What is the network data limit, why is it there, how do I change it?

Development Programming & Scripting Multiplayer & Networking
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1

Hello Epic and Friends,

I am experiencing some issues with sending data over the network capping at roughly 10kBps, I have some assumed reasons behind this, but I would like to know the following:

What is the network data limit?
Why is there a network data limit?
How does one go about changing it?

Thanks!

Spiris

2

I believe that in this stream: Networking Framework: Tips & Tricks | Feature Highlight | Unreal Engine - YouTube
towards the end where they answer questions one of the epic staff said something about a limit of 10 xyz. I’m not fully sure and at the moment I don’t have the time to watch the whole stream again, as far as I remember he said this value is hard coded into the engine.

If you find where he says that, please let me know :slight_smile:

3

John Pollard mentions it around 1:04:30, and explains that there is an game .ini code to change it, but there is no example or documentation on what that special combo of characters looks like.

1 Like
4

So today I took a look through some engine code and figured out that there is indeed config variable that can be set in the NetDriver class.
So I am a little confused as to what to change in the DefaultEngine.ini file.

Would it be…
[NetDriver]
MaxClientRate=20000
or some other weird permutation of it?

5

The variables you want are in UNetDriver. There are two values that you can set for your project. The first is the max data rate you want to use on a LAN before considering the connection saturated. The second is the max rate for Internet connections. Both are there for the same reason: namely to slow the amount of data sent so the client’s connection is not saturated. Here’s an example:

[/Script/OnlineSubsystemUtils.IpNetDriver]
MaxClientRate=15000
MaxInternetClientRate=10000
6

Thanks very much Joe! That explanation will surely help a lot of people.

Could you add what unit these variables are? I would guess it’s Bit/s, though that seems a bit low so it could also be Byte/s.

Does it count for both up and down at the same time or separately? Is there a way to set the limits individually for up and down?

The average internet speed in USA is 11.5 Mbit/s, so if the default limit in UE4 is 10.000 Bit/s then that would only use 0.0008% of the available connection, that sounds a bit strange to me. Doesn’t that introduce unnecessary lag?
I’m sure Epic set the limit to that number for a reason, I just can’t see what that is. Epic has shipped a lot of multiplayer games so that number does surely make sense, I would just like to know why I should not set it to something like using 50% of the available connection?

7

Sorry, the units are Bytes/s. It’s both up/down total. The client typically sends very little data upstream, mostly downstream. The server sends quit a bit upstream, less downstream. That’s why separating them doesn’t make sense. As for available bandwidth, Gears was targeted at 5-7k range. Remember on a server for Gears that’s 50-70k (10 connections). Client speed isn’t as important as the server. You can set those numbers higher, but a large portion of your audience will get a bad experience.

8

So just copying the 3 lines you mentioned into the DefaultEngine.ini and set the speed in Byte/s should work, thats very nice to know :slight_smile: Thanks again!

9

Thanks a lot Joe , i changed everything and nothing worked till tried your method .

10

Is this still valid? Can’t find those variables in IPNetDriver.h

Have those been change to the following?

  1. [/Script/Engine.GameNetworkManager]
  2. TotalNetBandwidth=10000
  3. MaxDynamicBandwidth=10000
  4. MinDynamicBandwidth=4000

EDIT: Found them in NetDriver.h