In many cases, I can measure my bandwidth at between 55 and 125 Mbps. Then I see that OC-1 and OC-3 speeds are 55 and 155 Mbps, respectively. Am I to believe that I have an OC-1 or OC-3 level connection to the Internet wherever I experience these speeds? What in the wide world of sports is going on?
OC-3 (and all the others) refers to the specifications for transmission of data over SONET. It was designed for long-haul, point-to-point connections. It's a completely different technology (circuit-switched) than Ethernet, Wi-Fi, or anything else you might actually use. The fact that you have similar bandwidth only shows how obsolete that technology is.