I have been having problems with my internet going slow periodically and sometimes just cutting out completely. I narrowed it down to the Noise Margin of my downstream power levels being too high. Doing some quick research, the acceptable levels for the Noise Margin are between -7 & 7 dB, whereas my levels are consistently 8 and above.
Knowing this information, the next time I started experiencing slow broadband, I quickly checked the Noise Margin, and noticed that the third channel was 0, unlike the other two which where still in the +8 range.
With this post, I was hoping to find some solution in order to lower the Noise Margin back into acceptable levels so that the internet can become more consistent and reliable, as currently that is not the case.
Target SNR is generally set at 6dB, anything higher indicates that DLM is compensating for noise, or interference on the line. Are you noticing any issues with the voice service? Have you tried connecting at the test socket? Subject to that, get in touch with the support team by calling 0330 041 2518.