I've been having problems for the past few months with my internet disconnecting seemingly randomly for a few minutes at a time. Sometimes it happens several times a day, sometimes it doesn't happen at all for days at a time (at least not noticeably). Rebooting the modem seems to resolve the issue, but I think it's just due to the issue normally lasting only a few minutes, so by the time I'm done rebooting it, the issue has resolved itself. If I do not reboot the modem, the issue will go away after a few minutes.
I have a NETGEAR CM500-100NAS modem and a NETGEAR N900 router. I have been in contact with support, but from what I can tell, they simply reboot my modem remotely and declare the problem fixed because it's intermittent and random, so of course I can't replicate it.
I have some screenshots of my modem connection statistics, with the first two being instances where the internet is not functioning and the second two being instances where the internet is functioning.
It seems that some of your upstream levels are intermittently spiking out of spec and/or losing a channel showing a possible impairment in the return path. Do you have any splitters? If so, bypass them temporarily. Also, call Comcast to obtain the Upstream Receive Power, Upstream SNR, and the In Channel Frequency Response.
I do not have any splitters, but I do live in an apartment, so anything outside of my unit is outside of my control. My setup is simply coax from the wall into the modem.
For that to be happening then, I think you might need a technician visit to rectify the upstream problem. Something that could be wrong is a possible bad splitter in the apartment somewhere causing intermittent spikes, or some internal problem, but it also possible it could be a problem beyond you somewhere. However, keep in mind, if the problem is found to be your wiring, you will be charged for the visit. If the problem is not found to be your wiring, you will not be charged for the visit.
Can you post your error/event log pls? Also if you have a wall outlet for coax connection, pull it off the wall and look at the connection on the inside. It's a common failure point. Make sure that connector is compliant and in good shape.
See the troubleshooting guide for more info about connectors.
However, keep in mind, if the problem is found to be your wiring, you will be charged for the visit. If the problem is not found to be your wiring, you will not be charged for the visit.
The customer would only be charged if there was a configuration issue inside the apartment or if the issue is CPE. Since it's an apartment building (an MDU or Multiple Dwelling Unit in Comcast-speak) the tenant does not own the wiring and is not billed for repairs.
I called last night and they (apparently) sent a tech out today to check the status of things for my building. I haven't been online all day, but the event log is empty after 11 PM yesterday. I'll attach the log from last night when I was having issues.
Does anyone have any more input on this? I am still getting t3, t4, and "Dynamic Range Window violation" errors that are causing me to lose connection for several minutes at a time.
Supposedly a tech came out the other day to check the lines for my apartment building, but I didn't hear anything about it and the problem is still present. Is it something that could be my modem or is it almost assuredly something to do with the lines/signal?
Interesting thing just happened. Net dropped like usual for 5 mins or so, and during that time I couldn't get into my modem settings. Typical internet page saying page can't load etc. (tried multiple browsers and devices), but this continued even after the internet came back for 5-10 minutes. No idea why I wouldn't be able to get into my modem settings if the internet is working.
Because of this, I couldn't get the levels while the net was actually down.
Hi, aspergej - Let me check your signal levels from my side. Could you please send me a private message with your full name and the account holder's name as it's listed on the billing statement? Click on my name ComcastElla, then click Send a message.