First, from the router's diagnostics home screen, what IP are you getting? This will be 2nd option down on right. For privacy reasons, all I need is the first two octets to know if private or public. For instance mine is 68.226.x.x.
Second, could you take a picture of the modem? I don't mind translating some chinese. I can google EVERYTHING!

"Down: 28 MB/s, Up: 3MB/s. Wireless on router: Down: 11MB/s, Up: 7MB/s."
Do you mean Megabits(Mb) or MegaBytes(MB)? 87Mb would be about right assuming you're 2011 has the 2x2 MIMO (BCM4322) instead of the newer 3x3 MIMO, and assuming you have moderate to moderate-low signal. Also, why does the above statement conflict with " I get through d-link 890 is 100Mbps on 5Ghz. "