03-07-2021 11:52 - edited 03-07-2021 11:56
Hello,
We've been having intermittent connection problems with our Virgin Media broadband over the last few weeks. Before this, the connection was rock solid for a couple of years.
We have a SH3 in modem mode connected to an Asus RT-AC68U router. The connection can be restored by powering off the SH3 for a good few minutes and then restarting it but the issue reappears any time between a couple of hours and a couple of days later.
I've checked the connections to the wall and the SH3 are all finger tight and the ASUS router and PC are hard-wired so it's not a Wifi problem.
Checking the Network logs, I noticed these errors at the time of the last disconnection (yesterday):
02/07/2021 16:04:32 | Warning! | RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
02/07/2021 16:04:32 | critical | SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
02/07/2021 16:04:31 | Warning! | RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
02/07/2021 16:04:31 | critical | SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
02/07/2021 16:04:30 | Warning! | RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
02/07/2021 16:04:29 | critical | SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
02/07/2021 16:04:27 | Warning! | RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
02/07/2021 16:04:27 | critical | SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
02/07/2021 16:04:25 | Warning! | RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
02/07/2021 16:04:25 | critical | SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
02/07/2021 16:04:23 | Warning! | RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
02/07/2021 16:04:23 | critical | SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
02/07/2021 16:04:22 | Warning! | RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
02/07/2021 16:04:22 | critical | SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
02/07/2021 16:04:21 | Warning! | RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
02/07/2021 16:04:21 | critical | SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
02/07/2021 16:04:19 | Warning! | RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
02/07/2021 16:04:19 | critical | SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
02/07/2021 16:04:19 | Warning! | RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
on 03-07-2021 11:52
and here is the rest of the info from the SH3:
Downstream bonded channels
Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID
1 | 298750000 | 5.4 | 38 | 256 qam | 21 |
2 | 138750000 | 5.5 | 40 | 256 qam | 1 |
3 | 146750000 | 5.5 | 40 | 256 qam | 2 |
4 | 154750000 | 5.5 | 40 | 256 qam | 3 |
5 | 162750000 | 5.4 | 40 | 256 qam | 4 |
6 | 170750000 | 5.4 | 40 | 256 qam | 5 |
7 | 178750000 | 5.1 | 40 | 256 qam | 6 |
8 | 186750000 | 5.3 | 38 | 256 qam | 7 |
9 | 194750000 | 5.3 | 40 | 256 qam | 8 |
10 | 202750000 | 5.1 | 40 | 256 qam | 9 |
11 | 210750000 | 5.3 | 40 | 256 qam | 10 |
12 | 218750000 | 5.3 | 40 | 256 qam | 11 |
13 | 226750000 | 5.4 | 40 | 256 qam | 12 |
14 | 234750000 | 5.4 | 40 | 256 qam | 13 |
15 | 242750000 | 5 | 40 | 256 qam | 14 |
16 | 250750000 | 5 | 40 | 256 qam | 15 |
17 | 258750000 | 5.1 | 40 | 256 qam | 16 |
18 | 266750000 | 5.5 | 40 | 256 qam | 17 |
19 | 274750000 | 5.5 | 40 | 256 qam | 18 |
20 | 282750000 | 5.5 | 40 | 256 qam | 19 |
21 | 290750000 | 5.3 | 40 | 256 qam | 20 |
22 | 306750000 | 5.4 | 40 | 256 qam | 22 |
23 | 314750000 | 5.5 | 40 | 256 qam | 23 |
24 | 322750000 | 5.8 | 40 | 256 qam | 24 |
Downstream bonded channels
Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors
1 | Locked | 38.9 | 13 | 0 |
2 | Locked | 38.9 | 8 | 0 |
3 | Locked | 40.3 | 8 | 0 |
4 | Locked | 40.3 | 14 | 0 |
5 | Locked | 40.3 | 5 | 0 |
6 | Locked | 40.3 | 5 | 0 |
7 | Locked | 40.3 | 7 | 0 |
8 | Locked | 38.9 | 7 | 0 |
9 | Locked | 40.9 | 15 | 0 |
10 | Locked | 40.3 | 11 | 0 |
11 | Locked | 38.9 | 21 | 0 |
12 | Locked | 40.3 | 8 | 0 |
13 | Locked | 40.3 | 8 | 0 |
14 | Locked | 40.3 | 7 | 0 |
15 | Locked | 40.3 | 14 | 0 |
16 | Locked | 40.3 | 8 | 0 |
17 | Locked | 40.3 | 4 | 0 |
18 | Locked | 40.3 | 9 | 0 |
19 | Locked | 40.3 | 8 | 0 |
20 | Locked | 40.3 | 15 | 0 |
21 | Locked | 40.3 | 13 | 0 |
22 | Locked | 40.3 | 6 | 0 |
23 | Locked | 40.9 | 13 | 0 |
24 | Locked | 40.3 | 9 | 0 |
Upstream bonded channels
Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID
1 | 60300000 | 42 | 5120 | 64 qam | 1 |
2 | 46200010 | 42.5 | 5120 | 64 qam | 3 |
3 | 39400068 | 42.5 | 5120 | 64 qam | 4 |
4 | 53700000 | 41.5 | 5120 | 32 qam | 2 |
Upstream bonded channels
Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts
1 | ATDMA | 0 | 0 | 0 | 0 |
2 | ATDMA | 0 | 0 | 1 | 0 |
3 | ATDMA | 0 | 0 | 0 | 0 |
4 | ATDMA | 0 | 0 | 0 | 0 |
and a link to the BQM I (only just) set up as requested in some of the other threads that I have read:
https://www.thinkbroadband.com/broadband/monitoring/quality/share/65a938ee5980a218e08cb30ba441eb9d4b2f06e7
Would somebody be kind enough to have a look at this info and suggest steps to resolve the issues?
Thanks,
Karim
on 03-07-2021 15:05
on 03-07-2021 15:54
Thanks very much for taking the time to have a look John. I've switched out the cable between the hub and the router as you suggested, will see if that makes a difference.
on 05-07-2021 12:56
Good afternoon @karimkanji
Welcome back to the forums and thank you for taking the time to post.
I am sorry to hear that you are having some issues with your services.
I have taken a look over your account and there doesn't seem to be any issues of note, all the power levels are within spec. I also checked the network and there is nothing there either, there is no utilisation work and no SNR issues.
I would advise returning the hub into modem mode for 24 hours, monitor the BQM graph and see how we go from there.
Kind regards,
Zak_M
on 05-07-2021 14:02
Hi Zak,
Thanks for taking a look. Unfortunately, having been ok all weekend, the connection has been up and down again today, starting i think just after your reply. Router logs below:
Downstream bonded channels
Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID
1 | 298750000 | 5.4 | 38 | 256 qam | 21 |
2 | 138750000 | 5.5 | 38 | 256 qam | 1 |
3 | 146750000 | 5.5 | 38 | 256 qam | 2 |
4 | 154750000 | 5.5 | 38 | 256 qam | 3 |
5 | 162750000 | 5.3 | 40 | 256 qam | 4 |
6 | 170750000 | 5.3 | 40 | 256 qam | 5 |
7 | 178750000 | 5 | 38 | 256 qam | 6 |
8 | 186750000 | 5.3 | 38 | 256 qam | 7 |
9 | 194750000 | 5.1 | 40 | 256 qam | 8 |
10 | 202750000 | 5 | 40 | 256 qam | 9 |
11 | 210750000 | 5.1 | 38 | 256 qam | 10 |
12 | 218750000 | 5.3 | 38 | 256 qam | 11 |
13 | 226750000 | 5.3 | 38 | 256 qam | 12 |
14 | 234750000 | 5.4 | 40 | 256 qam | 13 |
15 | 242750000 | 5 | 38 | 256 qam | 14 |
16 | 250750000 | 4.9 | 40 | 256 qam | 15 |
17 | 258750000 | 5.1 | 38 | 256 qam | 16 |
18 | 266750000 | 5.4 | 38 | 256 qam | 17 |
19 | 274750000 | 5.4 | 40 | 256 qam | 18 |
20 | 282750000 | 5.5 | 40 | 256 qam | 19 |
21 | 290750000 | 5.1 | 38 | 256 qam | 20 |
22 | 306750000 | 5.4 | 40 | 256 qam | 22 |
23 | 314750000 | 5.5 | 40 | 256 qam | 23 |
24 | 322750000 | 5.6 | 40 | 256 qam | 24 |
Downstream bonded channels
Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors
1 | Locked | 38.6 | 4450 | 36735 |
2 | Locked | 38.9 | 4644 | 50043 |
3 | Locked | 38.9 | 4584 | 56404 |
4 | Locked | 38.9 | 4264 | 59344 |
5 | Locked | 40.3 | 4437 | 67802 |
6 | Locked | 40.3 | 4525 | 62940 |
7 | Locked | 38.9 | 4272 | 59932 |
8 | Locked | 38.9 | 3958 | 57398 |
9 | Locked | 40.3 | 4440 | 64604 |
10 | Locked | 40.3 | 4631 | 58810 |
11 | Locked | 38.9 | 4261 | 75552 |
12 | Locked | 38.9 | 4173 | 56964 |
13 | Locked | 38.9 | 4672 | 55395 |
14 | Locked | 40.3 | 4688 | 63544 |
15 | Locked | 38.6 | 4574 | 56955 |
16 | Locked | 40.3 | 4277 | 66579 |
17 | Locked | 38.9 | 1996 | 24192 |
18 | Locked | 38.9 | 4458 | 54141 |
19 | Locked | 40.3 | 4444 | 59898 |
20 | Locked | 40.3 | 4679 | 59498 |
21 | Locked | 38.9 | 4212 | 54707 |
22 | Locked | 40.3 | 4788 | 64047 |
23 | Locked | 40.3 | 4710 | 56076 |
24 | Locked | 40.3 | 3965 | 60339 |
Upstream bonded channels
Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID
1 | 60300000 | 42.3 | 5120 | 64 qam | 1 |
2 | 46200108 | 42.5 | 5120 | 64 qam | 3 |
3 | 39400076 | 42.5 | 5120 | 64 qam | 4 |
4 | 53700000 | 42.5 | 5120 | 32 qam | 2 |
Upstream bonded channels
Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts
1 | ATDMA | 0 | 0 | 0 | 0 |
2 | ATDMA | 0 | 0 | 1 | 0 |
3 | ATDMA | 0 | 0 | 0 | 0 |
4 | ATDMA | 0 | 0 | 0 | 0 |
on 05-07-2021 14:04
Network Log
Time Priority Description
05/07/2021 12:10:10 | Warning! | RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
05/07/2021 12:10:10 | critical | SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
05/07/2021 12:10:1 | Warning! | RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
05/07/2021 12:10:1 | critical | SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
05/07/2021 12:09:53 | Warning! | RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
05/07/2021 12:09:53 | critical | SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
05/07/2021 12:09:39 | Warning! | RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
05/07/2021 12:09:39 | critical | SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
05/07/2021 12:09:33 | Warning! | RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
05/07/2021 12:09:33 | critical | SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
05/07/2021 12:09:28 | Warning! | RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
05/07/2021 12:09:28 | critical | SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
05/07/2021 12:09:23 | Warning! | RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
05/07/2021 12:09:23 | critical | SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
05/07/2021 12:09:18 | Warning! | RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
05/07/2021 12:09:18 | critical | SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
05/07/2021 12:09:10 | Warning! | RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
05/07/2021 12:09:10 | critical | SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
05/07/2021 12:09:7 | Warning! | RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
05/07/2021 12:09:7 | critical | SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0; |
and the BQM graph:
https://www.thinkbroadband.com/broadband/monitoring/quality/share/7104a1c80268b26cc64acc549baf2ac8f7869a11-05-07-2021
on 05-07-2021 14:16
on 05-07-2021 14:47
on 05-07-2021 15:26
Thanks for the replies. I replaced the Cat 6 cable between SH3 and Asus router a couple of days ago after you suggested it initially but this doesn't seem to have made any difference.
Could the connection between the router and hub also cause the timing synchronisation errors that show up in the log?
Using the SH3 in router mode (instead of having the Asus do the routing) will be tricky especially because those errors only seem to show up when the connection fails which sometimes only happens every 2 or 3 days. The errors don't just tick up constantly. For example, when I checked last night (Sunday) there were still zero errors after I reset the hub on Friday lunchtime.