One other aspect you need to be aware of is the Contention Ratio, which is the number of other users on the same network segment as you. The bandwidth figure you're given (e.g. 2 Mb/s) might be limited for you individually (at the ISP's switch), but that doesn't mean you're guaranteed to get that all the time. You might have 40+ users on a segment, each limited to 2 or 3Mb/s, but the total traffic on the segment only 20 Mb/s, not 80-120 Mb/s as you might calculate. If they're all on YouTube... as always, hell is other people.