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Gig1 Connection stability issues

Travelstar
Dialled in

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
13310000008.740QAM 25625
213900000010.540QAM 2561
314700000010.340QAM 2562
41550000009.740QAM 2563
51630000009.340QAM 2564
6171000000940QAM 2565
71790000008.940QAM 2566
81870000008.840QAM 2567
91950000008.840QAM 2568
102030000008.840QAM 2569
112110000008.940QAM 25610
122190000008.940QAM 25611
132270000008.740QAM 25612
142350000008.840QAM 25613
152430000008.940QAM 25614
162510000008.741QAM 25615
172590000008.641QAM 25616
182670000008.441QAM 25617
192910000008.840QAM 25620
20299000000941QAM 25621
213070000009.141QAM 25622
22315000000941QAM 25623
233230000008.940QAM 25624
243390000008.840QAM 25626
253470000008.840QAM 25627
263550000008.841QAM 25628
27363000000941QAM 25629
28371000000941QAM 25630
293790000009.241QAM 25631
303870000008.841QAM 25632
31395000000941QAM 25633
324030000008.641QAM 25634

3.0 Downstream channels

Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors
1Locked40790
2Locked40160
3Locked40160
4Locked4010
5Locked4020
6Locked4020
7Locked4020
8Locked40110
9Locked40100
10Locked4090
11Locked40130
12Locked40110
13Locked4080
14Locked40100
15Locked40100
16Locked41160
17Locked4190
18Locked41190
19Locked40350
20Locked41330
21Locked41420
22Locked41720
23Locked40650
24Locked401050
25Locked401160
26Locked411250
27Locked411100
28Locked41980
29Locked411320
30Locked411510
31Locked41630
32Locked41710

3.1 Downstream channels

Channel Channel Width (MHz) FFT Type Number of Active Subcarriers Modulation (Active Profile) First Active Subcarrier (Hz)
159944K1840QAM 40961108

3.1 Downstream channels

Channel ID Locked Status RxMER Data (dB) PLC Power (dBmV) Corrected errors (Active Profile) Uncorrectable errors (Active Profile)
159Locked438.418095552680

 

3.0 Upstream channels

Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID
04960000046.85120QAM 641
14310000046.85120QAM 642
236600000475120QAM 643
330100000475120QAM 644
42360000047.55120QAM 645

3.0 Upstream channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts
0ATDMA0130
1ATDMA0100
2ATDMA0100
3ATDMA0100
4ATDMA0100

3.1 Upstream channels

Channel Channel Width (MHz) Power (dBmV) FFT Type Modulation
61040.52KQAM 256

3.1 Upstream channels

Channel Channel Type Number of Active Subcarriers First Active Subcarrier (Hz) T3 Timeouts T4 Timeouts
6OFDMA2007400000000

 

Network Log

Time Priority Description
04-02-2024 14:58:01warningDBC-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 14:58:01noticeUS 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 13:50:20noticeUS 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 13:50:20warningDBC-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 07:44:38noticeUS 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 07:44:38warningDBC-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 07:34:34noticeUS 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 07:34:34warningDBC-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 00:05:50warningDBC-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 14:55:23errorDHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-02-2024 14:25:49warningDynamic Range Window violation
03-02-2024 14:25:49warningRNG-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 14:25:49noticeUS 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 14:25:49warningDBC-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 14:25:46criticalNo Maintenance Broadcasts for Ranging opportunities received - T2 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-02-2024 14:25:46warningTCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-02-2024 14:25:46noticeREGISTRATION COMPLETE - Waiting for Operational status
03-02-2024 14:25:36warningDynamic Range Window violation
03-02-2024 14:25:36warningREG-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 14:25:36warningRNG-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 14:25:36warningRNG-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 14:25:36warningRNG-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 14:25:36warningDynamic Range Window violation
03-02-2024 14:25:36warningDynamic Range Window violation
03-02-2024 14:25:36warningDynamic Range Window violation
03-02-2024 14:25:36warningRNG-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 14:25:30noticeDS 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 14:25:27noticeTLV-11 - unrecognized OID;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-02-2024 14:25:24warningDHCP WARNING - Non-critical field invalid in response ;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-02-2024 14:25:22noticeHonoring MDD; IP provisioning mode = IPv4
03-02-2024 14:25:04criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-02-2024 14:24:59criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
 

 

9 REPLIES 9

legacy1
Alessandro Volta

setup a BQM post live link

Broadband Quality Monitor | thinkbroadband

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Cardiffman282
Problem sorter

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. 

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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.

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

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.


@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

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Tudor
Very Insightful Person
Very Insightful Person

"

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.


Tudor
There are 10 types of people: those who understand binary and those who don't and F people out of 10 who do not understand hexadecimal c1a2a285948293859940d9a49385a2

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.

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.