There can be several reasons online speed tests return low results.
The testing application lists throughput in Layer3 values; however, circuits KanREN procures also must carry Layer 1 and Layer 2 portions of the path. This additional overhead can result in tests showing 5–7% lower then actual circuit speed.
If the speed test server’s traffic flows through congested segments of the Internet results can be erratic. Pay close attention to which server is selected (if there is an option) when running the test and where the testing server is located. These details can help the KanREN NOC troubleshoot any congestion issues. It’s also often helpful to test with multiple servers or speed testing services to try and replicate poor performance issues.
LAN traffic will contend equally with the speed test traffic. For example, if you have a 1Gbps connection, and are currently using 700Mbps of it, the best a speed test will show is 300Mbps.