I almost for got to tell you a secret most internet service providers don't tell you untill you have major problems with you cable modem.

All cable modems lose sync sometimes, if it gets to slow for all internet access all of a sudden for no reason, you need to "cycle its power" bascialy you need to shut it off for 15-20 secounds and then turn it back on and wait about 2-3 minutesyou should be back at a faster speed.