Virgin Media Community

[jmeisenberg]

Hi all, I've looked around for a while, and the values I see on this forum for dB and SNR vary widely. 

I'm on the 1gig package with a hub 4. It's in modem mode, with Ubiquiti UDM-Pro controlled network internally. Getting frequent internet disconnects lasting a few minutes each time. Ubiquiti kit is always completely stable and isn't showing anything unusual in the logs. 

I didn't see a huge variance over a few minutes of refreshing on the dB/SNR values below.

Appreciate any advice you can give me. Thanks.

3.0 Downstream channels

Channel	Frequency (Hz)	Power (dBmV)	SNR (dB)	Modulation	Channel ID
1	139000000	1.7	39	QAM256	1
2	147000000	1.5	39	QAM256	2
3	155000000	1.4	40.4	QAM256	3
4	163000000	1.3	40.4	QAM256	4
5	171000000	1.2	40.4	QAM256	5
6	179000000	1.4	40.4	QAM256	6
7	187000000	1.5	40.4	QAM256	7
8	195000000	1.5	40.4	QAM256	8
9	203000000	1.5	40.9	QAM256	9
10	211000000	1.2	40.4	QAM256	10
11	219000000	1.1	40.4	QAM256	11
12	227000000	1.3	40.4	QAM256	12
13	235000000	1.4	39	QAM256	13
14	243000000	1.4	39	QAM256	14
15	251000000	1.2	39	QAM256	15
16	259000000	1.3	40.4	QAM256	16
17	267000000	1.7	40.4	QAM256	17
18	275000000	2.1	40.4	QAM256	18
19	283000000	1.6	39	QAM256	19
20	291000000	1.3	39	QAM256	20
21	299000000	1.1	39	QAM256	21
22	307000000	1.3	39	QAM256	22
23	315000000	1.9	40.4	QAM256	23
24	323000000	2.4	40.4	QAM256	24
25	363000000	1.4	39	QAM256	25
26	371000000	1.6	40.4	QAM256	26
27	379000000	1.8	39	QAM256	27
28	387000000	1.8	38.6	QAM256	28
29	395000000	1.8	39	QAM256	29
30	403000000	1.3	39	QAM256	30
31	411000000	1	39	QAM256	31

[jmeisenberg]

More data:

3.0 Downstream channels

Channel	Lock Status	RxMER (dB)	Pre RS Errors	Post RS Errors
1	Locked	38.983261	347	0
2	Locked	38.983261	528	0
3	Locked	40.366287	670	0
4	Locked	40.366287	484	0
5	Locked	40.366287	345	0
6	Locked	40.366287	16	0
7	Locked	40.366287	0	0
8	Locked	40.366287	0	0
9	Locked	40.946209	0	0
10	Locked	40.366287	0	0
11	Locked	40.366287	0	0
12	Locked	40.366287	0	0
13	Locked	38.983261	0	0
14	Locked	38.983261	0	0
15	Locked	38.983261	0	0
16	Locked	40.366287	0	0
17	Locked	40.366287	0	0
18	Locked	40.366287	0	0
19	Locked	38.983261	0	0
20	Locked	38.983261	0	0
21	Locked	38.983261	0	0
22	Locked	38.983261	0	0
23	Locked	40.366287	0	0
24	Locked	40.366287	0	0
25	Locked	38.983261	0	0
26	Locked	40.366287	0	0
27	Locked	38.983261	0	0
28	Locked	38.605377	0	0
29	Locked	38.983261	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	QAM256	759

3.1 Downstream channels

Channel ID	Lock Status	RxMER Data (dB)	PLC Power (dBmV)	Correcteds (Active Profile)	Uncorrectables (Active Profile)
159	Locked	41	-0.4	0	0

3.0 Upstream channels

Channel	Frequency (Hz)	Power (dBmV)	Symbol Rate (ksps)	Modulation	Channel ID
1	39400000	51.5	5120 KSym/sec	64QAM	4
2	46200000	52.3	5120 KSym/sec	64QAM	3
3	53700000	52.8	5120 KSym/sec	64QAM	2
4	60300000	53.3	5120 KSym/sec	64QAM	1

3.0 Upstream channels

Channel	Channel Type	T1 Timeouts	T2 Timeouts	T3 Timeouts	T4 Timeouts
1	US_TYPE_STDMA	0	0	10	0
2	US_TYPE_STDMA	0	0	10	0
3	US_TYPE_STDMA	0	0	12	0
4	US_TYPE_STDMA	0	0	12	0

[Z92]

Post a BQM so we check the stability of the line

You may need to put the virgin hub back into router mode so vm staff can interrogate more. 

[lotharmat]

Upstream power looks to be too high - Also should the DOCSIS 3.1 channel be at 4096 QAM?

[jmeisenberg]

I'll have to come back to you on that. I've got the UI kit to silently drop ICMP. Thanks.

[jmeisenberg]

I have no idea! 😂

I wouldn't even know how to change it or what that means. Admittedly, I only skimmed through the DOCSIS primer once... 

[jmeisenberg]

ok, here's a question - what's BQM's source IPs for whitelisting? I don't mind opening up a little of my network, but don't want to disable the firewall just for this...
Any thoughts?

[jmeisenberg]

Found them as
80.249.99.164
and
80.249.99.171

[jmeisenberg]

Hi mate, quick update: Gone to BQM, found the source IPs, but getting 100% dropped packets despite opening up ICMP... still trying.

[jmeisenberg]

Quick update:

Went back to router mode last night, BQM still showing 100% dropped packets even though everything is reset to factory defaults (changed admin password and SSID only).

https://www.thinkbroadband.com/broadband/monitoring/quality/share/96e9f285e76d2ad8ae82da823de1faaeb8...

I've also taken an updated reading for power and SNR since, big difference from the first one:

3.0 Downstream channels

Channel	Frequency (Hz)	Power (dBmV)	SNR (dB)	Modulation	Channel ID
1	139000000	0.5	39	QAM256	1
2	147000000	0.3	38.6	QAM256	2
3	155000000	0.2	39	QAM256	3
4	163000000	0.1	39	QAM256	4
5	171000000	0	38.6	QAM256	5
6	179000000	0.3	40.4	QAM256	6
7	187000000	0.5	39	QAM256	7
8	195000000	0.4	39	QAM256	8
9	203000000	0.4	39	QAM256	9
10	211000000	0.1	38.6	QAM256	10
11	219000000	0	39	QAM256	11
12	227000000	0.2	39	QAM256	12
13	235000000	0.4	39	QAM256	13
14	243000000	0.4	38.6	QAM256	14
15	251000000	0.3	38.6	QAM256	15
16	259000000	0.5	38.6	QAM256	16
17	267000000	0.8	38.6	QAM256	17
18	275000000	1.2	38.6	QAM256	18
19	283000000	0.8	38.6	QAM256	19
20	291000000	0.6	38.6	QAM256	20
21	299000000	0.3	39	QAM256	21
22	307000000	0.5	39	QAM256	22
23	315000000	1.1	40.4	QAM256	23
24	323000000	1.6	39	QAM256	24
25	363000000	0.5	39	QAM256	25
26	371000000	0.8	39	QAM256	26
27	379000000	1	38.6	QAM256	27
28	387000000	1	38.6	QAM256	28
29	395000000	1.1	39	QAM256	29
30	403000000	0.8	38.6	QAM256	30
31	411000000	0.3	38.6	QAM256	31