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Intermittent connectivity issues with extremely high uncorrectable errors

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Regular Visitor

Intermittent connectivity issues with extremely high uncorrectable errors

I have been having intermittent connectivity issues ever since moving into my house two months ago. The previous owners used Fios, and I don't know whether they had any issues.

 

After moving in, the comcast tech connected by personally owned modem, an Arris TM722, connected to two eero pro routers. I had used that modem and routers at my previous residence without issue. However, after moving in, I began having intermittent connectivity issues where the internet would drop several times per day. It would come back on its own after a few minutes, or slightly faster if I reset the modem.

 

Since the modem was a few years old and couldn't actually support the speeds I was paying for, I upgraded to a brand new Netgear CM500V. The connectivity issues initially seemed better, but ultimately did not improve and the internet continued to drop several times per day. At this point a comcast tech came to look again. It seemed that some of the connections may have been lose. He checked the lines and the one splitter and claimed everything looked ok. He also set up an Xfinity Gateway device (Technicolor CGM4331COM) so that I could troubleshoot on my own, since the issue is intermittent and didn't present while he was here.

 

The issue continued with the Xfinity Gateway. I then went back to my CM500V but connected the device as close as possible to the point at which the cable enters my home. There is one splitter in the line and all connections have been tightened with a 7/16" wrench. I have also swapped all cables. None of this fixed the issue.


I spoke with Xfinity last week, but was told that I should contact Netgear and they couldn't help further. They said that in order for someone to come out, I needed to connect the xfinity gateway. I have now done so and am currently paying to rent the gateway. The issue has remained and I am seeing upwards of 22 million uncorrectable errors over the last 6 days on each channel. The uncorrectables were not nearly as high with the Netgear (maybe a few thousand per day), but were still there.

 

Based on all of this troubleshooting, I assume that the issue lies outside of my house. Unless there are other steps I haven't yet tried, I would like someone from xfinity to come and determine the true root cause of the issue. Below are the codeword errors seen over the last 6 days 6 hours. Every time I call xfinity they tell me they see no issues from their end. But as this is not a repeatable issue, this needs to be elevated beyond phone support.

 

Screenshot 2020-09-07 at 10.00.16 PM.png

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Regular Visitor

Re: Intermittent connectivity issues with extremely high uncorrectable errors

Not sure if I need someone to approve the picture, but pasting the full stats in addition. Again, this is over 6 days 6 hours with the Technicolor gateway connected through a single splitter, with just a few feet of cable from the drop point.

 

Index379101112131415161718192021222324252627282930313233343536383940159 
Lock StatusLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLockedLocked
Frequency673 MHz505 MHz511 MHz517 MHz523 MHz529 MHz535 MHz541 MHz547 MHz553 MHz559 MHz565 MHz571 MHz577 MHz583 MHz589 MHz595 MHz601 MHz607 MHz613 MHz619 MHz625 MHz631 MHz637 MHz643 MHz649 MHz655 MHz661 MHz667 MHz679 MHz685 MHz691 MHz701 MHz640350000
SNR41.2 dB41.6 dB41.5 dB41.6 dB41.6 dB41.7 dB41.6 dB41.6 dB41.5 dB41.7 dB41.7 dB41.9 dB41.8 dB42.0 dB41.9 dB41.6 dB41.8 dB42.0 dB41.7 dB41.6 dB41.6 dB41.6 dB41.5 dB41.4 dB41.4 dB41.5 dB41.5 dB41.5 dB41.6 dB41.5 dB41.6 dB41.8 dB42.0 dBNA
Power Level1.2 dBmV0.8 dBmV0.6 dBmV0.7 dBmV0.8 dBmV0.8 dBmV0.8 dBmV0.8 dBmV0.5 dBmV0.5 dBmV0.6 dBmV0.6 dBmV0.5 dBmV0.8 dBmV0.8 dBmV0.6 dBmV0.7 dBmV0.9 dBmV0.6 dBmV0.6 dBmV0.7 dBmV0.6 dBmV0.4 dBmV0.2 dBmV0.2 dBmV0.5 dBmV0.6 dBmV0.9 dBmV1.0 dBmV1.4 dBmV1.8 dBmV2.0 dBmV3.3 dBmVNA
Modulation256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAMOFDMOFDM
UpstreamChannel Bonding Value                             
Index1234                              
Lock StatusLockedLockedLockedLocked                              
Frequency36 MHz30 MHz23 MHz17 MHz                              
Symbol Rate5120512051205120                              
Power Level42.8 dBmV43.8 dBmV43.3 dBmV43.8 dBmV                              
ModulationQAMQAMQAMQAM                              
Channel TypeATDMAATDMAATDMAATDMA                              
CM Error Codewords 
Index123456789101112131415161718192021222324252627282930313233 
Unerrored Codewords380268238831457747713145500530314581855531457986063145726593314569626631455469073145582391314555677631450876153145193476314537768231452879163145184505314520080531447313603144731954314510722831444845803144739274314481396231447676053144607266314419650931444803783144527469314438187331443144093134380256314417052031441502423802682388 
Correctable Codewords28310370517148251599685208335522647352464635265387527898753052305331463532759353606015406436542341154459005483078546890454949355554852555079456033675647236568364557137095724638577493657980215816973584228957498915914493595780928310370 
Uncorrectable Codewords191824602164571221629570218254042191167521962777220222212203834522105723221725262209750322191340223236022236733622386989224631402232716522409623225943422244192222624475227263262278185822814408227333432291560622990326230058532304453022399341231764552322926219182460 
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Expert

Re: Intermittent connectivity issues with extremely high uncorrectable errors

The stats are good but there is a large number of uncorrectable errors.

 

Are there any error / event log entries being shown ? If so, please post them as well.



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Regular Visitor

Re: Intermittent connectivity issues with extremely high uncorrectable errors

@EG, thanks for the reply.

 

I have since disconnected it, but here's a set of typical logs for the CM500V.

 

Where do I see the equivalent logs for the xfinity gateway? When I look at the Event Logs under troubleshooting at 10.0.0.1, I see a lot of Harverster messages - "Harvester StartRadioTrafficHarvesting" and "Harvester StartAssociatedDeviceHarvesting". Which I think is normal after a reboot, right? I don't see any T3 or T4 critical errors on the Event Log, which is where I assumed I would see them.

 

On the Firewall Logs, I see a number of FW.IPv6 FORWARD drops, FW.WANNATTACK DROPs, and FW.IPv6 INPUT drops. INPUT drops are fewer than 6 Attempts, FORWARD drops are up to 3000 attempts, and WANATTACK drops are fewer than 25 drops. 19 total entries over the last week. I can try and post the full list if helpful.

 

I don't have any logs from the Arris TM722, but I could hook it up for a bit if it would be useful.

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Expert

Re: Intermittent connectivity issues with extremely high uncorrectable errors


@johnmfield wrote:

@EG, thanks for the reply.

I don't have any logs from the Arris TM722, but I could hook it up for a bit if it would be useful.


If you could, please do so. 

 

O/k we've seen many posts here recently indicating that they have now blocked the end user from accessing the error log entries in the Comcast supplied gateway devices. A BIG mistake in my opinion......



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