[Steve Viegas]

There are many issues that could affect speed. I would guess the cable modem that you purchased is good upto 23MBPS, but that is not guaranteed. They cannot guarantee it because there are many things that happen between when the information you request is sent to you, and when you receive it. The information that you request is broken up into small packets. Those packets are then sent to your computer. Each packet may take a different route to get there, but due to address tables built into routers, they are supposed to all get there eventually (eventually can be a very short period of time). Due to the nature of how this happens, sometimes, information may travel on quicker 'pipes' and sometimes slower. While your cable modem is capable of receiving information at a given speed, not everyone can deliver at that given speed.