Virgin Media Community

[sgabello]

Hello everyone,

I've been experiencing a choppy connection for some time now... and I was wondering if anyone could help me making any sense of the network status logs of my modem.

It's the 100Mb service on a SuperHub 2. Last reset was 4 days ago.

There is one 3dB forward path attenuator installed on the modem.

Are the numbers below acceptable?

Downstream 

				Rx Power	RxMER	Pre RS Errors	Post RS Errors
Locked	1	138750000 Hz	256 QAM	-1.9 dBmV	36.0 dB	404782	22879
Locked	2	146750000 Hz	256 QAM	-1.3 dBmV	37.1 dB	23812	6632
Locked	3	154750000 Hz	256 QAM	-1.6 dBmV	36.8 dB	22111	1297
Locked	4	162750000 Hz	256 QAM	-1.8 dBmV	36.6 dB	4366135	1466
Locked	5	170750000 Hz	256 QAM	-1.9 dBmV	37.4 dB	328024	677
Locked	6	178750000 Hz	256 QAM	-1.6 dBmV	37.1 dB	8637	561
Locked	7	186750000 Hz	256 QAM	-1.7 dBmV	37.6 dB	7476	1206
Locked	8	194750000 Hz	256 QAM	-2.0 dBmV	37.6 dB	13335	686

Upstream 

Locked	5	32600000 Hz	ATDMA	46.3 dBmV	64QAM	6400000 Hz	5120 Ksym/sec
Locked	2	53700000 Hz	ATDMA	45.0 dBmV	64QAM	6400000 Hz	5120 Ksym/sec
Locked	3	46200000 Hz	ATDMA	44.5 dBmV	64QAM	6400000 Hz	5120 Ksym/sec
Locked	4	39400000 Hz	ATDMA	45.3 dBmV	64QAM	6400000 Hz	5120 Ksym/sec

Thank you so much to anyone willing to help.

[Andrew-G]

There's far too many downstream post-RS (uncorrectable) errors given the run time of the hub, so that would explain a poor connection.  Given that your downstream SNR is adequate but not brilliant, might be worth removing the attenuator, seeing if that helps.  If the post-RS errors continue, then it will require a technician visit to diagnose and resolve the problem, but in that case I'd wait on the forum staff to advise.  You could try phoning it in, but the offshore staff will simply stick to their scripts, and probably get you to restart the hub, and then tell you all is fixed. 

[sgabello]

Hey Andrew,

Thank you so much for your advice. I tried and I removed the attenuator as you suggested. The connection still isn't great.

Do the values below look any better? The modem has been running for ~10 hours now.

Downstream

						Pre RS Errors	Post RS Errors
Locked	1	138750000 Hz	256 QAM	1.3 dBmV	36.0 dB	28198	699
Locked	2	146750000 Hz	256 QAM	1.9 dBmV	36.8 dB	4034	719
Locked	3	154750000 Hz	256 QAM	1.6 dBmV	36.8 dB	4123	1174
Locked	4	162750000 Hz	256 QAM	1.5 dBmV	36.6 dB	6935	835
Locked	5	170750000 Hz	256 QAM	1.3 dBmV	37.4 dB	6681	467
Locked	6	178750000 Hz	256 QAM	1.6 dBmV	37.1 dB	3817	554
Locked	7	186750000 Hz	256 QAM	1.5 dBmV	37.6 dB	2705	591
Locked	8	194750000 Hz	256 QAM	1.2 dBmV	37.1 dB	1108	505

Upstream

Locked	1	60300000 Hz	ATDMA	45.3 dBmV	64QAM	6400000 Hz	5120 Ksym/sec
Locked	2	53700000 Hz	ATDMA	44.5 dBmV	64QAM	6400000 Hz	5120 Ksym/sec
Locked	3	46200000 Hz	ATDMA	44.3 dBmV	64QAM	6400000 Hz	5120 Ksym/sec
Locked	4	39400000 Hz	ATDMA	45.0 dBmV	64QAM	6400000 Hz	5120 Ksym/sec

[nnnnnnn999]

The power levels may deteriorate over time and require you to restart your modem to fix. I had this issue a few years ago.

The coax from the blue or brown box outside the property had a splitter and then when the cable was fed into the property, It had another splitter + attenuator. Very weird but the VM Engineer seemed very incompetent. Removed one and power levels are now around 4-6 (dBmV).

You haven't changed the cable or used a different type of coaxial cable have you ?

[Andrew-G]

Removing the attenuator hasn't materially changed things - power levels are up by a few dBmV as we'd expect, although that's not made any obvious difference to SNR or error levels.  If in ten hours you've got around 6,000 post-RS errors, then there's a noise problem that probably requires a technician visit to fix.  I'll flag this for the forum staff to advise, and they'll book a technician if needed.

[Steven_L · Accepted solution]

Hey @sgabello,

Thanks for taking the time to post on our forums and I'm really sorry for the issues that you're having at the moment.

I have been able to locate your account via your community profile and can confirm as @Andrew-G suggested there are some issues with the SNR levels that need a technician visit to resolve.

We will need to confirm a few details, so that we can get this visit booked in, I will send a private message over in a moment, please look out for this.

Regards,

Steven_L

[sgabello]

@Steven_L Thank you so much for looking into this! I've just replied to the DM.

@nnnnnnn999 Thanks for the suggestion. I went through a full power-cycle multiple times, also before removing the attenuator for this last test.

@Andrew-G Thank you again for the support and flagging the post to the admins. FYI it looks like the line generates ~3000 post-RS error every 10 hours.

I'm now at ~30 hours from the last reset and these are the stats (just for educational purposes):

Locked	1	138750000 Hz	256 QAM	1.3 dBmV	36.0 dB	62507	1237
Locked	2	146750000 Hz	256 QAM	1.9 dBmV	36.8 dB	13293	1328
Locked	3	154750000 Hz	256 QAM	1.7 dBmV	36.2 dB	13080	2039
Locked	4	162750000 Hz	256 QAM	1.5 dBmV	36.2 dB	12217	1461
Locked	5	170750000 Hz	256 QAM	1.3 dBmV	37.4 dB	9832	704
Locked	6	178750000 Hz	256 QAM	1.6 dBmV	37.1 dB	9095	859
Locked	7	186750000 Hz	256 QAM	1.5 dBmV	37.4 dB	8453	1037
Locked	8	194750000 Hz	256 QAM	1.2 dBmV	37.1 dB	7676	751

[Steven_L]

Thanks for confirming your information @sgabello.

I have arranged for the appointment and you can find all the information that you need about your appointment on your online account and clicking My Account and Track Your Order.

Regards,

Steven_L

[sgabello]

@Steven_L thank you so much.

At the moment I can't see the appointment under the "My Account" area as it say it could take up to 24 hours to show up.

Would you mind to send me the detail of the day/time in a DM so I can make sure I'm available?

Many Many thanks!

[Steven_L]

 No problem @sgabello, I will send that over now.

Thanks,

Steven_L