Menu
Reply
Bill_Carson
  • 22
  • 0
  • 0
Tuning in
3,073 Views
Message 1 of 36
Flag for a moderator

SYNC Timing Synchronization failure - Loss of Sync

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;

 

 

Tags (2)
0 Kudos
Reply
Bill_Carson
  • 22
  • 0
  • 0
Tuning in
3,071 Views
Message 2 of 36
Flag for a moderator

Re: SYNC Timing Synchronization failure - Loss of Sync

Levels:

Downstream bonded channels

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

1291000000-3.740256 qam20
2267000000-3.538256 qam17
3275000000-3.240256 qam18
4283000000-3.740256 qam19
5299000000-2.938256 qam21
6307000000-2.740256 qam22
7315000000-2.540256 qam23
8323000000-2.738256 qam24
9331000000-2.740256 qam25
10339000000-2.738256 qam26
11347000000-2.740256 qam27
12355000000-340256 qam28
13363000000-2.940256 qam29
14371000000-2.940256 qam30
15379000000-2.940256 qam31
16387000000-340256 qam32
17395000000-3.238256 qam33
18403000000-3.938256 qam34
19411000000-4.238256 qam35
20419000000-4.440256 qam36
21427000000-4.240256 qam37
22435000000-4.238256 qam38
23443000000-4.440256 qam39
24451000000-440256 qam40



Downstream bonded channels

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

1Locked40.340
2Locked38.940
3Locked40.350
4Locked40.3120
5Locked38.960
6Locked40.950
7Locked40.360
8Locked38.950
9Locked40.310
10Locked38.950
11Locked40.350
12Locked40.360
13Locked40.360
14Locked40.350
15Locked40.330
16Locked40.350
17Locked38.940
18Locked38.900
19Locked38.660
20Locked40.350
21Locked40.360
22Locked38.960
23Locked40.340
24Locked40.950

 

Upstream bonded channels

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

1537000004.65512064 qam2
2394000004.575512064 qam4
3462000004.625512064 qam3
4326000004.55512064 qam5



Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1ATDMA0000
2ATDMA0000
3ATDMA0000
4ATDMA0000

 

 

Another thing i have noticed, i seem to flat out at 160Mb/s download and never get the advertised 350Mb/s and thats connected to the device wired:

https://www.speedtest.net/result/9645355882

0 Kudos
Reply
Bill_Carson
  • 22
  • 0
  • 0
Tuning in
3,063 Views
Message 3 of 36
Flag for a moderator

Re: SYNC Timing Synchronization failure - Loss of Sync

I should also add, im on the 350Mb/s service, up until now i have never really experienced any issues with my service. I am a heavy user, as i work from home well before any of this covid 19 stuff kicked off, so i need a reliable connection.

 

i called VM helpdesk and the guy on the phone said it was a problem with the wireless portion of the hub so is sending out a new hub that will be with me on wednesday?? even though i explained to him it wasnt a wifi issue, and that i was hard wired.

0 Kudos
Reply
Bill_Carson
  • 22
  • 0
  • 0
Tuning in
3,022 Views
Message 4 of 36
Flag for a moderator

Re: SYNC Timing Synchronization failure - Loss of Sync

Network Log

Time Priority Description

22/06/2020 20:47:5Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
22/06/2020 20:47:5criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

 

 

0 Kudos
Reply
Roger_Gooner
  • 6.74K
  • 490
  • 1.19K
Legend
3,007 Views
Message 5 of 36
Flag for a moderator
Helpful Answer

Re: SYNC Timing Synchronization failure - Loss of Sync

It obviously isn't a WiFi problem. Can you check that all your coax connections are tight?

--
Hub 3.0, TP-Link Archer C8, TP-Link TL-SG108S 8-port gigabit switch, V6
My Broadband Ping - Roger's VM Broadband Connection
Andrew-G
  • 7.01K
  • 1.22K
  • 3.06K
Very Insightful Person
Very Insightful Person
2,979 Views
Message 6 of 36
Flag for a moderator
Helpful Answer

Re: SYNC Timing Synchronization failure - Loss of Sync

Synchronisation failure is where the hub can't maintain a lock on one or more of the 28 channels it uses to connect with the gear in the street cabinet.  And when it does lose synch, that loss of one or more channels becomes a "partial service".  What that means for the customer is slowdowns, disconnection and poor latency.  The hub does try and renegotiate the lost channel, but that takes time, and the problem will recur.

The underlying cause is usually noise on the upstream, because it is those channels that the hub uses to communicate with the gear in the street cabinet.  The upstream looks OK on the data you've posted, but that's most likely because you've recently rebooted the hub (I can tell that from the low error counts).  Rebooting causes the hub to renegotiate all 28 channels, and usually provides a temporary fix, but because the underlying cause isn't fixed, it will recur.  Replacing the hub won't make a blind bit of difference - that's a cheap fix by agents who know nothing about the technology.  If they'd looked at your network log and knew what it meant they'd have sent out a technician to find the real problem.  

You can try dialling it in, but chances are you'll get more of a run around by the utter clowns that VM use as offshore technical support.  Better to wait (maybe a day or two) for the UK based VM forum staff to get round to this post and advise on next steps.  They're usually very helpful, but don't accept the excuse "I've had a look and everything appears OK from our side" - the Network log is crystal clear on the fault and the impact on your service, and that's been recorded by VM's own equipment.  You need a technician.

I'm a Very Insightful Person, I'm here to share knowledge, I don't work for Virgin Media. Learn more

Have I helped? Click Mark as Helpful Answer or use Kudos to say thanks

Chris_W1
  • 4.06K
  • 185
  • 255
Forum Team
Forum Team
2,948 Views
Message 7 of 36
Flag for a moderator

Re: SYNC Timing Synchronization failure - Loss of Sync

Hi Bill_Carson, thanks for the message and we are sorry to hear that you have been having issues with the service? If so, we will fire over a private message to you. Chris 

0 Kudos
Reply
Bill_Carson
  • 22
  • 0
  • 0
Tuning in
2,909 Views
Message 8 of 36
Flag for a moderator

Re: SYNC Timing Synchronization failure - Loss of Sync

Thanks, i checked and the cable is tight. apologies for the delayed response been busy with work so totally haven't had the time to jump on here.

0 Kudos
Reply
Bill_Carson
  • 22
  • 0
  • 0
Tuning in
2,908 Views
Message 9 of 36
Flag for a moderator

Re: SYNC Timing Synchronization failure - Loss of Sync

Thanks for your response i received the new router, i guess there is no point plugging it in. 

0 Kudos
Reply
Bill_Carson
  • 22
  • 0
  • 0
Tuning in
2,907 Views
Message 10 of 36
Flag for a moderator

Re: SYNC Timing Synchronization failure - Loss of Sync

Hi, I am still having issues.

0 Kudos
Reply