Net Layer question

[Archimedian]

This has be posted in a few places (WoW elitistjerks forums in particular) as a ping reduction tweak:

A few weeks ago I posted this fix from the ElitistJerks forums and it worked well for most of the people but it's not really safe and it was supposed to be fixed in 2.3.2, however it seems that the Nagle Algorythm fix in the 2.3.2 patch isn't as effective as expected for most of the players, and if you're in desperate need of a lower ping this is still the best way to go.

<><><> Read this first <><><>
1 - It might have side effects, like slowing down your download speed or affecting your performance on other softwares. (In most case, it doesn't change anything, but you've been warned)
2 - If you're not sure about what you're doing, just don't do it. I don't want to be responsible because you crashed your computer in some way because you made a huge error when editing the registry.
2.1 - Seriously, if you don't know what you're doing, don't do it.
3 - If you don't have the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSMQ\ directory, you can download and apply this file to your registry.
4 - Windows Vista users might want to check this post too.

Source - Elitistjerks.com

1 - TcpAckFrequency - NOTE if you are running Windows Vista this setting may not have any effect - a hotfix is needed which i'm tracking down. This works fine under Windows XP

Type "regedit" in windows "run.." dialog to bring up registry menu

Then find:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\

There will be multiple NIC interfaces listed in there, find the one you use to connect to the internet, there will be several interfaces listed (they have long names like {7DBA6DCA-FFE8-4002-A28F-4D2B57AE8383}. Click each one, the right one will have lots of settings in it and you will see your machines IP address listed there somewhere. Right-click in the right hand pane and add a new DWORD value, name it TcpAckFrequency, then right click the entry and click Modify and assign a value of 1.

You can change it back to 2 (default) at a later stage if it affects your other TCP application performance. it tells windows how many TCP packets to wait before sending ACK. if the value is 1, windows will send ACK every time it receives a TCP package.

2 - TCPNoDelay
This one is pretty simple (Discussed here)

Type "regedit" in windows "run.." dialog to bring up registry menu

Then find:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSMQ\Parameters

Right-click in the right hand pane and add a new DWORD value, name it TCPNoDelay, then right click the entry and click Modify and assign a value of 1.

Click Ok and close the registry editor, then reboot your PC.

My assumption here is that this in effect doubles your TCP budget (obviously the acks are pretty small but you have a scaling issue) and in turn doubles the process requests for what ever application is listening and responding.  Yes/No, good news/bad news?

I know it's a windows tweak but I assume once again when designing these things are taken into account or maybe not.

PS: To be edited in case my bbcode sucks and I need to quote instead of code it.

[Mrbloodworth]

I would follow rule 2.1 in the above.

[Zetor]

Theoretically this has been fixed in 2.3.2, so no need to do the registry tweaking anymore.

I've applied the fix before that patch, and it worked ok -- I play from Europe, so my ping is naturally horrible, but it went down to 300 from 700ish. So yeah, it works.

Edit: It helps to read the post :p so yeah, I don't know exactly what 2.3.2 did, only that it was supposed to fix this same problem. But this does work, and hasn't resulted in any slowdowns in other software [including other games like TF2, etc].


-- Z.

[Trippy]

You could try messing with TCPNoDelay to see if that helps.

I would be wary about changing TcpAckFrequency unless WoW is the only program you use that uses TCP/IP (highly unlikely since you posted this) or you are willing to go through the trouble of benchmarking various networking tasks. Lowering it to 1 could very well, in effect, reduce your bandwidth and it may not even lower your ping in game.