In the "olden days", signals on your cable provider's cable only went one direct: cable company to customer. However with the advent of smart cable technology, information travels in both directions. (Think buying a pay=per-view event, etc.) With a modern DOCSIS 3 modem, there are multiple channels or streams of data (on different frequencies0 all running together. Ideally, signal strengths on all of those channels should be equal and within a certain range. However, sometimes bad connections, lengths of cable and excessive numbers of splitters can degrade the performance.
When things get too far out of whack, your modem will trouble as it can mo longer make up for the deficiencies mentioned above. I had a problem a while back and my modem would reboot on its own and disconnect my home network from the internet. In my case, the wiring method in my house (and the cable drop to my house) wasn't up to current standards and it was too hard for the modem to send data back to the cable provider.
I was able to determine my problem by logging into my cable modem and monitor both the downstream and upstream signals strength as well as the signal to noise ratios and packet loss on each of the aforementiioned DOCSIS channels. In my case, I could open a web browser on my computer and access the modem's system info web page at 192.168.100.1 This may work for you but you may want to research if and how this is done with your cable provider. In my case my modem was trying to ramp up upstream power but was still falling short and was unable to overcome all of the points of signal loss. I ended up rewiring my house with new cable, installed an "active return" amp/splitter and showed the cable company that their cable drop was bad and needed replacing. (Getting in touch with the proper personnel at my cable provider was no easy task and it took a good deal of persistence.)
I'd recommend seeing if you can locate a sytem page on your modem to see if you can monitor its behavior. I've added a few links that will help you gain a greater understanding of what information you'll be looking to obtain and how to decode it.
I hope this helps.
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