Forum Discussion

edbris's avatar
edbris
Joining in
7 months ago

Frequent Internet dropouts and Superhub logs "SYNC Timing Synchronization failure"

Hi,

Historically my Virgin Media broadband has been very stable - which is good as I work from home and rely on it!

However in the last few days I've increasingly had a number of short (< 5min) dropouts.  I've noted about 6 so far today.  I rebooted the Superhub Friday, and again this morning, but they continue,

The network log on my SuperHub (v3) has these messages at the same time "SYNC Timing Synchronization failure - Loss of Sync" - recent log entries provided below.  I've also included Upstream and Downstream status below.
I would observe that the connection box where the cable comes from the street and splits at my house looks pretty dodgy.

 

Hope someone can help!
Cheers, Ed

 

Upstream bonded channels

Channel

Frequency (Hz)

Power (dBmV)

Symbol Rate (ksps)

Modulation

Channel ID

1

49600000

51

5120

64 qam

1

Upstream bonded channels

Channel

Channel Type

T1 Timeouts

T2 Timeouts

T3 Timeouts

T4 Timeouts

1

ATDMA

0

0

0

0

 

Downstream bonded channels

Channel

Frequency (Hz)

Power (dBmV)

SNR (dB)

Modulation

Channel ID

1

187000000

4.6

40

256 qam

7

2

139000000

4.8

40

256 qam

1

3

147000000

4.8

40

256 qam

2

4

155000000

4.5

38

256 qam

3

5

163000000

4.5

38

256 qam

4

6

171000000

4.6

40

256 qam

5

7

179000000

4.8

40

256 qam

6

8

195000000

4.6

40

256 qam

8

9

203000000

5

40

256 qam

9

10

211000000

5.5

40

256 qam

10

11

219000000

6

34

256 qam

11

12

227000000

6

38

256 qam

12

13

235000000

5.4

40

256 qam

13

14

243000000

4.5

40

256 qam

14

15

251000000

4.4

40

256 qam

15

16

259000000

4.8

40

256 qam

16

17

267000000

5.3

40

256 qam

17

18

275000000

5

40

256 qam

18

19

283000000

4.9

40

256 qam

19

20

291000000

5

40

256 qam

20

21

299000000

5.1

40

256 qam

21

22

307000000

5.1

40

256 qam

22

23

315000000

5.3

40

256 qam

23

24

323000000

5

40

256 qam

24

Downstream bonded channels

Channel

Locked Status

RxMER (dB)

Pre RS Errors

Post RS Errors

1

Locked

40.3

191

28769

2

Locked

40.3

459

36

3

Locked

40.3

5819678

4

4

Locked

38.6

999644

0

5

Locked

38.9

104

0

6

Locked

40.3

83

0

7

Locked

40.9

77

0

8

Locked

40.3

64

0

9

Locked

40.9

61

0

10

Locked

40.3

31

0

11

Locked

34.9

1916

0

12

Locked

38.9

73

0

13

Locked

40.3

66

0

14

Locked

40.3

79

0

15

Locked

40.3

92

0

16

Locked

40.3

86

0

17

Locked

40.9

55

0

18

Locked

40.3

57

0

19

Locked

40.3

58

0

20

Locked

40.3

84

0

21

Locked

40.3

84

0

22

Locked

40.3

68

0

23

Locked

40.3

93

0

24

Locked

40.3

122

0

 

29/07/2024 14:57:19

critical

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=X;CMTS-MAC=X;CM-QOS=1.1;CM-VER=3.0;

29/07/2024 14:57:2

critical

SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=X;CMTS-MAC=X;CM-QOS=1.1;CM-VER=3.0;

29/07/2024 14:04:49

critical

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=X;CMTS-MAC=X;CM-QOS=1.1;CM-VER=3.0;

29/07/2024 14:04:31

critical

SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=X;CMTS-MAC=X;CM-QOS=1.1;CM-VER=3.0;

 

  • Tudor's avatar
    Tudor
    Very Insightful Person

    Serious error there. You will not get a response quickly on the board. See this: 

    Check with Area faults on 0800 561 0061 If you have a VM landline 150 this goes down to post code level. You could also try the web page status, but this is not recommended as it only covers issues that affect a very large number of customers.

    VM will not dispatch any technicians while an area fault exists.

    If no area faults found:

    The primary place to report faults or for service requests is Customer Services on 0345 454 1111/150 if you have a VM landline or wait two or three days for a VM staff member to get to your post. This board is not a fault reporting system.

  • Client62's avatar
    Client62
    Alessandro Volta

    Upstream bonded channels

    Channel

    Frequency (Hz)

    Power (dBmV)

    Symbol Rate (ksps)

    Modulation

    Channel ID

    1

    49600000

    51

    5120

    64 qam

    1


    We usually have between four and six Upstream bonded channels.
    In this case there is only one, that is a fault that you can mention to Customer Services.

  • Sephiroth's avatar
    Sephiroth
    Alessandro Volta

    Not only just one upstream channel, but it’s at the maximum of its power range hence the T4 time out (which causes a Hub reset).  While this is going on, you’ll have little or no useable service.

  • Thanks for the feedback all.
    I've called VM and have an engineer due Thursday afternoon
    Will keep my fingers crossed that sorts it, and try and limp on till then!