Intermittent Internet Issues with Arris S33 Modem

FWIW. The downstream power is what is "received" by the modem from the Comcast system. The upstream power is *transmitted* by the modem to the system.

That said. The downstream is o/k / in spec but the upstream power is marginal to out of spec, and it may be intermittently fluctuating even farther out of spec. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels.

In an effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1000 MHz, bi-directional, and no gold colored garbage from Radio Shack, Home Depot, Target, etc. Splitters should be swapped with known to be good / new ones to test.

Also check the coax cable for any damage such as cuts, nicks, kinks, sharp bends, etc.

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two-way splitter connected directly off of the drop from the street / pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.

Good luck with it !

Thank you for your response!

I replaced the splitter with one within the parameters you suggested earlier today. You are correct. The Upstream does fluctuate even further out of spec. I just checked again and it appears even worse than when I looked earlier. I could attempt to remove the splitter to see if it helps but we have a cable box in the room with the modem, hence the splitter.

I have also checked the wiring to the best of my ability and it all seems to be in good shape. It looks like a tech visit may be the best solution as you suggested unless you have any other ideas before I take that route.

I will also include error messages below with the updated upstream bonded channels. 

Thanks again!

@user_5ce29d 

Please redact all of the CM MAC and the CMTS MAC addresses in your error log entries for your privacy. They are considered to be personal information. The posting of personally identifiable information is a violation of their forum guidelines. The forum bot will not allow your post to be seen publically. It flagged your post as "Private".

I fixed that. Very sorry.

No worries ! So if there is nothing more that can be done to improve the connection quality, then you'll need a tech visit as stated. 

Bear in mind that if the premises facing techs can not find or fix a problem at your home, it is they who are responsible for escalating it to their line / network / maintenance dept. techs. The problem may lie beyond your home in the local neighborhood infrastructure somewhere but it is their S.O.P. to start at the home. And if the problem is found to be on their side of the demarcation point, there will not be any charge.

Good luck !

Thank you for your help! It is much appreciated.

Quite welcome ! Please post back here with how things turn out, thanks.