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nk3
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Pre and Post RS Errors

Hi,

I wonder if someone can help. My broadband bandwidth is meant to be 100Mb/s Wifi connection keeps dropping very poor.

I've rebooted and hard reset my hub3 many times, but no change.

I've checked the network status - and have lots of errors.

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

Is this an issue at my end? or i need an engineer to get it fixed

N.

Downstream bonded channels

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

11387500001.240256 qam1
21467500001.240256 qam2
31547500000.940256 qam3
41627500000.940256 qam4
51707500000.540256 qam5
61787500000.240256 qam6
7186750000-0.240256 qam7
8194750000-140256 qam8
9202750000-140256 qam9
10210750000-1.540256 qam10
11218750000-1.540256 qam11
12226750000-2.240256 qam12
13234750000-2.940256 qam13
14242750000-340256 qam14
15250750000-3.240256 qam15
16258750000-3.740256 qam16
17266750000-3.740256 qam17
18274750000-4.240256 qam18
19282750000-4.440256 qam19
20290750000-4.540256 qam20
21298750000-4.540256 qam21
22306750000-4.540256 qam22
23314750000-4.940256 qam23
24322750000-4.440256 qam24

 

Downstream bonded channels

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

1Locked40.9743846290427
2Locked40.313498516868
3Locked40.927869911874
4Locked40.9470724121437
5Locked40.3317603382
6Locked40.928313715248
7Locked40.334497209
8Locked40.316907146
9Locked40.314066174
10Locked40.311951151
11Locked40.98844160
12Locked40.38291177
13Locked40.38525137
14Locked40.36707203
15Locked40.36258132
16Locked40.95285211
17Locked40.35889208
18Locked40.37863164
19Locked40.39601119
20Locked40.36975183
21Locked40.36095119
22Locked40.96619134
23Locked40.38948118
24Locked40.3613394
 
Upstream bonded channelsChannel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID
15370009346.3512064 qam6
26030018745.8512064 qam5
33940010845.3512064 qam8
44620000045.5512064 qam7


Upstream bonded channelsChannel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts
1ATDMA0040
2ATDMA0030
3ATDMA0010
4ATDMA0030

 

 

Network Log
Time Priority Description
09/05/2021 16:24:12 notice LAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
09/05/2021 10:21:22 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
08/05/2021 17:39:32 critical No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
08/05/2021 17:09:11 Error DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
08/05/2021 11:38:43 notice LAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
07/05/2021 22:38:5 critical No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
07/05/2021 10:02:3 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

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Richw1982
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Re: Pre and Post RS Errors

Your Downstream levels should be between -6 and +10 with a slope no greater than +/-8.   Your DS levels are getting quite low and have a 7ish db slope on only a snapshot of the frequency's.  I would check all connections and remove any attenuators (little rectangular devices that usually come in 3/6/10 values).  Then reboot the hub and recheck the levels its reporting.

 

 

I work for VMO2 but all opinions are my own and are based on my own experiences
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Andrew-G
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Re: Pre and Post RS Errors

Yep, that's a manky set of hub status data, showing problems on downstream power, downstream errors counts, upstream timeouts, and the network log problems.  I've flagged that for staff to advise, chances are that it's an easy fix for a field technician, and if needed the forum staff will book one for you.

Incidentally, don't worry about pre-RS errors - those occur in normal operation, and are corrected by the hub's processing without any impact on performance.  It's the post-RS errors that cause problems, because those are uncorrectable, causing corrupt or missing data, slowing downloads and sabotaging video call s and gaming.

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Andrew-G
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Re: Pre and Post RS Errors

@Richw1982 An observation only: I've yet to see a VM hub work properly with a downstream power range greater than 4.5 dBmV, and I've seen Arris publications for similar DOCSIS 3.0 hubs that indicate the makers believe the acceptable range is 3 dBmV.  VM won't be drawn on the range they consider acceptable.

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Richw1982
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Re: Pre and Post RS Errors

Virgin stats are Forward path -6 to +10 and Return 33 to 51.  On fibre its the same downstream but return path 27-45.  Light levels at ONU 0 to -4.  

Whats making me think is the return is 45 so ideally the levels should be between 0 to 4 on forward which isnt the case, so its either an attenuator, damaged cable or network is out of spec..

I work for VMO2 but all opinions are my own and are based on my own experiences
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Tudor
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Re: Pre and Post RS Errors

or your connection has been moved to a wrong tap on the street cabinet. 


Tudor
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Zak_M
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Re: Pre and Post RS Errors

Good morning @nk3 

 

Welcome to the forums and thank you for taking the time to post. 

 

I am really sorry to hear that you have had some issues with your broadband. 

 

I have taken a look over your account and there are some with your down stream power levels, we are going to need to get an engineer out to you. 

 

I will pop you over a PM so that I can confirm your address. 

 

Kind regards,

Zak_M 

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