said by Paultergeist:
If packets are getting lost, is that a pretty good indication of a problem within the ISP side of the fence, as opposed to my equipment and/or wiring?
Not necessarily. Cabling problems in the home are actually the most common cause of problems
damaged/kinked cables, loose or improperly installed fittings, and unterminated connections cause impedance mismatches that allow for ingress and microreflections - more colloquially known as "noise"
Noise in the cable plant whether in the home or outside will cause the modem and CMTS to have to resend packets that cannot be mathematically corrected and this can manifest as IP packet loss.
The techs should be able to troubleshoot this both with centrally located analysis tools (for Cox these are Edgehealth and Proviso) and the DSAM's that the techs should be carrying that identify uncorrectable errors, T3 and T4 counts and other data that can help identify and isolate the sources of noise.