My internet hasn't been working for the past week and a half. The other times when it is working, I get horrible speeds. Right now it is working fine. I have called my ISP multiple times and they said it was due to an outage, but now they are saying my modem is dying on me. How can I tell if the problem is my modem or it is their problem? I have a SB5120. Signal to Noise Ratio 28 dB Downstream Power Level -8 dBmV Upstream Power Level 54 dBmV My ISP states the SNR should be >33, downstream power level should be between -12 and 12, and upstream power level should be between 35-50.