cancel
Showing results for 
Search instead for 
Did you mean: 

Question about downstream values dropping after local maintenance outage

fizz
Superfast

Just a question here. We have had some maintenance in our area today and I have had a couple of outages this morning. However, I have noticed my down stream values have dropped by about 3-4dbmv from around 8 to around 4. What would explain this and should I be concerned or need to take any action? Also pre and post errors seem to be increasing. I may have to obvioulsy wait until the maintenance has donw with tomorrow but the errors have actually been happening for a few days but I have noticed no affect on my broadband.

My Broadband Ping - Virgin
14 REPLIES 14

cje85
Trouble shooter

The ideal downstream power is 0, so your figures have actually improved. Anything between around -6 and +10 is OK.

Adduxi
Very Insightful Person
Very Insightful Person

Drop could simply be replaced components are of better quality, or they have increased power for more users?  PreRS errors can be ignored, it's the PostRS errors that need looked at.  Wait until the work is finished and reboot your Hub for a clean slate.  Monitor the errors then, and if they mount up then come back and post all your power levels and network log for comment.

I'm a Very Insightful Person, I'm here to share knowledge, I don't work for Virgin Media. Learn more

Have I helped? Click Mark as Helpful Answer or use Kudos to say thanks

Well I did wonder that and I have an attenuator on the back of mine too I was just worried that perhaps I didn't need it any more for example 🙂

 

My Broadband Ping - Virgin

fizz
Superfast

I rebooted yesterday evening after the work was confirmed as complete and have noticed pre-rs errors going up (the did not before for weeks at a time sometimes). I will reset again and come back but my power levels are a lot different to what they were to be honest and a bigger spread too..

My Broadband Ping - Virgin

Adduxi
Very Insightful Person
Very Insightful Person

That's a fairly decent BQM since 12am.  PreRS errors are fine, as they have been corrected.  It's the PostRS errors that are bad.

I'm a Very Insightful Person, I'm here to share knowledge, I don't work for Virgin Media. Learn more

Have I helped? Click Mark as Helpful Answer or use Kudos to say thanks

fizz
Superfast

Thanks adduxi. Looks like I am back to my problems after 4pm again. Had this for about 6 months and 5 engineers and cable repulls could not fix the issue. Keeping an eye on it as modem mode seems to help a lot for me. Will post back tomorrow of stats are rubbish.

My Broadband Ping - Virgin

fizz
Superfast

For reference here are my figures after a reboot at 9pm last night -

3.0 Downstream channels

Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID
13310000003.738QAM 25625
22670000004.438QAM 25617
32750000004.238QAM 25618
42830000004.138QAM 25619
52910000004.138QAM 25620
6299000000438QAM 25621
73070000003.838QAM 25622
83150000003.438QAM 25623
93230000003.538QAM 25624
10339000000438QAM 25626
113470000004.338QAM 25627
123550000004.238QAM 25628
133630000004.238QAM 25629
143710000004.438QAM 25630
153790000004.338QAM 25631
16387000000438QAM 25632
17395000000438QAM 25633
184030000003.638QAM 25634
194110000003.437QAM 25635
204190000003.238QAM 25636
214270000003.237QAM 25637
224350000003.338QAM 25638
234430000003.638QAM 25639
244510000003.838QAM 25640
254590000003.738QAM 25641
264670000003.538QAM 25642
274750000003.638QAM 25643
284830000003.538QAM 25644
294910000003.437QAM 25645
304990000003.237QAM 25646
315070000003.137QAM 25647
325150000002.937QAM 25648

3.0 Downstream channels

Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors
1Locked3800
2Locked3800
3Locked3800
4Locked3800
5Locked3800
6Locked3800
7Locked3800
8Locked3800
9Locked3800
10Locked3800
11Locked3800
12Locked3800
13Locked3830
14Locked3810
15Locked3800
16Locked3800
17Locked3810
18Locked3800
19Locked3700
20Locked3800
21Locked3700
22Locked3800
23Locked3800
24Locked3800
25Locked3800
26Locked3810
27Locked3800
28Locked3810
29Locked3700
30Locked3710
31Locked3700
32Locked3720

3.1 Downstream channels

Channel Channel Width (MHz) FFT Type Number of Active Subcarriers Modulation (Active Profile) First Active Subcarrier (Hz)
1591904K3736QAM 4096148

3.1 Downstream channels

Channel ID Locked Status RxMER Data (dB) PLC Power (dBmV) Corrected errors (Active Profile) Uncorrectable errors (Active Profile)
159Locked392.45206841100
 

3.0 Upstream channels

Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID
04960000043.85120QAM 641
14310000043.85120QAM 642
23660000043.85120QAM 643
330100000435120QAM 644
42360000042.85120QAM 645

3.0 Upstream channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts
0ATDMA0000
1ATDMA0000
2ATDMA0000
3ATDMA0000
4ATDMA0000

3.1 Upstream channels

Channel Channel Width (MHz) Power (dBmV) FFT Type Modulation
61038.02KQAM 256

3.1 Upstream channels

Channel Channel Type Number of Active Subcarriers First Active Subcarrier (Hz) T3 Timeouts T4 Timeouts
6OFDMA200740000000

0

 

07-03-2024 21:05:25warningDBC-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;
07-03-2024 21:05:25noticeUS 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;
07-03-2024 21:05:21noticeREGISTRATION COMPLETE - Waiting for Operational status
My Broadband Ping - Virgin

Hi @fizz, thank you for your posts.

We're sorry to hear about the concerns you have 😔

I've taken a look on our side, but I cannot see any issues that could be causing this. How have things been since you last posted?

Please pop back to us at your earliest convenience.

Thank you for your support @Adduxi 👍

Regards,
Daniel

fizz
Superfast

Hi Daniel,

I didn't really have an issue just that all my stats on the downstream dropped quite dramatically and now I'm getting more prers errors that I used to. Connectivity seems fine in all honesty.

My Broadband Ping - Virgin