QAM woes, again.

[Icantcrabhere]

Hi, this may be a somewhat lengthy post,
I'll have to split hub readings from the other day / after a restart today.

The basics out of the way first:

Superhub 3, modem mode. - wired
I have made sure all connections are finger tight.
I have checked both the online fault checker and the phone one

The following first set of logs I post will be from then (Before rebooting the hub).

The other night, 7th July - I noticed a huge latency spike, this turned out to be a Partial service error.

Obviously along with that comes a flood of post-RS errors, as expected.


The following first set of logs I post will be from then (Before rebooting the hub).
I am sorry for the formatting on this particular section:

Time Priority Description
07/07/2022 00:07:15 critical SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
07/07/2022 00:07:14 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
07/07/2022 00:07:14 critical SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
07/07/2022 00:06:16 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
07/07/2022 00:06:15 critical SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
07/07/2022 00:05:14 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
07/07/2022 00:05:14 critical SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
07/07/2022 00:03:28 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

Downstream bonded channels
Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors
1 Locked 40.3 3057 6731
2 Locked 40.9 1858 7104
3 Locked 40.9 1836 7435
4 Locked 40.9 1828 5666
5 Locked 40.3 1621 5757
6 Locked 40.3 1627 5633
7 Locked 40.3 1811 5775
8 Locked 40.3 1808 5749
9 Locked 40.3 1573 5101
10 Locked 40.3 1876 5284
11 Locked 40.3 1689 5669
12 Locked 40.3 1896 5574
13 Locked 40.3 2822 6718
14 Locked 40.3 1878 6648
15 Locked 40.9 1831 6211
16 Locked 40.3 1893 6552
17 Locked 40.3 2115 6110
18 Locked 38.9 2531 7290
19 Locked 40.3 2399 7146
20 Locked 38.6 3513 7108
21 Locked 38.9 3432 7220
22 Locked 38.9 3493 6851
23 Locked 38.9 3308 6668
24 Locked 38.6 3401 6886

Upstream bonded channels
Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts
1 ATDMA 0 0 10 0
2 ATDMA 0 0 12 0
3 ATDMA 0 0 6 0
4 ATDMA 0 0 12 0


Even through this, all my upstream QAM were locked to 64,
Until today, that is.
The following posts will show todays logs AFTER a reboot.

[Icantcrabhere]

ownstream bonded channels

Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID

1	539000000	-1.5	38	256 qam	17
2	411000000	1.2	40	256 qam	1
3	419000000	1	40	256 qam	2
4	427000000	0.7	40	256 qam	3
5	435000000	0.4	40	256 qam	4
6	443000000	0	40	256 qam	5
7	451000000	0	40	256 qam	6
8	459000000	0	40	256 qam	7
9	467000000	0	40	256 qam	8
10	475000000	-0.2	40	256 qam	9
11	483000000	-0.4	40	256 qam	10
12	491000000	-0.5	38	256 qam	11
13	499000000	-0.9	38	256 qam	12
14	507000000	-0.9	40	256 qam	13
15	515000000	-1	40	256 qam	14
16	523000000	-1	40	256 qam	15
17	531000000	-1.2	38	256 qam	16
18	547000000	-2	38	256 qam	18
19	555000000	-1.9	38	256 qam	19
20	563000000	-2	38	256 qam	20
21	571000000	-2.2	38	256 qam	21
22	579000000	-2.5	38	256 qam	22
23	587000000	-2.5	38	256 qam	23
24	595000000	-2.2	38	256 qam	24

Downstream bonded channels

Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors

1	Locked	38.9	4	0
2	Locked	40.9	13	0
3	Locked	40.9	4	0
4	Locked	40.3	0	0
5	Locked	40.3	0	0
6	Locked	40.3	4	0
7	Locked	40.3	4	0
8	Locked	40.3	6	0
9	Locked	40.3	5	0
10	Locked	40.3	5	0
11	Locked	40.3	6	0
12	Locked	38.9	5	0
13	Locked	38.9	0	0
14	Locked	40.3	5	0
15	Locked	40.3	5	0
16	Locked	40.3	5	0
17	Locked	38.9	6	0
18	Locked	38.9	0	0
19	Locked	38.9	5	0
20	Locked	38.6	7	0
21	Locked	38.9	6	0
22	Locked	38.9	0	0
23	Locked	38.6	5	0
24	Locked	38.6	6	0

Upstream bonded channels

Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID

1	46200000	41.8	5120	64 qam	1
2	25800000	40.5	5120	16 qam	4
3	32600069	41	5120	16 qam	3
4	39400000	41.5	5120	16 qam	2

Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1	ATDMA	0	0	0	0
2	ATDMA	0	0	0	0
3	ATDMA	0	0	0	0
4	ATDMA	0	0	0	0

Network Log

Time Priority Description

08/07/2022 12:03:8	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
07/07/2022 00:07:15	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
07/07/2022 00:07:14	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
07/07/2022 00:07:14	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
07/07/2022 00:06:16	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
07/07/2022 00:06:15	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
07/07/2022 00:05:14	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
07/07/2022 00:05:14	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
07/07/2022 00:03:28	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2022 16:26:48	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2022 10:56:52	Error	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
03/07/2022 18:41:33	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
01/07/2022 22:56:51	Error	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
30/06/2022 05:06:16	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
28/06/2022 10:56:51	Error	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
26/06/2022 03:37:31	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
24/06/2022 22:56:51	Error	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
22/06/2022 17:53:17	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/06/2022 10:56:50	Error	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
18/06/2022 12:39:43	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

[Icantcrabhere]

Adding my BQM here, since I forgot to in the first post.
Live Graph:

https://www.thinkbroadband.com/broadband/monitoring/quality/share/99d0211a42b0af7eea816fe43594835dbd...

The red line just after 5PM was me rebooting.

This is becoming a very annoying problem in my area, with the QAM/possible SNR issues cropping up repeatedly,
hopefully there can be some indepth looks into this, since it seems like each time it's fixed it decides to want to come back very shortly after. (well, a few months or so)

I'd hope this can be properly investigated and truly fixed, rather than just having repeat occurrences with so little time between.

Many thanks as always,
Jo.

[newapollo]

Hi Jo,

It would be interesting to see your current Downstream bonded channels information as the Pre RS errors were very low, and the Post RS errors were reset to zero when you last posted around 5 hours ago. It would help show how quickly (if at all) they are increasing

To be honest the rest of your stats appear to be OK, it's just thethree  64 qams showing as only being 16.

I often get that if my white coaxial cable has worked loose. It needs to be finger tight both from the wall and into the hub, and also at the splitter if there is one attached.

[Icantcrabhere]

Hi Dave, thank you for your reply!

ownstream bonded channels

Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID

1	539000000	-1.5	38	256 qam	17
2	411000000	1.2	40	256 qam	1
3	419000000	1	40	256 qam	2
4	427000000	0.9	40	256 qam	3
5	435000000	0.4	40	256 qam	4
6	443000000	0.2	40	256 qam	5
7	451000000	0.2	40	256 qam	6
8	459000000	0.2	40	256 qam	7
9	467000000	0	40	256 qam	8
10	475000000	0	40	256 qam	9
11	483000000	-0.2	40	256 qam	10
12	491000000	-0.4	38	256 qam	11
13	499000000	-0.7	38	256 qam	12
14	507000000	-0.7	40	256 qam	13
15	515000000	-0.7	40	256 qam	14
16	523000000	-1	40	256 qam	15
17	531000000	-1.2	40	256 qam	16
18	547000000	-1.9	38	256 qam	18
19	555000000	-1.7	38	256 qam	19
20	563000000	-1.9	38	256 qam	20
21	571000000	-2.2	38	256 qam	21
22	579000000	-2.4	38	256 qam	22
23	587000000	-2.4	38	256 qam	23
24	595000000	-2.2	38	256 qam	24

Downstream bonded channels

Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors

1	Locked	38.9	4	0
2	Locked	40.9	13	0
3	Locked	40.9	4	0
4	Locked	40.3	0	0
5	Locked	40.3	0	0
6	Locked	40.3	4	0
7	Locked	40.3	4	0
8	Locked	40.3	6	0
9	Locked	40.3	5	0
10	Locked	40.3	5	0
11	Locked	40.3	6	0
12	Locked	38.9	5	0
13	Locked	38.9	0	0
14	Locked	40.3	5	0
15	Locked	40.3	5	0
16	Locked	40.3	5	0
17	Locked	38.9	6	0
18	Locked	38.9	0	0
19	Locked	38.9	5	0
20	Locked	38.6	7	0
21	Locked	38.9	6	0
22	Locked	38.9	0	0
23	Locked	38.6	5	0
24	Locked	38.6	6	0

As requested, as you can see they've hardly climbed.
However 3 channels are still dipping between 16/32 QAM which is somewhat of an issue.
I've made sure to double check the connections, all seem truly in place. - however I will go for "Third time lucky" as it can't hurt, right? 🙂

[newapollo]

Hi again Jo,

It wouldn't hurt, but I forgot to ask before...since you have a wired connection it might be worthwhile trying a different ethernet cable, also try a different ethernet port.

It might also be an idea to test in router mode as it may be an issue with your modem or the modem connection to the hub.

I must admit the BQM doesn't look that healthy, but that's possibly caused by the three 16 qam's.   .

Hopefully one of the forum guru's will have a look and be able to work some magic for you

[Icantcrabhere]

Hi again Dave,

I don't believe my router/cable would be the cause of the QAM drop, however definitely a good troubleshooting option,

In regards to the BQM, this is the exact way it looked when we had an SNR issues in March, crazy amounts of spikes and jittery average latency.
It seems, unfortunately, that in my area SNR/QAM issues seem super common 😞

This seems to be following the same trend as before too, where it was another household bringing noise on to the network:

After midnight the QAM has once again resettled to 64. - then by the morning when other houses are online it goes back to terrible modulation.

Upstream bonded channels

Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID

1	46199932	41.5	5120	64 qam	1
2	25800000	40.3	5120	64 qam	4
3	32600000	40.8	5120	64 qam	3
4	39400000	41.3	5120	64 qam	2

the joys(or rather lack of) in regards to a DOCSIS connection, aha

hopefully it's a quick fix this time around!

[Ilyas_Y]

Hey @Icantcrabhere, thanks for reaching out to us.

I'm sorry to see the issues occur on your broadband.
I will investigate this further and send you a private message - watch out for the purple envelope 🙂

Kind regards.

[Icantcrabhere]

Hi!

The technician has been,
Although intermittent: he agrees the issue is not within my house.

He mentioned how it should be flagged/forwarded to the network team.
Can you see if this has been escalated/forwarded?

Thanks again for your help so far,
Jo.

[John_GS]

Hi @Icantcrabhere

Thanks for coming back to the thread. I have checked the SNR (signal to noise ratio) level, and higher but not out of spec on either the daily report or the weekly one. I've therefore reached out to your Field Manager for an update regarding the tech visit. We'll be in touch when we know more.

Best,