SYNC Timing Synchronization failure - Loss of Sync

[Bill_Carson]

Hi All,

first post here, and its for syc timing errors. this issues started a few days ago , the internet was cutting out and then coming back. i have rebooted all the kit. switched it off for 10 mins and then turned it back on etc etc. still getting the same issue. called VM and the automated system said they needed to send a signal to the kit, did that and it rebooted everything. still same issue.

Network Log:

Time	Priority	Description
22/06/2020 10:35:56	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
22/06/2020 10:35:56	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
22/06/2020 09:00:45	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
22/06/2020 06:41:17	Error	DHCP REBIND WARNING - Field invalid in response;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/06/2020 23:10:52	Error	DHCP RENEW sent - No response for IPv4;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/06/2020 18:03:14	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/06/2020 17:58:32	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/06/2020 17:28:4	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/06/2020 15:40:31	Error	DHCP RENEW sent - No response for IPv4;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/06/2020 09:14:47	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/06/2020 09:13:50	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/06/2020 08:22:22	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/06/2020 00:39:48	Error	DHCP RENEW sent - No response for IPv4;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
20/06/2020 21:58:27	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
20/06/2020 21:58:27	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
20/06/2020 21:57:0	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
20/06/2020 21:18:8	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
20/06/2020 21:16:36	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

[jongosling]

 today’s BQM. I’ve managed to fight through the VM support and a technician will be with me Monday.

[Megan_L]

Hi Jongosling,

Thanks for using the Community Forums to get this issue with your services looked into, I am sorry if this has been causing some frustration 😥 But I am glad to hear you managed to get a technician visit for Monday.

Can I ask how this visit went please? If you're still having issues then please let us know and we will continue to help.

Thanks,

Megan_L

[jongosling]

Megan, The engineer came on Mon 29 and changed all the connectors in and outside the house. The issue has improved, but still remains. See below BQMs and router status.

Tue 30 Apr, improved, but still a few disconnects.

Wed 1 May, more droputs and some odd high latency 11-12.

Thu 2 May, very odd day - with block issues in within the common dropout windows (essentially working hours)

This could well be a cabling issue in the house, as the previous owners built units in front of / over the fibre so I can't check for damage. The fibre also goes into and out of a splitter (input from street and one output to hub, other output unused) which is no longer required (for an old Virgin TV input?).

I would appreciate any recommendations or support!

Downstream bonded channels

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

1	203000000	4.8	38	256 qam	9
2	211000000	4.4	38	256 qam	10
3	219000000	5	38	256 qam	11
4	227000000	4	38	256 qam	12
5	235000000	4.4	38	256 qam	13
6	243000000	5	40	256 qam	14
7	251000000	5.1	40	256 qam	15
8	259000000	5.5	38	256 qam	16
9	267000000	5.6	38	256 qam	17
10	275000000	5.5	40	256 qam	18
11	283000000	5.8	38	256 qam	19
12	291000000	6.3	40	256 qam	20
13	299000000	6.8	38	256 qam	21
14	307000000	6.6	38	256 qam	22
15	315000000	6.5	38	256 qam	23
16	323000000	6.3	38	256 qam	24
17	331000000	6.5	40	256 qam	25
18	339000000	6.5	38	256 qam	26
19	347000000	6.8	38	256 qam	27
20	355000000	6.8	38	256 qam	28
21	363000000	7	40	256 qam	29
22	371000000	7	40	256 qam	30
23	379000000	6.9	38	256 qam	31
24	387000000	6.5	40	256 qam	32

Downstream bonded channels

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

1	Locked	38.9	35357	71393
2	Locked	38.9	26654	65381
3	Locked	38.9	22022	41290
4	Locked	38.9	23519	64087
5	Locked	38.9	30125	51049
6	Locked	40.3	25790	23131
7	Locked	40.3	22071	16777
8	Locked	38.9	3368782	11911
9	Locked	38.9	84969050	8590
10	Locked	40.9	366202021	8313
11	Locked	38.6	568588668	9958
12	Locked	40.3	328837557	9110
13	Locked	38.9	371744526	8016
14	Locked	38.9	647350680	6953
15	Locked	38.9	371645472	6237
16	Locked	38.9	373815939	6054
17	Locked	40.3	638421294	5481
18	Locked	38.9	363924672	4926
19	Locked	38.9	367846065	4512
20	Locked	38.9	649008049	4224
21	Locked	40.3	353210190	4152
22	Locked	40.3	365416941	3650
23	Locked	38.9	564905409	3189
24	Locked	40.3	63835549	2955

[jongosling]

Upstream bonded channels

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

1	36600000	45	5120	64 qam	3
2	43100000	46.5	5120	64 qam	2
3	30100098	46.5	5120	64 qam	4
4	23599991	47	5120	64 qam	5
5	49600000	48.3	5120	64 qam	1

Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1	ATDMA	0	0	0	0
2	ATDMA	0	0	2	0
3	ATDMA	0	0	0	0
4	ATDMA	0	0	0	0
5	ATDMA	0	0	3	0

Network Log

Time Priority Description

03/05/2024 07:19:28	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
03/05/2024 07:19:28	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
03/05/2024 06:31:36	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
03/05/2024 06:27:1	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
03/05/2024 05:04:18	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
03/05/2024 05:04:18	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/05/2024 22:57:29	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/05/2024 22:37:51	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/05/2024 20:38:32	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/05/2024 20:22:7	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/05/2024 19:51:27	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/05/2024 19:51:27	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/05/2024 11:51:40	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/05/2024 10:53:35	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/05/2024 08:04:0	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/05/2024 07:50:41	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/05/2024 07:15:6	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/05/2024 07:08:14	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/05/2024 06:19:16	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/05/2024 06:19:16	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

[jpeg1]

Something seriously wrong there according to the RS numbers. You could start by removing the unused splitter and connecting the used cable straight into the Hub. 

[jongosling]

jpeg, Unfortunately, the fibre has been covered by floorboards and units, and the splitter is a metre away from the hub, coming from / going to the floor (madness). So unless I remove both in & out cables from the splitter, tape them together and hope to god I can pull them through to the hub, I’ll have to live with it / call out an engineer again to remedy (join the cables?)

[jpeg1]

You can't join the cables yourself. You could replace the splitter with a back-back connector, but this may not be the whole answer. In your place I'd get a technician in to sort it. May be a £25 cost depending what they find. 

[Carley_S]

Hi @jongosling 

I've double checked the systems at our side and cannot see anything that might be causing these issues for you. 

Did the engineer say anything in regards to the cabling under the floor boards when they were there or was this something you notice after they left? 

[jongosling]

We discussed the concealed cabling, it would be a challenge to replace, as you’d likely have to remove the units built into the walls and the floor boards. VM online Support have sent me another WiFi pod to resolve the issue (as expected and likely to be useless). Removing the splitter would be my next suggestion before any attempts to replace the cabling to the street. The engineer couldn’t find any issues beyond simply changing all the connectors (street to hub including splitter).

Today the connection dropped in line with every spike on the BQM. Great.

Any ideas / assistance would be welcome. I’ve convinced VM to not bill me for 2 months due to this poor service.

[Joseph_B]

Thanks for getting back to us @jongosling.

Having another look into the systems we do not see anything further causing an issue, with this we would recommended that it probably is worth going about either swapping the splitter, or fully replacing the cables to see if this goes about correcting the issue you face.

Joe