SYNC Timing Synchronization failure - Loss of Sync

[astaig]

Hi

Have noted many entries here regarding issues with loss of connectivity relating to this error message.  I've been experiencing this for a while and noted 3 events in the last 4 hours.

Can you please help me?

Andy

https://www.thinkbroadband.com/broadband/monitoring/quality/share/5ce4cad34749e2a46cac36cb79716d265aa025f6

Network Log

Time Priority Description

12/04/2024 13:02:19	notice	LAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
12/04/2024 12:50:47	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
12/04/2024 12:50:47	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
12/04/2024 11:41:36	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
12/04/2024 11:41:36	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
12/04/2024 11:41:35	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
12/04/2024 09:38:57	notice	LAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
12/04/2024 09:07:43	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
12/04/2024 09:07:42	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

[Adduxi]

Could be a local area fault, something amiss with your power levels on the Hub, or a bad connection.  Post the power levels for comment.  Also check all the connections from the Hub back to the outside omnibox, ensuring they are not loose.

Try checking with Area faults on 0800 561 0061 or if you have a VM landline 150 as small local faults are not listed on the VM status page.

[astaig]

Hi, the connections appear tight.  Here are the power levels

Downstream bonded channels

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

1	226750000	5	40	256 qam	12
2	138750000	5	38	256 qam	1
3	146750000	4.9	38	256 qam	2
4	154750000	4.5	40	256 qam	3
5	162750000	4.6	40	256 qam	4
6	170750000	4.9	40	256 qam	5
7	178750000	4.8	38	256 qam	6
8	186750000	4.9	38	256 qam	7
9	194750000	4.9	40	256 qam	8
10	202750000	5	40	256 qam	9
11	210750000	4.9	38	256 qam	10
12	218750000	5	40	256 qam	11
13	234750000	4.6	40	256 qam	13
14	242750000	4.8	40	256 qam	14
15	250750000	5	40	256 qam	15
16	258750000	5	40	256 qam	16
17	266750000	5	40	256 qam	17
18	274750000	5	40	256 qam	18
19	282750000	5.1	40	256 qam	19
20	290750000	5.1	40	256 qam	20
21	298750000	5.4	40	256 qam	21
22	306750000	5.3	40	256 qam	22
23	314750000	5.5	40	256 qam	23
24	322750000	5.5	40	256 qam	24

Downstream bonded channels

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

1	Locked	40.3	2402	1832
2	Locked	38.9	2744	2050
3	Locked	38.9	2665	2251
4	Locked	40.3	2689	2485
5	Locked	40.3	2497	2310
6	Locked	40.3	2395	2320
7	Locked	38.9	2145	2555
8	Locked	38.9	2091	2181
9	Locked	40.9	1918	2051
10	Locked	40.3	2067	2047
11	Locked	38.9	2068	2325
12	Locked	40.3	2053	2241
13	Locked	40.3	2516	2211
14	Locked	40.3	2494	2358
15	Locked	40.3	2612	2385
16	Locked	40.9	2552	2820
17	Locked	40.3	2725	2526
18	Locked	40.3	2661	2676
19	Locked	40.3	2856	2478
20	Locked	40.3	2874	2535
21	Locked	40.3	2896	2608
22	Locked	40.3	2847	2284
23	Locked	40.3	2757	2181
24	Locked	40.9	2556	2354

Upstream bonded channels

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

1	30100000	42	5120	64 qam	10
2	36600000	42	5120	64 qam	9
3	43100010	42.8	5120	64 qam	8
4	49599948	43.3	5120	64 qam	7
5	23600045	41.3	5120	64 qam	11

Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

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

[Adduxi]

Power levels all look okay.  However there should be zero PostRS errors as these indicate that data has to be retransmitted due to faults. You will need VM to send a tech to ascertain why this is happening.

[Sephiroth]

The important thing with the Post-RS errors is that they are not rising.  The initial values may be down to the gibberish that arrives during a rest and before the modem is sync’s. 

[Matthew_ML]

Hey astaig, thank you for reaching out and I am sorry to hear you are having some issues.

I am going to send you a DM to look into this.