Starting to see increased latency and noise

[rs888]

Hi all.

I am starting see a lot of noise on the downstream channels, I have checked that all of my connections are tight.

The LED ring has failed around the front of the Hub 4, on Gig1 also not sure that it matters. Hub is in router mode for the time being.

Channel 18 has always given me issues. Noise on 1 to 11 is new.

Latency.

Logs to follow.

[rs888]

Cable Modem Status	Online	DOCSIS 3.1
Primary downstream channel	Locked	SC-QAM
DOCSIS 3.0 channels	31	4
DOCSIS 3.1 channels	1	0

3.0 Downstream channels

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

3	155000000	6.099998	40.366287	QAM256	3
1	139000000	7.000000	40.946209	QAM256	1
2	147000000	6.300003	40.366287	QAM256	2
4	163000000	6.099998	40.946209	QAM256	4
5	171000000	5.900002	40.366287	QAM256	5
6	179000000	5.900002	40.946209	QAM256	6
7	187000000	5.800003	40.366287	QAM256	7
8	195000000	5.699997	40.366287	QAM256	8
9	203000000	5.500000	40.946209	QAM256	9
10	211000000	5.300003	40.946209	QAM256	10
11	219000000	5.099998	40.366287	QAM256	11
12	227000000	5.000000	40.946209	QAM256	12
13	235000000	5.099998	40.366287	QAM256	13
14	243000000	5.300003	40.366287	QAM256	14
15	251000000	5.300003	40.366287	QAM256	15
16	259000000	5.800003	40.946209	QAM256	16
17	267000000	6.199997	40.946209	QAM256	17
18	275000000	6.199997	38.605377	QAM256	18
19	283000000	5.900002	40.366287	QAM256	19
20	291000000	5.900002	40.366287	QAM256	20
21	299000000	5.699997	40.946209	QAM256	21
22	307000000	6.199997	40.946209	QAM256	22
23	315000000	6.300003	40.366287	QAM256	23
24	323000000	6.599998	40.366287	QAM256	24
25	363000000	6.400002	40.946209	QAM256	25
26	371000000	6.400002	40.366287	QAM256	26
27	379000000	6.400002	40.946209	QAM256	27
28	387000000	6.099998	40.946209	QAM256	28
29	395000000	6.000000	40.946209	QAM256	29
30	403000000	5.900002	40.946209	QAM256	30
31	411000000	5.699997	40.366287	QAM256	31

3.0 Downstream channels

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

3	Locked	40.366287	10610	0
1	Locked	40.946209	1479	0
2	Locked	40.366287	16066	0
4	Locked	40.946209	10054	0
5	Locked	40.366287	5757	0
6	Locked	40.946209	2624	0
7	Locked	40.366287	16137	0
8	Locked	40.366287	10457	0
9	Locked	40.946209	4247	0
10	Locked	40.946209	2946	0
11	Locked	40.366287	15769	0
12	Locked	40.946209	0	0
13	Locked	40.366287	0	0
14	Locked	40.366287	0	0
15	Locked	40.366287	0	0
16	Locked	40.946209	0	0
17	Locked	40.946209	0	0
18	Locked	38.605377	27085117	9675
19	Locked	40.366287	0	0
20	Locked	40.366287	0	0
21	Locked	40.946209	0	0
22	Locked	40.946209	0	0
23	Locked	40.366287	0	0
24	Locked	40.366287	0	0
25	Locked	40.946209	0	0
26	Locked	40.366287	0	0
27	Locked	40.946209	0	0
28	Locked	40.946209	0	0
29	Locked	40.946209	0	0
30	Locked	40.946209	0	0
31	Locked	40.366287	0	0

3.1 Downstream channelsChannel Channel Width (MHz) FFT Type Number of Active Subcarriers Modulation (Active Profile) First Active Subcarrier (Hz)

159

96

4K

1880

QAM4096

759

3.1 Downstream channelsChannel ID Lock Status RxMER Data (dB) PLC Power (dBmV) Correcteds (Active Profile) Uncorrectables (Active Profile)

159

Locked

42

6.4

326487287

0

[rs888]

3.0 Upstream channels

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

1	53700000	47.520599	5120 KSym/sec	64QAM	2
2	39400000	46.770599	5120 KSym/sec	64QAM	4
3	46200000	47.270599	5120 KSym/sec	64QAM	3
4	60300000	48.270599	5120 KSym/sec	64QAM	1

3.0 Upstream channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1	US_TYPE_STDMA	0	0	0	0
2	US_TYPE_STDMA	0	0	0	0
3	US_TYPE_STDMA	0	0	0	0
4	US_TYPE_STDMA	0	0	0	0

General Configuration

Network access	true
Maximum Number of CPEs	1
Baseline Privacy	true
DOCSIS Mode	3.1
Config file	ncxv9873254k;fg87dsfd;kfo

Primary Downstream Service Flow

SFID	794
Max Traffic Rate	1200000450
Max Traffic Burst	42600
Min Traffic Rate	0

Primary Upstream Service Flow

SFID	793
Max Traffic Rate	55000270
Max Traffic Burst	42600
Min Traffic Rate	0
Max Concatenated Burst	16320
Scheduling Type	bestEffort

Network Log

Time Priority Description

Mon May 24 07:08:54 2021	4	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Mon May 24 07:08:54 2021	6	DHCP Renew - lease parameters tftp file-cmreg-vmdg640-bbt076-b.cm modified;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Wed May 26 12:12:51 2021	3	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Thu May 27 19:08:54 2021	4	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Thu May 27 19:08:54 2021	6	DHCP Renew - lease parameters tftp file-cmreg-vmdg640-bbt076-b.cm modified;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Fri May 28 15:10:37 2021	3	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Mon May 31 07:08:54 2021	4	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Mon May 31 07:08:54 2021	6	DHCP Renew - lease parameters tftp file-cmreg-vmdg640-bbt076-b.cm modified;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Thu Jun 3 03:35:54 2021	3	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Thu Jun 3 19:08:54 2021	4	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Thu Jun 3 19:08:54 2021	6	DHCP Renew - lease parameters tftp file-cmreg-vmdg640-bbt076-b.cm modified;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 4 01:31:48 2021	3	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Mon Jun 7 07:08:54 2021	4	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Mon Jun 7 07:08:55 2021	6	DHCP Renew - lease parameters tftp file-cmreg-vmdg640-bbt076-b.cm modified;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Wed Jun 9 07:37:41 2021	3	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Thu Jun 10 19:08:55 2021	4	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Thu Jun 10 19:08:55 2021	6	DHCP Renew - lease parameters tftp file-cmreg-vmdg640-bbt076-b.cm modified;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Mon Jun 14 07:08:55 2021	4	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Mon Jun 14 07:08:55 2021	6	DHCP Renew - lease parameters tftp file-cmreg-vmdg640-bbt076-b.cm modified;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Thu Jun 17 03:10:40 2021	3	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Thu Jun 17 19:08:55 2021	4	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Thu Jun 17 19:08:55 2021	6	DHCP Renew - lease parameters tftp file-cmreg-vmdg640-bbt076-b.cm modified;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Sat Jun 19 07:52:36 2021	3	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Mon Jun 21 07:08:55 2021	4	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;

[legacy1]

Looks ok maybe you did a upload between 9pm-10pm? packets buffer as hub don't do QoS.

if your was not uploading or downloading at the time maybe a DoS or utilisation problem.

[rs888]

Between 9 and 10pm last night was just normal Youtube and Twitch streaming.

Still seeing T3 timeouts which are not being reported on the main log.

Snapshot with T3 and spikes from this morning to now.

[Zak_M]

Good afternoon @rs888 

I have taken a further look over the account, all the power levers are where they are supposed to be. There is nothing on the network to indicate that this is the issue. 

The hub hasn't been rebooted for 9 days, please could you pinhole set the hub. 

Kind regards,

Zak_M

[rs888]

Hi Zak_M.

I have done the pinhole reset as requested yesterday. It's the red line on the BQM snapshot.

Unfortunately the reset has not made any difference with the increased latency and noise I am currently seeing.

Updated logs to follow.

[rs888]

3.0 Downstream channels

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

1	139000000	6.699997	40.366287	QAM256	1
2	147000000	6.199997	40.946209	QAM256	2
3	155000000	5.800003	40.366287	QAM256	3
4	163000000	5.900002	40.946209	QAM256	4
5	171000000	5.699997	40.946209	QAM256	5
6	179000000	5.599998	40.946209	QAM256	6
7	187000000	5.500000	40.946209	QAM256	7
8	195000000	5.400002	40.366287	QAM256	8
9	203000000	5.199997	40.946209	QAM256	9
10	211000000	5.099998	40.946209	QAM256	10
11	219000000	5.000000	40.946209	QAM256	11
12	227000000	4.800003	40.946209	QAM256	12
13	235000000	4.800003	40.366287	QAM256	13
14	243000000	5.000000	40.366287	QAM256	14
15	251000000	5.000000	40.946209	QAM256	15
16	259000000	5.500000	40.946209	QAM256	16
17	267000000	5.800003	40.366287	QAM256	17
18	275000000	5.800003	38.605377	QAM256	18
19	283000000	5.500000	40.366287	QAM256	19
20	291000000	5.500000	40.366287	QAM256	20
21	299000000	5.199997	40.946209	QAM256	21
22	307000000	5.599998	40.366287	QAM256	22
23	315000000	5.800003	40.366287	QAM256	23
24	323000000	6.099998	40.366287	QAM256	24
25	363000000	5.900002	40.366287	QAM256	25
26	371000000	5.800003	40.366287	QAM256	26
27	379000000	5.800003	40.946209	QAM256	27
28	387000000	5.699997	40.946209	QAM256	28
29	395000000	5.500000	40.366287	QAM256	29
30	403000000	5.300003	40.366287	QAM256	30
31	411000000	5.099998	40.946209	QAM256	31

3.0 Downstream channels

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

1	Locked	40.366287	718	0
2	Locked	40.946209	246	0
3	Locked	40.366287	208	0
4	Locked	40.946209	604	0
5	Locked	40.946209	63	0
6	Locked	40.946209	146	0
7	Locked	40.946209	338	0
8	Locked	40.366287	754	0
9	Locked	40.946209	40	0
10	Locked	40.946209	147	0
11	Locked	40.946209	242	0
12	Locked	40.946209	0	0
13	Locked	40.366287	0	0
14	Locked	40.366287	0	0
15	Locked	40.946209	0	0
16	Locked	40.946209	0	0
17	Locked	40.366287	0	0
18	Locked	38.605377	3343206	183
19	Locked	40.366287	0	0
20	Locked	40.366287	0	0
21	Locked	40.946209	0	0
22	Locked	40.366287	0	0
23	Locked	40.366287	0	0
24	Locked	40.366287	0	0
25	Locked	40.366287	0	0
26	Locked	40.366287	0	0
27	Locked	40.946209	0	0
28	Locked	40.946209	0	0
29	Locked	40.366287	0	0
30	Locked	40.366287	0	0
31	Locked	40.946209	0	0

3.1 Downstream channelsChannel Channel Width (MHz) FFT Type Number of Active Subcarriers Modulation (Active Profile) First Active Subcarrier (Hz)

159

96

4K

1880

QAM4096

759

3.1 Downstream channelsChannel ID Lock Status RxMER Data (dB) PLC Power (dBmV) Correcteds (Active Profile) Uncorrectables (Active Profile)

159

Locked

42

5.3

101329485

0

[rs888]

3.0 Upstream channels

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

1	39400000	47.770599	5120 KSym/sec	64QAM	4
2	46200000	48.270599	5120 KSym/sec	64QAM	3
3	53700000	48.770599	5120 KSym/sec	64QAM	2
4	60300000	49.270599	5120 KSym/sec	64QAM	1

3.0 Upstream channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1	US_TYPE_STDMA	0	0	1	0
2	US_TYPE_STDMA	0	0	0	0
3	US_TYPE_STDMA	0	0	0	0
4	US_TYPE_STDMA	0	0	0	0

Network LogTime Priority Description

Thu Jan 1 00:01:30 1970	4	Missing Mandatory MDD TLV on primary DS Channel;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Thu Jan 1 00:01:50 1970	3	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Sun Jul 18 19:25:12 2021	5	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Sun Jul 18 19:37:26 2021	5	DBC-REQ Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;

[Andrew-G]

Your problem appears to me likely to be down to noise ingress on 275 MHz, visible as post-RS (uncorrectable) errors on the downstream, both before and after the restart.   The higher number of pre-RS errors isn't materal as those are corrected on the fly, but the difference between channels confirms what the post-RS data shows.  That frequency could easily be a UHF military radio system, as that frequency is commonly used for airfield comms or approach radars, but that's largely academic as the problem is not the source, but that there's a fault on VM's coax that's allowing that in as radio frequency noise.

And that's what VM need to send out a man to fix.