Modem Debugging
Here’s some great advice on how to make sure your broadband internet connection is working properly:
For example, if you buy your own modem, NEVER say “I need my new modem INSTALLED.” Say “I need my new modem PROVISIONED”. 95% of the support people will know right away what you need and won’t bother asking you about Windows and you’ll be online 15 minutes later.
Know how to get to the status page of your modem (usually http://192.168.100.1/ [192.168.100.1] but may vary depending on model). Know that your downstream signal needs to be between -10 and +10 dBmV. Know that your downstream SNR should be above 33. Know that your upstream power should be between +30 and +50 dBmV. When my signal dropped because of a splice in the line gone bad, I didn’t tell Comcast “my internet don’t work”, I told them, “my downstream power is -16, which is out-of-spec, I need a tech to take a look at this”. I had a tech out the very next morning and was back online by the afternoon.
The above is from a Slashdot comment I ran across a while back. Filed for future reference.