Gig1 Connection stability issues

[Travelstar]

Looks like my connection is being a bit glitchy at the moment (sometimes dropped packets). Restarted my modem yesterday which vaguely helped, but still seeing frequent T2 and T3 timeouts. In addition to this, I currently have a 6db attenuator, and whilst I would love to increase this to 9 or 12db, however my upstream then goes out of spec to 53/54 or higher causing even worse connection issues. In an ideal world I think they would have used a forward path equaliser in the past (which I believe leaves the upstream largely untouched), but I am not sure Virgin Media does this anymore. Since the recent warming weather changes, things have definitely gotten worse.

I did get a tech out a few months back who moved me onto another tap which did definitely help, but I get the feeling there is a bit of noise on my cable. There is also a possibility I might need a repull based on the numbers I am seeing, possibly even the cabling from street to house/room.

Ideally hoping someone from the forum team can take a quick look at this, as I know if I contact customer service, they will literally have no clue what I am talking about.

Cable stats below:

3.0 Downstream channels

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

1	331000000	8.7	40	QAM 256	25
2	139000000	10.5	40	QAM 256	1
3	147000000	10.3	40	QAM 256	2
4	155000000	9.7	40	QAM 256	3
5	163000000	9.3	40	QAM 256	4
6	171000000	9	40	QAM 256	5
7	179000000	8.9	40	QAM 256	6
8	187000000	8.8	40	QAM 256	7
9	195000000	8.8	40	QAM 256	8
10	203000000	8.8	40	QAM 256	9
11	211000000	8.9	40	QAM 256	10
12	219000000	8.9	40	QAM 256	11
13	227000000	8.7	40	QAM 256	12
14	235000000	8.8	40	QAM 256	13
15	243000000	8.9	40	QAM 256	14
16	251000000	8.7	41	QAM 256	15
17	259000000	8.6	41	QAM 256	16
18	267000000	8.4	41	QAM 256	17
19	291000000	8.8	40	QAM 256	20
20	299000000	9	41	QAM 256	21
21	307000000	9.1	41	QAM 256	22
22	315000000	9	41	QAM 256	23
23	323000000	8.9	40	QAM 256	24
24	339000000	8.8	40	QAM 256	26
25	347000000	8.8	40	QAM 256	27
26	355000000	8.8	41	QAM 256	28
27	363000000	9	41	QAM 256	29
28	371000000	9	41	QAM 256	30
29	379000000	9.2	41	QAM 256	31
30	387000000	8.8	41	QAM 256	32
31	395000000	9	41	QAM 256	33
32	403000000	8.6	41	QAM 256	34

3.0 Downstream channels

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

1	Locked	40	79	0
2	Locked	40	16	0
3	Locked	40	16	0
4	Locked	40	1	0
5	Locked	40	2	0
6	Locked	40	2	0
7	Locked	40	2	0
8	Locked	40	11	0
9	Locked	40	10	0
10	Locked	40	9	0
11	Locked	40	13	0
12	Locked	40	11	0
13	Locked	40	8	0
14	Locked	40	10	0
15	Locked	40	10	0
16	Locked	41	16	0
17	Locked	41	9	0
18	Locked	41	19	0
19	Locked	40	35	0
20	Locked	41	33	0
21	Locked	41	42	0
22	Locked	41	72	0
23	Locked	40	65	0
24	Locked	40	105	0
25	Locked	40	116	0
26	Locked	41	125	0
27	Locked	41	110	0
28	Locked	41	98	0
29	Locked	41	132	0
30	Locked	41	151	0
31	Locked	41	63	0
32	Locked	41	71	0

3.1 Downstream channels

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

159

94

4K

1840

QAM 4096

1108

3.1 Downstream channels

Channel ID Locked Status RxMER Data (dB) PLC Power (dBmV) Corrected errors (Active Profile) Uncorrectable errors (Active Profile)

159

Locked

43

8.4

1809555268

0

3.0 Upstream channels

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

0	49600000	46.8	5120	QAM 64	1
1	43100000	46.8	5120	QAM 64	2
2	36600000	47	5120	QAM 64	3
3	30100000	47	5120	QAM 64	4
4	23600000	47.5	5120	QAM 64	5

3.0 Upstream channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

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

3.1 Upstream channels

Channel Channel Width (MHz) Power (dBmV) FFT Type Modulation

6

10

40.5

2K

QAM 256

3.1 Upstream channels

Channel Channel Type Number of Active Subcarriers First Active Subcarrier (Hz) T3 Timeouts T4 Timeouts

6

OFDMA

200

74000000

0

0

Network Log

Time Priority Description

04-02-2024 14:58:01	warning	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;
04-02-2024 14:58:01	notice	US profile assignment change. US Chan ID: 6; Previous Profile: 12 13; New Profile: 11 13.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
04-02-2024 13:50:20	notice	US profile assignment change. US Chan ID: 6; Previous Profile: 11 13; New Profile: 12 13.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
04-02-2024 13:50:20	warning	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;
04-02-2024 07:44:38	notice	US profile assignment change. US Chan ID: 6; Previous Profile: 13; New Profile: 11 13.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
04-02-2024 07:44:38	warning	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;
04-02-2024 07:34:34	notice	US profile assignment change. US Chan ID: 6; Previous Profile: 11 13; New Profile: 13.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
04-02-2024 07:34:34	warning	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;
04-02-2024 00:05:50	warning	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;
03-02-2024 14:55:23	error	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-02-2024 14:25:49	warning	Dynamic Range Window violation
03-02-2024 14:25:49	warning	RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-02-2024 14:25:49	notice	US profile assignment change. US Chan ID: 6; Previous Profile: 13; New Profile: 11 13.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-02-2024 14:25:49	warning	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;
03-02-2024 14:25:46	critical	No Maintenance Broadcasts for Ranging opportunities received - T2 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-02-2024 14:25:46	warning	TCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-02-2024 14:25:46	notice	REGISTRATION COMPLETE - Waiting for Operational status
03-02-2024 14:25:36	warning	Dynamic Range Window violation
03-02-2024 14:25:36	warning	REG-RSP-MP Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-02-2024 14:25:36	warning	RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-02-2024 14:25:36	warning	RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-02-2024 14:25:36	warning	RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-02-2024 14:25:36	warning	Dynamic Range Window violation
03-02-2024 14:25:36	warning	Dynamic Range Window violation
03-02-2024 14:25:36	warning	Dynamic Range Window violation
03-02-2024 14:25:36	warning	RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-02-2024 14:25:30	notice	DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-02-2024 14:25:27	notice	TLV-11 - unrecognized OID;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-02-2024 14:25:24	warning	DHCP WARNING - Non-critical field invalid in response ;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-02-2024 14:25:22	notice	Honoring MDD; IP provisioning mode = IPv4
03-02-2024 14:25:04	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-02-2024 14:24:59	critical	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;

[legacy1]

setup a BQM post live link

Broadband Quality Monitor | thinkbroadband

[Cardiffman282]

All I can say is that a few of the downstream channels are out of spec but I am sure you already knew this. One for a tech again. 

[Travelstar]

Yes - aware two are definitely out of spec. The real issue is if I put on a slightly higher attenuator, my upstream goes out of spec.

The balance is not in my favour.

[Sabrina_B]

Hi @Travelstar 👋.

thanks for reaching out to us, apologies you are having issues with your internet service. Could you please run the diagnostics again ensuring that all third party equipment such as additional Hubs has been removed the our equipment is in router mode and post the updated results so we can look into this further.

Thanks

Sabrina

[Travelstar]

Thanks for your message.

I can't see how changing things to router mode will impact line conditions. The router/model will have zero impact on the actual coax line conditions. Also I should point out that most of my devices with the exception of my IoT equipment is connected via ethernet.

I still have 2 downstream channels which are out of spec most of the time (i.e. above 10 dBmV), and my upstream sits around 47 dBmV. This means going above the 6 dB attenuator which is currently on the coax line can easily exceed upstream tolerances.

I've had less issues in the last week, but I suspect the milder temps may have helped. Obviously change of overall temperatures impact the conductivity of the line in general, and the recent weather changes we have had probably caused a lot of the recent problems I have had. That said, we really should not be in a situation where small temperatures changes cause so many issues.

A couple of months ago a tech moved me to another tap, so I do strongly suspect there is a bit of line noise coming from somewhere.

[legacy1]

---

@Travelstar wrote:I can't see how changing things to router mode will impact line conditions. The router/model will have zero impact on the actual coax line conditions.

---

VM just want to drag your problem out really they can test some stuff over 10. but router mode lets them test speed to the hub which again is limited as it don't test over a Ethernet port should that be faulty.

Setup a BQM

[Tudor]

"

out of spec most of the time (i.e. above 10 dBmV), and my upstream sits around 47 dBmV. This means going above the 6 dB attenuator which is currently on the coax line can easily exceed upstream tolerances.".
FYI the attenuators fitter are forward path only ones which means they only affect the downstream power levels, not the upstream ones.

[Travelstar]

I know if I add another, it makes the upstream worse. For example 2 x 6 attenuators ends up with 52/53 on the upstream, bringing another set of issues to my connection.

[Travelstar]

Agree.

Personally I think I might have multiple issues. Whilst I'm not bothered about the Pre CRC errors that constantly come up (I've rarely seen a Post CRC error), the fact that they come up at all with this hub is somewhat telling.

My previous Hub 4 did not have these, although there was definitely some line noise somewhere based on some of the other readings that came in from time to time.

The question is therefore whether this is a hub based issue partially, or something about the cable running in the street, or noise generated somewhere in the general network vicinity.

The problem is that this week I am not seeing lots of drops, but in another week or two, I am sure they will be back again. Changes in weather also tend to precipitate this to a large extent.