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Upstream Modulation Changing

avi68
Dialled in

Hi,

I have a Hub 5 in modem mode. Ive noticed that the Upstream modulation has started to fluctuate between 32QAM and 64QAM. This has been happening for over a month now. Initially the modulation would drop to 16QAM and stay between 16 and 32. However, more recently its been sticking at 32QAM, then jumping to 64 and then going back to 32.

Speeds seem to be ok but I have started to notice random packet loss. Last Thursday evening packet loss was very bad but it seems to have stabilised. I have called CS multiple times but the script they follow doesnt seem to have an answer to my issue. Packet loss is still occurring, not as bad, just small amounts randomly. Dont know if anyone can see an issue with my levels?

 

Cable Modem Status

Item

Status

Type

Cable Modem Status

Online

DOCSIS 3.0

Primary downstream channel

Locked

SC-QAM

Channel Overview

Downstream

Upstream

DOCSIS 3.0 channels

31

5

DOCSIS 3.1 channels

1

1

3.0 Downstream channels

Channel

Frequency (Hz)

Power (dBmV)

SNR (dB)

Modulation

Channel ID

1

331000000

6.9

41

QAM 256

25

2

139000000

9.4

40

QAM 256

1

3

147000000

9.3

40

QAM 256

2

4

155000000

9.2

40

QAM 256

3

5

163000000

8.9

40

QAM 256

4

6

171000000

8.8

39

QAM 256

5

7

179000000

8.5

39

QAM 256

6

8

187000000

8.4

39

QAM 256

7

9

195000000

8.3

39

QAM 256

8

10

203000000

8.1

39

QAM 256

9

11

211000000

8.2

39

QAM 256

10

12

219000000

8.1

39

QAM 256

11

13

227000000

7.8

38

QAM 256

12

14

235000000

7.6

38

QAM 256

13

15

243000000

7.3

38

QAM 256

14

16

251000000

7

39

QAM 256

15

17

259000000

6.8

39

QAM 256

16

18

267000000

6.7

39

QAM 256

17

19

275000000

6.6

39

QAM 256

18

20

283000000

6.5

40

QAM 256

19

21

291000000

6.7

40

QAM 256

20

22

299000000

6.7

40

QAM 256

21

23

307000000

7

40

QAM 256

22

24

315000000

7

40

QAM 256

23

25

323000000

7.1

41

QAM 256

24

26

339000000

7

41

QAM 256

26

27

347000000

6.7

41

QAM 256

27

28

355000000

6.7

41

QAM 256

28

29

363000000

6.5

41

QAM 256

29

30

371000000

6.5

41

QAM 256

30

31

379000000

6.5

41

QAM 256

31

3.0 Downstream channels

Channel

Locked Status

RxMER (dB)

Pre RS Errors

Post RS Errors

1

Locked

41

52

0

2

Locked

40

0

0

3

Locked

40

0

0

4

Locked

40

0

0

5

Locked

40

0

0

6

Locked

39

1

0

7

Locked

39

0

0

8

Locked

39

0

0

9

Locked

39

6

0

10

Locked

39

6

0

11

Locked

39

18

0

12

Locked

39

10

0

13

Locked

38

17

0

14

Locked

38

21

0

15

Locked

38

29

0

16

Locked

39

39

0

17

Locked

39

50

0

18

Locked

39

98

0

19

Locked

39

116

0

20

Locked

40

115

0

21

Locked

40

60

0

22

Locked

40

73

0

23

Locked

40

55

0

24

Locked

40

73

0

25

Locked

41

47

0

26

Locked

41

45

0

27

Locked

41

95

0

28

Locked

41

81

0

29

Locked

41

123

0

30

Locked

41

126

0

31

Locked

41

156

0

3.1 Downstream channels

Channel

Channel Width (MHz)

FFT Type

Number of Active Subcarriers

Modulation (Active Profile)

First Active Subcarrier (Hz)

41

94

4K

1840

QAM 4096

1108

3.1 Downstream channels

Channel ID

Locked Status

RxMER Data (dB)

PLC Power (dBmV)

Corrected errors (Active Profile)

Uncorrectable errors (Active Profile)

41

Locked

41

4.9

809061304

65

3.0 Upstream channels

Channel

Frequency (Hz)

Power (dBmV)

Symbol Rate (ksps)

Modulation

Channel ID

0

49600000

44.5

5120

QAM 32

1

1

43100000

44.3

5120

QAM 32

2

2

36600000

44.3

5120

QAM 32

3

3

30100000

44

5120

QAM 32

4

4

23600000

43.8

5120

QAM 32

5

3.0 Upstream channels

Channel

Channel Type

T1 Timeouts

T2 Timeouts

T3 Timeouts

T4 Timeouts

0

ATDMA

0

0

0

0

1

ATDMA

0

0

9

0

2

ATDMA

0

0

0

0

3

ATDMA

0

0

0

0

4

ATDMA

0

0

0

0

3.1 Upstream channels

Channel

Channel Width (MHz)

Power (dBmV)

FFT Type

Modulation

6

11

40.0

2K

QAM 256

3.1 Upstream channels

Channel

Channel Type

Number of Active Subcarriers

First Active Subcarrier (Hz)

T3 Timeouts

T4 Timeouts

6

OFDMA

220

74000000

0

0

 

31 REPLIES 31

avi68
Dialled in

avi68_0-1708425660231.png

 

Hey avi68, thank you for reaching out and I am sorry to see this.

Thank you for sending all these screenshots and evidence over.

I am going to send you a DM so we can look into this 

Matt - Forum Team


New around here?

Replied, thank you 

Hi @avi68 

Thanks for getting back to me with your details via PM.

I've gone ahead and booked in an engineer appointment for you.

There’ll be no charge for this visit unless:

 

 The technician finds that the issue isn’t due to our network or equipment, for example if it relates to equipment or other systems not provided by us, or it’s been damaged.

 

 You miss the appointment for any reason, or someone over 18 isn’t in at the time of the appointment.

 

Otherwise, the appointment would be free of charge.

The technician will confirm if a charge is applicable and a £25 Appointment Charge or a £25 Missed Appointment Charge may be applied to your account.

If you need to change or cancel your appointment you can reply to the SMS you’ll receive, or you can manage this through the My Virgin Media App up to 4pm the day before the appointment.


Let us know how the visit goes and if you need anything else 😊

 

Beth

Hi Beth,

I dont understand why an engineer has been booked? Ive probably had over 5 engineers attend in the last 2 months. None of which could do anything. I was told the fault was currently with the networks team as there was a wider impact. There is physically nothing the engineers can do. 

Please also note that other members of this forum are also getting the disconnection issues on the days and times I have mentioned. So this isnt just isloated to me.

It would be better to get an update from the networks team to find out if they've found the issue, as having an engineer attend isnt going to help me much.

Thanks

Hi @avi68 

We book an engineer when we can see that there are issues with the Hub specs that we cannot resolve ourselves. If there is work needed with the network teams then the engineer will be able diagnose and then raise this to the teams. We would book an engineer when there are issues showing that we cannot resolve ourselves.

Hi Ashleigh,

So if you can see issues why can’t the engineers that have attended not see any? Like previously mentioned it’s already raised with the networks team because the previous engineer raised it to them and they did see issues with my connection (they mentioned it to the engineer whilst he was at my property). This is why I have asked for an update from my previous post.

The rebooting issue, I’m not the only one having this, there are a few users on this forum reporting the exact same thing. So it would be nice to get an update on this or to even escalate to the appropriate teams so that the issue can be fixed.

Hi @avi68, thank you for your response.

What did the latest engineer to visit the property advise exactly in terms of any follow-up action that'd be taken?

Please pop back to us at your earliest convenience.

Regards,
Daniel

Hi Daniel,

So the engineer called the networks team to ask them about the issues I have raised. Networks said they were not aware of any "rebooting" issues and they cant see any area issues. The networks team didnt seem that interested/helpful.

The engineer said he hasnt heard about the hub 5 rebooting issues but he did mention that the hub 5 has issues in modem mode. I told him I took it out of modem mode for one night and still had the reboot. 

The engineer found some issues (noise) on the internal cabling. I told him it was all replaced in October/November last year (so its fairly new cabling). He re-terminated both ends of the internal cable and changed the attenuator. 

So far the hub has not rebooted (which is a good sign) but I believe that isnt to do with what the engineer did. I believe it is something else on VM's side thats changed to stop the reboots. 

Power levels are looking a lot healthier, especially on the 3.1 US channels. The 3.0 US channels are not flapping like before. 

So at the moment I am happy with what the engineer has done and things are working well. I just hope it stays that way.

Thanks

I am having the same issues, also problems but with downstream 3.1 now, uncorrected errors, was having problems on upstream profile 11,13 too. Engineer rang me said my area bristol is well not good in his words... slightly different words. Hasn't rang back since, still waiting, complaints told me to get hold of faults, yet there is no ticket number for me to reference. Out at the min will post stats later. After 60 second no ethernet reset uncorrected errors presented on the 3.1 instantly daily profile changes, routing profile problem?.