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Solved
CM1000 intermittent connection loss on XFinity cable
Hi All, I'm troubleshooting what seems to be intermittent drops throughout the day on XFinity cable... and the culprit is either the CM1000 going bad, or some kind of line quality/hardware issues...
So here's an update to my situation... it seems that Googalabosh was experiencing similar issues, so I'll write down my findings/experience here...
1.) XFinity tech came out and ran tests from the entry point to my CM1000 cable modem - no problems (and no, there are no splitters... it's a straigh run)
2.) XFinity tech ran a test from the entry point to the junction box at the street - no problem.
3.) XFinity tech ran a test from the junction box at the street, to the nearest node - again, no problems...
He said everything according to his readings were within parameters and nothing looked abnormal. This was frustrating both to me and him, since we couldn't pinpoint anything weird. I asked him if he could put a network monitor on our account, which he was happy to do -- and I would *recommend* you asking for this same thing. This will give them detailed reports of when things misbehave, which is what I suspect happened in my case.
After the tech left, my device continued to drop for the next few days off and on throughout the day... then, things stabilized. My connection has not dropped for almost 4 days straight now., which is unheard of. :) The tech said he or someone else would call back and give an update, but I have not heard anything yet. I will definitely find out what the problem was, but I suspect it had to do with some changes at the upstream node.
I started keeping careful track of what my modem stats were looking like throughout the day, and found that if the downstream channels power dropped below -4.5 or -5 dBmV, which also seems to drop the SNR/MER to below 36dB, then I would start accumulating more and more uncorrectable codewords, including drops. Since they did something on their end, my power has remained around -2 or -3dBmV and the SNR/MER remains at 40dB on average...
I would focus on ensuring that these values are in the middle of the range (Power should ideally be at 0dBmV and SNR/MER should ideally be at 40dB), but it fluctuates up or down... which typically is still OK, but I guess certain modems/connections are more finicky than others. Hope this helps!
Have you factory reset the modem?
Be sure your using good quality RG6 coax cable up to the modem.
I would contact NG support and ask for additional help and information. Ask about a RMA if thats an option.
https://www.netgear.com/support/#
I thought about factory resetting... but wasn't sure if that was going to cause me to have to work with XFinity support to get it hooked back up again, if it wasn't automatically going to be able to reconnect after the factory reset? Any ideas?
Cable quality is good up to the modem... I really feel it's either cable from the street to the house, or a connector somewhere. These things don't seem to last our in the hot, humid, wet florida weather eventhough they're in a box.
FURRYe38 wrote:Have you factory reset the modem?
Be sure your using good quality RG6 coax cable up to the modem.
I would contact NG support and ask for additional help and information. Ask about a RMA if thats an option.
https://www.netgear.com/support/#
Resets are ok. They only reset the modem and don't deactivate the ISP side. The ISP just has the mac address associated with there services. You can factory reset or reboot the modem all day long. ISP doesn't care.
Have a friend or family member you can take the modem to and connect it at a different location to see if the problem follows?So here's an update to my situation... it seems that Googalabosh was experiencing similar issues, so I'll write down my findings/experience here...
1.) XFinity tech came out and ran tests from the entry point to my CM1000 cable modem - no problems (and no, there are no splitters... it's a straigh run)
2.) XFinity tech ran a test from the entry point to the junction box at the street - no problem.
3.) XFinity tech ran a test from the junction box at the street, to the nearest node - again, no problems...
He said everything according to his readings were within parameters and nothing looked abnormal. This was frustrating both to me and him, since we couldn't pinpoint anything weird. I asked him if he could put a network monitor on our account, which he was happy to do -- and I would *recommend* you asking for this same thing. This will give them detailed reports of when things misbehave, which is what I suspect happened in my case.
After the tech left, my device continued to drop for the next few days off and on throughout the day... then, things stabilized. My connection has not dropped for almost 4 days straight now., which is unheard of. :) The tech said he or someone else would call back and give an update, but I have not heard anything yet. I will definitely find out what the problem was, but I suspect it had to do with some changes at the upstream node.
I started keeping careful track of what my modem stats were looking like throughout the day, and found that if the downstream channels power dropped below -4.5 or -5 dBmV, which also seems to drop the SNR/MER to below 36dB, then I would start accumulating more and more uncorrectable codewords, including drops. Since they did something on their end, my power has remained around -2 or -3dBmV and the SNR/MER remains at 40dB on average...
I would focus on ensuring that these values are in the middle of the range (Power should ideally be at 0dBmV and SNR/MER should ideally be at 40dB), but it fluctuates up or down... which typically is still OK, but I guess certain modems/connections are more finicky than others. Hope this helps!
Looks like this was a ISP signal issue. Glad it's working now. Thankts for the details.
Please mark your thread as solved so others will know.
Enjoy.