I suspect I had a brain cramp and completely got occupied with other stuff......... LOL
But in answer to your question, the speedtest tool works ok. but still, you would want an analysis tool. My recommendation here would be for Wireshark. It’s freeware and can be loaded on your PC.
Here’s some info on it:
http://en.wikipedia.org/wiki/Wireshark
http://www.wireshark.org/download.html
Oh, well, thanks for the eventual response! I’d forgotten all about it as I started using Speedtest (recommendation from the ISP when they installed the DSP service.) However, Wireshark looks very interesting - thanks for the link!