My router and Internet Connection Status Window indicate that I'm currently connected at 8.1Mbps. My ISP's software shows this: Any ideas please?
It's his ISP showing it. Although I'd be interested to know which, looks like Nildram MaxDSL is rate adaptive, so the tests never officialy end per se. What you'll probably find is if you keep at your current line rate your MSR (Maximum Stable Rate) will climb to match it. Currently you won't be able to download faster than 3424kbps.
