SYNC Timing Synchronization failure

[nsumm]

Hello,

I've been with virgin media at my current address for a couple of years now and while I originally had good speed and connectivity, it has worsen over time to the point where I get regular drops in connection and my speed is far lower than it should be.

Looking at the network log, it repeatedly shows 'SYNC Timing Synchronization failure'. Like others, I have found that rebooting the router temporarily improves things before reverting to how they were previously.

I've seen a few other people with this problem on the forum and the answer seems to be to share the relevant data here and wait for the Forum Team to pick it up, so I'm doing the same (fingers crossed).

Network Log

Time Priority Description

26/10/2023 12:15:17	notice	LAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
26/10/2023 12:15:13	Warning!	LAN login FAILED : Incorrect Username / Password / ConnectionType;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
25/10/2023 17:54:5	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
24/10/2023 22:34:1	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
24/10/2023 17:23:55	Error	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
23/10/2023 14:41:51	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
23/10/2023 08:40:30	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
22/10/2023 16:30:49	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/10/2023 14:26:30	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/10/2023 08:51:34	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/10/2023 08:21:28	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/10/2023 05:23:55	Error	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
20/10/2023 08:14:0	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
19/10/2023 23:37:21	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
17/10/2023 22:04:29	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
17/10/2023 17:23:55	Error	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
17/10/2023 07:48:18	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
15/10/2023 12:27:43	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
15/10/2023 04:11:37	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/10/2023 05:23:55	Error	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

[jbrennand]

Post up the 2 tables from the Downstream, 2 from the Upstream pages. Don't worry too much about the formatting it can be easily read & DON’T include personal data or MAC addresses - blank them out - if you copy/paste the data, the board software will do this for you (you may need to click the "submit" button again). If character limits are “exceeded” - just do two posts

Also, If you haven’t already, set up a free, secure and “offlsite” - “Broadband Quality Monitor” to continually monitor the state of your connection and record any true network dropouts , latency issues, packet drops, etc - it will thus allow you to differentiate between those and simple wifi dropouts. It does it 24/7/365 and it keeps a visual record of any/all of your network disconnections, useful data to have to match to the Network logs (in your Hub settings) and also in discussions with VM - note it will take a few hours to start seeing a sensible picture - post up the “link” to the “share live graph”. 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 then click OK
https://www.thinkbroadband.com/broadband/monitoring/quality

[nsumm]

Thanks John, I've pasted the data and an image of the boradband monitor below.

Downstream bonded channels

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

1	139000000	5.9	37	256 qam	1
2	147000000	6	38	256 qam	2
3	155000000	5.5	38	256 qam	3
4	163000000	4.8	38	256 qam	4
5	171000000	4.5	38	256 qam	5
6	179000000	5	38	256 qam	6
7	187000000	5	38	256 qam	7
8	195000000	4.3	38	256 qam	8
9	203000000	3.7	35	256 qam	9
10	211000000	4.4	38	256 qam	10
11	235000000	3.5	38	256 qam	13
12	243000000	3.9	38	256 qam	14
13	251000000	3.9	40	256 qam	15
14	259000000	2.7	38	256 qam	16
15	267000000	2	38	256 qam	17
16	275000000	2.5	38	256 qam	18
17	283000000	3.2	38	256 qam	19
18	291000000	1.9	38	256 qam	20
19	299000000	2	38	256 qam	21
20	307000000	2.9	38	256 qam	22
21	315000000	3	38	256 qam	23
22	323000000	2	38	256 qam

Downstream bonded channels

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

1	Locked	37.6	6846	28010
2	Locked	38.9	1344	6531
3	Locked	38.9	441	101
4	Locked	38.6	942	193
5	Locked	38.9	1201	1124
6	Locked	38.6	413	138
7	Locked	38.9	427	156
8	Locked	38.6	632	197
9	Locked	35.7	7663262	607162
10	Locked	38.9	139	102
11	Locked	38.9	614	131
12	Locked	38.9	309	65
13	Locked	40.3	77	15
14	Locked	38.9	248	75
15	Locked	38.9	552	41
16	Locked	38.9	90	12
17	Locked	38.9	30	0
18	Locked	38.9	162	0
19	Locked	38.9	157	0
20	Locked	38.9	100	0
21	Locked	38.9	81	0
22	Locked	38.9	209	0

Upstream bonded channels

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

1	23600034	45.5	5120	64 qam	11
2	30100000	46.3	5120	64 qam	8
3	49600000	48.5	5120	64 qam	5
4	36600000	48.3	5120	64 qam	7
5	43100000	50.5	5120	64 qam	6

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
3	ATDMA	0	0	0	0
4	ATDMA	0	0	1	0
5	ATDMA	0	0	0	0

[Travis_M]

Hi @nsumm 

Thanks for your response!
 

How has your connection been over the weekend? Have you noticed any improvement at all?

Regards

[nsumm]

Hi Travis,

No change. I've attached the two of the latest broadband monitor images

Thanks

Nathan S

  

[nsumm]

Hi @Travis_M 

Do you need any further info? What should my next steps be?

Thanks,

Nathan S.

[Sabrina_B]

Hi @nsumm 

Thanks for the image update. Can I ask is channel optimization on with your Hub? If not could you please turn it on and run the same check again and let us know if there are any changes.

Sabrina

[nsumm]

Hi Sabrina,

Yes, channel optimization has been on since the hubs installation.

[Zach_R]

Hi @nsumm, 

Thank you for confirming. I've checked things on our systems and I'm unable to detect any faults currently that would explain this.

Is this problem ongoing today? If so, can you share your live BQM instead of screenshots? That way we can look at your connection quality in real-time.

Thanks,
 

[nsumm]

Hi Zach,

Here's the link: https://www.thinkbroadband.com/broadband/monitoring/quality/share/3e5a9e2f90aaad6d47a7227a373397c8e3...