[2.0.8] Slow multiplayer map downloading speed

[KikuGIe]

I'm hosting a Space Age server for myself and the map download speed is unreasonably slow. The server is hosted on a second laptop on the same WiFi network.
The Factorio download speed peaks at 50-60kB/s. I've also used iperf3 to test the bandwidth to the laptop:

Code: Select all

Connecting to host 192.168.2.82, port 5201
[  5] local 192.168.2.185 port 35442 connected to 192.168.2.82 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  5.46 MBytes  45.8 Mbits/sec    0    229 KBytes       
[  5]   1.00-2.00   sec  8.82 MBytes  74.0 Mbits/sec    0    578 KBytes       
[  5]   2.00-3.00   sec  6.24 MBytes  52.3 Mbits/sec    0    839 KBytes       
[  5]   3.00-4.00   sec  3.75 MBytes  31.4 Mbits/sec    0    882 KBytes       
[  5]   4.00-5.00   sec  1.25 MBytes  10.5 Mbits/sec    0    882 KBytes       
[  5]   5.00-6.00   sec  2.50 MBytes  21.0 Mbits/sec    2    617 KBytes       
[  5]   6.00-7.00   sec  2.50 MBytes  21.0 Mbits/sec    0    617 KBytes       
[  5]   7.00-8.00   sec  6.25 MBytes  52.4 Mbits/sec    0    693 KBytes       
[  5]   8.00-9.00   sec  7.50 MBytes  62.9 Mbits/sec    0    764 KBytes       
[  5]   9.00-10.00  sec  6.25 MBytes  52.4 Mbits/sec    0    813 KBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  50.5 MBytes  42.4 Mbits/sec    2             sender
[  5]   0.00-10.07  sec  48.0 MBytes  40.0 Mbits/sec                  receiver

iperf Done.

I've also tested ping and it averages at 3ms. This test has normal speeds for connecting to a computer literally 1 meter away, so it's weird to see Factorio downloading the save file at a snails pace.

10-22-2024, 09-01-35.png (4.35 MiB) Viewed 661 times

[Wackelente]

Having the same problem. Is there already a solution?

[KikuGIe]

No, they game is insisting on me logging on once and STAYING THERE.

[vinzenz]

Hey there, thanks for the report. How much does your download speed improve when you connect by ethernet cable? Unfortunately the Factorio networking protocol is very sensitive to latency. You can also try to experiment with the segment size in server-settings.json.

[Wackelente]

Hey, thank you very much for answering! The speed does not improve very much. The speed is between 100 kbit/sec and 300 kbit/sec while using windows. On Ubuntu the speed goes up to 700 kbit/sec. However, there is no difference between LAN and WLAN. Pings are stable lower than 15ms.
I tried to experiment with the segment sizes. I'm not sure how to decide which values are fitting in this case. Nevertheless, increasing oder decreasing does not have a great impact on download speed. (Headless Server hosted on Hetzner dedicated)

[KikuGIe]

I tried doubling the default min and max segment sizes, but it didn't affect anything. The download speed was also the same for connecting through my local IP and the public one.
During the gameplay there are no connection issues.

10-29-2024, 09-43-13.png (96.37 KiB) Viewed 416 times

[KikuGIe]

Testing latency:
- client -> server

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--- 192.168.2.82 ping statistics ---
25 packets transmitted, 25 received, 0% packet loss, time 24112ms
rtt min/avg/max/mdev = 2.073/5.916/35.144/7.065 ms

- server -> client

Code: Select all

--- 192.168.2.229 ping statistics ---
24 packets transmitted, 24 received, 0% packet loss, time 23122ms
rtt min/avg/max/mdev = 1.839/5.587/41.931/8.306 ms

[shelmak.gc@gmail.com]

I think there is some problem with the map downloads, maybe when the save starts to get big, I don't know.

The thing is that on my case I host the server on my computer, I am connected by an ethernet cable, done speedtests and results were download of around 500mbps, upload of 600mbps. But my friends are downloading the save very slowly every time they connect.

They have good networks, speedtests were correct giving more than 300mbps of download speed for them, but it is taking a lot of time to download the map. I have no limits on the upload speed, so I don't know what could be happening, as this even happwn with firewall off and even using dmz.

[KikuGIe]

I don't know why exactly, but connecting a VPN fixed the issue. My theory is that the home router doesn't handle UDP that well and VPN makes it route through TCP.

[Gummiente27]

I don't know why exactly, but connecting a VPN fixed the issue. My theory is that the home router doesn't handle UDP that well and VPN makes it route through TCP.

You don't know which router messes it up, I'd say its likely not your home router, but some router inbetween you and your server which is overwhelmed and likes(is programmed to) to drop UDP packets first.

[morsk]

I had this issue 5 years ago and it was my router. I had to call Verizon and have them change settings so I could connect the router to the modem through Ethernet instead of Coax, and the problem went away.

It is still 1/2 or more Factorio's fault for failing when no other app on my entire home network failed. Factorio does something with UDP that some routers don't like. It does not surprise me that tunneling solved the problem. The game should just use its own tunneling then, right? Oh well.