Virgin Media Community

[karl3018]

Hi all,

This morning I noticed our broadband was acting up - pings wild/timing out for varying periods.  

I have the Hub 3.0 in Modem Mode, passed through to a Gigabit switch and then through to a virtualised OPNSense router.  This has been in place for over a year with no issues up to now.  

I have rebooted the modem and router numerous times today to no avail.  

Modem/Ping data below:

Downstream bonded channels
Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID
1 138750000 0 38 256 qam 1
2 146750000 -2 38 256 qam 2
3 154750000 -1.2 38 256 qam 3
4 162750000 0 38 256 qam 4
5 170750000 0 38 256 qam 5
6 178750000 0 38 256 qam 6
7 186750000 0.5 38 256 qam 7
8 194750000 0.4 39 256 qam 8
9 202750000 0.2 38 256 qam 9
10 210750000 0.2 38 256 qam 10
11 218750000 0.5 40 256 qam 11
12 226750000 -0.2 38 256 qam 12
13 234750000 -0.5 40 256 qam 13
14 242750000 0.5 38 256 qam 14
15 250750000 1 40 256 qam 15
16 258750000 0.4 38 256 qam 16
17 266750000 0 40 256 qam 17
18 274750000 0.2 38 256 qam 18
19 282750000 1.7 40 256 qam 19
20 290750000 1.9 40 256 qam 20
21 298750000 1.2 40 256 qam 21
22 306750000 0.9 40 256 qam 22
23 314750000 1.5 40 256 qam 23
24 322750000 2.7 40 256 qam 24

Downstream bonded channels
Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors
1 Locked 38.6 319201 112785
2 Locked 38.9 279707 157013
3 Locked 38.6 198375 424638
4 Locked 38.9 244653 866728
5 Locked 38.6 288930 206627
6 Locked 38.6 301859 359419
7 Locked 38.6 332377 240595
8 Locked 39.3 341951 95393
9 Locked 38.9 361200 61667
10 Locked 38.9 362520 37420
11 Locked 40.3 343300 10739
12 Locked 38.6 347335 25495
13 Locked 40.3 354400 53032
14 Locked 38.9 357221 50773
15 Locked 40.3 347871 33149
16 Locked 38.9 281292 97538
17 Locked 40.3 290634 163846
18 Locked 38.9 289566 149310
19 Locked 40.3 323905 87868
20 Locked 40.9 281382 31282
21 Locked 40.3 175664 44967
22 Locked 40.9 232416 39309
23 Locked 40.3 281847 11526
24 Locked 40.3 190753 695

Upstream bonded channels
Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID
1 53700288 51 5120 64 qam 2
2 60300351 51 5120 64 qam 1
3 39400283 51 5120 64 qam 4

Upstream bonded channels
Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts
1 ATDMA 0 0 1 0
2 ATDMA 0 0 0 0
3 ATDMA 0 0 0 0

Network Log
Time Priority Description
06/06/2021 12:11:30 critical SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
06/06/2021 12:11:29 critical Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
06/06/2021 12:11:23 critical SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
06/06/2021 12:11:0 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
06/06/2021 12:10:59 critical Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
06/06/2021 12:10:33 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
06/06/2021 12:10:29 critical Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
06/06/2021 12:10:12 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
06/06/2021 12:09:29 critical Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
06/06/2021 12:09:26 critical SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
06/06/2021 12:09:2 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
06/06/2021 12:08:59 critical Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
06/06/2021 12:08:39 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
06/06/2021 12:08:38 critical SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
06/06/2021 12:08:31 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
06/06/2021 12:08:29 critical Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
06/06/2021 12:08:18 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
06/06/2021 12:08:14 critical SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
06/06/2021 12:08:1 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
06/06/2021 12:07:59 critical Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

Pinging 8.8.8.8 with 32 bytes of data:
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Reply from 8.8.8.8: bytes=32 time=91ms TTL=116
Reply from 8.8.8.8: bytes=32 time=68ms TTL=116
Reply from 8.8.8.8: bytes=32 time=31ms TTL=116
Reply from 8.8.8.8: bytes=32 time=18ms TTL=116
Request timed out.
Reply from 8.8.8.8: bytes=32 time=78ms TTL=116
Reply from 8.8.8.8: bytes=32 time=44ms TTL=116
Reply from 8.8.8.8: bytes=32 time=34ms TTL=116
Reply from 8.8.8.8: bytes=32 time=44ms TTL=116
Reply from 8.8.8.8: bytes=32 time=189ms TTL=116
Reply from 8.8.8.8: bytes=32 time=25ms TTL=116
Reply from 8.8.8.8: bytes=32 time=152ms TTL=116
Reply from 8.8.8.8: bytes=32 time=139ms TTL=116
Reply from 8.8.8.8: bytes=32 time=67ms TTL=116
Reply from 8.8.8.8: bytes=32 time=253ms TTL=116
Reply from 8.8.8.8: bytes=32 time=13ms TTL=116
Reply from 8.8.8.8: bytes=32 time=14ms TTL=116
Reply from 8.8.8.8: bytes=32 time=22ms TTL=116
Reply from 8.8.8.8: bytes=32 time=41ms TTL=116
Reply from 8.8.8.8: bytes=32 time=36ms TTL=116
Reply from 8.8.8.8: bytes=32 time=41ms TTL=116
Reply from 8.8.8.8: bytes=32 time=167ms TTL=116
Reply from 8.8.8.8: bytes=32 time=112ms TTL=116
Reply from 8.8.8.8: bytes=32 time=61ms TTL=116
Reply from 8.8.8.8: bytes=32 time=104ms TTL=116
Reply from 8.8.8.8: bytes=32 time=166ms TTL=116
Reply from 8.8.8.8: bytes=32 time=101ms TTL=116
Reply from 8.8.8.8: bytes=32 time=47ms TTL=116
Reply from 8.8.8.8: bytes=32 time=143ms TTL=116
Reply from 8.8.8.8: bytes=32 time=28ms TTL=116
Reply from 8.8.8.8: bytes=32 time=32ms TTL=116
Request timed out.
Reply from 8.8.8.8: bytes=32 time=48ms TTL=116
Reply from 8.8.8.8: bytes=32 time=41ms TTL=116
Reply from 8.8.8.8: bytes=32 time=155ms TTL=116

Ping statistics for 8.8.8.8:
Packets: Sent = 40, Received = 33, Lost = 7 (17% loss),
Approximate round trip times in milli-seconds:
Minimum = 13ms, Maximum = 253ms, Average = 78ms

I know guidance is to call CS at 8am however I work 08:00-18:00 so sitting on the phone is not an option.  I know it is the slower route for responses, which I fully understand, but would appreciate if one of the Forum team could pick this up with me on this thread/via PM when available please.

Many thanks

Karl

[karl3018]

A downstream channel has now become "Not Locked":

Downstream bonded channels
Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID
1 138750000 0 38 256 qam 1
2 146750000 -2.2 38 256 qam 2
3 154750000 -1.5 38 256 qam 3
4 162750000 -0.2 38 256 qam 4
5 170750000 -0.4 38 256 qam 5
6 178750000 -0.2 38 256 qam 6
7 186750000 0.2 38 256 qam 7
8 194750000 0.2 40 256 qam 8
9 202750000 -0.2 38 256 qam 9
10 210750000 0 38 256 qam 10
11 218750000 0.2 40 256 qam 11
12 226750000 -0.5 38 256 qam 12
13 234750000 -0.7 39 256 qam 13
14 242750000 0.2 38 256 qam 14
15 250750000 0.7 40 256 qam 15
16 258750000 0.2 35 256 qam 16
17 266750000 -0.4 34 256 qam 17
18 274750000 0 38 256 qam 18
19 282750000 1.2 35 256 qam 19
20 290750000 1.5 37 256 qam 20
21 298750000 1 38 256 qam 21
22 306750000 0.7 38 256 qam 22
23 314750000 1.2 38 256 qam 23
24 322750000 2.5 39 256 qam 24

Downstream bonded channels
Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors
1 Locked 38.6 319201 112785
2 Locked 38.9 279707 157013
3 Locked 38.6 198375 424638
4 Locked 38.9 244653 866728
5 Locked 38.6 288930 206627
6 Locked 38.6 301859 359419
7 Locked 38.6 332377 240595
8 Locked 39.3 341951 95393
9 Locked 38.9 361200 61667
10 Locked 38.9 362520 37420
11 Locked 40.3 343300 10739
12 Locked 38.6 347335 25495
13 Locked 40.3 354400 53032
14 Locked 38.9 357221 50773
15 Locked 40.3 347871 33149
16 Locked 38.9 281292 97538
17 Locked 40.3 290634 163846
18 NotLocked 38.9 289566 149310
19 Locked 40.3 323905 87868
20 Locked 40.9 281382 31282
21 Locked 40.3 175664 44967
22 Locked 40.9 232416 39309
23 Locked 40.3 281847 11526
24 Locked 40.3 190753 695

[karl3018]

Dropped the Hub back in Router mode to bypass my home network and the Status screen shows Partial Service (US Only) - I presume Upstream Only.

[Steven_L]

Hey @karl3018,

Sorry to hear that you're having issues with your connection, I have looked into your account and cannot see anything that would be causing theses issues. All of your power levels are well within the correct levels as per our system and there are no problems in your area.

How is your connection at the moment? 

Regards,

Steven_L

[Roger_Gooner]

The upstream power levels are so high that only three upstream channels are locked. There is also something wrong to cause Post RS Errors on every downstream channel and the T4 Timeouts. You can try a reboot to see if that makes a difference.

Incidentally, a network switch can only work in modem mode if downstream of the router.

[karl3018]

Hi Steven,

Somewhat bizarrely, after switching the Hub back to modem mode, it picked up 4 US channels and stability returned.  Not entirely sure why, but perhaps a hub-initiated reboot rather than power cycling the hub in a dirty manner allowed things to gracefully reset.  

US power levels dropped to around 47dBmV over 4 channels rather than 51dBmV over the 3 when the issues were current.  DS power levels have increased to the 2.x range up from the +/- 0.5dBmV range previously seen.  

Cheers

Karl

[karl3018]

Hi Roger,

Not strictly true regarding the network switch needing to be downstream of the router. 

My Hub is in modem mode which then feeds in to a port on my Managed switch which is in a dedicated WAN VLAN.  I then have 3 Virtualisation Hosts which have each 1 WAN NIC and one LAN NIC, in respective VLANs. 

So, in my setup:

Hub --> Switch --> Router (via Virtualisation Host 1, 2 or 3)

That way, I can move my Virtual router between each of the Hosts for maintenance whilst maintaining an internet connection and keeping the wife happy 😅 

[Roger_Gooner]

karl,

My post is for the average punters who certainly won't know about a VLAN let alone implement one, and what they need is a network switch downstream of the router which allows additional LAN ports to be utilised.

[Akua_A]

Thank you for the update @karl3018

We are glad to see the issue was resolved. 

Please do not hesitate to contact us if you need any further help.

Thanks,