cancel
Showing results for 
Search instead for 
Did you mean: 

Climbing Post RS and uncorrectable errors

Sdavlaws
Tuning in

Hello,

We upgraded recently to add TV and phone to our package, since that upgrade something about the broadband was a little....off which after a few weeks of been like this mainly noticeable in gaming, remote desktop or other streaming I logged into the Hub to see Post RS Errors on the 3.0 channels where in the in the almost a year before it was 0 across the board. The 3.1 channel is also visible now with this showing errors

I have watched this over a period of a week or two and all area including upstream time outs are climbing over time. According to the VM webpage there isn't any broadband issues in my area, can anyone see any issues in the router stats below to see if I need to involve VM.

Thanks.

3.0 Downstream channels

Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID
1 331000000 2.4 39 QAM 256 25
2 139000000 3.4 38 QAM 256 1
3 147000000 3.4 38 QAM 256 2
4 155000000 3.3 39 QAM 256 3
5 163000000 3.5 39 QAM 256 4
6 171000000 3.3 39 QAM 256 5
7 179000000 3.7 39 QAM 256 6
8 187000000 3.6 39 QAM 256 7
9 195000000 4 39 QAM 256 8
10 203000000 3.7 39 QAM 256 9
11 211000000 4.2 39 QAM 256 10
12 219000000 4 39 QAM 256 11
13 227000000 3.9 39 QAM 256 12
14 235000000 3.9 39 QAM 256 13
15 243000000 3.6 39 QAM 256 14
16 251000000 3.5 39 QAM 256 15
17 259000000 3.2 39 QAM 256 16
18 267000000 3.1 39 QAM 256 17
19 275000000 2.9 39 QAM 256 18
20 283000000 2.5 39 QAM 256 19
21 291000000 2.8 39 QAM 256 20
22 299000000 2.4 39 QAM 256 21
23 307000000 2.6 39 QAM 256 22
24 315000000 2.3 39 QAM 256 23
25 323000000 2.4 39 QAM 256 24
26 339000000 2.5 39 QAM 256 26
27 347000000 2.9 39 QAM 256 27
28 355000000 2.7 39 QAM 256 28
29 363000000 3.2 39 QAM 256 29
30 371000000 3 39 QAM 256 30
31 379000000 3.3 39 QAM 256 31
3.0 Downstream channels

Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors
1 Locked 39 59 137
2 Locked 38 40 132
3 Locked 38 43 126
4 Locked 39 39 147
5 Locked 39 36 141
6 Locked 39 38 174
7 Locked 39 40 142
8 Locked 39 33 152
9 Locked 39 29 134
10 Locked 39 31 179
11 Locked 39 48 129
12 Locked 39 29 137
13 Locked 39 39 108
14 Locked 39 63 148
15 Locked 39 108 88
16 Locked 39 64 122
17 Locked 39 37 116
18 Locked 39 28 115
19 Locked 39 32 123
20 Locked 39 45 93
21 Locked 39 58 127
22 Locked 39 92 103
23 Locked 39 127 95
24 Locked 39 146 96
25 Locked 39 102 104
26 Locked 39 52 99
27 Locked 39 49 98
28 Locked 39 47 67
29 Locked 39 48 60
30 Locked 39 48 98
31 Locked 39 49 60
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 41 4.9 3198034475 103744

3.0 Upstream channels

Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID
0 60300000 41.5 5120 QAM 64 1
1 53700000 41.3 5120 QAM 64 2
2 46200000 42 5120 QAM 64 3
3 39400000 42 5120 QAM 64 4
4 32600000 41.8 5120 QAM 64 5
5 23600000 42 5120 QAM 64 6
3.0 Upstream channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts
0 ATDMA 0 1 1 0
1 ATDMA 0 1 0 0
2 ATDMA 0 1 0 0
3 ATDMA 0 1 2 0
4 ATDMA 0 1 18 0
5 ATDMA 0 1 0 0

 

6 REPLIES 6

Adduxi
Very Insightful Person
Very Insightful Person

Ideally you should have zero PostRS errors on the circuit.  These are packets that have to be re-transmitted as they cannot be corrected, unlike PreRS errors. So, there is an issue on the circuit, possibly noise ingress.  Also you have 18 T3 timeouts, which IMHO should be lower. 

Post the network log as well for completeness and comment, and setup a BQM to monitor the state of the circuit  www.thinkbroadband.com/ping

When done, post a link to the shared live graph.  It may show more information.

All you can do is make sure the connections are "finger" tight from the Hub to the outside omnibox on the wall.

Otherwise, wait here a day or two for a VM Mod to pick this up and discuss. 

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

Thanks for looking the network log is below, I'll get a BQM set up

15-11-2023 00:45:05noticeREGISTRATION COMPLETE - Waiting for Operational status
15-11-2023 00:44:59warningREG-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;
15-11-2023 00:44:54noticeDS 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;
15-11-2023 00:44:51noticeTLV-11 - unrecognized OID;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
15-11-2023 00:44:48warningDHCP WARNING - Non-critical field invalid in response ;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
15-11-2023 00:44:46noticeHonoring MDD; IP provisioning mode = IPv4
15-11-2023 00:44:31criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
15-11-2023 00:44:27criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
15-11-2023 00:44:26criticalCable Modem Reboot because of - Reboot UI
29-10-2023 12:57:00criticalStarted Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
29-10-2023 12:57:00criticalUnicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
29-10-2023 12:57:00critical16 consecutive T3 timeouts while trying to range on upstream channel 4;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
29-10-2023 12:55:00criticalStarted Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
29-10-2023 12:53:16criticalStarted Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
29-10-2023 12:53:00criticalStarted Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
29-10-2023 12:52:46criticalNo Maintenance Broadcasts for Ranging opportunities received - T2 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
29-10-2023 12:52:36criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
29-10-2023 12:52:25criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
29-10-2023 12:52:19criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
29-10-2023 12:52:17criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
12-10-2023 19:45:57criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
12-10-2023 19:45:56criticalCable Modem Reboot because of - HW or Power-On Reset
12-10-2023 18:41:18criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
12-10-2023 18:41:17criticalCable Modem Reboot because of - HW or Power-On Reset
03-10-2023 03:19:04criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-10-2023 03:18:58criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-10-2023 03:18:57criticalCable Modem Reboot because of - Software_Upgrade
25-09-2023 21:00:51criticalStarted Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
25-09-2023 21:00:01criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
25-09-2023 20:59:57criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
15-08-2023 03:18:19criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
04-07-2023 11:04:58criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;

Adduxi
Very Insightful Person
Very Insightful Person

That's not a good looking log, too many T3 and SYNC timing failures IMHO.  Lets hear what VM say from their end?

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

Hi @Sdavlaws, thank you for your post.

We're sorry to hear about the problems you've been having with your broadband service 😔

I've taken a look on our side, but I cannot see anything that could explain these. 

How have things been since you last posted? Advice on how to fix internet problems can be found here

Please pop back to us at your earliest convenience.

Thank you for your support @Adduxi 👍

Regards,
Daniel

Since my most recent modem reboot, the error rate has lowered still getting pre RS errors but nothing post RS, The DOCSIS 3.1 uncorrectable errors is still climbing though up to 24k now.

Hi @Sdavlaws,

I've just checked over things on our systems and I'm unable to detect any faults currently. Are these connection issues ongoing for you today?

Thanks,
 


Zach - Forum Team
New around here? To find out more about the Community Forums, take a look at our FAQs!