said by ViRGEdx:That is very good information, thank you. I wonder if this approx 10% error is close to the 7.37% one generated by the reference JL had above about the 1000/1024 based counters.
I'm in one of the areas where the service recently went live. For anyone curious, here's how their meter compares to DD-WRT.
At the head of my network is a WRT54G v.6 running DD-WRT Micro, build 12307. The modem is a SB4200. For the month of December (the first month that Comcast's service had unquestionably complete stats), DD-WRT recorded 218GB of WAN traffic. Comcast meanwhile recorded 239GB.
Without knowing what traffic DD-WRT doesn't record and what traffic never makes it past the modem I can't identify the cause of the difference, but right now it looks like there's a 10% skew between what DD-WRT and Comcast sees. I don't really have a way of determining to what degree Comcast is over, and DD-WRT is under.