Intermittent Modem Connection - no power on 21 of 32 channels

Trying to post again without the screenshots on last nights post as post said "private" in purple letters - no idea why.

And update - as of this morning, seeing T4 and T3 errors being logged just about every minute. When it is up I am seeing under 50 Mbps download - getting 176 Mbps upload.

Working great - checked modem admin screen (Netgear CM3000) power on all channels 3.1 - 4.1 ish SNR 43 ish. Starting around 5:30 PM EST I started seeing the Internet drop off and on. Checked modem and saw 10 - 100's of thousands or uncorrectable erros on channels 12 and higher. Rebooted modem a few times - same thing every time. Called Support. CSR sent a signal down the line which she said should fix things and do a reprovision.

After the process was complete (20 minutes) I now no longer had any power or SNR on channels 12 and higher. For the first 11 channels, channels 2,3, and 4 bounce between being locked with power of 3.0 and SNR of 43 ish then 5 - 10 minutes later show unlocked with no power or SNR. Repeats reguarly. To be clear when the issue started and throughout several reboots I had power on all 32 channels. 

CSR telling me that Xfinity cannot configure the modem - um, yes, they can as they are the only ones that can provision it and upgrade firmware.

Bypassed all internal wiring with new coax from block on house to modem - no change. 

CSR won't check neighbors lines to see if a wider area issue. Internet is working, so most people would not know there is an issue - I only knew as I was here at the time of the drops and my modem's downstream light blinks when there is an issue.

While I expect that they will find an issue likely at the node as no storms or winds today that would be impacting the lines, I wonder if it not showing channels above 11 having power/SNR could be due to a provissioning issue.

Tech won't be out until Thursday afternoon.

In almost 20 years this is the first real issue I have had with Xfinity Internet other than when a storm/accident takes down a line. Not happy with the support I am receiving and the lack of Xfinity to the power on each channel.  800 Mbps plan - actually see 930 Mbps on speed test very consitantly.

Thoughts?

@XfinityShawn 

Update  - rebooted modem Sat AM at 9 AM. I monitored until noon on Sunday noontime - zero errors on any channel. 

Was then away for 24 hours. When back at noon on Monday I had 647 million correctable errors and 176 million uncorrectable errors on each of the top 20 frequency channels. Rebooted the modem and had zero errors until 4 PM Monday afternoon,  when errors came back and started growing. 

Called support - after refreshing modem with no impact, they moved my tech appointment to the next morning, and scheduled me for a call back from the advanced support team at 6:45 PM. Sadly they never called. When I called back at 8 PM I was told by the agent that they could see I had a call scheduled but were unable to schedule another.

Throughput dropped from the normal over 900 Mbps down to .85 Mbps with many complete dropouts of service. SNR on the upper 20 channels dropped to 38-39 from the normal 43 - 44 range.  Around 11 PM SNR was back to normal range and throughput  came back to 150 Mbps, but at 2 AM it was back down to 50 Mbps.  

By 9 AM Tue no further errors were being logged and throughput was back to the normal 900+ Mbps. Tech arrived at 10AM by which time every thing looked fine - no new errors - no power or SNR issues. We reviewed the issue and trouble shooting I had done which included installing a new grounding block and a new cable directly to the modem - connecting the modem directly to the line from the pole - etc. 

Tech replaced connectors at both ends of the brand new cable, installed a new grounding block, ran a new cable from the pole to the house, and installed a new attenuator (power without it is too high). He tested the line when done and it looked perfect - no errors - capable of 2 GB throughput.

Rebooted modem to clear things and had zero errors all day - until 7 PM Tue night when they started up again - and as usual only on the top 20 frequency channels. The errors continued to slowly climb all night, but at a much slower rate than before. Wed morning at 8:30 AM the errors stopped and I had zero new errors all day Wed until bedtime.

Woke this morning (Thursday) and see that the errors came back overnight and are currently climbing at a much higher rate than Tue night - still only on the top 20 frequency channel and nothing in the event log. 16,000 new errors on each of the 20 channels since last night.  The errors stopped at 8:15 AM.

Since the issue is almost always overnight and clears by 9 AM each morning the Tech was going to ask his boss to call me this morning with a game plan on how to monitor/resolve the issue which has been ongoing for over a week now.  That call has not come - very disappointed in that. I asked Tech if I should call support again if I saw the issue come back and his response was that I should wait for call from manager since he has done everything he can do and the plant maintenance team would be need for further trouble shooting past the connection to the tap.

I've also started including the current temp in my monitoring as it appears that it could be temp related (below 22 degrees seems to be the cutoff) Watching it closely this morning, the error rate slowed as the temp warmed up and stopped when the outside temp was above 22 degrees!

With new everything to the tap on the pole, this must be an issue in the "plant". This morning when the temp hit 22+ degrees the errors stopped.

Something must be wrong when the errors  are only occurring on some channels and only starting in the evening and/or with low temp and clearing in the morning when temps have warmed up. At some point the error rate becomes too much for the modem to handle and throughput decreases/ dropouts occur. Or like the other day in 24 hours there are millions of uncorrectable errors on the 20 of the 32 channels.

Question for you - how can I escalate to the field manager or to the "plant crew" 

If I call the support number while the issue is ongoing, they can see an issue on the line, but they cannot do anything beyond refreshing the modem and then dispatching a tech. But since it clears on it's own by 9 AM each morning they will never be there when the issue is occurring. 

Help Please!

@XfinityShawn Called support in hopes of getting maint team out, but nop - dispatched a tech who will be out Sat AM - put notes in ticket to tech to open a ticket to maint team. Will continue to watch cable connection  log, but with the current forecasted low temp of 26 degrees between now and the Tech visit I may not see any new error counts. We will see. 

Still extremely disappointed that fidel manager has not called me as his tech requested on Tuesday. 

@XfinityJon @XfinityMarshante @XfinityShawn 

UPDATE - I now have documentation showing that any night where the temp dropped below 22 degrees I started seeing correctable errors and some uncorrectable errors shich continued until the temp rose above 22 degrees. When the temp is above 22 degrees I have zero errors. The error are uniform across 21 of the 32 channels.

This morning I recorded the amount of errors every 10 minutes from 5:40 AM until 9 AM. As the temp dropped (or stayed below 22 degrees) the rate of the errors increased. When the temp started rising again, the rate of errors declined until they completely stoped when the temp went above 22 degrees. During this time the signal looked fine - power was  between 2.0 - 2.9  with SNR between 43.7 - 44.4 on all 32 channels. 

What appears to be happening is that errors start as uncorrectable until the rate is such that the modem (Netgear CM3000) can no longer keep up and starts logging uncorrectables. And if that goes on long enough I see service interruptions. A week ago in a 24 hour period I had 647 million correctable errors and 176 million uncorrectable errors in a 24 hour period when the temp went down to near zero degrees and was below 22 degrees for much of that time frame.

Not sure what the tech can do during the appointment tomorrow as the line will look perfect by the time he arrives. But will show them the logs and info in hopes that will get the plant maint team/SRO team engaged to dig further. Seems to be an issue back at the CMTS versus the tap or node since the signal typically looks great even when there are errors until it gets real bad?

@XfinityEva @XfinityJon @XfinityMarshante @XfinityShawn or anybody else at Xfinity that can assist.


Tech was suppose to arrive between 8 and 10 AM but didn't arrive until almost 1:30 PM. Last night the temp dropped to a low of 5 dgrees so it was a very bad  night. Complete outage at one point - SNR dropped from typical 44 to the low 30's and shortly after lost all signal on channels 12 - 32. Rebooted modem at 3:42 AM and by 9 AM had 66+ million correctable errors, 16+ million uncorrectable errors, and 8 million uncorrectable codewords. Then by `0:15 AM the temp had risen and everything was back to normal.

Tech checked the line and of course everything looked perfect at that point. After looking at the info I showed him showing the trend and speedtest results where service dropped to under 10 Mbps (normal us 900+ Mbps) he agreed at was a temp related issue and that the "Plant" maint team needed to bne involved. But since the line looks good during the daylight hours when they would be looking at it, he was sending the info to his Field Supervisor  asking hime to escalate it, as they are experiencing a lot of issues with the "mid split" hardware and might not give my issue the attention  needed if they just looked at the line and saw it looking good.  They need to come to my house at midnight on a night where the temp is below 20 degrees.

The Tech also gave me his field supervisor's email address so I could send him a lot more info than he could type into a phone. 

So - if I do not hear back from him, how do I escalate this and/or get a status that somebody is actually working on resolving the issue. Tonight the temp is already down to 16 degrees and falling, and the errors have started and are climing. 

This has been impacting me since Dec 8th - it technically may gave been an issue since before then, just one that didn't cause a slow down or outage for me.

And - while calling in to see the status of when the tech would arrive, they tried to sell me on a 1 GB 5 year preice guarantee for $5 a month more than I am paying now for 800 Mbps service which is already complete overkill for my needs - only have it as Xfinity kep increasing the bandwidth for the same price. Already paying more for for 800 Mbps than what I can get Fidium Fiber (1 GB). Just want somebody to own the issue, keep me informed on the status and eta, and resolve it. 24 years with Xfinity/Comcast and don't want to switch, but the current situation is unacceptable. 

Please reply back with next steps to escalate this please.