How do I configure my application to test LAN, other high-speed networks, or high-latency scenarios?

Team Ookla -

Ookla Speedtests come configured with parameters targeting the most common current range of broadband speeds. Currently this is considered download speeds between 1 and 25 Mbps and upload speeds below 10 Mbps. However, you can tweak the test parameters to be reliably accurate up to 100mbps (and improve measurements beyond that).


To overcome throughput limits caused by response times and the TCP window, the Ookla Speedtest engine supports multiple parallel threads. HTTP standards limit us to two concurrent connections per host. HTTP standards limit us to two concurrent connections per host. To get around this we must provide alternate hosts (or host names for the same machine) for each additional pair of threads. Using as an example, create up to three additional DNS entries like this: 


<server url=""
url4="" />

To use files from other hostnames, Flash usually needs to receive permission from a crossdomain.xml file on those hostnames. See the What is crossdomain.xml and why do I need it? article for information on how to set that up. 

Once done you will be able to use as many as eight parallel threads (the maximum allowed) for both the download and upload tests. Threads can be either 1 or done in pairs, so the possible values are 1, 2, 4, 6, 8. Use the lowest number that achieves proper speed measurement for your situation! Each additional thread uses more CPU on the client which can impact results on older/slower computers. Eight threads should only be needed when measuring speeds in excess of 100 Mbps.


<download testlength="10" threads="8" maximagesize="40M" />


<upload testlength="10" ratio="1" threads="8" maxchunksize="1M" maxchunkcount="100" />
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