My own take.
Personally, I think people just need to use common sense, and to use their understanding of the english language, to take things literally.
“upto 25 Mbps” includes all speeds, from dialup modem speeds and less, upwards, but excluding anything above 25 Mbps. “Upto 1,000,000,000 Mbps” also includes all speeds from dialup and less, upwards, excluding anything above quoted limit. The expression “Upto” defines the maximum, not the minimum, and not even the median.
It doesn’t help that ‘upto’ has been adopted as the defensive clause in BBC and other news reports, when unsure of their facts. They’ll say for example “ upto 300 people are affected” (by whatever) when the mean “about 300 people are affected”. Don’t ask me why, but BBC & etc never say “about” these days, it is always “upto”.
Even so, most people in UK should be capable of a command of our language. “Upto” is an upper limit, nothing more, and carries no implication as a minimum. Why do native UK, English speaking people find that hard to understand? Sorry, but I just don’t get it.