Factorio Forums

While playing on a direct 2 player IP connection, My friend and I have begun to get a gradual accumulation of "hiccup lag", where the game becomes unplayably choppy. As soon as he disconnects, the game returns to normal, and then when he reconnects, it goes right back to the hiccuping. Some things we have noticed:
The very only fix we have found is for him to reset his modem (Which takes about 10 minutes)
Starting a new map, restarting computers, or restarting MY modem does NOT cause the hiccuping to go away. Only restarting his modem does, which always turns out to only be a temporary fix.
There were no de-syncs involved in between resets, so it is not de-sync related
Aliens seem to play some part in this. Playing from a fresh modem reset on a map with aliens->normal-normal-normal allowed us to play for 5 hours before we had any hiccuping. In a new map after a modem reset with aliens->Very big-very big-very good left us with unplayable hiccuping after about 3 mins of play.
Both of us are windows 8, I have a cisco modem on a cable connection, and he has a motorolla modem on a DSL connection.

I would like to stress that it is clear that it is not a system problem, as both of us do not have the issues at all in single player. It seems to be a straight network issue, with some kind of gradual increase to his packet loss.(possibly as a result of an increased biter count?)

But packet loss is a problem of the modem and not of Factorio!?

I mean: Nearly any application cannot work properly, if the Internet connection looses too much packets. There is always a point, where the repeating of the lost packets will lead to an overhead, which makes the application unuseable.

Hmmmm. What Factorio can do is A) to show the players, that there is a network problem. B) to handle this loosing line by doing some "tricks", like sending every packet by default twice.

I think B is only an option, if there are too many players, having this problem. The better solution is to ask the Internet provider, why the line looses so much packets, cause they can normally measure that much better.

While I would agree normally that this kind of issue would be an ISP issue, there seems to be something in factorio that is exacerbating the problem. Typically my friend might need to reset his modem once a month due to the "bog down" of this type, and that is playing a variety of games, including MMOs. Factorio with high alien settings causes it within minutes. Besides, Im not saying it is packet loss I guess, just that it behaves a lot like it. And again, why does factorio only take minutes to cause it while other games take a month?

bug in router/modem firmware, maybe not handling udp packets correctly, nat traversal issue, etc..?
can the affected modem get a firmware upgrade?

there seems to be something in factorio that is exacerbating the problem.

Perhaps cause most other games play with TCP/IP and not UDP/IP? I mean it is interesting, and perhaps you are right, but all experience says: Check first the line!

Long ago I was a big player of Homeworld2. But I had problems to connect, when I opened the game. Half a year later I found out: It was not the router, nor the cables, no it was the switch! The switch didn't implement some ARP-protocol specialities correctly. New switch and I suddenly could open my games.

I have a feeling it will have something to do with packet fragmentation. When you are fighting you keep sending much more input dataand it is possible that the data won't fit into a single packet which makes your friend's router unhappy. I don't know how to fix this, but I'll keep it in mind :-)

Just to confirm this hypothesis, could you try to wait for these lags to start and then both of you retreat to a base and not do anything for a while? If my guess is correct the fragmented packets should flow away and the lags should stop after a few seconds.