. I think it should be safe to cache packs/indices because they're supposed to be write-once data.