[0.14.20] Slow multiplayer map downloads

[xtremeqg]

I suspect this has been reported to death but a quick search turned up nothing. It's not really a problem, mostly a nuisance. In all multiplayer games, all users but the host of the game need to wait several seconds to minutes for the map to download to their system. This process can be fairly lengthy and often complained about as can be seen on many Youtube videos.

Curiously, the download speed has absolutely nothing to do with your connection. For example, running a multiplayer game on local LAN with gigabit still ends up with other players waiting for the map download. Despite the network tested to be capable of speeds exceeding 80MB/s, Factorio chugs along at a mere 1.2MB/s. Loading the save file itself as the host is actually faster than others downloading it. Is there any particular reason for this?

[Klonan]

Thanks for the report,

The 'waiting' isnt the sending of the map, but the server saving the map to send to the player

[WipeKIller]

You're really lucky if you get it up to 1.2mb/s... My friend and I have tried 'fixing' this problem several times, but gave up. We're using a LAN software for us to connect to eachothers networks. It wasn't a problem back before we connected our Factorio to steam, mostly because I also had my ports opened for him to access my network without using a LAN software. But currently I'm running a 100/100mbit/s internet and he's got 20/5, but we barely reach 100kb/s when he's connecting to the server, even though the map is merely 8MB.. So when we're playing Factorio, we have to start over every time because of this issue. We've also tried to continue on a map, but then I get this message on the top of my screen saying "Player is being dropped', or something like that.

Okay, so a few facts here:
We're both living in Denmark. (Really good internet here)
We've both got decent computers.
And we're both pretty good at IT.

So... Any suggestions on how to fix this?

[orzelek]

Did you try to use tracert or WinMTR to see if connection between you two is really that good?

Also from what you are writing it seems you need to go back to direct connection since it was working better then with LAN emulation software. You can still use it even from steam version of Factorio.
Also with recent changes you shouldn't need to open ports since from 0.14 there is a nat punching implemented which should take care of that.