Menu
Reply
karimkanji
  • 7
  • 0
  • 1
Tuning in
202 Views
Message 1 of 12
Flag for a moderator

SYNC Timing Synchronization failures

Hello,

We've been having intermittent connection problems with our Virgin Media broadband over the last few weeks. Before this, the connection was rock solid for a couple of years. 

We have a SH3 in modem mode connected to an Asus RT-AC68U router. The connection can be restored by powering off the SH3 for a good few minutes and then restarting it but the issue reappears any time between a couple of hours and a couple of days later.

I've checked the connections to the wall and the SH3 are all finger tight and the ASUS router and PC are hard-wired so it's not a Wifi problem.

Checking the Network logs, I noticed these errors at the time of the last disconnection (yesterday):

 

02/07/2021 16:04:32Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/07/2021 16:04:32criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/07/2021 16:04:31Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/07/2021 16:04:31criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/07/2021 16:04:30Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/07/2021 16:04:29criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/07/2021 16:04:27Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/07/2021 16:04:27criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/07/2021 16:04:25Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/07/2021 16:04:25criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/07/2021 16:04:23Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/07/2021 16:04:23criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/07/2021 16:04:22Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/07/2021 16:04:22criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/07/2021 16:04:21Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/07/2021 16:04:21criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/07/2021 16:04:19Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/07/2021 16:04:19criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/07/2021 16:04:19Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

 

 

0 Kudos
Reply
karimkanji
  • 7
  • 0
  • 1
Tuning in
201 Views
Message 2 of 12
Flag for a moderator

Re: SYNC Timing Synchronization failures

and here is the rest of the info from the SH3:

Downstream bonded channels

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

12987500005.438256 qam21
21387500005.540256 qam1
31467500005.540256 qam2
41547500005.540256 qam3
51627500005.440256 qam4
61707500005.440256 qam5
71787500005.140256 qam6
81867500005.338256 qam7
91947500005.340256 qam8
102027500005.140256 qam9
112107500005.340256 qam10
122187500005.340256 qam11
132267500005.440256 qam12
142347500005.440256 qam13
15242750000540256 qam14
16250750000540256 qam15
172587500005.140256 qam16
182667500005.540256 qam17
192747500005.540256 qam18
202827500005.540256 qam19
212907500005.340256 qam20
223067500005.440256 qam22
233147500005.540256 qam23
243227500005.840256 qam24



Downstream bonded channels

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

1Locked38.9130
2Locked38.980
3Locked40.380
4Locked40.3140
5Locked40.350
6Locked40.350
7Locked40.370
8Locked38.970
9Locked40.9150
10Locked40.3110
11Locked38.9210
12Locked40.380
13Locked40.380
14Locked40.370
15Locked40.3140
16Locked40.380
17Locked40.340
18Locked40.390
19Locked40.380
20Locked40.3150
21Locked40.3130
22Locked40.360
23Locked40.9130
24Locked40.390

 

Upstream bonded channels

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

16030000042512064 qam1
24620001042.5512064 qam3
33940006842.5512064 qam4
45370000041.5512032 qam2



Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1ATDMA0000
2ATDMA0010
3ATDMA0000
4ATDMA0000

 

and a link to the BQM I (only just) set up as requested in some of the other threads that I have read:

https://www.thinkbroadband.com/broadband/monitoring/quality/share/65a938ee5980a218e08cb30ba441eb9d4b2f06e7

 Would somebody be kind enough to have a look at this info and suggest steps to resolve the issues?

Thanks,

Karim

0 Kudos
Reply
jbrennand
  • 24.07K
  • 2.54K
  • 4.37K
Very Insightful Person
Very Insightful Person
169 Views
Message 3 of 12
Flag for a moderator

Re: SYNC Timing Synchronization failures

Hub stats look good. Logs are odd though - someone with more knowledge of logs needs to comment on them.

BQM only starting to build now will need 24h for a full picture. Meanwhile have you tried changing the ethernet cable from Hub to Asus to a new cat6 one ? I would also change your other ones just to be sure. A bad connection in one of the connectors could be the cause.

--------------------
John
--------------------

I do not work for VM. My services: HD TV on VIP (+ Sky Sports & Movies & BT sport), x3 V6 boxes (1 wired 2 WiFi,) SH2 in modem mode with Airport Extreme Router +2 Airport Express's. On VIVID200, Talk Anytime Phone, x2 Mobile SIM only iPhones.
0 Kudos
Reply
karimkanji
  • 7
  • 0
  • 1
Tuning in
164 Views
Message 4 of 12
Flag for a moderator

Re: SYNC Timing Synchronization failures

Thanks very much for taking the time to have a look John. I've switched out the cable between the hub and the router as you suggested, will see if that makes a difference.

0 Kudos
Reply
Zak_M
  • 4.45K
  • 259
  • 421
Forum Team
Forum Team
92 Views
Message 5 of 12
Flag for a moderator

Re: SYNC Timing Synchronization failures

Good afternoon @karimkanji 

 

Welcome back to the forums and thank you for taking the time to post. 

 

I am sorry to hear that you are having some issues with your services. 

 

I have taken a look over your account and there doesn't seem to be any issues of note, all the power levels are within spec.  I also checked the network and there is nothing there either, there is no utilisation work and no SNR issues. 

 

I would advise returning the hub into modem mode for 24 hours, monitor the BQM graph and see how we go from there. 

 

Kind regards,

Zak_M 

0 Kudos
Reply
karimkanji
  • 7
  • 0
  • 1
Tuning in
86 Views
Message 6 of 12
Flag for a moderator

Re: SYNC Timing Synchronization failures

Hi Zak,

Thanks for taking a look. Unfortunately, having been ok all weekend, the connection has been up and down again today, starting i think just after your reply. Router logs below:

Downstream bonded channels

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

12987500005.438256 qam21
21387500005.538256 qam1
31467500005.538256 qam2
41547500005.538256 qam3
51627500005.340256 qam4
61707500005.340256 qam5
7178750000538256 qam6
81867500005.338256 qam7
91947500005.140256 qam8
10202750000540256 qam9
112107500005.138256 qam10
122187500005.338256 qam11
132267500005.338256 qam12
142347500005.440256 qam13
15242750000538256 qam14
162507500004.940256 qam15
172587500005.138256 qam16
182667500005.438256 qam17
192747500005.440256 qam18
202827500005.540256 qam19
212907500005.138256 qam20
223067500005.440256 qam22
233147500005.540256 qam23
243227500005.640256 qam24



Downstream bonded channels

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

1Locked38.6445036735
2Locked38.9464450043
3Locked38.9458456404
4Locked38.9426459344
5Locked40.3443767802
6Locked40.3452562940
7Locked38.9427259932
8Locked38.9395857398
9Locked40.3444064604
10Locked40.3463158810
11Locked38.9426175552
12Locked38.9417356964
13Locked38.9467255395
14Locked40.3468863544
15Locked38.6457456955
16Locked40.3427766579
17Locked38.9199624192
18Locked38.9445854141
19Locked40.3444459898
20Locked40.3467959498
21Locked38.9421254707
22Locked40.3478864047
23Locked40.3471056076
24Locked40.3396560339

 

Upstream bonded channels

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

16030000042.3512064 qam1
24620010842.5512064 qam3
33940007642.5512064 qam4
45370000042.5512032 qam2



Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1ATDMA0000
2ATDMA0010
3ATDMA0000
4ATDMA0000
0 Kudos
Reply
karimkanji
  • 7
  • 0
  • 1
Tuning in
84 Views
Message 7 of 12
Flag for a moderator

Re: SYNC Timing Synchronization failures

Network Log

Time Priority Description

05/07/2021 12:10:10Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 12:10:10criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 12:10:1Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 12:10:1criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 12:09:53Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 12:09:53criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 12:09:39Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 12:09:39criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 12:09:33Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 12:09:33criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 12:09:28Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 12:09:28criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 12:09:23Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 12:09:23criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 12:09:18Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 12:09:18criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 12:09:10Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 12:09:10criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 12:09:7Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/07/2021 12:09:7criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

 

and the BQM graph:

https://www.thinkbroadband.com/broadband/monitoring/quality/share/7104a1c80268b26cc64acc549baf2ac8f7869a11-05-07-2021
0 Kudos
Reply
lotharmat
  • 2.54K
  • 188
  • 462
Trouble shooter
79 Views
Message 8 of 12
Flag for a moderator

Re: SYNC Timing Synchronization failures

Yikes that is a lot of PostRS errors! - Looks like noise ingress somewhere in the circuit!



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

0 Kudos
Reply
jbrennand
  • 24.07K
  • 2.54K
  • 4.37K
Very Insightful Person
Very Insightful Person
67 Views
Message 9 of 12
Flag for a moderator

Re: SYNC Timing Synchronization failures

There have been a number of threads where the RS errors were due t the connection to the 3d party router.

First thing is to swap the ethernet cable (they do "fail") with a new and shielded Cat6 one. And see if clears it up.

If not - disconnect the Asus and use the Hub in router mode, reset the errors to 0 and check to see if the RS errors are still increasing over a few hours.

--------------------
John
--------------------

I do not work for VM. My services: HD TV on VIP (+ Sky Sports & Movies & BT sport), x3 V6 boxes (1 wired 2 WiFi,) SH2 in modem mode with Airport Extreme Router +2 Airport Express's. On VIVID200, Talk Anytime Phone, x2 Mobile SIM only iPhones.
0 Kudos
Reply
karimkanji
  • 7
  • 0
  • 1
Tuning in
62 Views
Message 10 of 12
Flag for a moderator

Re: SYNC Timing Synchronization failures

Thanks for the replies. I replaced the Cat 6 cable between SH3 and Asus router a couple of days ago after you suggested it initially but this doesn't seem to have made any difference.

Could the connection between the router and hub also cause the timing synchronisation errors that show up in the log?

Using the SH3 in router mode (instead of having the Asus do the routing) will be tricky especially because those errors only seem to show up when the connection fails which sometimes only happens every 2 or 3 days. The errors don't just tick up constantly. For example, when I checked last night (Sunday) there were still zero errors after I reset the hub on Friday lunchtime.

0 Kudos
Reply