Menu
Reply
apbliv
  • 25
  • 0
  • 0
Tuning in
960 Views
Message 1 of 29
Flag for a moderator

1Gig downloads slower than previous M600

Hi

About 2 weeks ago I upgraded to 1Gbps. I was previously on M600 and getting consistently over 550mbps downloads. I installed the Hub4, and every since have been getting slower downloads. I read on here that the Hub4 can take time to settle, so I have waited (in vain). The previous SH3 had a 10 db inline attenuator, which I have kept. I run the Hub4 in modem mode, but if I run it as a hub and then run samknows with my PC directly connected to the Hub4 by Cat6 I get this:

apbliv_0-1615804767905.png

It seems my speed to the hub 4 is fine, but the hub 4 then gives me a lower speed than I got from my SH3 on M600 (by about 20%). Other speed checkers confirm that I cannot get more than ~440 mbps to a wired connection. The upload speed is consistently at expected level.

Hub4 data in next post

0 Kudos
Reply
apbliv
  • 25
  • 0
  • 0
Tuning in
957 Views
Message 2 of 29
Flag for a moderator

Re: 1Gig downloads slower than previous M600

3.0 Downstream channels

Channel

Frequency (Hz)

Power (dBmV)

SNR (dB)

Modulation

Channel ID

1

139000000

-0.1

39

QAM256

1

2

147000000

-0.3

39

QAM256

2

3

155000000

-0.8

39

QAM256

3

4

163000000

-1

39

QAM256

4

5

171000000

-1.2

39

QAM256

5

6

179000000

-1.4

39

QAM256

6

7

187000000

-1.7

39

QAM256

7

8

195000000

-1.9

39

QAM256

8

9

203000000

-2

38.6

QAM256

9

10

211000000

-2.2

39

QAM256

10

11

219000000

-2.4

38.6

QAM256

11

12

227000000

-2.7

38.6

QAM256

12

13

235000000

-2.7

38.6

QAM256

13

14

243000000

-2.8

38.6

QAM256

14

15

251000000

-2.9

38.6

QAM256

15

16

259000000

-2.9

38.6

QAM256

16

17

267000000

-2.7

39

QAM256

17

18

275000000

-2.2

38.6

QAM256

18

19

283000000

-2

39

QAM256

19

20

291000000

-2.1

39

QAM256

20

21

299000000

-2.7

39

QAM256

21

22

307000000

-3.4

38.6

QAM256

22

23

315000000

-4.1

38.6

QAM256

23

24

323000000

-4.2

37.6

QAM256

24

25

331000000

-4.1

38.6

QAM256

25

26

339000000

-3.8

38.6

QAM256

26

27

347000000

-3.7

39

QAM256

27

28

355000000

-3.9

38.6

QAM256

28

29

363000000

-3.4

37.6

QAM256

29

30

371000000

-3

39

QAM256

30

31

379000000

-3

39

QAM256

31

 

3.0 Downstream channels

Channel

Lock Status

RxMER (dB)

Pre RS Errors

Post RS Errors

1

Locked

38.983261

0

0

2

Locked

38.983261

0

0

3

Locked

38.983261

0

0

4

Locked

38.983261

0

0

5

Locked

38.983261

0

0

6

Locked

38.983261

0

0

7

Locked

38.983261

0

0

8

Locked

38.983261

0

0

9

Locked

38.605377

0

0

10

Locked

38.983261

0

0

11

Locked

38.605377

0

0

12

Locked

38.605377

0

0

13

Locked

38.605377

0

0

14

Locked

38.605377

0

0

15

Locked

38.605377

0

0

16

Locked

38.605377

0

0

17

Locked

38.983261

0

0

18

Locked

38.605377

0

0

19

Locked

38.983261

0

0

20

Locked

38.983261

0

0

21

Locked

38.983261

0

0

22

Locked

38.605377

0

0

23

Locked

38.605377

0

0

24

Locked

37.636276

0

0

25

Locked

38.605377

0

0

26

Locked

38.605377

0

0

27

Locked

38.983261

0

0

28

Locked

38.605377

0

0

29

Locked

37.636276

0

0

30

Locked

38.983261

0

0

31

Locked

38.983261

0

0

 

3.1 Downstream channels

Channel

Channel Width (MHz)

FFT Type

Number of Active Subcarriers

Modulation (Active Profile)

First Active Subcarrier (Hz)

159

96

4K

1880

QAM4096

759

 

3.1 Downstream channels

Channel ID

Lock Status

RxMER Data (dB)

PLC Power (dBmV)

Correcteds (Active Profile)

Uncorrectables (Active Profile)

159

Locked

37

-10.1

514235361

0

0 Kudos
Reply
apbliv
  • 25
  • 0
  • 0
Tuning in
957 Views
Message 3 of 29
Flag for a moderator

Re: 1Gig downloads slower than previous M600

3.0 Upstream channels

Channel

Frequency (Hz)

Power (dBmV)

Symbol Rate (ksps)

Modulation

Channel ID

1

32600000

40.5

5120 KSym/sec

64QAM

13

2

39400000

41

5120 KSym/sec

64QAM

12

3

46200000

41.5

5120 KSym/sec

64QAM

11

4

53700000

42.5

5120 KSym/sec

64QAM

10

 

3.0 Upstream channels

Channel

Channel Type

T1 Timeouts

T2 Timeouts

T3 Timeouts

T4 Timeouts

1

US_TYPE_STDMA

0

0

0

0

2

US_TYPE_STDMA

0

0

3

0

3

US_TYPE_STDMA

0

0

0

0

4

US_TYPE_STDMA

0

0

1

0

 

Any advice on how to improve things would be much appreciated. The SH3 has gone back, so I can't re-install that to get higher download speeds.

Thanks

Alan

0 Kudos
Reply
Akua_A
  • 2.9K
  • 71
  • 188
Forum Team
Forum Team
873 Views
Message 4 of 29
Flag for a moderator

Re: 1Gig downloads slower than previous M600

Hi @apbliv,

 

Welcome back to our community forums.

 

Sorry to hear you are having issues with your broadband speeds.

 

Have you tried rebooting your device to see if the problem persists? Have you also tried changing your Ethernet cord to see if the issue remains?

 

Please let us know how you get on.

 

Thanks,

Akua_A
Forum Team



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


0 Kudos
Reply
apbliv
  • 25
  • 0
  • 0
Tuning in
869 Views
Message 5 of 29
Flag for a moderator

Re: 1Gig downloads slower than previous M600

Hi Akua_M

thanks for the reply. I have tried rebooting, switching between modem and hub mode and different cables. I will try a rest at some point, but I don't hold out much hope that will make a difference. Everything is the same as when I had M600 with a SH3 in modem mode, but the download speed is slower.

Best regards

Alan

0 Kudos
Reply
Akua_A
  • 2.9K
  • 71
  • 188
Forum Team
Forum Team
861 Views
Message 6 of 29
Flag for a moderator

Re: 1Gig downloads slower than previous M600

Thanks for getting back to us @apbliv.

 

Is the speed still slow in safe mode? Is it also slow in modem mode?

 

Also please let us know how the reset goes.

 

Many thanks,

 

 

Akua_A
Forum Team



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


0 Kudos
Reply
Anonymous
Not applicable
854 Views
Message 7 of 29
Flag for a moderator

Re: 1Gig downloads slower than previous M600

I'd suggest that your DOCSIS 3.1 channel needs an adjustment on power level:

3.1 Downstream channels

Channel ID

Lock Status

RxMER Data (dB)

PLC Power (dBmV)

Correcteds (Active Profile)

Uncorrectables (Active Profile)

159

Locked

37

-10.1

514235361

0

 

You could try removing the attenuator, however this will increase the other channels power levels, as well as affect upstream power, which could knock them out of spec!

0 Kudos
Reply
apbliv
  • 25
  • 0
  • 0
Tuning in
784 Views
Message 8 of 29
Flag for a moderator

Re: 1Gig downloads slower than previous M600

Thanks to those who made some suggestions. I have been a bit busy the last few days, but managed to rest the Hub4 and then test it with and without the 10dB attenuator.

Samknows got worse!

Hub Mode after reboot with 10dB attenuator (17 Mar 2021)

apbliv_0-1616159602302.png

3.1 Downstream channels

Channel

Channel Width (MHz)

FFT Type

Number of Active Subcarriers

Modulation (Active Profile)

First Active Subcarrier (Hz)

159

96

4K

1880

QAM4096

759




3.1 Downstream channels

Channel ID

Lock Status

RxMER Data (dB)

PLC Power (dBmV)

Correcteds (Active Profile)

Uncorrectables (Active Profile)

159

Locked

38

-9.6

806400

0

 

apbliv_1-1616159684086.png



3.1 Downstream channels

Channel

Channel Width (MHz)

FFT Type

Number of Active Subcarriers

Modulation (Active Profile)

First Active Subcarrier (Hz)

159

96

4K

1880

QAM4096

759




3.1 Downstream channels

Channel ID

Lock Status

RxMER Data (dB)

PLC Power (dBmV)

Correcteds (Active Profile)

Uncorrectables (Active Profile)

159

Locked

39

1.3

3826518

2863

 

I then set the Hub 4 to modem mode and Speedtest gave me this with and without the attenuator - back to ~500Mbps.

apbliv_2-1616159857487.png

To test my local network I download a 6Gb movie file from my NAS and got these speeds:

apbliv_3-1616159977377.png

 

My NAS does other things like monitor CCTV, but the transfer indicates I can get 1Gig speeds on my wired network.

So, I suspect the Hub is the issue. Maybe I need to sit a fan underneath it as someone else has suggested. I will have time to phone VM next week which may be the best way to solve this.

Alan

 

 

0 Kudos
Reply
Chris_W1
  • 4.62K
  • 207
  • 303
Forum Team
Forum Team
781 Views
Message 9 of 29
Flag for a moderator
Helpful Answer

Re: 1Gig downloads slower than previous M600

Hi Alan, I am sorry to hear that you are having issues with the connection. I have arranged for an engineer to check this for you and the appointment can be viewed in the online account ^Chris

apbliv
  • 25
  • 0
  • 0
Tuning in
574 Views
Message 10 of 29
Flag for a moderator

Re: 1Gig downloads slower than previous M600

Thanks for organising the technician. He duly arrived and tested things.

He confirmed 1Gig to the Hub 4 but then found, as I did, that the speed to my PC was half that in modem mode through my Asus router, but SLOWER if the PC was directly connected to the Hub4 in hub mode using his Cat6 cable.

He found that download speed discrepancy odd and agreed to try a new Hub4, but that had the same effect. He left bemoaning the fact that VM do not supply their tech staff with a device that can confirm the speed coming out of the Hub4 when directly connected to it. He had no further suggestions other than it must be my equipment on the basis two hubs gave the same result. However, he could not demonstrate that the Hub4 delivered 1 gig. 

The delay in posting this response is because I have been busy. I have replaced two 10-year-old NetGear gigabit switches with new ones, and also replaced Cat5 cables with Cat6 - the last one from the ground floor room where the Hub4 is up to my 2nd floor office today. These upgrades have changed nothing as regards download speeds from the Hub 4. My office laptop (HP Elitebook 840G5) typically downloads at ~300 Mbps on a wired connection (it gets 97 MBps file transfer from my NAS drive on the ground floor indicating the Cat6 is working). My Pixel 4a phone just got 450mbps (!) through wifi (I have a Mesh Wi-Fi network with Ethernet wired backhaul).

Something is throttling download speeds, but I am at a loss to work out what.

 

Alan

0 Kudos
Reply