Orbi WiFi 7 RBE973

CM1000 - Another Speed Drop Woe (From Gigabit/900Mbps to 400Mbps to 20Mbps)


CM1000 - Another Speed Drop Woe (From Gigabit/900Mbps to 400Mbps to 20Mbps)

Hi all. Just posting to see if I can get any assistance with my Netgear CM1000 cable modem. It was purchased in June of 2019, so nearing a two year life in two months. Over the past few months, I would estimate it as the past three months, I noticed I no longer receive my full ISP's speed of "up to 900Mbps". A technician appeared yesterday and tested the lines up to the modem and confirmed the speed is rating at 1100Mbps via his tool connected to the line, with the line quality being solid and no issues. He then connected his device to the modem via ethernet (his own cord) and determined there was a drop in speed of around 800Mbps at the time. This seems consistent with what I would experience for max speed in a day.


However, 2-3 times daily now I experience a drop to around 250-400Mbps. And once daily for around two hours the speed will suddenly drop to 8-14Mbps and climb, slowly, back up to 400Mbps over two hours (using various speed test sites to determine this over hours). Each time over the past three nights that this has happened (though it has happened longer as noted) I have contacted my ISP's support chat and they claim everything appears fine on their end. They last night, for the first time, even though the modem is online on my end and showing fully connected their side is showing up as "offline". A reset signal was received, however, and the modem then appeared online on their end but the slow speed still remained.


One would think turning the device off and on (either via the 30 second rule, the switch, the outlet, etc) may fix the issue if it was related to the modem. Doing so does not resolve the issue and the slow speed continued for the night regardless of how many times the modem is reset. Eventually, as mentioned, it returns to it normal speed.


My tests all revolve around being connecting directly to a single computer, and I have swapped devices and cords to verify it is not a PC network card issue or ethernet cord issue. I am currently at a loss and exploring all options to see about resolving this after my ISP has stated there is nothing more they can do on their end as everything appears normal for them.


I have noticed, in the modem's information, that it states the following firmware, which contrasts with Netgear's own info:

(This is for a CM1000, not v2, and not CM1100)

Hardware Version2.02
Firmware Version


However, the knowledge base page for modem firmwares states the latest firmware for my ISP (Cox) to be V3.01.04. Could this pose an issue? https://kb.netgear.com/000036375/What-s-the-latest-firmware-version-of-my-NETGEAR-cable-modem-or-mod...


To my understanding, my Event Logs are pretty clean, and I believe (I may be wrong) that my cable connection information shows a pretty stable setup. (Added as attachments.)

Model: CM1000|Ultra-High Speed Cable Modem—DOCSIS® 3.1 Ready
Message 1 of 1
Top Contributors
Discussion stats
  • 0 replies
  • 0 kudos
  • 1 in conversation

Orbi 770 Series