Ok, you have 22 megabit per second internet access. Straight up math with no overhead works out to 22,000,000 / 8 bits to 1 byte = 2,750,000 bytes per second. So, roughly 2.7 megabytes per second.
Therefore, if you are getting 2.8 megabytes per second..you are pretty much maxing out your connection and getting exactly what you are paying for.
I've got service advertised at speeds up to 15Mb/s and I probably get around 12Mb/s which seems to max out around 1.1-1.3 megabytes per second.