Menu
Reply
Doron
  • 11
  • 0
  • 0
Tuning in
262 Views
Message 1 of 20
Flag for a moderator

SYNC Timing Synchronization failure - Loss of Sync

My internet connection keeps dropping intermittently, sometimes for 30 seconds sometimes for as many as 5 minutes. It always comes back by itself but the outages obviously interfere with Zoom calls and such. In the network logs I can see many critical events:

Time Priority Description

13/07/2021 14:16:51criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
13/07/2021 13:31:41noticeLAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
13/07/2021 13:05:40criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
13/07/2021 13:04:15noticeLAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
13/07/2021 12:54:15criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
13/07/2021 12:50:59criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
13/07/2021 12:22:6criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
13/07/2021 12:18:16criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
13/07/2021 11:59:37criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
13/07/2021 11:58:12criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
13/07/2021 11:39:6criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
13/07/2021 11:37:55noticeLAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
13/07/2021 11:37:18Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
13/07/2021 11:36:15criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
13/07/2021 11:34:18criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
13/07/2021 10:55:49Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
13/07/2021 10:53:54criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
13/07/2021 10:42:57noticeLAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
13/07/2021 10:41:14criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
12/07/2021 18:40:47criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

 

I've tried all the usual resolution techniques (restart the router, check cables are tight, etc) and none of them resolve the issue. Other similar forum posts suggest that an engineer visit is required to identify the issue. Any other suggestions or do I need to wait for someone from VM to book an engineer?

0 Kudos
Reply
lotharmat
  • 2.54K
  • 189
  • 462
Trouble shooter
259 Views
Message 2 of 20
Flag for a moderator

Re: SYNC Timing Synchronization failure - Loss of Sync

Post up the rest of the hub stats! - Someone should be able to see what the problem could be!

The log looks very bad!

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!



------------------------------------------------------------------
Hub 3 - Modem Mode - TP-Link Archer C7

Doron
  • 11
  • 0
  • 0
Tuning in
259 Views
Message 3 of 20
Flag for a moderator

Re: SYNC Timing Synchronization failure - Loss of Sync

Downstream bonded channels

ChannelFrequency (Hz)Power (dBmV)SNR (dB)ModulationChannel ID
1139000000-1.536256 qam1
2147000000-1.936256 qam2
3155000000-236256 qam3
4163000000-236256 qam4
5171000000-1.736256 qam5
6179000000-2.236256 qam6
7187000000-1.936256 qam7
8195000000-2.537256 qam8
9203000000-3.236256 qam9
10211000000-3.736256 qam10
11219000000-4.236256 qam11
12227000000-536256 qam12
13235000000-5.236256 qam13
14243000000-7.436256 qam14
15251000000-6.436256 qam15
16259000000-4.936256 qam16
17267000000-4.936256 qam17
18275000000-4.436256 qam18
19283000000-3.736256 qam19
20291000000-3.237256 qam20
21299000000-2.937256 qam21
22307000000-2.737256 qam22
23315000000-2.737256 qam23
24323000000-2.237256 qam24



Downstream bonded channels

ChannelLocked StatusRxMER (dB)Pre RS ErrorsPost RS Errors
1Locked36.33189186511402455
2Locked36.63793258285975
3Locked36.660659853631
4Locked36.6102411385740
5Locked36.635910623455
6Locked36.632340818338
7Locked37.343628819938
8Locked37.374868764658
9Locked36.642489729367
10Locked36.61739602816
11Locked36.31687142676
12Locked36.654833819350
13Locked36.356854824799
14Locked36.32216084929
15Locked36.31113381028
16Locked36.369749976
17Locked36.640120841
18Locked36.357755913
19Locked36.617400396
20Locked37.37659318
21Locked37.33488107
22Locked37.32727212
23Locked37.63232233
24Locked37.3589398
0 Kudos
Reply
Doron
  • 11
  • 0
  • 0
Tuning in
258 Views
Message 4 of 20
Flag for a moderator

Re: SYNC Timing Synchronization failure - Loss of Sync

Upstream bonded channels

ChannelFrequency (Hz)Power (dBmV)Symbol Rate (ksps)ModulationChannel ID
13260004951512064 qam3
23940005851512064 qam2
34619997551512064 qam1
42579993651512064 qam4



Upstream bonded channels

ChannelChannel TypeT1 TimeoutsT2 TimeoutsT3 TimeoutsT4 Timeouts
1ATDMA0070
2ATDMA0030
3ATDMA0050
4ATDMA00130
0 Kudos
Reply
Doron
  • 11
  • 0
  • 0
Tuning in
255 Views
Message 5 of 20
Flag for a moderator

Re: SYNC Timing Synchronization failure - Loss of Sync

TB graph available at:

https://www.thinkbroadband.com/broadband/monitoring/quality/share/65b7abc4caad29ce1dfd0560e731ce7cc6014a58

 

0 Kudos
Reply
lotharmat
  • 2.54K
  • 189
  • 462
Trouble shooter
252 Views
Message 6 of 20
Flag for a moderator

Re: SYNC Timing Synchronization failure - Loss of Sync

Upstream is maxed out
Downstream is too low

VM Definitely need to send a tech!



------------------------------------------------------------------
Hub 3 - Modem Mode - TP-Link Archer C7

Akua_A
  • 1.22K
  • 31
  • 79
Forum Team
Forum Team
219 Views
Message 7 of 20
Flag for a moderator

Re: SYNC Timing Synchronization failure - Loss of Sync

Hi @Doron

 

Welcome to our community forums and thank you for your first posts.

 

Sorry to hear you have been experiencing ongoing intermittent issues. We can understand this is not ideal especially when working from home. I have just sent you a private message regarding this. Please look out for the purple envelope on the top right hand corner of the page and provide a response when you can.

 

Thanks,

Akua_A
Forum Team



New around here? To find out more about the Community check out our Getting Started guide


0 Kudos
Reply
Doron
  • 11
  • 0
  • 0
Tuning in
195 Views
Message 8 of 20
Flag for a moderator

Re: SYNC Timing Synchronization failure - Loss of Sync

Hi @Akua_A, thanks for your reply. I don't see anything from you in my inbox - are you sure it was sent?

0 Kudos
Reply
Akua_A
  • 1.22K
  • 31
  • 79
Forum Team
Forum Team
134 Views
Message 9 of 20
Flag for a moderator

Re: SYNC Timing Synchronization failure - Loss of Sync

Thank you for letting me know @Doron

 

How strange! I will send you another private message.

 

Please let me know if you are able to see it.

 

Thanks,

 

Akua_A
Forum Team



New around here? To find out more about the Community check out our Getting Started guide


0 Kudos
Reply
Doron
  • 11
  • 0
  • 0
Tuning in
95 Views
Message 10 of 20
Flag for a moderator

Re: SYNC Timing Synchronization failure - Loss of Sync

Thanks for your help identifying the problem @lotharmat. I want to understand how it is that you know that my broadband connection is 'very bad'? What about the numbers that you see in what I pasted identifies this? How do you know the upstream is maxed out and the downstream is too low? Do you know what 'normal' values for these metrics should be?

0 Kudos
Reply