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NOTICE: CM3000 cable modem v6.01.04 Firmware Released
Getting some reports that this version of FW is being seen on CM3000 series modems from CC/XF ISP. Not sure if other ISPs will be seeing this. Maybe at some point.
This seems to follow up on la...
Ok, Looking at your power levels, seem a bit all over the place on the upper side across channels. A couple channels are on or near the max for the upper limit:
https://kb.netgear.com/24311/Power-level-guidelines-for-a-NETGEAR-cable-modem-router
You might check into a -3dbm or -6dbm coax line attenuator to install.
Any Criticals, Errors or Warnings seen in the event logs needs to be reviewed and resolved by the ISP. Indicates a signal issue on the ISP line up to the modem.
Have the ISP check the signal and line quality UP to the modem. Be sure the ISP provisions the modem correctly.
Be sure there are no coax cable line splitters in the between the modem and ISP service box.
Be sure your using good quality RG6 coax cable up to the modem.
Start with removing any amplifiers, signal attenuators, or splitters from the coax.
From there check the line for kinks, damage, moisture in the line.
Check the connectors for improperly made ends, foil touching the copper coax line, loose connections, bad/old/cheap connectors, or corroded connections. Replace them if you do.
Be sure to power OFF the modem for 1 minute then back ON.
https://www.duckware.com/tech/solving-intermittent-cable-modem-issues.html
https://highspeed.tips/docsis-events/
I'll see if I can get some review from NG on this as well.
Thanks- I appreciate the information. This is a new construction house with all new coax including the run from the demarcation box outside the house to the Cox pedestal 30 feet away in the front yard. Terminations look good but I cannot inspect the run the guys came by and trenched in the yard a week ago (but there was no change in reliability from that work). I made sure there is only 1 coax connected at the demarc and it runs straight to the modem with no splitters, no amplifiers or even connectors. And that run from the demarc to the modem is about 20 feet in the crawl space (looks fine).
I agree on power levels and I typically try to get +2 dBmV across the channels and hope for 44-ish dB SNR. This configuration is way off but still in the window for the CM3000. I had Cox re-provision the modem this morning and so far it's holding the Internet but has lost the upstream OFDM lock as the modem status shows.
With Cox when you bring your own modem they simply look the other way and say you're on your own for tech support. Therefore they will not assist in analyzing the CM3000 error log even though it points to them for problems. They only care about getting a signal on the cable at the modem-- beyond that, they don't care and won't lift a finger to help. I do have some testers (Klein) to ring out the coax runs but I do not have a high frequency signal source or a scope to get a look at the frequency response.
I've read about far too many issues with the CM3000 on Cox and that is why I plan to decommission it when the Arris arrives.
The power levels should all be withing 3 dbmv of each other. Yours range from 0.9 to 7.2. So out of spec. And thats just the connected channels. The others could be further out of spec. When the modem itself tells you the connection is poor, its poor. Usually we're troubleshooting logs but your line needs work. A new modem might help for a little bit because it connects to other channels but that isn't even 100%.
