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JayEnBee
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SYNC Timing Synchronization failure - Loss of Sync;CM

I suffer frequent short breaks in service. The HUB 3 Network Log shows "SYNC Timing Synchronization failure - Loss of Sync", No Ranging Response received ", "RCS Partial Service;CM" issues, and the "Downstream Bonded Channels" shows many "Post RS Errors", which I guess suggests problems between the HUB 3 and the VM Network. A copy of the DownStream Bonded Channels log is shown below:

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

1Locked40.39023584632096
2Locked40.39687825711729
3Locked40.39781765730529
4Locked40.39694414801126
5Locked40.99619838819908
6Locked40.99541280818951
7Locked40.39459596669537
8Locked40.39427910654139
9Locked40.39410239614866
10Locked40.39436753827853
11Locked40.39422775794028
12Locked38.99315169764360
13Locked38.99357534817780
14Locked40.39237361795195
15Locked40.39285800762320
16Locked40.39263285734984
17Locked40.39276062666104
18Locked40.39248001794817
19Locked38.99122479753218
20Locked40.39065474763361
21Locked38.69062449775609
22Locked38.69107021777263
23Locked40.39093609811173
24Locked38.98948675753434

Please can someone in VM sort out these network issues. The constant interruptions in service is beginning to convionce me to move to another network!

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Steven_L
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Message 2 of 31
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Re: SYNC Timing Synchronization failure - Loss of Sync;CM

Hey @JayEnBee

 

Thanks for getting in touch with us and sorry for the issues that you're having.

 

I have been able to look into your account and cannot  see anything that would be causing such issues.  How are things looking at the moment?

 

Regards

Steven_L 

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JayEnBee
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Message 3 of 31
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Re: SYNC Timing Synchronization failure - Loss of Sync;CM

Hi Steven,

Thanks for your message. Things do seem to have got better over the last 18 hours, with no "Warning" or "Critical " messages in the HUB 3 Network log since 11:56  am yesterday, which had 2 such records..

Looking solely at this month, the number of Network Log records were:

3 March   . . . 2

4 March  . . . . 8

5 March  . . . . 2

6 March  . . . . 1

7 March  . . . . 5

8 March . . . .  1

9 March . . . .  4

10 March  . . . 2

11 March . . . .. 0

12 March . . . .  0

13 March  . . . . .1

14 March  . . . . .2

Though the numbers seem relatively low, my impression is that the interruptions to service are in fact more frequent, despite nothing showing in the Network Log. Hopefully it's a declining trend.

I notice the VM Help page suggests switching off the HUB 3 and restarting. Is this likely to help should the trouble continue, please?

Many thanks,

JayEnBee

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JayEnBee
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Re: SYNC Timing Synchronization failure - Loss of Sync;CM

Sadly I spoke far too soon. Having just lost internet service, at 19:08 this evening, I immediately looked at the Network Log - when the HUB 3 finally decided to talk to me - and found 20 entries, almost all "Critical" (SYNC Timing Synchronization failure) or "Warning" (RCS Partial Service;CM-MAC), all today from 12:48 until the last at 19:08.

The PC was not in use today until early evening, so with little internet use today, I wasn't aware of any of these earlier problems.

Ironically that last one, which certainly interrupted service for several minutes, had a priority of "Notice", and was shown as "LAN login Success;CM-MAC=". 

Please can you advise whether this is a faulty HUB 3, a line problem, or a problem with the exchange equipment?

Thanks for your help,

JayEnBee

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stabilo00
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Message 5 of 31
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Re: SYNC Timing Synchronization failure - Loss of Sync;CM

"LAN login Success;CM-MAC=". Just means you logged into hub ok
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Sasha_W
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Message 6 of 31
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Re: SYNC Timing Synchronization failure - Loss of Sync;CM

Hi @JayEnBee

 

Thanks for reporting back to us, 

I have taken another look at your account and still can't see that there are any faults or outages, but have noticed you haven't rebooted your hub in 65 days, it might be worth giving this a go just to see if this improves anything. 

 

Please do let us know, 

Many thanks, 

Sasha 

 

Sasha - Forum Team


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JayEnBee
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Message 7 of 31
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Re: SYNC Timing Synchronization failure - Loss of Sync;CM

Whilst there are several categories - "Notice", Warning", "Critical" - each has a common factor in the description that they all refer to the Cable MAC address for my Hub 3, AND the CMTS - cable modem termination system - MAC Address **:**:**:**:**:**. The first part of this MAC address, '00-01-5C' , indicates the equipment is manufactured by CADANT Ltd, and would be situated in the exchange and/or Virgin Media premises..

Surely this clearly indicates  that there is a regular, repeated service interruption between these two points, and certainly not within the HUB 3 nor on the WiFi network emanating from the Hub 3.

I have this evening tried the suggestion to switch of the Hub 3 and reinitialise. I await now to see the result!

      

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Ayisha_B
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Message 8 of 31
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Re: SYNC Timing Synchronization failure - Loss of Sync;CM

Hi @JayEnBee,

 

Just following up on your last message- have you noticed any improvements since the reboot?

 

Hope to hear from you soon 🙂

Ayisha_B
Forum Team



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JayEnBee
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Message 9 of 31
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Re: SYNC Timing Synchronization failure - Loss of Sync;CM

Absolutely no improvement at all! 

From the data extracted from the Network Log (which I suspect has limited capacity to store data!), there were 19 "Warning" / "Critical" events logged on 21 March, and so far 20 today, 22 March. 

As before, each event identifies my WAN MAC address, and the MAC Address of the CADENT Inc CMTS. As the latter is within your Virgin Media equipment/network, I await VM's resolution of the problem.

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Akua_A
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Message 10 of 31
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Re: SYNC Timing Synchronization failure - Loss of Sync;CM

Thanks for getting back to us @JayEnBee.

 

Sorry to hear the issue is ongoing.

 

Can you please check the coax cable connections to see if this may be the cause of the issue? If this is not the case, I can arrange for a technician appointment for you.

 

Please let us know how you get on.

 

Thanks,

Akua_A
Forum Team



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