How to Fix Your Latency in World of Warcraft & Other Online Games

Posted by bilingue | 7 comments

Ok, if you play online games, you probably know what I am talking about. It is a pain in the butt to try and use a melee class when you have more than 150 ms. Even harder to break that polymorph with your Shadow Word: Death or pull that clutch SAP. In the past I was a loyal customer of Lowerping; it was easy an easy way to play with less latency using a proxy server. LP was reliable and cheap, it’s still the solution for many gamers.

In my case, I am trying to cut expenses to make room for the new member of my family: My future baby daughter Abigail.  Anyway, let me get back to topic. Leatrix has implemented a Latency Fix for World of Warcraft that just WORKS! Yes, I used “works” with bold, italic letters because is that good. Normally, I have close to 200ms; LP lowers that to 150ms on my current server. Guess what? Leatrix’s solution lowered my ping to 90ms and it works with other Online games as well.  You can download the fix on WoWinterface (Sorry but I think CurseGaming is a cestpool of viruses) or you can visit Leatrix website.

Here’s the overview taken from the WoWinterface page:

What does it do?

Leatrix Latency Fix will reduce your World of Warcraft latency significantly by increasing the frequency of TCP acknowledgements sent to the game server. For the technically minded, this is a script which will modify TCPAckFrequency.

You will also see reduced latency in other online games such as Aion, Warhammer and Lord of the Rings. The average reduction in latency (based on feedback from comments) is 66%. Click the Change Log tab above to see a summary of player feedback.

System Requirements

Leatrix Latency Fix is supported on these operating systems only.

• Windows XP (SP2 or higher)
• Windows Vista (SP1 or higher)
• Windows 7

Both 32-bit and 64-bit versions of Windows are supported.
Macintosh users should read the relevant section in the FAQ below.

Installation Instructions

In the download, you’ll find 3 script files – Install, Remove and Checker. Simply run the Install script and follow the prompts (as shown here).

If you’re logged into your computer with an account which doesn’t have Administator privileges (or you’re using Windows Vista or Windows 7 with User Account Control enabled), you’ll be prompted to enter the credentials of a user account which has Administrator privileges (as shown here).

After the installation, you should see a confirmation window (as shown here). Simply do what it says and restart your computer. If you don’t see a confirmation window, or have any other problems with any of the scripts, read the FAQ below.

Once you’ve restarted your computer, you can login to Wow with reduced latency!

If you want to be sure that Leatrix Latency Fix is installed at any time, run the Checker script and it’ll tell you (as shown here). To uninstall Leatrix Latency Fix, run the Remove script.

I recommend that you read this entire page to better understand the process and hopefully any questions you may have will be answered in the FAQ.

How It Works

Wow uses the TCP protocol which requires that network segments sent to your computer be acknowledged in order to provide a reliable connection.

Windows bundles these acknowledgements together and sends them in pairs. While this is an efficient way of dealing with them generally, the inevitable delays caused by the bundling process increase latency considerably.

This is because when Windows queues up an acknowledgement in order to bundle it with the following one, the game server has to wait for the acknowledgement timer to expire before sending new data.

Leatrix Latency Fix removes the acknowledgement bundling process so that an acknowledgement is sent immediately for every segment that’s received. This produces a significant reduction in latency as there is no longer a delay before new data is sent to your computer.

In a normal networking environment, you would prioritise network efficiency over latency and use the Windows defaults, but in Wow the opposite is true and you want the lowest latency you can possibly get.

Typical Scenario

If you could listen to a conversation between your computer and the game server, this is what you would hear.

Before Leatrix Latency Fix is installed:

• Server: “Ok computer, I just sent a data packet over to you, got it?”
• Your computer: …
• Server: “Come on, answer me! I don’t have all day!”
• Your computer: …
• Server: “Ok, forget it, I’ve waited long enough, sending another one over! Got it?”
• Your computer: “Yep, got that one, also got the one you sent before, thanks.”
• Server: “Well, why didn’t you acknowledge the first one when I sent it? I was waiting ages!”
• Your computer: “Sorry, I’m just trying to make the network more efficient by bundling the acknowledgements together in pairs.”
• Server: “Nevermind efficiency, this isn’t a corporate domain you know. You do realise that the longer you take to acknowledge a packet, the more time I have to spend waiting around instead of sending more data?”
• Your computer: “Well sorry but this is how I’m setup by default.”

After Leatrix Latency Fix is installed:

• Server: “Ok computer, I just sent a data packet over, got it?”
• Your computer: “Yep, send the next!”
• Server: “That was fast! Ok, here’s another, got that?”
• Your computer: “Yep, send the next!”
• Server: “Wow! What an improvement! Now that’s more like it! Much better than giving me the silent treatment so I am forced to wait for acknowledgement timeouts, isn’t it?
• Your computer: “Yep, it’s certainly keeping me on my toes, thanks!”

Frequently Asked Questions

Got a question? You may find it’s already been answered below.

The TcpAckFrequency Change

• Isn’t this the infamous TCP ACK fix?
  Yes, but it’s packaged in a neat little script which will make the required changes for you, so you don’t need to go messing about with the registry.

• Doesn’t more acknowledgements mean more upload bandwidth used?
  Leatrix Latency Fix doesn’t produce more acknowledgements. It produces more frequent acknowledgements.

  
  

  
  

  
  

  
  

  
  

  
  

  Windows, by default, sends two acknowledgements for every two segments received. Leatrix Latency Fix sends one acknowledgement for every segment received. The number of acknowledgements sent in either case is the same, it’s only the frequency which is different. The only additional upload bandwidth used is for packet headers.

• Didn’t Blizzard disable this already?
  This is a common misconception but the answer is no. What Blizzard did was disable nagling, way back in patch 2.3.2.

  
  

  
  

  
  

  
  

  
  

  
  

  Nagling bundles small packets together into larger ones for more efficient transmission. The effects are similar – bundling packets together always produces higher latency which is why it’s bad for online games. Blizzard disabled nagling because of this, however, the acknowledgement queueing system used by the TCP protocol remains.

  For the technically minded, Blizzard made the TCPNoDelay function redundant, as Wow now includes it by default. They didn’t change TcpAckFrequency. Leatrix Latency Fix changes that.

• The displayed latency is lower but in-game latency is the same isn’t it?
  As previously stated, when the game server sends data to your computer, the faster that your computer acknowledges that data, the faster the next lot of data is sent.

  
  

  
  

  
  

  
  

  
  

  
  

  Leatrix Latency Fix makes your computer acknowledge packets immediately, so subsequent data is sent to your computer in the shortest possible time. Anyone who thinks that this doesn’t produce a genuine reduction in latency has failed to understand this simple process.

  The in-game latency stat is accurate. However, the amount of latency reduced and how much you notice the benefits depends on your connection and what your character is doing in the game world (since some activities will produce much more traffic than others).

• Doesn’t Wow use UDP for game data?
  No, Wow uses TCP port 3724 for game data and TCP port 1119 for Battle.net authentication. You can prove this to yourself by blocking all outgoing UDP traffic on your computer/router but keeping TCP ports 3724 and 1119 open, the game will still work. But if you block TCP ports 3724 and 1119 then it won’t work, it doesn’t matter whether UDP ports are open or not.

• Is Leatrix Latency Fix against the World of Warcraft terms of service?
  Of course not, it’s a local change to your computer’s network configuration, nothing more. It’s completely safe to use and it’s nothing to do with Blizzard at all, or any other game publisher.

• Does Leatrix Latency Fix work with tunneling services?
  Using LLF with a tunneling service probably won’t give you any benefit, so you should decide to go with one or the other. There really is no way to find out which works best for you other than trying both yourself. The results really depend on a number of factors which are unique to your connection.

  
  

  
  

  
  

  
  

  
  

  
  

  But be aware. Tunneling services are essentially proxy servers which are rerouting game traffic and your account may be banned if you use these services because Blizzard may interpret your network routing to be suspicious.

  The Terms of Service state that “You agree that you shall not, under any circumstances..redirect the communication protocols used by Blizzard Entertainment in any way.., including.. tunneling.. or any other techniques.. including.. network play utilizing commercial or non-commercial gaming networks. All connections to the Game and/or the Service, whether created by the Game Client or by other tools and utilities, may only be made through methods and means expressly approved by Blizzard Entertainment.”

  So use tunneling services at your own risk.

  Leatrix Latency Fix, on the other hand, is a local change to your computer’s network configuration and is not against the Terms of Service.

Your Computer

• Will Leatrix Latency Fix damage my computer? Can I remove it?
  There’s a removal script included in the download which will completely erase all traces that Leatrix Latency Fix was ever installed. This isn’t one of those scripts that changes all of your network settings and you have to reinstall Windows to get things back to normal. The installation script makes a simple change. The removal script reverses that change. You have nothing to lose.

• Are there any down sides to running Leatrix Latency Fix?
  Your PC will process acknowledgements faster so it will have to work a bit harder. This may produce a small drop in framerates.

  
  

  
  

  
  

  
  

  
  

  
  

  Remember that Windows networks aren’t designed for online games. They’re designed for general desktop computing in large networks where traffic efficiency has the highest priority. In these environments, network latency isn’t important at all and bundling acknowledgements together makes sense.

  However, Wow players are rather unique in that they’ll often use a single TCP based application (the game client) for hours at a time and they’ll want to give that application priority over any other function of their PC. It’s for these players that Leatrix Latency Fix is designed for.

  Leatrix Latency Fix should not be installed on computers where you want to put more emphasis on network efficiency. Fortunately, this doesn’t apply to most Wow players and having reduced latency is of considerably more importance.

• Does Leatrix Latency Fix work with wireless networks?
  Yes, but for the best latency you should be using a wired connection to your router. Wireless connections have additional overheads and are subject to interference and signal quality. They also can’t carry as much data as wired networks which can be a hindrance to the way that Leatrix Latency Fix works. If in doubt, install Leatrix Latency Fix and see for yourself. It won’t break anything and there’s a removal script included if you need it.

• Does Leatrix Latency Fix work with routers?
  Of course. The router only forwards packets between your computer and the game server. It doesn’t control what packets are forwarded. If your computer acknowledges every single TCP segment or every other TCP segment, it makes no difference, the router will just do what it’s told.

  
  

  
  

  
  

  
  

  
  

  
  

  However, routers use a buffering system for forwarding packets and the increased frequency of acknowledgements sent to the game server may cause this buffer to fill up, which will give you lag spikes. This is more likely to happen if you have multiple computers connected to your router, or you’re running network intensive applications in the background while playing Wow. There really is no way to find out whether your router will do this other than to try LLF for yourself.

• Does Leatrix Latency Fix work with any other games?
  Leatrix Latency Fix modifies the way in which Windows handles acknowledgements to TCP segments. As such, it will affect any application that you have installed which uses the TCP protocol to transfer data. A lot of games use UDP so won’t be affected but for the games that use TCP (such as World of Warcraft and Aion), you should see a significant reduction in latency.

• Is there a Macintosh version?
  Leatrix Latency Fix isn’t supported on Macs. However, you can achieve lower latency in OSX by entering the following command in a terminal window. This will disable delayed acknowledgements until you restart your computer.

  
  

  
  

  
  

  
  

  
  

  
  

  sudo sysctl -w net.inet.tcp.delayed_ack=0

  To disable them permanently, create a text file under “/etc/” called “sysctl.conf” and copy/paste the following line then restart your computer.

  net.inet.tcp.delayed_ack=0

  To set things back to default, just delete the “sysctl.conf” file and restart your computer.

  If you’re not familiar with /etc, it’s actually a symbolic link which goes to /private/etc. This is a hidden root folder which isn’t normally visible in the Finder.

  To be able to see hidden folders in the Finder, open up a terminal window and type the following:

  defaults write com.apple.finder AppleShowAllFiles TRUE

  Then restart the Finder. To do that, hold down the option key then click and hold on the Finder icon in the dock. When the context menu appears, click Relaunch and the Finder will restart. You should now see all the hidden folders in the Finder, including /etc (either find the Symbolic Link or the actual folder which is inside /private).

  When you’re done and you want to hide the hidden folders again, bring up a terminal window and enter the following:

  defaults write com.apple.finder AppleShowAllFiles FALSE

  Then restart the Finder in the same way as before. The hidden folders should now be hidden again.

  Hidden folders contain critical system configuration files so be careful that you don’t delete or move anything by mistake while they are visible in the Finder.

The Leatrix Latency Fix Script File

• I use Windows Vista or Windows 7 and User Account Control prevents me from running scripts. Can I get around it?
  Leatrix Latency Fix includes bypass support for UAC. If you are stuck behind UAC, it will ask you for the credentials of an account which has Administrator rights so that it can run (as shown here).

  
  

  
  

  
  

  
  

  
  

  
  

  Alternatively, you can run Leatrix Latency Fix from an elevated command prompt, which you can access by right-clicking Command Prompt from the start menu while holding down shift and choosing Run As Administrator.

• Can I install Leatrix Latency Fix without restarting my computer?
  Leatrix Latency Fix will request that you restart your computer after installation. If you really don’t want to do this, you can choose not to and instead disable and re-enable your network card.

• Can I install Leatrix Latency Fix silently from a batch file?
  Yes, just use ‘cscript