The data throughput and responce time with the Avisaro wireless module can be significantly improved if the so called "Delayed Ack" feature of Microsoft Windows is turned off. This feature have (unfortunately turned on by default) almost all modern TCP stacks. While it is an advantage of Internet surfing, it has more disadvantages in the embedded area. In order to eliminate "Delayed Ack" on a Windows based PC, as you can go to the website:

• German: http://support.microsoft.com/default.aspx?scid=kb;de;328890
• English: http://support.microsoft.com/kb/328890

Configuration Tools

Turning of the 'delayed ack' can be done manually or by using these tools. Operating the tools is easy:

1) Use "Install.vbs" to turn of the delayed ack (recommended)

2) Use "Remove.vbs" to enable delayed ack again.

The tool is provided by www.leatrix.com. A manual can be found in the 'gaming comunity' here (gamers also have a need for short network delays).

Tools to disable and enable the delayed ack (Windows XP, VISTA, WIN7) (DE, ZIP)

Test Tools

Avisaro provides a test tool to check network performance particularly with embedded WLAN devices. For this test to run, follow the steps:

1) Install the script "av_4-1.txt" on the Avisaro WLAN. Configure on page "Scripting" a '0' for listening.

2) Run the Java Tool "Avisaro Performance Test". Enter IP adress of Avisaro device and click 'run'.

This gives a clear picture of whether the performance is sufficient.

Script "av_4-1.txt" und "Avisaro Performance Test" Tool (Java) (DE, ZIP)

Example

If you see a FTP performance of about 50 kbit/s the Delayed Ack is very likely turned on. If set properly, the FTP performance should be 500 - 1000 kbit/s (0.5 to 1.0 Mbit/s).

Registry Entry for Delayed Ack (click to enlarge)