Re: CM500 - Ridiculously Slow Upload Speeds

neals725 · ‎2020-08-15

Hello,

A few months ago, I installed the CM500 modem to go with the R7000 Nighthawk router I've had for a few months longer. We've had a lot of internet troubles, so we assumed it was our Xfinity internet plan (which wasn't the best anyway) was the issue. So we upgraded to a plan that gives us 300 Mbps download speed and 20 Mbps upload speed. We still experienced some issues, until I finally decided to check the upload speed, and it's nearly 0 Mbps. I've done quite a few speedtests, reset my modem and router multiple times, and made sure the firmware in both devices was up to date. I called Xfinity to see if they knew or could fix the issue, and they said to contact Netgear.

Speed Test Results:

Wireless: 264.7 Mbps down, 0.05 Mbps up
Wired to Router: 294.2 Mbps down, 0.12 Mbps up
Wired to Modem: 279.0 Mbps down, 0.08 Mbps up

Does anyone here know how I could fix this issue?

FURRYe38 · ‎2020-08-17

Have the ISP check the signal and line quality UP to the modem.
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.

Reset the modem and connect a wired PC to the back of the modem and test with ooklas installable speed test app.

Try a different PC to compare.

Markinct · ‎2020-09-23

Did you get this resolved? If so, what was the fix?

FURRYe38 · ‎2020-09-23

Have the ISP check the signal and line quality UP to the modem.
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.

Reset the modem and connect a wired PC to the back of the modem and test with ooklas installable speed test app.

Try a different PC to compare.

@Markinct wrote:
Did you get this resolved? If so, what was the fix?

neals725 · ‎2020-09-23

I have not yet resolved the issue, but we believe it is due to a wiring issue in the cable box.