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High uncorrectables on three channels; High incidence of packet loss as a result

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New Poster

High uncorrectables on three channels; High incidence of packet loss as a result

For the past few weeks, I have been dealing with interrmittent periods of heavy packet loss. Given that it came and went, I wondered if it might be a wifi interference issue or a router issue; however after checking a number of other potential causes I noticed that three channels are showing significant amounts of corrected and uncorrectables on downstream in the modem's log.. This issue seems to persist on the same channels even after modem resets. The strangest factor is that the interference is completely random-we can have days of perfectly functional internet, then suddenly packet loss so severe it makes online gaming and video streaming impossible.

Yes, I have checked the coax connection to the modem (a single cable routed directly into our apartment through the floor near a wall) so I'm assuming the problem here is somewhere outside? This wouldn't be due to a failing modem, correct?

These are the readings only about 10-20 minutes after a reset:

 

EDIT: Picture isn't showing up, so here's a more recent reading:

Channel Lock Status Modulation Channel ID Frequency Power SNR Corrected Uncorrectables
1 Locked QAM256 25 627000000 Hz -9.5 dBmV 38.4 dB 0 0
2 Locked QAM256 17 579000000 Hz -9.5 dBmV 0.0 dB 0 0
3 Locked QAM256 18 585000000 Hz -9.9 dBmV 0.0 dB 29649 129286
4 Locked QAM256 19 591000000 Hz -10.1 dBmV 0.0 dB 0 0
5 Locked QAM256 20 597000000 Hz -10.4 dBmV 0.0 dB 4203868 1033089
6 Locked QAM256 21 603000000 Hz -10.4 dBmV 0.0 dB 0 0
7 Locked QAM256 22 609000000 Hz -10.1 dBmV 31.0 dB 13960393 1346828
8 Locked QAM256 23 615000000 Hz -9.9 dBmV 38.2 dB 0 0
9 Locked QAM256 24 621000000 Hz -9.4 dBmV 38.5 dB 0 0
10 Locked QAM256 26 633000000 Hz -9.6 dBmV 38.4 dB 0 0
11 Locked QAM256 27 639000000 Hz -9.9 dBmV 38.1 dB 0 0
12 Locked QAM256 28 645000000 Hz -10.3 dBmV 37.9 dB 0 0
13 Locked QAM256 30 651000000 Hz -10.5 dBmV 37.6 dB 0 0
14 Locked QAM256 31 657000000 Hz -10.6 dBmV 37.5 dB 0 0
15 Locked QAM256 32 663000000 Hz -10.6 dBmV 37.4 dB 0 0
16 Locked QAM256 33 669000000 Hz -10.5 dBmV 37.4 dB 0 0
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Diamond Problem Solver

Re: High uncorrectables on three channels; High incidence of packet loss as a result

The correctable/uncorrectanles ate the least of the worries. It’s the fact that all your downstream channels are out of spec, the SNR is below spec or 0 on some channels, that should be the concern. You should also post upstream channels. Being in an apartment, you’re going to need a tech out to troubleshoot.

I am a Retired Official Comcast Employee
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New Poster

Re: High uncorrectables on three channels; High incidence of packet loss as a result

Here is  upstream and downstream:

 

Downstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power SNR Corrected Uncorrectables
1 Locked QAM256 25 627000000 Hz -9.4 dBmV 38.4 dB 0 0
2 Locked QAM256 17 579000000 Hz -9.5 dBmV 0.0 dB 0 0
3 Locked QAM256 18 585000000 Hz -9.9 dBmV 0.0 dB 29649 129286
4 Locked QAM256 19 591000000 Hz -10.1 dBmV 0.0 dB 0 0
5 Locked QAM256 20 597000000 Hz -10.4 dBmV 0.0 dB 4219634 1078691
6 Locked QAM256 21 603000000 Hz -10.5 dBmV 0.0 dB 0 0
7 Locked QAM256 22 609000000 Hz -10.0 dBmV 29.7 dB 20464358 1907002
8 Locked QAM256 23 615000000 Hz -9.8 dBmV 38.2 dB 0 0
9 Locked QAM256 24 621000000 Hz -9.3 dBmV 38.5 dB 0 0
10 Locked QAM256 26 633000000 Hz -9.5 dBmV 38.4 dB 0 0
11 Locked QAM256 27 639000000 Hz -9.9 dBmV 38.1 dB 0 0
12 Locked QAM256 28 645000000 Hz -10.2 dBmV 37.9 dB 0 0
13 Locked QAM256 30 651000000 Hz -10.5 dBmV 37.5 dB 0 0
14 Locked QAM256 31 657000000 Hz -10.6 dBmV 37.5 dB 0 0
15 Locked QAM256 32 663000000 Hz -10.6 dBmV 37.3 dB 0 0
16 Locked QAM256 33 669000000 Hz -10.5 dBmV 37.4 dB 0 0

 

 
Upstream Bonded Channels
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 18 5120 Ksym/sec 29400000 Hz 43.3 dBmV
2 Locked ATDMA 17 5120 Ksym/sec 35800000 Hz 42.5 dBmV
3 Locked ATDMA 19 5120 Ksym/sec 23000000 Hz 44.5 dBmV
4 Locked ATDMA 20 5120 Ksym/sec 16600000 Hz 51.0 dBmV