OFDMA and resets in vCMTS/CMTS.

[thewho2018]

I have been at it for days with Perplexity Pro and have gotten quite far to actually understand why my internet goes out a bunch of times per day. According to AI this is related to my missing OFDMA. "US Power" is far to high. It's around 90dBmV and should be under 50 dBmV for DOCSIS 3.1. I have included that my ISP use "Harmonic Oyster Low-Power DAA Node" and according to AI then the vCMTS/CMTS will reset connection and this explains why i get dropouts. Smokeping also confirm's this.

Have anyone else had similar experiences?

DOCSight – DOCSIS Cable Connection Status Report

Context

This is a status report from a DOCSIS cable modem generated by DOCSight.
DOCSIS (Data Over Cable Service Interface Specification) is the standard for internet over coaxial cable.
Analyze this data and provide insights about connection health, problematic channels, and recommendations.

• Export Mode: Full Context (48h)

Overview

• ISP: Tele2 Sweden
• Health: critical
• Issues: Upstream power critically high, Upstream power slightly low
• Timestamp: 2026-03-24 13:02:07

Summary

Metric	Value
Downstream Channels	26
DS Power (Min/Avg/Max)	5.2 / 6.6 / 8.0 dBmV
DS SNR (Min/Avg)	44.0 / 44.7 dB
DS Correctable Errors	4,877,429,298
DS Uncorrectable Errors	35,220
Upstream Channels	5
US Power (Min/Avg/Max)	40.8 / 59.2 / 87.0 dBmV

Downstream Channels

Ch	Frequency	Power (dBmV)	SNR (dB)	Modulation	Corr. Errors	Uncorr. Errors	DOCSIS	Health
1	450 MHz	5.2	44.0	256QAM	1,416	1,659	3.0	good
2	458 MHz	5.4	44.0	256QAM	3,069	1,936	3.0	good
3	466 MHz	5.6	44.0	256QAM	3,123	1,900	3.0	good
4	474 MHz	5.5	44.0	256QAM	2,959	1,855	3.0	good
5	482 MHz	5.5	44.0	256QAM	3,001	1,645	3.0	good
6	490 MHz	5.8	45.0	256QAM	3,065	1,740	3.0	good
7	498 MHz	5.8	44.0	256QAM	3,007	1,580	3.0	good
8	506 MHz	6.2	45.0	256QAM	2,999	1,682	3.0	good
9	514 MHz	6.5	45.0	256QAM	2,358	1,038	3.0	good
10	522 MHz	6.4	45.0	256QAM	2,808	1,567	3.0	good
11	530 MHz	6.3	45.0	256QAM	2,808	1,557	3.0	good
12	538 MHz	6.6	45.0	256QAM	2,811	1,519	3.0	good
13	546 MHz	6.7	44.0	256QAM	3,537	756	3.0	good
14	554 MHz	6.7	45.0	256QAM	2,710	1,521	3.0	good
15	562 MHz	7.0	45.0	256QAM	2,771	1,375	3.0	good
16	570 MHz	7.2	45.0	256QAM	2,628	1,388	3.0	good
17	578 MHz	7.3	45.0	256QAM	2,575	1,441	3.0	good
18	586 MHz	7.3	45.0	256QAM	2,598	1,260	3.0	good
19	594 MHz	7.5	45.0	256QAM	2,617	1,175	3.0	good
20	602 MHz	7.8	45.0	256QAM	2,557	1,232	3.0	good
21	610 MHz	7.6	45.0	256QAM	2,555	1,027	3.0	good
22	618 MHz	7.2	45.0	256QAM	2,407	1,184	3.0	good
23	626 MHz	7.3	45.0	256QAM	2,502	1,289	3.0	good
24	634 MHz	7.5	45.0	256QAM	2,406	1,106	3.0	good
193	666 MHz	6.6	44.0	OFDM	2,745,822,521	353	3.1	good
194	870 MHz	8.0	45.0	OFDM	2,131,541,490	435	3.1	good

Upstream Channels

Ch	Frequency	Power (dBmV)	Modulation	Multiplex	DOCSIS	Health
1	38 MHz	41.0	ATDMA	ATDMA	3.0	tolerated
2	31.6 MHz	41.0	ATDMA	ATDMA	3.0	tolerated
3	25.2 MHz	40.799999	ATDMA	ATDMA	3.0	tolerated
41	104.8 MHz	87.0	OFDMA		3.1	critical
42	14.8 MHz	86.0	OFDMA		3.1	critical

Events (Last 48h)

Timestamp	Severity	Type	Message
2026-03-24T07:03:14Z	info	channel_change	US channel count changed from 4 to 5
2026-03-24T07:03:14Z	warning	power_change	US power avg shifted from 52.4 to 59.2 dBmV
2026-03-24T07:02:09Z	info	channel_change	US channel count changed from 5 to 4
2026-03-24T07:02:09Z	warning	power_change	US power avg shifted from 59.2 to 52.4 dBmV
2026-03-24T03:33:20Z	info	channel_change	US channel count changed from 4 to 5
2026-03-24T03:33:20Z	warning	power_change	US power avg shifted from 52.4 to 59.2 dBmV
2026-03-24T03:32:15Z	info	channel_change	US channel count changed from 5 to 4
2026-03-24T03:32:15Z	warning	power_change	US power avg shifted from 59.2 to 52.4 dBmV
2026-03-23T23:16:01Z	info	monitoring_started	Monitoring started (Health: critical)
2026-03-23T23:06:59Z	info	channel_change	US channel count changed from 5 to 0
2026-03-23T23:06:59Z	info	channel_change	DS channel count changed from 26 to 0
2026-03-23T23:06:59Z	critical	snr_change	DS SNR min dropped to 0 dB (critical threshold: 29.0)
2026-03-23T23:06:59Z	warning	power_change	US power avg shifted from 59.2 to 0 dBmV
2026-03-23T23:06:59Z	warning	power_change	DS power avg shifted from 6.5 to 0 dBmV
2026-03-23T23:06:59Z	info	health_change	Health recovered from critical to good
2026-03-23T23:05:58Z	info	monitoring_started	Monitoring started (Health: critical)
2026-03-23T23:03:04Z	info	channel_change	US channel count changed from 5 to 0
2026-03-23T23:03:04Z	info	channel_change	DS channel count changed from 26 to 0
2026-03-23T23:03:04Z	critical	snr_change	DS SNR min dropped to 0 dB (critical threshold: 29.0)
2026-03-23T23:03:04Z	warning	power_change	US power avg shifted from 59.2 to 0 dBmV
2026-03-23T23:03:04Z	warning	power_change	DS power avg shifted from 6.5 to 0 dBmV
2026-03-23T23:03:04Z	info	health_change	Health recovered from critical to good
2026-03-23T23:00:58Z	info	monitoring_started	Monitoring started (Health: critical)
2026-03-23T18:27:49Z	info	channel_change	US channel count changed from 5 to 0
2026-03-23T18:27:49Z	info	channel_change	DS channel count changed from 26 to 0
2026-03-23T18:27:49Z	critical	snr_change	DS SNR min dropped to 0 dB (critical threshold: 29.0)
2026-03-23T18:27:49Z	warning	power_change	US power avg shifted from 59.2 to 0 dBmV
2026-03-23T18:27:49Z	warning	power_change	DS power avg shifted from 6.5 to 0 dBmV
2026-03-23T18:27:49Z	info	health_change	Health recovered from critical to good
2026-03-23T18:25:44Z	info	monitoring_started	Monitoring started (Health: critical)
2026-03-23T05:44:14Z	warning	cm_packet_loss_warning	Target 2: 9.1% packet loss over 60s
2026-03-22T21:44:42Z	info	channel_change	US channel count changed from 4 to 5
2026-03-22T21:44:42Z	warning	power_change	US power avg shifted from 52.4 to 59.2 dBmV
2026-03-22T21:43:37Z	info	channel_change	US channel count changed from 5 to 4
2026-03-22T21:43:37Z	warning	power_change	US power avg shifted from 59.2 to 52.4 dBmV

Speedtest Results (Last 10)

Timestamp	Download	Upload	Ping	Jitter	Packet Loss
2026-03-24T11:00:29Z	419.40 Mbps	512.11 Mbps	14.27 ms	3.78 ms	0.0%
2026-03-24T05:00:20Z	2.21 Gbps	1.14 Gbps	17.21 ms	1.82 ms	0.0%
2026-03-23T23:07:18Z	2.26 Gbps	1.14 Gbps	12.61 ms	1.38 ms	0.0%
2026-03-23T23:03:25Z	2.30 Gbps	1.14 Gbps	14.28 ms	3.8 ms	0.0%
2026-03-23T23:00:18Z	2.08 Gbps	1.11 Gbps	12.48 ms	7.89 ms	0.0%
2026-03-23T18:28:11Z	2.31 Gbps	1.08 Gbps	11.0 ms	2.19 ms	0.0%
2026-03-23T17:00:29Z	287.87 Mbps	869.94 Mbps	11.79 ms	4.96 ms	0.0%
2026-03-23T11:00:22Z	2.31 Gbps	1.06 Gbps	16.67 ms	3.61 ms	0.0%
2026-03-23T05:44:35Z	2.28 Gbps	1.09 Gbps	10.66 ms	2.25 ms	0.0%
2026-03-23T05:00:25Z	2.13 Gbps	1.05 Gbps	14.32 ms	2.24 ms	0.0%

Cross-Source Correlation

Speedtest performance correlated with modem signal health at the time of each test.

Speedtest Time	Download	Modem Health	DS SNR Min	DS Power Avg	Uncorr. Errors
2026-03-24T11:00	419.40 Mbps	critical	44.0 dB	6.6 dBmV	35,220
2026-03-24T05:00	2.21 Gbps	critical	44.0 dB	6.6 dBmV	35,220
2026-03-23T23:07	2.26 Gbps	good	0 dB	0 dBmV	0
2026-03-23T23:03	2.30 Gbps	good	0 dB	0 dBmV	0
2026-03-23T23:00	2.08 Gbps	good	0 dB	0 dBmV	0
2026-03-23T18:28	2.31 Gbps	good	0 dB	0 dBmV	0
2026-03-23T17:00	287.87 Mbps	critical	44.0 dB	6.6 dBmV	35,220
2026-03-23T11:00	2.31 Gbps	critical	44.0 dB	6.6 dBmV	35,220
2026-03-23T05:44	2.28 Gbps	critical	44.0 dB	6.7 dBmV	35,220
2026-03-23T05:00	2.13 Gbps	critical	44.0 dB	6.7 dBmV	35,220

Reference Values (Vodafone Kabel Deutschland)

Downstream Power (dBmV)

Modulation	Good	Tolerated	Critical
1024QAM	-2.0 to 15.0	-4.0 to 16.0	< -6.0 or > 16.0
256QAM	-4.0 to 13.0	-6.0 to 15.0	< -8.0 or > 16.0
4096QAM	-2.0 to 15.0	-4.0 to 16.0	< -6.0 or > 16.0
64QAM	-10.0 to 7.0	-12.0 to 12.0	< -14.0 or > 16.0

Upstream Power (dBmV)

Channel Type	Good	Tolerated	Critical
ofdma	44.1 to 47.0	40.1 to 48.0	< 38.0 or > 50.0
sc_qam	41.1 to 47.0	37.1 to 51.0	< 35.0 or > 53.0

SNR / MER (dB, absolute)

Modulation	Good	Tolerated	Critical
1024QAM	>= 39.0	>= 37.0	< 36.0
256QAM	>= 33.0	>= 31.0	< 29.0
4096QAM	>= 40.0	>= 38.0	< 36.0
64QAM	>= 27.0	>= 25.0	< 23.0
ofdm	>= 27.0	>= 25.5	< 24.5

Uncorrectable Errors: Tolerated >= 1.0%, Critical >= 3.0%

[thewho2018]

Here is my follow-up. My line is now worse then ever. I had a tech here day before yesterday and ran a temp cable and measured with a older Viavi Solutions (limited to 1300/1300 and seem to lack a lot of features to check for Solar/EV chargers.

Direct cable from Remote-PHY:
temp cable.txt

My guess is that Tele2 have messed up the configuration in Harmonics vCMTS. (Profiles for the modems)

The tool the tech used shows values in dBµV and the modem shows dBmV.

It showed 99.8 dBµV (AI told me that is 39.8 dBmV)
the modem show 86 dBmV (AI told me 146 dBµV)

I have gone WAAAY further with this. I have contacted Viavi Solutions and also Harmonic Inc for support.

Correctable goes up to 8500 and then the soft reset happens and this is done by Harmonic vCMTS according to AI.

DOCSight – DOCSIS Cable Connection Status Report

Context

This is a status report from a DOCSIS cable modem generated by DOCSight.
DOCSIS (Data Over Cable Service Interface Specification) is the standard for internet over coaxial cable.
Analyze this data and provide insights about connection health, problematic channels, and recommendations.

• Export Mode: Full Context (48h)

Overview

• ISP: Tele2 Sweden
• Health: critical
• Issues: Upstream power critically high, Upstream power slightly low
• Timestamp: 2026-04-02 12:21:50

Summary

Metric	Value
Downstream Channels	26
DS Power (Min/Avg/Max)	5.2 / 6.6 / 7.8 dBmV
DS SNR (Min/Avg)	43.0 / 44.6 dB
DS Correctable Errors	7,898,994,865
DS Uncorrectable Errors	11,681
Upstream Channels	5
US Power (Min/Avg/Max)	40.8 / 59.2 / 87.0 dBmV

Downstream Channels

Ch	Frequency	Power (dBmV)	SNR (dB)	Modulation	Corr. Errors	Uncorr. Errors	DOCSIS	Health
1	450 MHz	5.2	43.0	256QAM	228	354	3.0	good
2	458 MHz	5.4	44.0	256QAM	204	409	3.0	good
3	466 MHz	5.6	44.0	256QAM	218	417	3.0	good
4	474 MHz	5.5	44.0	256QAM	226	433	3.0	good
5	482 MHz	5.5	44.0	256QAM	206	311	3.0	good
6	490 MHz	5.8	45.0	256QAM	258	345	3.0	good
7	498 MHz	5.8	44.0	256QAM	327	437	3.0	good
8	506 MHz	6.1	45.0	256QAM	369	411	3.0	good
9	514 MHz	6.5	45.0	256QAM	317	493	3.0	good
10	522 MHz	6.4	45.0	256QAM	298	422	3.0	good
11	530 MHz	6.3	45.0	256QAM	221	361	3.0	good
12	538 MHz	6.5	45.0	256QAM	214	374	3.0	good
13	546 MHz	6.7	44.0	256QAM	29	0	3.0	good
14	554 MHz	6.7	45.0	256QAM	191	337	3.0	good
15	562 MHz	7.0	45.0	256QAM	176	339	3.0	good
16	570 MHz	7.1	45.0	256QAM	182	382	3.0	good
17	578 MHz	7.3	45.0	256QAM	211	432	3.0	good
18	586 MHz	7.3	45.0	256QAM	194	356	3.0	good
19	594 MHz	7.5	45.0	256QAM	179	370	3.0	good
20	602 MHz	7.8	45.0	256QAM	210	432	3.0	good
21	610 MHz	7.6	45.0	256QAM	203	497	3.0	good
22	618 MHz	7.3	45.0	256QAM	194	439	3.0	good
23	626 MHz	7.3	45.0	256QAM	164	347	3.0	good
24	634 MHz	7.6	45.0	256QAM	212	382	3.0	good
193	666 MHz	6.6	44.0	OFDM	3,954,106,671	754	3.1	good
194	870 MHz	7.8	44.0	OFDM	3,944,882,963	1,847	3.1	good

Upstream Channels

Ch	Frequency	Power (dBmV)	Modulation	Multiplex	DOCSIS	Health
1	38 MHz	41.0	ATDMA	ATDMA	3.0	tolerated
2	31.6 MHz	41.0	ATDMA	ATDMA	3.0	tolerated
3	25.2 MHz	40.799999	ATDMA	ATDMA	3.0	tolerated
41	104.8 MHz	87.0	OFDMA		3.1	critical
42	14.8 MHz	86.0	OFDMA		3.1	critical

Events (Last 48h)

Timestamp	Severity	Type	Message
2026-04-01T19:46:37Z	info	monitoring_started	Monitoring started (Health: critical)
2026-04-01T15:59:11Z	info	monitoring_started	Monitoring started (Health: critical)
2026-04-01T15:48:01Z	info	monitoring_started	Monitoring started (Health: critical)
2026-04-01T15:41:03Z	warning	cm_packet_loss_warning	Target 2: 8.3% packet loss over 60s
2026-04-01T12:45:13Z	warning	cm_packet_loss_warning	Target 1: 9.1% packet loss over 60s
2026-04-01T12:45:13Z	warning	cm_packet_loss_warning	Target 3: 9.1% packet loss over 60s
2026-04-01T12:45:13Z	warning	cm_packet_loss_warning	Target 2: 9.1% packet loss over 60s
2026-04-01T10:03:38Z	info	channel_change	US channel count changed from 4 to 5
2026-04-01T10:03:38Z	warning	power_change	US power avg shifted from 52.7 to 59.4 dBmV
2026-04-01T10:02:33Z	info	channel_change	US channel count changed from 5 to 4
2026-04-01T10:02:33Z	warning	power_change	US power avg shifted from 59.4 to 52.7 dBmV
2026-04-01T07:57:15Z	info	channel_change	US channel count changed from 4 to 5
2026-04-01T07:57:15Z	warning	power_change	US power avg shifted from 64.0 to 59.4 dBmV
2026-04-01T07:54:52Z	info	channel_change	US channel count changed from 5 to 4
2026-04-01T07:54:52Z	warning	power_change	US power avg shifted from 59.4 to 64.0 dBmV
2026-04-01T07:33:04Z	info	channel_change	US channel count changed from 4 to 5
2026-04-01T07:33:04Z	warning	power_change	US power avg shifted from 52.7 to 59.4 dBmV
2026-04-01T07:31:59Z	info	channel_change	US channel count changed from 5 to 4
2026-04-01T07:31:59Z	warning	power_change	US power avg shifted from 59.4 to 52.7 dBmV
2026-03-31T18:50:46Z	warning	cm_packet_loss_warning	Target 2: 9.1% packet loss over 60s
2026-03-31T17:36:59Z	warning	cm_packet_loss_warning	Target 3: 9.1% packet loss over 60s
2026-03-31T17:28:11Z	warning	cm_packet_loss_warning	Target 2: 9.1% packet loss over 60s
2026-03-31T17:00:40Z	warning	cm_packet_loss_warning	Target 2: 9.1% packet loss over 60s
2026-03-31T11:42:36Z	warning	error_spike	Uncorrectable errors jumped by 8,409 (from 2,296 to 10,705)
2026-03-31T11:41:18Z	warning	cm_packet_loss_warning	Target 2: 8.3% packet loss over 60s
2026-03-31T11:41:18Z	warning	cm_packet_loss_warning	Target 3: 8.3% packet loss over 60s
2026-03-31T11:41:18Z	warning	cm_packet_loss_warning	Target 1: 8.3% packet loss over 60s
2026-03-31T11:25:02Z	warning	error_spike	Uncorrectable errors jumped by 2,296 (from 0 to 2,296)
2026-03-31T11:25:02Z	info	channel_change	US channel count changed from 0 to 5
2026-03-31T11:25:02Z	info	channel_change	DS channel count changed from 0 to 26
2026-03-31T11:25:02Z	warning	power_change	US power avg shifted from 0 to 58.1 dBmV
2026-03-31T11:25:02Z	warning	power_change	DS power avg shifted from 0 to 5.7 dBmV
2026-03-31T11:25:02Z	critical	health_change	Health changed from good to critical
2026-03-31T11:24:08Z	info	cm_target_recovered	Target 3 recovered after 81 timeouts
2026-03-31T11:24:08Z	info	cm_target_recovered	Target 1 recovered after 81 timeouts
2026-03-31T11:24:08Z	info	cm_target_recovered	Target 2 recovered after 81 timeouts
2026-03-31T11:22:04Z	warning	cm_packet_loss_warning	Target 3: 100.0% packet loss over 60s
2026-03-31T11:22:04Z	warning	cm_packet_loss_warning	Target 2: 100.0% packet loss over 60s
2026-03-31T11:22:04Z	warning	cm_packet_loss_warning	Target 1: 100.0% packet loss over 60s
2026-03-31T11:18:54Z	info	channel_change	US channel count changed from 2 to 0
2026-03-31T11:18:54Z	info	channel_change	DS channel count changed from 26 to 0
2026-03-31T11:18:54Z	critical	snr_change	DS SNR min dropped to 0 dB (critical threshold: 29.0)
2026-03-31T11:18:54Z	warning	power_change	US power avg shifted from 86.5 to 0 dBmV
2026-03-31T11:18:54Z	warning	power_change	DS power avg shifted from -46.9 to 0 dBmV
2026-03-31T11:18:54Z	info	health_change	Health recovered from critical to good
2026-03-31T11:17:54Z	critical	modulation_change	Modulation dropped on 24 channel(s)
2026-03-31T11:17:54Z	info	channel_change	US channel count changed from 5 to 2
2026-03-31T11:17:54Z	warning	power_change	US power avg shifted from 59.2 to 86.5 dBmV
2026-03-31T11:17:54Z	warning	power_change	DS power avg shifted from 6.7 to -46.9 dBmV
2026-03-31T11:17:34Z	critical	cm_target_unreachable	Target 2 unreachable (5 consecutive timeouts)
2026-03-31T11:17:34Z	critical	cm_target_unreachable	Target 3 unreachable (5 consecutive timeouts)
2026-03-31T11:17:34Z	critical	cm_target_unreachable	Target 1 unreachable (5 consecutive timeouts)
2026-03-31T11:17:01Z	warning	cm_packet_loss_warning	Target 2: 9.1% packet loss over 60s
2026-03-31T11:17:01Z	warning	cm_packet_loss_warning	Target 3: 9.1% packet loss over 60s
2026-03-31T11:17:01Z	warning	cm_packet_loss_warning	Target 1: 9.1% packet loss over 60s
2026-03-31T10:31:28Z	warning	cm_packet_loss_warning	Target 2: 10.0% packet loss over 60s

Speedtest Results (Last 10)

Timestamp	Download	Upload	Ping	Jitter	Packet Loss
2026-04-02T10:00:37Z	2.35 Gbps	480.62 Mbps	14.65 ms	2.87 ms	0.0%
2026-04-02T04:00:29Z	2.02 Gbps	1.05 Gbps	11.6 ms	1.07 ms	0.0%
2026-04-01T22:00:27Z	2.31 Gbps	1.05 Gbps	13.11 ms	0.66 ms	0.0%
2026-04-01T16:00:24Z	2.33 Gbps	988.93 Mbps	13.05 ms	0.26 ms	0.0%
2026-04-01T15:41:28Z	2.28 Gbps	962.15 Mbps	12.93 ms	0.08 ms	0.0%
2026-04-01T12:45:32Z	2.35 Gbps	1.08 Gbps	10.41 ms	2.09 ms	0.0%
2026-04-01T10:00:29Z	269.83 Mbps	469.26 Mbps	11.96 ms	1.95 ms	0.0%
2026-04-01T04:00:26Z	2.36 Gbps	566.60 Mbps	13.0 ms	0.38 ms	0.0%
2026-03-31T22:00:23Z	2.27 Gbps	1.02 Gbps	11.7 ms	1.1 ms	0.0%
2026-03-31T18:51:06Z	2.35 Gbps	955.19 Mbps	13.01 ms	1.46 ms	0.0%

Cross-Source Correlation

Speedtest performance correlated with modem signal health at the time of each test.

Speedtest Time	Download	Modem Health	DS SNR Min	DS Power Avg	Uncorr. Errors
2026-04-02T10:00	2.35 Gbps	critical	44.0 dB	6.6 dBmV	11,681
2026-04-02T04:00	2.02 Gbps	critical	44.0 dB	6.6 dBmV	11,681
2026-04-01T22:00	2.31 Gbps	critical	44.0 dB	6.4 dBmV	11,681
2026-04-01T16:00	2.33 Gbps	critical	44.0 dB	6.6 dBmV	11,681
2026-04-01T15:41	2.28 Gbps	critical	44.0 dB	6.6 dBmV	11,681
2026-04-01T12:45	2.35 Gbps	critical	44.0 dB	6.5 dBmV	11,681
2026-04-01T10:00	269.83 Mbps	critical	44.0 dB	6.6 dBmV	11,681
2026-04-01T04:00	2.36 Gbps	critical	44.0 dB	6.6 dBmV	11,681
2026-03-31T22:00	2.27 Gbps	critical	44.0 dB	6.6 dBmV	11,681
2026-03-31T18:51	2.35 Gbps	critical	44.0 dB	6.7 dBmV	11,681

Reference Values (Vodafone Kabel Deutschland)

Downstream Power (dBmV)

Modulation	Good	Tolerated	Critical
1024QAM	-2.0 to 15.0	-4.0 to 16.0	< -6.0 or > 16.0
256QAM	-4.0 to 13.0	-6.0 to 15.0	< -8.0 or > 16.0
4096QAM	-2.0 to 15.0	-4.0 to 16.0	< -6.0 or > 16.0
64QAM	-10.0 to 7.0	-12.0 to 12.0	< -14.0 or > 16.0

Upstream Power (dBmV)

Channel Type	Good	Tolerated	Critical
ofdma	44.1 to 47.0	40.1 to 48.0	< 38.0 or > 50.0
sc_qam	41.1 to 47.0	37.1 to 51.0	< 35.0 or > 53.0

SNR / MER (dB, absolute)

Modulation	Good	Tolerated	Critical
1024QAM	>= 39.0	>= 37.0	< 36.0
256QAM	>= 33.0	>= 31.0	< 29.0
4096QAM	>= 40.0	>= 38.0	< 36.0
64QAM	>= 27.0	>= 25.0	< 23.0
ofdm	>= 27.0	>= 25.5	< 24.5

Uncorrectable Errors: Tolerated >= 1.0%, Critical >= 3.0%

Questions

Please analyze this data and provide:

1. Overall connection health assessment
2. Channels that need attention (with reasons)
3. Error rate analysis and whether it indicates a problem
4. Specific recommendations to improve connection quality

[itsDNNS]

Hey, interesting case. I've been thinking about your numbers since your first post and did some reading on OFDMA power reporting in Remote PHY setups.

The 86-87 dBmV on your OFDMA channels jumped out at me. That's way beyond what any CM should physically transmit. For context, DOCSIS 3.1 OFDMA upstream typically tops out around 50 dBmV even in worst-case scenarios. So either the modem is genuinely overdriving (which would likely damage the transmitter over time), or the value is not what it appears to be.

What got me digging was the mismatch with your tech's Viavi reading. 39.8 dBmV at the RPD vs 86 dBmV on the modem UI is too large to be explained by cable loss alone. After looking into it, I think there's a real chance the modem firmware is reporting OFDMA power differently than SC-QAM power. In multi-vendor R-PHY deployments (Harmonic CableOS + whatever CM chipset you have), the way OFDMA total power vs per-subcarrier power is exposed can vary. Some modems report aggregate channel power for OFDMA while showing per-carrier for ATDMA, which makes the OFDMA number look impossibly high in comparison.

That doesn't mean there's no problem. The resets, channel flapping (your US count bouncing between 4 and 5), and the correctable error pattern clearly show upstream instability. But the cause might not be "power too high" in the literal sense. It could be:

• Profile/modulation churn on the OFDMA channel (the vCMTS adjusting profiles and the modem struggling to keep up)
• Noise or ingress on the upstream path that the OFDMA channel is more sensitive to than ATDMA
• An interop issue between your modem's firmware and Harmonic's CableOS in how ranging/power adjustments are negotiated

A few things that would help narrow it down:

• What's your exact modem model and firmware version?
• Do the ATDMA channels (Ch 1-3) stay stable and at normal power while the OFDMA ones show the high values?
• Does DOCSight show modulation drops on the OFDM downstream channels right before the resets happen?
• Have you asked Tele2 if other subscribers on the same node see the same OFDMA power anomaly?

Good call on contacting Harmonic directly. If they can pull the CableOS logs for your CM MAC, they can see exactly what profiles the vCMTS is pushing and whether the modem is failing ranging.

On the DOCSight side, your case is good feedback. Right now it just flags the raw value as critically high, but for OFDMA specifically I should add a sanity check that flags values like 86 dBmV as a suspected reporting anomaly rather than treating it purely as a power issue. Will look into that.

Keep the exports coming if you can, they're useful for improving the diagnostics.

[thewho2018]

Thank you so much Dennis for spending a lot of time on this!!

What AI told me was "DOCSIS 3.1. Max 50–53 dBmV with Extended Upstream (ECo)" and also makes it very clear that my 86 dBmV is clearly a incorrect configuration in vCMTS from Tele2's side. I'm guessing a tech saw a picture from a onsite tech and that screenshot is dBµV and then inputted it into a dBmV field (or CLI).

i did go to three other apartment complexes where i live and the three people i convinced to check had around 99 dBmV. 99 dBµV. 99 dBµV is 39 dBmV. That would be "fine". But this is just a guess from my side so far.

Tech did both tests at RPD and in my apartment with "Teleste 4TS210 (-10db)" and after that a "Teleste 4TS212 (-12dB)" and my on the old cable (that is right up against Solar and EV cables) going up to my apartment and the apartment above mine is a "Teleste 4API108" and the outlet itself is a "Teleste 4APF302" The apartment above mine still have a old 5-1000MHz outlet.

• Sagemcom F@ST 3896 CHWU (I guess CH means ComHem). Part.nr. 253813245. Firmware: FAST3896_WIFIHUBC3_sw18.83.15.17w-6
• I had to ask AI. "Yes, ATDMA channels (Ch 1-3) remain stable at normal ~41 dBmV, while OFDMA (Ch 41/42) spikes to 86–88 dBmV."
• Don't know how to check this and AI gave a long answer that was to wide.
• Tele2 "NET" Tech called yesterday and wore not interested in helping at all and mostly just listened and when i asked her about dBmV/dBµV or if she had good knowledge of CableOS and vCMTS she was just rude. When i asked her to check correctable/uncorrectable she did a quick status check again and told me everything wore fine so i asked again if she checked correctable/uncorrectable, She said "I did not do a deep dive". When i asked about correctable goes to 8500M and then resets she told me she have not seen any resets in the logs. Then she treatend to close my account. She also made it very clear that "Net" department are sure the problem is my pfSense router. My hardware does not control "RF Parameters".

DOCSight – DOCSIS Cable Connection Status Report

Context

This is a status report from a DOCSIS cable modem generated by DOCSight.
DOCSIS (Data Over Cable Service Interface Specification) is the standard for internet over coaxial cable.
Analyze this data and provide insights about connection health, problematic channels, and recommendations.

• Export Mode: Full Context (48h)

Overview

• ISP: Tele2 Sweden
• Health: critical
• Issues: Upstream power critically high, Upstream power slightly low
• Timestamp: 2026-04-03 13:13:32

Summary

Metric	Value
Downstream Channels	26
DS Power (Min/Avg/Max)	5.2 / 6.6 / 7.8 dBmV
DS SNR (Min/Avg)	43.0 / 44.6 dB
DS Correctable Errors	8,172,140,521
DS Uncorrectable Errors	11,681
Upstream Channels	5
US Power (Min/Avg/Max)	40.8 / 59.4 / 88.0 dBmV

Downstream Channels

Ch	Frequency	Power (dBmV)	SNR (dB)	Modulation	Corr. Errors	Uncorr. Errors	DOCSIS	Health
1	450 MHz	5.2	44.0	256QAM	230	354	3.0	good
2	458 MHz	5.4	44.0	256QAM	205	409	3.0	good
3	466 MHz	5.6	44.0	256QAM	220	417	3.0	good
4	474 MHz	5.5	44.0	256QAM	226	433	3.0	good
5	482 MHz	5.5	44.0	256QAM	210	311	3.0	good
6	490 MHz	5.8	44.0	256QAM	266	345	3.0	good
7	498 MHz	5.8	44.0	256QAM	352	437	3.0	good
8	506 MHz	6.1	44.0	256QAM	392	411	3.0	good
9	514 MHz	6.5	45.0	256QAM	330	493	3.0	good
10	522 MHz	6.4	45.0	256QAM	307	422	3.0	good
11	530 MHz	6.3	45.0	256QAM	228	361	3.0	good
12	538 MHz	6.6	45.0	256QAM	220	374	3.0	good
13	546 MHz	6.7	43.0	256QAM	31	0	3.0	good
14	554 MHz	6.7	45.0	256QAM	194	337	3.0	good
15	562 MHz	7.0	45.0	256QAM	176	339	3.0	good
16	570 MHz	7.2	45.0	256QAM	182	382	3.0	good
17	578 MHz	7.3	45.0	256QAM	211	432	3.0	good
18	586 MHz	7.3	45.0	256QAM	194	356	3.0	good
19	594 MHz	7.5	45.0	256QAM	179	370	3.0	good
20	602 MHz	7.8	45.0	256QAM	210	432	3.0	good
21	610 MHz	7.6	45.0	256QAM	203	497	3.0	good
22	618 MHz	7.3	45.0	256QAM	194	439	3.0	good
23	626 MHz	7.3	45.0	256QAM	164	347	3.0	good
24	634 MHz	7.6	45.0	256QAM	212	382	3.0	good
193	666 MHz	6.5	45.0	OFDM	4,039,365,882	754	3.1	good
194	870 MHz	7.8	44.0	OFDM	4,132,769,303	1,847	3.1	good

Upstream Channels

Ch	Frequency	Power (dBmV)	Modulation	Multiplex	DOCSIS	Health
1	38 MHz	41.299999	ATDMA	ATDMA	3.0	good
2	31.6 MHz	41.0	ATDMA	ATDMA	3.0	tolerated
3	25.2 MHz	40.799999	ATDMA	ATDMA	3.0	tolerated
41	104.8 MHz	88.0	OFDMA		3.1	critical
42	14.8 MHz	86.0	OFDMA		3.1	critical

Events (Last 48h)

Timestamp	Severity	Type	Message
2026-04-02T20:13:20Z	warning	cm_packet_loss_warning	Target 2: 9.1% packet loss over 60s
2026-04-02T18:34:18Z	warning	cm_packet_loss_warning	Target 1: 10.0% packet loss over 60s
2026-04-01T19:46:37Z	info	monitoring_started	Monitoring started (Health: critical)
2026-04-01T15:59:11Z	info	monitoring_started	Monitoring started (Health: critical)
2026-04-01T15:48:01Z	info	monitoring_started	Monitoring started (Health: critical)
2026-04-01T15:41:03Z	warning	cm_packet_loss_warning	Target 2: 8.3% packet loss over 60s
2026-04-01T12:45:13Z	warning	cm_packet_loss_warning	Target 1: 9.1% packet loss over 60s
2026-04-01T12:45:13Z	warning	cm_packet_loss_warning	Target 3: 9.1% packet loss over 60s
2026-04-01T12:45:13Z	warning	cm_packet_loss_warning	Target 2: 9.1% packet loss over 60s

Speedtest Results (Last 10)

Timestamp	Download	Upload	Ping	Jitter	Packet Loss
2026-04-03T10:00:43Z	2.33 Gbps	941.54 Mbps	16.67 ms	4.85 ms	0.0%
2026-04-03T04:00:42Z	249.42 Mbps	1.04 Gbps	12.15 ms	5.21 ms	0.0%
2026-04-02T22:00:26Z	463.22 Mbps	636.31 Mbps	13.31 ms	0.75 ms	0.0%
2026-04-02T20:13:40Z	2.29 Gbps	1.05 Gbps	13.16 ms	2.58 ms	0.0%
2026-04-02T18:34:42Z	1.71 Gbps	881.40 Mbps	9.25 ms	2.7 ms	0.0%
2026-04-02T10:00:37Z	2.35 Gbps	480.62 Mbps	14.65 ms	2.87 ms	0.0%
2026-04-02T04:00:29Z	2.02 Gbps	1.05 Gbps	11.6 ms	1.07 ms	0.0%
2026-04-01T22:00:27Z	2.31 Gbps	1.05 Gbps	13.11 ms	0.66 ms	0.0%
2026-04-01T16:00:24Z	2.33 Gbps	988.93 Mbps	13.05 ms	0.26 ms	0.0%
2026-04-01T15:41:28Z	2.28 Gbps	962.15 Mbps	12.93 ms	0.08 ms	0.0%

Cross-Source Correlation

Speedtest performance correlated with modem signal health at the time of each test.

Speedtest Time	Download	Modem Health	DS SNR Min	DS Power Avg	Uncorr. Errors
2026-04-03T10:00	2.33 Gbps	critical	43.0 dB	6.5 dBmV	11,681
2026-04-03T04:00	249.42 Mbps	critical	44.0 dB	6.5 dBmV	11,681
2026-04-02T22:00	463.22 Mbps	critical	44.0 dB	6.5 dBmV	11,681
2026-04-02T20:13	2.29 Gbps	critical	44.0 dB	6.5 dBmV	11,681
2026-04-02T18:34	1.71 Gbps	critical	44.0 dB	6.6 dBmV	11,681
2026-04-02T10:00	2.35 Gbps	critical	44.0 dB	6.6 dBmV	11,681
2026-04-02T04:00	2.02 Gbps	critical	44.0 dB	6.6 dBmV	11,681
2026-04-01T22:00	2.31 Gbps	critical	44.0 dB	6.4 dBmV	11,681
2026-04-01T16:00	2.33 Gbps	critical	44.0 dB	6.6 dBmV	11,681
2026-04-01T15:41	2.28 Gbps	critical	44.0 dB	6.6 dBmV	11,681

Reference Values (Vodafone Kabel Deutschland)

Downstream Power (dBmV)

Modulation	Good	Tolerated	Critical
1024QAM	-2.0 to 15.0	-4.0 to 16.0	< -6.0 or > 16.0
256QAM	-4.0 to 13.0	-6.0 to 15.0	< -8.0 or > 16.0
4096QAM	-2.0 to 15.0	-4.0 to 16.0	< -6.0 or > 16.0
64QAM	-10.0 to 7.0	-12.0 to 12.0	< -14.0 or > 16.0

Upstream Power (dBmV)

Channel Type	Good	Tolerated	Critical
ofdma	44.1 to 47.0	40.1 to 48.0	< 38.0 or > 50.0
sc_qam	41.1 to 47.0	37.1 to 51.0	< 35.0 or > 53.0

SNR / MER (dB, absolute)

Modulation	Good	Tolerated	Critical
1024QAM	>= 39.0	>= 37.0	< 36.0
256QAM	>= 33.0	>= 31.0	< 29.0
4096QAM	>= 40.0	>= 38.0	< 36.0
64QAM	>= 27.0	>= 25.0	< 23.0
ofdm	>= 27.0	>= 25.5	< 24.5

Uncorrectable Errors: Tolerated >= 1.0%, Critical >= 3.0%

Questions

Please analyze this data and provide:

1. Overall connection health assessment
2. Channels that need attention (with reasons)
3. Error rate analysis and whether it indicates a problem
4. Specific recommendations to improve connection quality

[thewho2018]

@itsDNNS AI just explained what we missed..

Issue: Sagemcom DOCSIS 3.1 modem (Tele2 network) displays 86 dBmV upstream power on OFDMA channel while showing symbol rate = 0 ksym/s (inactive).

Table Data:

text
Channel | Freq | Power | Modulation | Symbol Rate | Channel ID
1 | 23.4 MHz | 41.0 | etdma | 5120 | 1
3 | 10.5-30 MHz | 47.8 | etdma | 0 | 3
4 | 18 MHz | 86.0 | OFDMA | 0 | 4

Root Cause Analysis:

86 dBmV is NOT actual transmit power - it's a CMTS/vCMTS threshold/cap value displayed when OFDMA channel is inactive (symbol rate = 0).

Normal DOCSIS 3.1 behavior:

    Active SC-QAM upstream: 41 dBmV ✓ (healthy range: 35-50 dBmV)

    Inactive OFDMA: 86 dBmV = hardware/firmware CAP limit from vCMTS profile, not real Tx power

vCMTS Profile Control: Tele2 CMTS dynamically enables OFDMA only during high upstream traffic (>100-200 Mbps). Inactive channels show profile maximums rather than measured power levels.

[thewho2018]

Tele2 is ghosting me and also Primär (field tech's).

Tele2 have now removed a OFDMA channel and values got a lot worse also for ATDMA.

I just wish i was able to move away from this. I have talked to PTS and Telekområdgivarna today and they just told me to contact ARN (The National Board for Consumer Disputes).

DOCSight – DOCSIS Cable Connection Status Report

Context

This is a status report from a DOCSIS cable modem generated by DOCSight.
DOCSIS (Data Over Cable Service Interface Specification) is the standard for internet over coaxial cable.
Analyze this data and provide insights about connection health, problematic channels, and recommendations.

• Export Mode: Update (6h)

Overview

• ISP: Tele2 Sweden
• Health: critical
• Issues: Upstream power critically high, Upstream power slightly low
• Timestamp: 2026-04-07 23:27:20

Summary

Metric	Value
Downstream Channels	26
DS Power (Min/Avg/Max)	5.3 / 6.7 / 8.0 dBmV
DS SNR (Min/Avg)	44.0 / 44.6 dB
DS Correctable Errors	5,347,801,846
DS Uncorrectable Errors	11,681
Upstream Channels	4
US Power (Min/Avg/Max)	40.5 / 51.9 / 86.0 dBmV

Downstream Channels

Ch	Frequency	Power (dBmV)	SNR (dB)	Modulation	Corr. Errors	Uncorr. Errors	DOCSIS	Health
1	450 MHz	5.3	44.0	256QAM	237	354	3.0	good
2	458 MHz	5.4	44.0	256QAM	211	409	3.0	good
3	466 MHz	5.6	44.0	256QAM	226	417	3.0	good
4	474 MHz	5.5	44.0	256QAM	231	433	3.0	good
5	482 MHz	5.6	44.0	256QAM	213	311	3.0	good
6	490 MHz	5.8	44.0	256QAM	273	345	3.0	good
7	498 MHz	5.8	45.0	256QAM	394	437	3.0	good
8	506 MHz	6.2	44.0	256QAM	440	411	3.0	good
9	514 MHz	6.5	45.0	256QAM	352	493	3.0	good
10	522 MHz	6.4	45.0	256QAM	310	422	3.0	good
11	530 MHz	6.3	45.0	256QAM	232	361	3.0	good
12	538 MHz	6.6	45.0	256QAM	223	374	3.0	good
13	546 MHz	6.7	44.0	256QAM	35	0	3.0	good
14	554 MHz	6.7	45.0	256QAM	196	337	3.0	good
15	562 MHz	7.0	45.0	256QAM	178	339	3.0	good
16	570 MHz	7.2	45.0	256QAM	183	382	3.0	good
17	578 MHz	7.3	45.0	256QAM	211	432	3.0	good
18	586 MHz	7.3	45.0	256QAM	194	356	3.0	good
19	594 MHz	7.5	45.0	256QAM	179	370	3.0	good
20	602 MHz	7.8	45.0	256QAM	211	432	3.0	good
21	610 MHz	7.6	45.0	256QAM	204	497	3.0	good
22	618 MHz	7.3	45.0	256QAM	194	439	3.0	good
23	626 MHz	7.4	45.0	256QAM	165	347	3.0	good
24	634 MHz	7.6	45.0	256QAM	212	382	3.0	good
193	666 MHz	6.7	44.0	OFDM	2,521,394,594	754	3.1	good
194	870 MHz	8.0	44.0	OFDM	2,826,401,748	1,847	3.1	good

Upstream Channels

Ch	Frequency	Power (dBmV)	Modulation	Multiplex	DOCSIS	Health
1	38 MHz	40.5	ATDMA	ATDMA	3.0	tolerated
2	31.6 MHz	40.5	ATDMA	ATDMA	3.0	tolerated
3	25.2 MHz	40.5	ATDMA	ATDMA	3.0	tolerated
41	104.8 MHz	86.0	OFDMA		3.1	critical

Events (Last 6h)

Timestamp	Severity	Type	Message
2026-04-07T20:36:08Z	info	channel_change	US channel count changed from 3 to 4
2026-04-07T20:36:08Z	warning	power_change	US power avg shifted from 40.5 to 51.9 dBmV
2026-04-07T20:36:08Z	critical	health_change	Health changed from tolerated to critical
2026-04-07T20:35:03Z	info	channel_change	US channel count changed from 4 to 3
2026-04-07T20:35:03Z	warning	power_change	US power avg shifted from 51.9 to 40.5 dBmV
2026-04-07T20:35:03Z	info	health_change	Health recovered from critical to tolerated
2026-04-07T20:18:35Z	warning	cm_packet_loss_warning	Target 2: 10.0% packet loss over 60s
2026-04-07T20:18:35Z	warning	cm_packet_loss_warning	Target 3: 10.0% packet loss over 60s
2026-04-07T20:18:35Z	warning	cm_packet_loss_warning	Target 1: 10.0% packet loss over 60s
2026-04-07T20:18:32Z	info	channel_change	US channel count changed from 5 to 4
2026-04-07T20:18:32Z	warning	power_change	US power avg shifted from 59.5 to 52.8 dBmV
2026-04-07T19:19:21Z	warning	cm_packet_loss_warning	Target 2: 9.1% packet loss over 60s
2026-04-07T18:02:33Z	warning	cm_packet_loss_warning	Target 2: 9.1% packet loss over 60s
2026-04-07T17:24:11Z	warning	cm_packet_loss_warning	Target 2: 9.1% packet loss over 60s
2026-04-07T17:15:58Z	warning	cm_packet_loss_warning	Target 2: 9.1% packet loss over 60s
2026-04-07T16:37:28Z	warning	cm_packet_loss_warning	Target 2: 8.3% packet loss over 60s
2026-04-07T16:32:24Z	warning	cm_packet_loss_warning	Target 2: 16.7% packet loss over 60s
2026-04-07T16:27:21Z	warning	cm_packet_loss_warning	Target 2: 16.7% packet loss over 60s
2026-04-07T16:22:21Z	warning	cm_packet_loss_warning	Target 2: 9.1% packet loss over 60s
2026-04-07T16:10:19Z	warning	cm_packet_loss_warning	Target 2: 9.1% packet loss over 60s
2026-04-07T15:54:41Z	warning	cm_packet_loss_warning	Target 2: 9.1% packet loss over 60s
2026-04-07T15:48:01Z	warning	cm_packet_loss_warning	Target 2: 9.1% packet loss over 60s
2026-04-07T15:42:38Z	warning	cm_packet_loss_warning	Target 2: 9.1% packet loss over 60s

Speedtest Results (Last 3)

Timestamp	Download	Upload	Ping	Jitter	Packet Loss
2026-04-07T20:36:32Z	2.35 Gbps	670.70 Mbps	12.93 ms	3.81 ms	0.0%
2026-04-07T20:19:05Z	208.49 Mbps	372.64 Mbps	17.76 ms	57.87 ms	0.0%
2026-04-07T19:19:50Z	333.93 Mbps	936.43 Mbps	12.77 ms	5.55 ms	0.0%

Cross-Source Correlation

Speedtest performance correlated with modem signal health at the time of each test.

Speedtest Time	Download	Modem Health	DS SNR Min	DS Power Avg	Uncorr. Errors
2026-04-07T20:36	2.35 Gbps	critical	43.0 dB	6.7 dBmV	11,681
2026-04-07T20:19	208.49 Mbps	critical	44.0 dB	6.6 dBmV	11,681
2026-04-07T19:19	333.93 Mbps	critical	43.0 dB	6.6 dBmV	11,681

Reference Values (Vodafone Kabel Deutschland)

Downstream Power (dBmV)

Modulation	Good	Tolerated	Critical
1024QAM	-2.0 to 15.0	-4.0 to 16.0	< -6.0 or > 16.0
256QAM	-4.0 to 13.0	-6.0 to 15.0	< -8.0 or > 16.0
4096QAM	-2.0 to 15.0	-4.0 to 16.0	< -6.0 or > 16.0
64QAM	-10.0 to 7.0	-12.0 to 12.0	< -14.0 or > 16.0

Upstream Power (dBmV)

Channel Type	Good	Tolerated	Critical
ofdma	44.1 to 47.0	40.1 to 48.0	< 38.0 or > 50.0
sc_qam	41.1 to 47.0	37.1 to 51.0	< 35.0 or > 53.0

SNR / MER (dB, absolute)

Modulation	Good	Tolerated	Critical
1024QAM	>= 39.0	>= 37.0	< 36.0
256QAM	>= 33.0	>= 31.0	< 29.0
4096QAM	>= 40.0	>= 38.0	< 36.0
64QAM	>= 27.0	>= 25.0	< 23.0
ofdm	>= 27.0	>= 25.5	< 24.5

Uncorrectable Errors: Tolerated >= 1.0%, Critical >= 3.0%

Questions

Please analyze this data and provide:

1. Overall connection health assessment
2. Channels that need attention (with reasons)
3. Error rate analysis and whether it indicates a problem
4. Specific recommendations to improve connection quality

[thewho2018]

I'm starting to feel sick.. Tele2 have now removed my OFDMA so now i get 66mbit upload... I should get between 600-1200mbit..

DOCSight – DOCSIS Cable Connection Status Report

Context

This is a status report from a DOCSIS cable modem generated by DOCSight.
DOCSIS (Data Over Cable Service Interface Specification) is the standard for internet over coaxial cable.
Analyze this data and provide insights about connection health, problematic channels, and recommendations.

• Export Mode: Update (6h)

Overview

• ISP: Tele2 Sweden
• Health: tolerated
• Issues: Upstream power slightly low
• Timestamp: 2026-04-08 20:50:01

Summary

Metric	Value
Downstream Channels	26
DS Power (Min/Avg/Max)	5.3 / 6.7 / 7.9 dBmV
DS SNR (Min/Avg)	44.0 / 44.7 dB
DS Correctable Errors	2,851,352,572
DS Uncorrectable Errors	11,681
Upstream Channels	3
US Power (Min/Avg/Max)	40.5 / 40.5 / 40.5 dBmV

Downstream Channels

Ch	Frequency	Power (dBmV)	SNR (dB)	Modulation	Corr. Errors	Uncorr. Errors	DOCSIS	Health
1	450 MHz	5.3	44.0	256QAM	242	354	3.0	good
2	458 MHz	5.4	44.0	256QAM	215	409	3.0	good
3	466 MHz	5.6	44.0	256QAM	230	417	3.0	good
4	474 MHz	5.5	44.0	256QAM	235	433	3.0	good
5	482 MHz	5.6	44.0	256QAM	215	311	3.0	good
6	490 MHz	5.8	45.0	256QAM	277	345	3.0	good
7	498 MHz	5.8	45.0	256QAM	409	437	3.0	good
8	506 MHz	6.2	45.0	256QAM	464	411	3.0	good
9	514 MHz	6.5	45.0	256QAM	364	493	3.0	good
10	522 MHz	6.4	45.0	256QAM	318	422	3.0	good
11	530 MHz	6.3	45.0	256QAM	237	361	3.0	good
12	538 MHz	6.6	45.0	256QAM	223	374	3.0	good
13	546 MHz	6.7	44.0	256QAM	35	0	3.0	good
14	554 MHz	6.7	45.0	256QAM	197	337	3.0	good
15	562 MHz	7.0	45.0	256QAM	178	339	3.0	good
16	570 MHz	7.2	45.0	256QAM	184	382	3.0	good
17	578 MHz	7.3	45.0	256QAM	211	432	3.0	good
18	586 MHz	7.4	45.0	256QAM	194	356	3.0	good
19	594 MHz	7.5	45.0	256QAM	179	370	3.0	good
20	602 MHz	7.8	45.0	256QAM	211	432	3.0	good
21	610 MHz	7.6	45.0	256QAM	204	497	3.0	good
22	618 MHz	7.3	45.0	256QAM	194	439	3.0	good
23	626 MHz	7.3	45.0	256QAM	165	347	3.0	good
24	634 MHz	7.6	45.0	256QAM	213	382	3.0	good
193	666 MHz	6.6	44.0	OFDM	1,196,260,159	754	3.1	good
194	870 MHz	7.9	44.0	OFDM	1,655,086,819	1,847	3.1	good

Upstream Channels

Ch	Frequency	Power (dBmV)	Modulation	Multiplex	DOCSIS	Health
1	38 MHz	40.5	ATDMA	ATDMA	3.0	tolerated
2	31.6 MHz	40.5	ATDMA	ATDMA	3.0	tolerated
3	25.2 MHz	40.5	ATDMA	ATDMA	3.0	tolerated

Events (Last 6h)

Timestamp	Severity	Type	Message
2026-04-08T18:24:28Z	info	channel_change	US channel count changed from 2 to 3
2026-04-08T18:23:21Z	info	channel_change	US channel count changed from 3 to 2

Speedtest Results (Last 3)

Timestamp	Download	Upload	Ping	Jitter	Packet Loss
2026-04-08T16:00:41Z	2.28 Gbps	66.64 Mbps	15.84 ms	4.04 ms	0.0%
2026-04-08T10:00:31Z	266.20 Mbps	73.15 Mbps	16.73 ms	1.97 ms	0.0%
2026-04-08T04:01:30Z	2.32 Gbps	73.56 Mbps	14.77 ms	4.02 ms	0.0%

Cross-Source Correlation

Speedtest performance correlated with modem signal health at the time of each test.

Speedtest Time	Download	Modem Health	DS SNR Min	DS Power Avg	Uncorr. Errors
2026-04-08T16:00	2.28 Gbps	tolerated	44.0 dB	6.5 dBmV	11,681
2026-04-08T10:00	266.20 Mbps	tolerated	44.0 dB	6.6 dBmV	11,681
2026-04-08T04:01	2.32 Gbps	tolerated	44.0 dB	6.6 dBmV	11,681

Reference Values (Vodafone Kabel Deutschland)

Downstream Power (dBmV)

Modulation	Good	Tolerated	Critical
1024QAM	-2.0 to 15.0	-4.0 to 16.0	< -6.0 or > 16.0
256QAM	-4.0 to 13.0	-6.0 to 15.0	< -8.0 or > 16.0
4096QAM	-2.0 to 15.0	-4.0 to 16.0	< -6.0 or > 16.0
64QAM	-10.0 to 7.0	-12.0 to 12.0	< -14.0 or > 16.0

Upstream Power (dBmV)

Channel Type	Good	Tolerated	Critical
ofdma	44.1 to 47.0	40.1 to 48.0	< 38.0 or > 50.0
sc_qam	41.1 to 47.0	37.1 to 51.0	< 35.0 or > 53.0

SNR / MER (dB, absolute)

Modulation	Good	Tolerated	Critical
1024QAM	>= 39.0	>= 37.0	< 36.0
256QAM	>= 33.0	>= 31.0	< 29.0
4096QAM	>= 40.0	>= 38.0	< 36.0
64QAM	>= 27.0	>= 25.0	< 23.0
ofdm	>= 27.0	>= 25.5	< 24.5

Uncorrectable Errors: Tolerated >= 1.0%, Critical >= 3.0%

Questions

Please analyze this data and provide:

1. Overall connection health assessment
2. Channels that need attention (with reasons)
3. Error rate analysis and whether it indicates a problem
4. Specific recommendations to improve connection quality

[itsDNNS]

Man that sucks. Really curious what the authority ends up telling you though - keep us posted on that.

[thewho2018]

Yesterday at 11 Tele2 readded OFDMA but like every time they don't inform me about anything. They have told me they closed the case. They did however not restart the modem so yesterday i had 1mbit down and 1mbit upload with 64% packet loss until i restarted the modem. I got so pissed of by the lack of information from their side so i emailed them:

Hello,

Thanks for reactivating OFDMA! Since you are not replying to my emails, I’m just writing based on what I can see from my side.

The OFDMA Ch41/42 levels are still at 86 dBmV:

• Maybe try lowering the target Rx power to 0 dBmV?

• Ingress on 14/104 MHz needs to be fixed.

New DOCSight report attached.

I have no problem with them troubleshooting, I would be fine if i just got information..

Like always they just ghosted me because Tele2 NOC/Analysavdelning are not required to replay. Also the company (Primär) that did the analysis at my apartment are also ghosting me. Same with Harmonic. So no progress at all.

Primär also did a test with a temp cable just from my modem down to the Harmonic Oyster in the basement but Tele2 did not inform Primär that by doing so you also need to change the vCMTS profile for the modem. So that test was useless. It was just done to reassure me "everything is fine and nothing is wrong.".

I have talked to PTS and also Telekområdgivarna (legal advice). Next step is to talk to ARN (The National Board for Consumer Disputes).

[thewho2018]

Today i got all from Tele2 NOC and he can now see that DS is fine but something is wrong with US. But when i asked about OFDMA being WAAAAY to high with 86 dBmV he told me that it could be related to a big coax net but we are only 14 on this Harmonic Oyster so that is not it.. But ha asked me to run PingPlotter for 24h and he added a probe on my modem and he will be calling tomorrow to check in. But he also said that a field tech might need to come and use a real probe to test US and find out what could be the reason.

This is the latest report from my modem.

DOCSight – DOCSIS Cable Connection Status Report

Context

This is a status report from a DOCSIS cable modem generated by DOCSight.
DOCSIS (Data Over Cable Service Interface Specification) is the standard for internet over coaxial cable.
Analyze this data and provide insights about connection health, problematic channels, and recommendations.

• Export Mode: Update (6h)

Overview

• ISP: Tele2 Sweden
• Health: critical
• Issues: Upstream power critically high, Upstream power slightly low
• Timestamp: 2026-04-15 23:42:44

Summary

Metric	Value
Downstream Channels	26
DS Power (Min/Avg/Max)	5.2 / 6.6 / 7.8 dBmV
DS SNR (Min/Avg)	44.0 / 44.7 dB
DS Correctable Errors	721,293,735
DS Uncorrectable Errors	0
Upstream Channels	5
US Power (Min/Avg/Max)	40.8 / 59.0 / 86.0 dBmV

Downstream Channels

Ch	Frequency	Power (dBmV)	SNR (dB)	Modulation	Corr. Errors	Uncorr. Errors	DOCSIS	Health
1	450 MHz	5.2	44.0	256QAM	0	0	3.0	good
2	458 MHz	5.3	44.0	256QAM	2	0	3.0	good
3	466 MHz	5.5	44.0	256QAM	2	0	3.0	good
4	474 MHz	5.4	44.0	256QAM	1	0	3.0	good
5	482 MHz	5.5	44.0	256QAM	0	0	3.0	good
6	490 MHz	5.7	45.0	256QAM	1	0	3.0	good
7	498 MHz	5.7	45.0	256QAM	1	0	3.0	good
8	506 MHz	6.1	45.0	256QAM	2	0	3.0	good
9	514 MHz	6.4	45.0	256QAM	9	0	3.0	good
10	522 MHz	6.3	45.0	256QAM	5	0	3.0	good
11	530 MHz	6.2	45.0	256QAM	0	0	3.0	good
12	538 MHz	6.5	45.0	256QAM	0	0	3.0	good
13	546 MHz	6.6	44.0	256QAM	0	0	3.0	good
14	554 MHz	6.6	45.0	256QAM	1	0	3.0	good
15	562 MHz	6.9	45.0	256QAM	1	0	3.0	good
16	570 MHz	7.1	45.0	256QAM	0	0	3.0	good
17	578 MHz	7.2	45.0	256QAM	0	0	3.0	good
18	586 MHz	7.3	45.0	256QAM	0	0	3.0	good
19	594 MHz	7.4	45.0	256QAM	0	0	3.0	good
20	602 MHz	7.7	45.0	256QAM	0	0	3.0	good
21	610 MHz	7.5	45.0	256QAM	0	0	3.0	good
22	618 MHz	7.2	45.0	256QAM	0	0	3.0	good
23	626 MHz	7.2	45.0	256QAM	0	0	3.0	good
24	634 MHz	7.5	45.0	256QAM	0	0	3.0	good
193	666 MHz	6.5	44.0	OFDM	329,322,522	0	3.1	good
194	870 MHz	7.8	44.0	OFDM	391,971,188	0	3.1	good

Upstream Channels

Ch	Frequency	Power (dBmV)	Modulation	Multiplex	DOCSIS	Health
1	38 MHz	41.299999	ATDMA	ATDMA	3.0	good
2	31.6 MHz	41.0	ATDMA	ATDMA	3.0	tolerated
3	25.2 MHz	40.799999	ATDMA	ATDMA	3.0	tolerated
41	104.8 MHz	86.0	OFDMA		3.1	critical
42	14.8 MHz	86.0	OFDMA		3.1	critical

Speedtest Results (Last 3)

Timestamp	Download	Upload	Ping	Jitter	Packet Loss
2026-04-15T16:00:28Z	2.29 Gbps	908.53 Mbps	11.96 ms	2.48 ms	0.0%
2026-04-15T10:00:28Z	2.34 Gbps	938.27 Mbps	17.44 ms	0.69 ms	0.0%
2026-04-15T09:46:57Z	2.34 Gbps	938.59 Mbps	18.51 ms	2.53 ms	0.0%

Cross-Source Correlation

Speedtest performance correlated with modem signal health at the time of each test.

Speedtest Time	Download	Modem Health	DS SNR Min	DS Power Avg	Uncorr. Errors
2026-04-15T16:00	2.29 Gbps	critical	44.0 dB	6.6 dBmV	0
2026-04-15T10:00	2.34 Gbps	critical	43.0 dB	6.6 dBmV	0
2026-04-15T09:46	2.34 Gbps	critical	43.0 dB	6.6 dBmV	0

Reference Values (Vodafone Kabel Deutschland)

Downstream Power (dBmV)

Modulation	Good	Tolerated	Critical
1024QAM	-2.0 to 15.0	-4.0 to 16.0	< -6.0 or > 16.0
256QAM	-4.0 to 13.0	-6.0 to 15.0	< -8.0 or > 16.0
4096QAM	-2.0 to 15.0	-4.0 to 16.0	< -6.0 or > 16.0
64QAM	-10.0 to 7.0	-12.0 to 12.0	< -14.0 or > 16.0

Upstream Power (dBmV)

Channel Type	Good	Tolerated	Critical
ofdma	44.1 to 47.0	40.1 to 48.0	< 38.0 or > 50.0
sc_qam	41.1 to 47.0	37.1 to 51.0	< 35.0 or > 53.0

SNR / MER (dB, absolute)

Modulation	Good	Tolerated	Critical
1024QAM	>= 39.0	>= 37.0	< 36.0
256QAM	>= 33.0	>= 31.0	< 29.0
4096QAM	>= 40.0	>= 38.0	< 36.0
64QAM	>= 27.0	>= 25.0	< 23.0
ofdm	>= 27.0	>= 25.5	< 24.5

Uncorrectable Errors: Tolerated >= 1.0%, Critical >= 3.0%

Questions

Please analyze this data and provide:

1. Overall connection health assessment
2. Channels that need attention (with reasons)
3. Error rate analysis and whether it indicates a problem
4. Specific recommendations to improve connection quality

[thewho2018]

Wednesday Tele2 NOC told me he would call back on Thursday, but I haven’t heard anything since.

At this point I’m convinced the issue has two parts:

1. Ingress in the building plant.

2. An upstream profile issue. All upstream channels appear to use effectively the same target level, and the OFDMA channels are being driven to 86 dBmV. From what I understand, OFDMA upstream should have its own target receive power configuration, separate from the SC‑QAM channels, and typically operate in a much lower range (around mid‑40s dBmV in common DOCSIS 3.1 examples).