Virgin Media Community

[TheGiraffe]

Hi,

I wonder if someone can help. My broadband bandwidth is meant to be 100Mb/s but i'm barely hitting 0.5Mb/s on download now. Everything was okay until ~ 2 days ago and now it's very poor.

I've rebooted my shub3 earlier today, but no change.

I've checked the network status - Channels 13, 14, 21, 22, 23, 24 have lots of errors and low(er) power.

Downstream , Upstream and Log follow. See errors in downstream and log.

Is this an issue at my end? Everything was okay until two days ago.

Cheers.

Downstream bonded channels
Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID
1 299000000 -0.2 38 256 qam 21
2 323000000 -1.5 38 256 qam 24
3 315000000 -1.2 38 256 qam 23
4 307000000 -0.5 40 256 qam 22
5 291000000 -0.4 38 256 qam 20
6 283000000 -0.5 40 256 qam 19
7 275000000 -0.5 40 256 qam 18
8 267000000 -0.5 40 256 qam 17
9 259000000 -0.5 40 256 qam 16
10 251000000 -0.5 38 256 qam 15
11 243000000 -0.9 38 256 qam 14
12 235000000 -1.2 37 256 qam 13
13 227000000 -1.4 32 256 qam 12
14 219000000 -0.7 33 256 qam 11
15 211000000 -0.5 38 256 qam 10
16 203000000 -0.7 37 256 qam 9
17 195000000 -1 37 256 qam 8
18 187000000 -1.2 38 256 qam 7
19 179000000 -1.4 37 256 qam 6
20 171000000 -0.7 37 256 qam 5
21 163000000 -1.7 32 256 qam 4
22 155000000 -1.7 28 256 qam 3
23 147000000 -1.2 31 256 qam 2
24 139000000 -0.7 32 256 qam 1

Downstream bonded channels
Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors
1 Locked 38.6 1172 245
2 Locked 38.9 1478 376
3 Locked 38.6 1231 340
4 Locked 40.3 1078 376
5 Locked 38.9 1393 542
6 Locked 40.3 1473 488
7 Locked 40.3 1498 46
8 Locked 40.9 1752 245
9 Locked 40.3 2531 251
10 Locked 38.6 2854 263
11 Locked 38.9 1940 271
12 Locked 37.3 3088 321
13 Locked 33 2276034 460
14 Locked 33.8 2741820 491
15 Locked 38.6 2788 644
16 Locked 37.6 4227 1670
17 Locked 37.3 4862 4116
18 Locked 38.6 1029 60944
19 Locked 37.3 4762 1109
20 Locked 37.3 14009 721
21 Locked 32.3 79911650 593
22 Locked 29.3 88009793 365275758
23 Locked 31.1 263075079 190205141
24 Locked 32.5 437553896 7061451

Upstream bonded channels
Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID
1 39400000 45.8 5120 16 qam 6
2 46200000 47.8 5120 16 qam 5
3 25800000 46.8 5120 16 qam 8
4 32600000 45.5 5120 16 qam 7

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
2019-02-08 13:53:12.00 Warning! Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-02-08 13:53:23.00 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-02-08 13:53:40.00 Warning! Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-02-08 13:56:48.00 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-02-08 13:56:56.00 Warning! Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-02-08 14:06:48.00 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-02-08 14:06:56.00 Warning! Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-02-08 14:07:18.00 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-02-08 14:07:30.00 Warning! Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-02-08 14:07:41.00 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-02-08 14:07:44.00 Warning! Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-02-08 14:07:48.00 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-02-08 14:07:54.00 Warning! Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-02-08 14:07:54.00 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-02-08 14:08:12.00 Warning! Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-02-08 14:16:41.00 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-02-08 14:38:58.00 Warning! Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-02-08 14:41:23.00 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-02-08 14:42:54.00 Warning! Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-02-08 14:47:18.00 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

[Dave_cq]

You have correctly identified Channels 13, 14, 21, 22, 23, 24 as having issues but it's not the power levels, all of which are within specification, it is the Signal-to-noise levels that are below the 34.5 db threshold that is the issue.  In other words you have a lot of noise on the line and you will need an engineer's visit to look into that.

[TheGiraffe]

Thanks for fast response. Are they the SNR values? What could cause noise now if it was okay a few days ago?

I'll book in an engineer

[Dave_cq · Accepted solution]

---

@TheGiraffe wrote:
Thanks for fast response. Are they the SNR values? What could cause noise now if it was okay a few days ago?

I'll book in an engineer

---

Yes, the downstream SNR levels should be greater than 34.5 db.  I should also have mentioned that whilst still within specification (less than 51dbmv) your Upstream power levels are at the high end of the scale and that together with all 4 Upstream channels being on 16 rather than 64 QAM would also suggest a noisy connection.

Check the security of the cable connections at the back of the hub and the wall socket and if they are tight then you've done all you can and an engineer will be needed.

Changes like this can be due to numerous reasons so I won't speculate.

[TheGiraffe]

Thanks, much appreciated

[Dave_cq]

You're welcome ... hope you get a speedy resolution.

[steambop]

I was hoping you could give some advice on a similar issue.

Recently got Virgin Media Hub 3.0 with 250 MBps internet and it doesn't seem to be working properly.
I checked in network status and the power levels and SNR all seem to be within nominal tolerance.

Despite this something seems to be really wrong with the Pre RS errors. They are growing continually at a very fast rate everytime I refresh the page.

I tried resetting the router, reconnecting the coax cable but with no success. 

Any ideas what could be causing this?

Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID
1 482000000 6 40 256qam 1
2 490000000 6 40 256qam 2
3 498000000 5 40 256qam 3
4 506000000 5 40 256qam 4
5 514000000 5 40 256qam 5
6 522000000 5 40 256qam 6
7 530000000 5 40 256qam 7
8 650000000 2 40 256qam 9
9 658000000 2 38 256qam 10
10 666000000 2 40 256qam 11
11 674000000 1 38 256qam 12
12 682000000 1 38 256qam 13
13 690000000 1 38 256qam 14
14 698000000 1 40 256qam 15
15 706000000 1 40 256qam 16
16 714000000 1 40 256qam 17
17 722000000 0 38 256qam 18
18 730000000 1 38 256qam 19
19 738000000 1 40 256qam 20
20 746000000 1 38 256qam 21
21 754000000 0 38 256qam 22
22 762000000 1 38 256qam 23
23 770000000 0 38 256qam 24
24 778000000 0 38 256qam 25

Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors
1 Locked 40.946 153501907 2474
2 Locked 40.946 151688657 5
3 Locked 40.366 151690393 6
4 Locked 40.946 151690316 0
5 Locked 40.366 151687004 4
6 Locked 40.946 151690844 5
7 Locked 40.946 151688632 0
8 Locked 40.366 151693503 2
9 Locked 38.983 151690675 6
10 Locked 40.366 151689456 6
11 Locked 38.983 151692746 6
12 Locked 38.983 151693743 6
13 Locked 38.983 151689478 6
14 Locked 40.366 151686268 8
15 Locked 40.366 151692571 5
16 Locked 40.366 151693107 0
17 Locked 38.983 151693928 0
18 Locked 38.983 151689654 6
19 Locked 40.366 151694568 1
20 Locked 38.605 151694695 1
21 Locked 38.605 151690028 3
22 Locked 38.983 151695620 12
23 Locked 38.983 151696345 8
24 Locked 38.983 151697208 16

05-06-2019 15:18:07 warning MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
01-01-1970 00:01:20 notice Cable Modem Reboot - CBN: Modem Mode changed, reboot system.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05-06-2019 14:11:34 critical No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05-06-2019 13:14:57 warning MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05-06-2019 13:14:49 notice Illegal - Dropped FORWARD packet: src=192.168.0.17 MAC=**:**:**:**:**:**;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;