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Intermittent connection and "SYNC Timing Synchronization failure"

My problem is similar to others, like mentioned here: https://community.virginmedia.com/t5/Networking-and-WiFi/SYNC-Timing-Synchronization-failure/td-p/41...

I've been fobbed off by VM 2nd-line tech support too, seems impossible to convince them of the problem, so I'm trying here too hoping that the tech info gets someone else's attention.

For the past couple of weeks we've had intermittent network connection to the internet - I use my hub (3.0) in modem mode connected to my own router. All devices will encounter the same drop in connectivity at the same time - I have tested internally vs. externally, while internal stays up connections to the outside world are dropped.

Here follows all the diagnostic info from the hub (image as text was too long...) that demonstrates the issue and tallies with the bad experiences from other posts. Please can someone contact me ASAP so we can arrange to have an engineer visit and resolve the issue - thanks.

Hub_Logs_2020-08-18Hub_Logs_2020-08-18

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Message 2 of 12
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Re: Intermittent connection and "SYNC Timing Synchronization failure"

Have you checked the 'Check Service Status' at the top of the page ?

If nothing is showing try phoning 0800 561 0061, this will tell you of more local issues that may be affecting the area. Be aware that it isn't a manned line.

Go round all the accessible co-ax connections and ensure that they are finger tight.

If everything above is OK we need do some troubleshooting; to start with …

 

Can you set up a Broadband Quality Monitor (BQM) at thinkbroadband.com - this will give you an insight into what is happening with the signal at the other side of the Hub, it will take a few hours to get any kind of trend showing although you can post the link straight away.

Post a link to your BQM on here.

Instructions for posting BQM Link

Under your BQM graph are two links in red.

Click the lower link (Share Live Graph) then click generate.

Copy the text in the Direct Link box, beware, there may be more text than you can see.

On here click the Link icon (2 links chain to the left of the camera icon)

In the URL box paste the link you copied and in the ‘text to display’ box write My BQM then click OK - you can post the link straight away.

Then

 

Can you please

Type 192.168.0.1 (192.168.100.1 in Modem mode) into your browser URL bar and press enter. 

When the page appears DO NOT LOG IN but click ‘Check Router Status’.

Copy and paste the contents of the Downstream, Upstream and Network Log tabs onto here, if you get a yellow warning click the Post button again.

A Guru will be along soon to decipher the info.

***********************************************************************************************************************************

Mike Robinson
Aircraft Engineer & Computer Based Training and Learning Designer for many of the world's Military Arms.


My Broadband Ping - 26_Aug_2020
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Message 3 of 12
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Re: Intermittent connection and "SYNC Timing Synchronization failure"

Hello - yes, both telephone and online service status monitors say there's no issue detected. I'll set up the monitor now.

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Message 4 of 12
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Re: Intermittent connection and "SYNC Timing Synchronization failure"

Here's the quality monitor URL (note the initial failures were ICMP denied by my router): HERE 

Here are the current router stats as of right now (can't post all at once due to 20k character limit error - and I repeatedly clicked the post button):

Downstream bonded channels

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

1139000000-240256 qam1
2147000000-240256 qam2
3155000000-240256 qam3
4163000000-1.540256 qam4
5171000000-1.540256 qam5
6179000000-1.440256 qam6
7187000000-1.740256 qam7
8195000000-1.540256 qam8
9203000000-1.540256 qam9
10211000000-1.740256 qam10
11219000000-240256 qam11
12227000000-1.940256 qam12
13235000000-240256 qam13
14243000000-2.540256 qam14
15251000000-2.440256 qam15
16259000000-2.540256 qam16
17267000000-2.940256 qam17
18275000000-2.940256 qam18
19283000000-340256 qam19
20291000000-2.740256 qam20
21299000000-2.940256 qam21
22307000000-340256 qam22
23315000000-2.740256 qam23
24323000000-3.240256 qam24


Downstream bonded channels

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

1Locked40.910370070820390463
2Locked40.982952821718566
3Locked40.91677922807281
4Locked40.92177178511627
5Locked40.31591852995748
6Locked40.91437724664828
7Locked40.31684256503666
8Locked40.32193281173860
9Locked40.3596501146303
10Locked40.3150078140726
11Locked40.9158978149039
12Locked40.9665193143684
13Locked40.3646781132055
14Locked40.3111470134523
15Locked40.3103610140090
16Locked40.990033135708
17Locked40.392437130199
18Locked40.9148474134245
19Locked40.392071136394
20Locked40.388048132532
21Locked40.391280126539
22Locked40.393494143420
23Locked40.388585141650
24Locked40.3100784133346
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Message 5 of 12
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Re: Intermittent connection and "SYNC Timing Synchronization failure"

Upstream bonded channels

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

1461999684.771512016 qam1
2394001974.8512016 qam2
3257998964.675512016 qam4
4326001794.725512016 qam3


Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1ATDMA0000
2ATDMA0000
3ATDMA0000
4ATDMA0000

  Network Log

Time Priority Description

18/08/2020 20:50:43criticalNo Ranging Response received - T3 time-out;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
18/08/2020 20:37:38Warning!Lost MDD Timeout;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
18/08/2020 20:31:17criticalNo Ranging Response received - T3 time-out;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
18/08/2020 20:01:50noticeLAN login Success;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
18/08/2020 19:21:0criticalNo Ranging Response received - T3 time-out;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
18/08/2020 19:12:7Warning!Lost MDD Timeout;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
18/08/2020 19:10:6criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
18/08/2020 19:09:9criticalNo Ranging Response received - T3 time-out;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
18/08/2020 19:06:30criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
18/08/2020 18:52:45criticalNo Ranging Response received - T3 time-out;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
18/08/2020 18:47:23criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
18/08/2020 18:44:27criticalNo Ranging Response received - T3 time-out;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
18/08/2020 18:20:39criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
18/08/2020 18:16:39criticalNo Ranging Response received - T3 time-out;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
18/08/2020 18:15:54criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
18/08/2020 18:13:59criticalNo Ranging Response received - T3 time-out;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
18/08/2020 18:06:43criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
18/08/2020 18:04:28criticalNo Ranging Response received - T3 time-out;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
18/08/2020 17:53:54criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
18/08/2020 17:50:1criticalNo Ranging Response received - T3 time-out;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;


If you need the MAC addresses I can send them privately. I'll post more stats later as graph data builds.

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Message 6 of 12
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Re: Intermittent connection and "SYNC Timing Synchronization failure"

My data from today - here's a direct link for stats from today, notice how there was terrible degradation last night, then an apparent complete outage lasting until about 08:15 this morning. Since then it has been considerably improved over yesterday, certainly for working from home. The latency is a bit spiky, but then that could have been down to my work activities.

Here follows the router logs for the day.

Downstream bonded channels

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

1139000000-1.540256 qam1
2147000000-1.740256 qam2
3155000000-1.540256 qam3
4163000000-1.240256 qam4
5171000000-140256 qam5
6179000000-140256 qam6
7187000000-1.240256 qam7
8195000000-1.240256 qam8
9203000000-1.240256 qam9
10211000000-1.440256 qam10
11219000000-1.540256 qam11
12227000000-1.740256 qam12
13235000000-1.740256 qam13
14243000000-2.240256 qam14
15251000000-2.240256 qam15
16259000000-2.240256 qam16
17267000000-2.740256 qam17
18275000000-2.740256 qam18
19283000000-2.740256 qam19
20291000000-2.540256 qam20
21299000000-2.540256 qam21
22307000000-2.740256 qam22
23315000000-2.540256 qam23
24323000000-340256 qam24

Downstream bonded channels

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

1Locked40.912878232733167917
2Locked40.9130458941798613
3Locked40.91793982820454
4Locked40.32330833525520
5Locked40.917432201010305
6Locked40.31595607680363
7Locked40.91805329517456
8Locked40.92325534191064
9Locked40.3675475158780
10Locked40.9198194153913
11Locked40.3204647161476
12Locked40.3723135155721
13Locked40.3700408147455
14Locked40.3154320146798
15Locked40.9147536152809
16Locked40.9135126147888
17Locked40.3142247142307
18Locked40.3197460146999
19Locked40.3143594148856
20Locked40.3140048144663
21Locked40.9145340139710
22Locked40.9149910156792
23Locked40.3141103155842
24Locked40.9156792146547
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Message 7 of 12
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Re: Intermittent connection and "SYNC Timing Synchronization failure"

Upstream bonded channels

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

1462001074.746512016 qam1
2394001184.75512016 qam2
3258003134.625512016 qam4
4326003434.675512016 qam3


Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1ATDMA0000
2ATDMA0000
3ATDMA0000
4ATDMA0000


Network Log

Time Priority Description

19/08/2020 16:40:0ErrorDHCP REBIND WARNING - Field invalid in response;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
19/08/2020 12:49:10ErrorDHCP RENEW sent - No response for IPv4;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
19/08/2020 09:36:36Warning!Lost MDD Timeout;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
19/08/2020 08:58:23ErrorDHCP RENEW sent - No response for IPv4;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
19/08/2020 07:32:19criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
19/08/2020 04:34:34criticalNo Ranging Response received - T3 time-out;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
19/08/2020 02:28:24Warning!RCS Partial Service;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
19/08/2020 02:28:24criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
19/08/2020 02:28:13Warning!RCS Partial Service;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
19/08/2020 02:28:13criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
19/08/2020 02:28:4Warning!RCS Partial Service;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
19/08/2020 02:28:4criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
19/08/2020 02:27:54Warning!RCS Partial Service;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
19/08/2020 02:27:53criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
19/08/2020 02:26:38criticalNo Ranging Response received - T3 time-out;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
19/08/2020 02:23:54Warning!RCS Partial Service;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
19/08/2020 02:23:54criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
19/08/2020 02:23:33Warning!RCS Partial Service;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
19/08/2020 02:23:33criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
19/08/2020 02:23:24Warning!RCS Partial Service;CM-MAC=xx;CMTS-MAC=xx;CM-QOS=1.1;CM-VER=3.0;
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Message 8 of 12
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Re: Intermittent connection and "SYNC Timing Synchronization failure"

Your upstream channels are out of spec (Should be 64 qam):

Upstream bonded channels

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

1462001074.746512016 qam1
2394001184.75512016 qam2
3258003134.625512016 qam4
4326003434.675512016 qam3

 

This can cause stability issues on your line, and also cause the 1000's of errors on your downstream channels.

VM need to investigate further.

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Message 9 of 12
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Re: Intermittent connection and "SYNC Timing Synchronization failure"

Thanks for the response Carl. It's as shonky as hell today again with repeated drop-outs, I use a VPN to connect to my work's network and I just can't keep that connected on the Virgin line. I'm having to now use my personal mobile (O2) tethered to my PC to get anything done.

Here's the BQM snapshot for today, it's clear to see.

Please can someone from VM look into this ASAP for me, as I'm certainly not getting my money's worth right now and I'm already looking at other solutions from different providers.

I'm happy to provide account details and whatever is needed to support teams via PM, as well as contact details etc.

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Message 10 of 12
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Re: Intermittent connection and "SYNC Timing Synchronization failure"

Here’s today’s graph, as you can see, just the same story.

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