Important Information
Windows Vista has an auto-tuning function that automatically adjusts your settings, so tweaking is not possible. You can disable auto-tuning for troubleshooting connectivity issues. Click here to find out how.

Step 1
Download DrTCP here and open the application.

Step 2
Select the network adapter associated with your broadband connection. Important Note: There may be more than one network adapter showing in the pull down menu for your PC.


Pictures by Andy Houtz

Step 3
Enter the suggested RWIN in the appropriate field and click Save. Select any other network adapters (if any) and enter the proper RWIN as needed. Remember, RWIN should always be an even multiple of your MSS. MSS is always your MTU size minus 40 bytes. An example of proper RWIN size is shown below:

1452 MSS
x 26 Even Multiple
37752 RWIN

Recommended RWIN initial settings (assumming an MTU of 1492):
FastAcces Extreme (6000/512) = 63888
FastAcces Extreme (3000/384) = 63888
FastAccess Ultra (1500/256) = 63888
FastAccess Lite (768/128)= 63888

Step 4
Restart your computer! The changes will not take effect until you do so!

Important Additional Note: If you are also using DrTCP to adjust your MTU never run an MTU larger than 1492 when utilizing PPPoE connectivity; which is the standard for FastAccess. Click here for more information.

Andy Houtz DSL

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by Andy Houtz edited by FAQFixer
last modified: 2009-03-20 10:25:48