SYNC Timing Synchronization failure errors

[Blakey47]

Good morning, hope someone can help.

I have a hub 4 and on the gig BB and on a regular basis now (usually during the night) the internet drops out and it doesn't reconnect itself - I have to turn the hub off and on.

The network log each time shows an error to do with Sync timing synchronisation errors. 

As it's been happening for a few days now when the internet stopped last night, I rebooted to get it going again and set up one of the think broadband quality monitoring things.

I have ran the realspeed speed checker after rebooting on two occasions now with the latest one showing a download to the hub 4 at 79.1 Mbps (although somehow it's 489 Mbps to the computer!)

Upload is 4.29 Mbps, latency 19.2ms and Jitter 1.82ms says 0.0 packet loss.

This is much lower than I would expect as well.

I noticed that when the internet has gone out that the usual 192.168.0.1 IP address to get in to look at the status doesnt work either - almost as if the hub isn't there.

I tried the online check your connection thing but this wouldn't work and said to try again later!

Thank you 🙂

[Blakey47]

Current broadband quality graph 

[lotharmat]

Can you post your Hub status and logs?
Someone should be spot if there is a problem
Navigate to http://192.168.0.1 (or http://192.168.100.1 - if in modem mode)
Don't log in!
Click on 'router status'
Copy/paste the data from each of the tabs. The forum software will remove the MAC addresses for you (you may need to click the 'post' button again).

Also, set up a 'Broadband Quality Monitor'. This will monitor the state of your connection and record any network dropouts etc - You can do this at ThinkBroadband (https://www.thinkbroadband.com/broadband/monitoring/quality)
Give it a while to gather data and then click 'Share Live graph' and paste the 'Direct Link' into the forum!

[Blakey47]

3.0 Downstream channels

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

1	138750000	-1.599998	35.779911	QAM256	1
2	146750000	-1.299999	35.595078	QAM256	2
3	154750000	-0.599998	36.386890	QAM256	3
4	162750000	-0.200001	36.609653	QAM256	4
5	170750000	-0.400002	37.636276	QAM256	5
6	178750000	-0.400002	37.355988	QAM256	6
7	186750000	-1.000000	37.636276	QAM256	7
8	194750000	-0.900002	36.609653	QAM256	8
9	202750000	-1.000000	36.609653	QAM256	9
10	210750000	-0.599998	37.355988	QAM256	10
11	218750000	-0.299999	36.386890	QAM256	11
12	226750000	-0.799999	36.609653	QAM256	12
13	234750000	-0.799999	37.355988	QAM256	13
14	242750000	-0.900002	37.636276	QAM256	14
15	250750000	-1.599998	37.636276	QAM256	15
16	258750000	-1.000000	37.636276	QAM256	16
17	266750000	-1.000000	37.636276	QAM256	17
18	274750000	-0.299999	37.636276	QAM256	18
19	282750000	0.599998	37.355988	QAM256	19
20	290750000	0.200001	37.355988	QAM256	20
21	298750000	0.200001	37.355988	QAM256	21
22	306750000	0.500000	37.636276	QAM256	22
23	314750000	0.700001	37.355988	QAM256	23
24	322750000	1.299999	37.636276	QAM256	24
25	330750000	1.599998	37.636276	QAM256	25
26	338750000	1.500000	38.605377	QAM256	26
27	346750000	1.400002	38.605377	QAM256	27
28	354750000	0.400002	37.636276	QAM256	28
29	362750000	0.299999	37.636276	QAM256	29
30	370750000	0.299999	37.636276	QAM256	30
31	378750000	-0.099998	37.636276	QAM256	31

3.0 Downstream channels

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

1	Locked	35.779911	310024	26515
2	Locked	35.595078	487713	646
3	Locked	36.386890	879	24
4	Locked	36.609653	185	24
5	Locked	37.636276	273	24
6	Locked	37.355988	98	14
7	Locked	37.636276	150	16
8	Locked	36.609653	114	4
9	Locked	36.609653	86	4
10	Locked	37.355988	66	5
11	Locked	36.386890	58	7
12	Locked	36.609653	30	11
13	Locked	37.355988	44	7
14	Locked	37.636276	30	3
15	Locked	37.636276	27	3
16	Locked	37.636276	31	0
17	Locked	37.636276	28	0
18	Locked	37.636276	28	0
19	Locked	37.355988	22	0
20	Locked	37.355988	19	0
21	Locked	37.355988	17	0
22	Locked	37.636276	10	0
23	Locked	37.355988	7	0
24	Locked	37.636276	8	0
25	Locked	37.636276	5	0
26	Locked	38.605377	1	0
27	Locked	38.605377	2	0
28	Locked	37.636276	0	0
29	Locked	37.636276	1	0
30	Locked	37.636276	2	0
31	Locked	37.636276	0	0

[Blakey47]

Wed 30/06/2021 23:00:183SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:00:446CM-STATUS message sent. Event Type Code: 5; Chan ID: 5; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:06:323SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:06:356CM-STATUS message sent. Event Type Code: 5; Chan ID: 5; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:12:173No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:16:203SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:16:286CM-STATUS message sent. Event Type Code: 5; Chan ID: 5; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:16:443SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:16:546CM-STATUS message sent. Event Type Code: 5; Chan ID: 5; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:16:593SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:17:356CM-STATUS message sent. Event Type Code: 5; Chan ID: 5; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:17:403SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:18:056CM-STATUS message sent. Event Type Code: 5; Chan ID: 5; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:18:093SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:18:156CM-STATUS message sent. Event Type Code: 5; Chan ID: 5; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:18:173SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:19:076CM-STATUS message sent. Event Type Code: 5; Chan ID: 5; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:27:053SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:27:086CM-STATUS message sent. Event Type Code: 5; Chan ID: 5; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:33:063SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:33:226CM-STATUS message sent. Event Type Code: 5; Chan ID: 5; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:35:033No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:36:043SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:36:106CM-STATUS message sent. Event Type Code: 5; Chan ID: 5; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:43:373SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:43:576CM-STATUS message sent. Event Type Code: 5; Chan ID: 5; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:47:283No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:48:053SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:48:246CM-STATUS message sent. Event Type Code: 5; Chan ID: 5; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:53:183SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Wed 30/06/2021 23:53:196CM-STATUS message sent. Event Type Code: 5; Chan ID: 5; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Thu 01/07/2021 00:01:213SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Thu 01/07/2021 00:01:326CM-STATUS message sent. Event Type Code: 5; Chan ID: 5; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;Thu 01/07/2021 00:07:063No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;

this is the network log - a bit messy 😞

[Blakey47]

3.0 Upstream channels

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

1	46200000	47.520599	5120 KSym/sec	64QAM	1
2	32600000	48.270599	5120 KSym/sec	16QAM	3
3	25800000	48.520599	5120 KSym/sec	32QAM	4
4	39400000	47.770599	5120 KSym/sec	64QAM	2

3.0 Upstream channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1	US_TYPE_STDMA	0	0	0	0
2	US_TYPE_STDMA	0	0	0	0
3	US_TYPE_STDMA	0	0	0	0
4	US_TYPE_STDMA	0	0	0	0

[Blakey47]

General Configuration

Network access	true
Maximum Number of CPEs	1
Baseline Privacy	true
DOCSIS Mode	3.1
Config file	cmreg-vmdg640-bbt076+voc-b.cm

Primary Downstream Service Flow

SFID	164342
Max Traffic Rate	1200000450
Max Traffic Burst	42600
Min Traffic Rate	0

Primary Upstream Service Flow

SFID	164341
Max Traffic Rate	55000270
Max Traffic Burst	42600
Min Traffic Rate	0
Max Concatenated Burst	42600
Scheduling Type	bestEffort

[Blakey47]

Cable Modem StatusItem Status CommentsChannel Overview Downstream Upstream

Cable Modem Status	Online	DOCSIS 3.1
Primary downstream channel	Locked	SC-QAM
DOCSIS 3.0 channels	31	4
DOCSIS 3.1 channels	1	0

I think I got it all!

[lotharmat]

Upstream QAM is all over the place!

RxMER looks a little on the low side for some D/S channels which will likely explain the PostRS errors!

VM need to take a look at it and book an engineer if they think it is needed!

[Blakey47]

Okay,

I phoned up VM and to be honest I'm not particularly impressed!!

According to their script the resolution to the issue is to use a factory reset - So I did that (as to be fair its not something I had done) but I can't see how this will resolve a sync issue.

Then I mentioned about the speed, I ran 3 seperate speed tests using the Sam Knows real speed and got between 290 and 350 Mbps on my 1gig BB to the hub itself.

The VM representative then went on to say that the number of WiFi devices will reduce the speed drastically as the hub only supports so many, then she looked at how many Wifi devices were connected - Zero.

And I went on to say that regardless of how many or how my internet connected devices are connected it wouldn't make the internet drop out with sync issues and she went on to say that the pinhole reset will solve all that.

She went in and put some ofcom speed complaint in (I've never heard of this) and apparently my internet speed will be monitored for the next 30 days - So whatever happened to the Ooomph package service guarantee which I recall stated they'd send round an engineer the next working day (providing issue was reported early enough) to resolve any issues?

She said as the factory reset cures the sync issues that if it happens again today to call them back....So lets see