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BumblingFool
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Broadband speed drops intermittently from 200M to 10-20M

Hi,

Recently (last 4-5 weeks) we occasionally see the broadband (speedtest.net, I have my hub in passthrough and a Netgear R6400 router) speed drop from a typical 190M to between 10 and 20 M. No Wi-Fi - direct 1Gb ethernet off the netgear.

A quick power off on the hub (superhub 2) solves the problem and I am back to 200M again. It seems to be getting more frequent, today it dropped back after 10 mins, but we have days of good service. If it was calbes I would expect to see it more often.

Any ideas, my environment has not changed for 4 years with very few issues.

Thanks.

 

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Andrew-G
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Re: Broadband speed drops intermittently from 200M to 10-20M

Could be that your connection has been moved onto a less suitable tap in the street cabinet in connection with other work, or that a fault has occurred that's introduced noise or upset power levels.  As a start, connect to the hub by clicking on this link http://192.168.100.1/  That should pull up the log in page for the hub.  But don't log in, just click on the link "Check router status"  That'll bring up a window with five tabs.  Open the Downstream tab.  Select all the text (Ctrl-A if using a keyboard), copy it (Ctrl-C), then paste it (Ctrl-V) into a reply here as text, not screenshots.  Post that, do the same for the Upstream and Network log.  You'll get an error message when you post the Network log, just click on "post" a second time.

Then we can check for any obvious problems with power, noise or error counts, and proceed from there.

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BumblingFool
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Message 3 of 12
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Re: Broadband speed drops intermittently from 200M to 10-20M

Hi,

Only problem being that the Virgin box is running in pass through mode to my own router so I cannot connect to it directly.

Let me see if I can find the time to reset the box to router mode and get the logs.

Thanks,

J

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Andrew-G
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Message 4 of 12
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Re: Broadband speed drops intermittently from 200M to 10-20M

Running in modem mode doesn't stop you accessing the hub's login page and stats - I'm running mine in modem mode, and can access the hub from any device on the LAN.

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BumblingFool
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Re: Broadband speed drops intermittently from 200M to 10-20M

Ok - here are the logs - needed to direct connect and set a static IP on the 192.168.100.x network to access the box.

Downstream DS-1 DS-2 DS-3 DS-4 DS-5 DS-6 DS-7 DS-8
Frequency (Hz) 139000000 147000000 155000000 163000000 171000000 179000000 187000000 195000000
Lock Status(QAM Lock/FEC Sync/MPEG Lock) Locked Locked Locked Locked Locked Locked Locked Locked
Channel ID 1 2 3 4 5 6 7 8
Modulation 256QAM 256QAM 256QAM 256QAM 256QAM 256QAM 256QAM 256QAM
Symbol Rate (Msym/sec) 6.952000 6.952000 6.952000 6.952000 6.952000 6.952000 6.952000 6.952000
Interleave Depth I=12
J=17 I=12
J=17 I=12
J=17 I=12
J=17 I=12
J=17 I=12
J=17 I=12
J=17 I=12
J=17
Power Level (dBmV) -6.21 -6.06 -5.27 -4.80 -4.65 -5.73 -4.80 -4.60
RxMER (dB) 34.35 34.93 35.60 35.25 35.78 35.42 36.17 36.17
Pre RS Errors
589849059 309947 17786 940924 19634 7308 4142 4242
Post RS Errors
1002458 1192 517 5102 661 753 422 367


Upstream US-1 US-2 US-3 US-4
Channel Type 2.0 2.0 2.0 2.0
Channel ID 1 3 2 4
Frequency (Hz) 60300000 46200000 53700000 39400000
Ranging Status Success Success Success Success
Modulation 64QAM 64QAM 64QAM 64QAM
Symbol Rate (Sym/sec) 5120000 5120000 5120000 5120000
Mini-Slot Size 2 2 2 2
Power Level (dBmV) 51.00 49.00 49.75 47.75
T1 Timeouts 0 0 0 0
T2 Timeouts 0 0 0 0
T3 Timeouts 1 0 0 1
T4 Timeouts 0 0 0 0


Network Log First Time Last Time Priority Error Number Description
22/04/2021 16:58:49 GMT 22/04/2021 16:58:49 GMT Critical (3) 82000200 No Ranging Response received - T3 time-out
22/04/2021 16:56:57 GMT 22/04/2021 16:56:57 GMT Warning (5) 84020200 Lost MDD Timeout
22/04/2021 16:56:48 GMT 22/04/2021 16:56:48 GMT Warning (5) 84020200 Lost MDD Timeout
22/04/2021 16:55:38 GMT 22/04/2021 16:55:38 GMT Warning (5) 84020200 Lost MDD Timeout
22/04/2021 16:55:31 GMT 22/04/2021 16:55:31 GMT Warning (5) 84020200 Lost MDD Timeout
22/04/2021 16:54:14 GMT 22/04/2021 16:54:14 GMT Warning (5) 84020200 Lost MDD Timeout
22/04/2021 16:54:04 GMT 22/04/2021 16:54:04 GMT Warning (5) 84020200 Lost MDD Timeout
22/04/2021 16:53:45 GMT 22/04/2021 16:53:45 GMT Warning (5) 84020200 Lost MDD Timeout
22/04/2021 13:35:55 GMT 22/04/2021 13:35:55 GMT Error (4) 68000407 TOD established
Time Not Established Time Not Established Critical (3) 82000200 No Ranging Response received - T3 time-out
Time Not Established Time Not Established Notice (6) 84000510 Downstream Locked Successfully
22/04/2021 13:31:03 GMT 22/04/2021 13:31:03 GMT Critical (3) 84000500 SYNC Timing Synchronization failure - Loss of Sync
22/04/2021 13:31:03 GMT 22/04/2021 13:31:03 GMT Critical (3) 84000500 SYNC Timing Synchronization failure - Loss of Sync
22/04/2021 13:31:01 GMT 22/04/2021 13:31:01 GMT Critical (3) 84000500 SYNC Timing Synchronization failure - Loss of Sync
22/04/2021 13:25:34 GMT 22/04/2021 13:25:34 GMT Warning (5) 84020200 Lost MDD Timeout
22/04/2021 13:24:34 GMT 22/04/2021 13:24:34 GMT Warning (5) 84020200 Lost MDD Timeout
22/04/2021 13:23:34 GMT 22/04/2021 13:23:34 GMT Warning (5) 84020200 Lost MDD Timeout
22/04/2021 13:22:34 GMT 22/04/2021 13:22:34 GMT Warning (5) 84020200 Lost MDD Timeout
22/04/2021 11:29:19 GMT 22/04/2021 11:29:19 GMT Error (4) 68000407 TOD established
Time Not Established Time Not Established Critical (3) 82000200 No Ranging Response received - T3 time-out

 

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Andrew-G
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Message 6 of 12
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Re: Broadband speed drops intermittently from 200M to 10-20M

Your issues are caused by power that's too low on your downstream channels, and upstream power that's too high, that'll destroy connection reliability and create the huge number of errors shown. 

I've flagged for staff to respond, they'll be able to book a technician visit for you, but you may have to put the hub into router mode so that they can interrogate the status data remotely, unless they can take the data you've posted as an acceptable level of proof.  To avoid high volumes of callouts that find no problem, the company have protocols that a fault has to be evidenced before a technician can be assigned, even though that can be inconvenient when customers know full well there's a problem with the VM side of things.

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BumblingFool
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Re: Broadband speed drops intermittently from 200M to 10-20M

Looking at the cable connection the line is connected with 4dB cable simulator and a 3dB forward attenuator, installed when the service was delivered many many years ago. Would it be worth removing either or both of those to improve the signal?

I can change the mode easily enough with a bit of prior notice as I work at home anyway, if it's required.

But if an engineer reads this, all has been working fine in this exact configuration for 4 years. It's only in the last month that I have had any issues.

Thanks for the help.

J

 

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Robert_P
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Re: Broadband speed drops intermittently from 200M to 10-20M

Hello BumblingFool

 

Sorry to hear of the broadbadn issues experienced, we appreciate you taking the time to contact us via the forums to make us aware.

 

I've booked a technician for tomorrow between 12pm and 4pm to look into this further for you, if you could let me know if there are any individuals shielding or if the appointment isn't convenient for you I can look to rearrange it. Please be aware though this was the earliest appointment available and any changes may delay the visit.

 

Thanks

 

Rob

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Message 9 of 12
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Re: Broadband speed drops intermittently from 200M to 10-20M

@BumblingFool Looking at the cable connection the line is connected with 4dB cable simulator and a 3dB forward attenuator, installed when the service was delivered many many years ago. Would it be worth removing either or both of those to improve the signal?

Since you've got a technician visit booked for tomorrow, I'd say don't fiddle.  For those with some knowledge of radio frequency matters (which doesn't include me) they may be able to conclude whether that might help or not, but for myself, and I suspect you, it would be simple trial and error that risks a temporary change that appears to fix things but then only delays a proper solution.  As an example, if your D/S power is too low with a value of around -6 dBmV, do you need higher or lower attenuation?  Linguistically it would seem you need less attenuation, in basic maths terms you need more attenuation (because the problem is the amplitude not the +/-), and in the important matter of RF signal management I don't have a scooby, and that last one is what matters, and what  VM pay their people to know.  I say keep a technician in a job by letting them sort it out (although that philosophy raises troubling thoughts about how to keep council litter pickers or policemen in a job).  

You might even get a new hub when the tech visits, and that would be a good thing simply because the Hub 3 is a superior cable modem to the SH2.

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BumblingFool
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Message 10 of 12
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Re: Broadband speed drops intermittently from 200M to 10-20M

Hi,

Tomorrow is fine, I will be in all day. There is no one shielding here.

Many thanks.

J

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