While hosting a server ,when my friend is downloading he can download my map only with speed of 60 kb/s.
My Internet max Upload Speed should be around 500 kb/s.
Is it possible that this is caused by not having opened ports on my friends router? (if yes can it be somehow bypassed because his ISP ...

I've been playing Factorio for a while on singleplayer and on multiplayer servers (as host) and one thing that bothers me is autosaves.
There are max 3 auto-saves regardles of amount of your maps , so my sugesstion is to make 3 autosaves per map so it would remove possibility of having save for map ...