Hi FanacooL , I really cannot comment on what will happen when you have multiple applications using the link. It would depend on their resource sharing rules.

The online tests that I have seen usually expect to be the only connection and calculate speeds based on sending a fixed amount of data.

You must be careful of the bits/bytes distinction and appreciate that the route will have an effect (how many hops). When you see a file being transferred you usually see the BYTES value not the bits one which is 8 times greater.

When I first got ADSL it was 512/256 download/upload. They subsequently increased the download speed to 2.2Mbps and I think that the upload is now 512Kbps.

Another thing you might consider is your security arrangements. If you are scanning all downloaded content for malware that could slow you down somewhat, particularly with e-mail.

I would expect your tools to report what they have measured, but those values may have been distorted by other factors?