Virgin Media Community

[zooneylfc]

Hi there

Package: Vivid 350
Area Reference: 05
Setup: Superhub 3.0 (modem mode), Netgear X4S R7800, Wired Windows 10 PC,

I've had packet loss issues since Saturday 26/01/19. It came on suddenly around 4pm and I noticed the impact of it immediately. I checked the service status and ran a test through my Virgin Media account and no issues were found. I restarted my router at this time, which did not help. It is probably worth mentioning that this looks very similar to an area fault I experienced a few months ago, which took weeks to get resolved.

See below a BQM graph for 26th Jan:

The issue still persists as of today 30th Jan. Performing a ping via cmd to google.com 500 times shows ~3% packet loss. There is no packet loss when performing ping tests between local devices on my network. General browsing is minimally impacted, but watching live broadcasts and gaming are impacted quite heavily. Latency spikes are also much more frequent.

Here is a direct link to my live BQM graph:

https://www.thinkbroadband.com/broadband/monitoring/quality/share/1b75bf977768cd6e589c40a2e13b206c527d0f02

Below are the upstream/downstream from my hub, obtained by going to 192.168.100.1 and checking the router status from the login screen. The hub was last reset on Sunday 27/01 at 8pm.

Channel 4 and 11 stand out in particular for the Post RS figures. The network log is a long long list of repeated "Lost MDD Timeout" / "RCS Partial Service" warnings. Unable to find the devices the MAC addresses relate to.

Downstream bonded channels

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

1	299000000	0.5	36	256 qam	17
2	323000000	0.7	36	256 qam	20
3	315000000	-0.2	37	256 qam	19
4	307000000	0.9	36	256 qam	18
5	283000000	0.9	37	256 qam	15
6	275000000	0.7	37	256 qam	14
7	267000000	0.7	37	256 qam	13
8	259000000	0.5	37	256 qam	12
9	251000000	0.9	37	256 qam	11
10	243000000	0	37	256 qam	10
11	235000000	0.5	33	256 qam	9
12	227000000	1	37	256 qam	8
13	219000000	2.5	37	256 qam	7
14	291000000	0.9	37	256 qam	16
15	211000000	1.9	37	256 qam	6
16	203000000	3.2	37	256 qam	5
17	195000000	3.2	38	256 qam	4
18	187000000	4.3	37	256 qam	3
19	179000000	4	38	256 qam	2
20	171000000	5.3	37	256 qam	1

Downstream bonded channels

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

1	Locked	36.6	2484987800	0
2	Locked	36.6	2347475874	0
3	Locked	37.3	2376025693	0
4	Locked	36.6	2741327161	278257300
5	Locked	37.3	2474449273	0
6	Locked	37.3	2477068272	0
7	Locked	37.3	2488203943	0
8	Locked	37.3	2457809460	0
9	Locked	37.3	2517228493	0
10	Locked	37.6	2410134871	0
11	NotLocked	32.6	670746398	2990291554
12	Locked	37.6	2358144298	0
13	Locked	37.6	2639632505	0
14	Locked	37.3	2494202181	0
15	Locked	37.6	2350216850	0
16	Locked	37.6	2711546228	2
17	Locked	38.6	2349152149	0
18	Locked	37.3	2451162751	0
19	Locked	38.6	2382412456	0
20	Locked	37.6	2296475299	0

Upstream bonded channels

Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID

1	24400000	40	5120	32 qam	27
2	31000000	40.5	5120	64 qam	26

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

Network Log

Time Priority Description

2019-01-30 15:58:54.00	Warning!	Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-01-30 15:58:55.00	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-01-30 15:59:01.00	Warning!	Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-01-30 15:59:03.00	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

I'm hoping someone can provide some guidance of how to resolve the packet loss issue, I have been posting this issue in another larger packet loss thread but it has not garnered any response. I'm making my own thread so I can be as detailed as possible and hope someone able to help sees it.

My previous posts regarding this issue (including traceroutes and other BQM graphs) can be found at: https://community.virginmedia.com/t5/Gaming-Support/packet-loss/td-p/3901146/page/25

If any further information is wanted to help diagnose the issue, please let me know!

Many thanks in advance

[zooneylfc]

Just an update that the problem appears to have worsened overnight.

Traceroute via WinMTR, showing packet loss via aztw-core-2b-xe-301-0.network.virginmedia.net and eislou2-ic-3-ae0-0.network.virginmedia.net

Here's my latest BQM:

[DreamOfCheese · Accepted solution]

Check all the coax connections leading to the Hub are tightly and securely connected, if that doesn't fix it you need to call the support number and request an engineer (or wait a few days for a member of the forum team to respond here) as you're having issues with your downstream channels, one of them so badly it hasn't even acquired lock.

Tracerouting won't help diagnose this as from the info you've supplied so far, it's an issue with your connection to the street cabinet.

[zooneylfc]

Cheers for the help, DreamOfCheese.

Had a brainwave as I was going around tightening the coax connections as you suggested. Can't believe I didn't try it earlier.

I've had some success by removing a no longer needed coax splitter. This seemed to bring all the SNR levels up to where they should be. dBmV levels increased by ~3 as a result of removing the splitter. Maybe a bit on the high side at the top end? Not caused any new issues so far though.

Unfortunately I still had an unlocked channel. However, re-locating the hub to where my virgin tv box used to be and using a different coax cable made all channels lock (for the most part).

Channel 12 is intermittently showing as not locked, and some packet loss is still present. Post RS errors are still happening on that channel too. 

I will keep an eye on it and request an engineer if it persists. I think I've done just about everything possible. 

Here's my downstream after all the above tinkering (~30 mins uptime)

Downstream bonded channels

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

1	299000000	4	37	256 qam	17
2	323000000	4.1	36	256 qam	20
3	315000000	3.2	37	256 qam	19
4	307000000	4.1	36	256 qam	18
5	291000000	4.5	36	256 qam	16
6	283000000	4.1	36	256 qam	15
7	275000000	4	37	256 qam	14
8	267000000	4.1	37	256 qam	13
9	259000000	3.9	37	256 qam	12
10	251000000	4	37	256 qam	11
11	243000000	3.5	37	256 qam	10
12	235000000	4.5	36	256 qam	9
13	227000000	4.5	37	256 qam	8
14	219000000	5.8	37	256 qam	7
15	211000000	5.1	37	256 qam	6
16	203000000	6.6	37	256 qam	5
17	195000000	6.4	37	256 qam	4
18	187000000	7.5	37	256 qam	3
19	179000000	7.5	38	256 qam	2
20	171000000	8.5	37	256 qam	1

Downstream bonded channels

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

1	Locked	37.3	15728369	0
2	Locked	36.3	15794034	0
3	Locked	37.3	15044800	0
4	Locked	36.6	16644772	0
5	Locked	36.6	16148931	0
6	Locked	36.6	16862847	0
7	Locked	37.3	15740960	0
8	Locked	37.3	15393790	0
9	Locked	37.6	15596460	0
10	Locked	37.3	17040389	0
11	Locked	37.6	15162783	0
12	Locked	36.8	9172921	17567452
13	Locked	37.3	15672750	6632
14	Locked	37.3	16866304	0
15	Locked	37.6	14887469	0
16	Locked	37.6	17425495	0
17	Locked	37.6	14871562	0
18	Locked	37.6	15499260	0
19	Locked	38.6	15118344	0
20	Locked	37.6	14507543	0

Thanks again for the help. Will provide updates for anyone else to see if there are any more developments.

[zooneylfc]

The packet loss seems to have resolved itself as of 3am this morning. All channels have been locked every time I've checked today too.

I've not made any adjustments to my network since my previous post, so it leads me to believe that at least part of the problem was out of my hands.

I'll leave it there for now, unless the problem resurfaces.

[zooneylfc]

The problem came back within 24 hours of my previous post and continues to be an issue.

I've since moved my hub to my old tivo box spot using a different cable. I've removed a 3.5db splitter. I've tried modem mode with my own router and the default setup. I've reset my hub and ensured its on the latest firmware (.608). All coax connections are at least hand-tight. 

Downstream - Channel 12 has been the main culprit for the past week, not locking some of the time. Post RS figures on that channel hit 10 figures after 48 hours uptime consistently.

See below for a snapshot of my current router stats (1hr uptime, no splitter - not ideal but I was doing a last bit of tinkering and a reboot before deciding to post again).

Downstream bonded channels

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

1	299000000	4	37	256 qam	17
2	323000000	4.3	36	256 qam	20
3	315000000	3.4	37	256 qam	19
4	307000000	4.3	36	256 qam	18
5	291000000	4.5	36	256 qam	16
6	283000000	4.3	36	256 qam	15
7	275000000	4	37	256 qam	14
8	267000000	4.4	37	256 qam	13
9	259000000	4.1	37	256 qam	12
10	251000000	4.3	37	256 qam	11
11	243000000	3.5	37	256 qam	10
12	235000000	4.3	36	256 qam	9
13	227000000	4.5	37	256 qam	8
14	219000000	5.9	37	256 qam	7
15	211000000	5.3	37	256 qam	6
16	203000000	6.9	37	256 qam	5
17	195000000	6.5	38	256 qam	4
18	187000000	7.6	37	256 qam	3
19	179000000	7.6	38	256 qam	2
20	171000000	8.8	38	256 qam	1

  Downstream bonded channels

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

1	Locked	37.3	25773358	0
2	Locked	36.6	27300652	319
3	Locked	37.3	24961669	0
4	Locked	36.6	28216846	0
5	Locked	36.6	27045705	0
6	Locked	36.6	28071248	0
7	Locked	37.3	26196769	0
8	Locked	37.3	25578196	0
9	Locked	37.3	25669207	0
10	Locked	37.3	28832528	0
11	Locked	37.6	25231430	0
12	NotLocked	36.6	20017934	22929592
13	Locked	37.3	25827855	0
14	Locked	37.3	28427474	0
15	Locked	37.6	24773831	0
16	Locked	37.6	29088674	0
17	Locked	38.6	24734296	0
18	Locked	37.6	25818800	0
19	Locked	38.6	25018190	0
20	Locked	38.6	23988569	0

Upstream bonded channels

Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID

1	24400000	36.5	5120	64 qam	27
2	31000000	37	5120	64 qam	26

Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1	ATDMA	0	0	0	0
2	ATDMA	0	0	0	0

I'm convinced the issue stems either from a fault outside my home or from the superhub 3 itself.

[DreamOfCheese]

You've still got the issue with channel 12 not locking and having an extreme amount of Post RS Errors (along with every channel having an extreme amount of Pre RS Errors), you'll need to call it in as a fault for a technician to come check and fix supply.

[zooneylfc]

Technician came Saturday and was helpful. Replaced the Superhub and coax where it entered my house. As it was rebooting he went and checked the local tap down the street and realised the problem was rooted there. He didn't explain exactly the issue, but something wasn't giving out any signal.

The proper engineers are out on the street today looking into it more and running various tests, keeping me up to date along the way. The latest is that another team will probably need to come in from Bristol and finish the repairs, either today or tomorrow.