Weird power level distribution and RS errors

[i_saw_drones]

Hi All,

I recently noticed a bit of lag now and again with my Hub 3, and I decided to check the stats on it and found that there's a bit of a discrepancy regarding the power levels of downstream - is it normal for some channels have very negative power and others positive power ?

There's also quite a lot of post-RS errors on those channels which have a more extreme power values.

Please could you let me know if this is an issue with my line, or I can do something else to improve this, or does this need an engineer visit? Thank you!

Below stats have been taken after the router has been on for around 6 hours.

Downstream bonded channels

Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID

1	259000000	-9.9	28	256 qam	16
2	147000000	7.5	40	256 qam	2
3	155000000	8	40	256 qam	3
4	163000000	8.3	40	256 qam	4
5	171000000	8.3	40	256 qam	5
6	179000000	7.9	40	256 qam	6
7	187000000	7.5	40	256 qam	7
8	195000000	7	40	256 qam	8
9	203000000	6.1	40	256 qam	9
10	211000000	5.4	40	256 qam	10
11	219000000	4.1	38	256 qam	11
12	227000000	2.7	38	256 qam	12
13	235000000	0.7	37	256 qam	13
14	243000000	-1.9	35	256 qam	14
15	251000000	-5.4	32	256 qam	15
16	267000000	-10	27	256 qam	17
17	275000000	-5.4	31	256 qam	18
18	283000000	-1.7	35	256 qam	19
19	291000000	0.5	37	256 qam	20
20	299000000	2.5	37	256 qam	21
21	307000000	3.7	38	256 qam	22
22	315000000	5.1	40	256 qam	23
23	323000000	6	40	256 qam	24
24	331000000	6.5	40	256 qam	25

Downstream bonded channels

Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors

1	Locked	28.2	391525920	38675
2	Locked	40.3	23	0
3	Locked	40.3	13	0
4	Locked	40.3	7	0
5	Locked	40.9	6	0
6	Locked	40.3	14	0
7	Locked	40.3	11	0
8	Locked	40.3	34	0
9	Locked	40.9	10	0
10	Locked	40.9	6	0
11	Locked	38.9	10	0
12	Locked	38.6	14	0
13	Locked	37.3	19	0
14	Locked	35	476	0
15	Locked	32.2	2394287	14
16	Locked	27.8	411019167	652719
17	Locked	31.9	5039281	0
18	Locked	35	641	0
19	Locked	37.3	21	0
20	Locked	37.6	33	0
21	Locked	38.9	10	0
22	Locked	40.3	9	0
23	Locked	40.3	18	0
24	Locked	40.9	3	0

[legacy1]

looks bad

[jpeg1]

That variation in signal levels strongly suggests a cable fault. Check all the coaxial connectors are fitting properly - remove each and check that the centre pins are straight and then refit carefully.

If you still see the same levels you will need to call for a technician to check outside. 

[i_saw_drones]

Just as a follow up to this, I swapped the cable between the hub and the wall plate for another VM one I had from a previous house, and the results are pretty much the same. So I guess that this is an issue between the wall plate and the exchange somewhere?

Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID

1	259000000	-9.7	28	256 qam	16
2	139000000	7	38	256 qam	1
3	147000000	7.9	40	256 qam	2
4	155000000	8.4	40	256 qam	3
5	163000000	8.5	40	256 qam	4
6	171000000	8.5	40	256 qam	5
7	179000000	8.1	40	256 qam	6
8	187000000	7.9	40	256 qam	7
9	195000000	7.3	40	256 qam	8
10	203000000	6.5	40	256 qam	9
11	211000000	5.6	40	256 qam	10
12	219000000	4.4	38	256 qam	11
13	227000000	2.9	37	256 qam	12
14	235000000	1	37	256 qam	13
15	243000000	-1.5	35	256 qam	14
16	251000000	-5.2	32	256 qam	15
17	267000000	-9.7	28	256 qam	17
18	275000000	-4.7	31	256 qam	18
19	283000000	-0.7	35	256 qam	19
20	291000000	1.4	37	256 qam	20
21	299000000	3.2	38	256 qam	21
22	307000000	4.6	38	256 qam	22
23	315000000	5.9	40	256 qam	23
24	323000000	6.5	40	256 qam	24

Downstream bonded channels

Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors

1	Locked	28.3	1934671112	100997
2	Locked	38.9	21	0
3	Locked	40.9	30	0
4	Locked	40.9	21	0
5	Locked	40.9	12	0
6	Locked	40.9	10	0
7	Locked	40.9	9	0
8	Locked	40.3	22	0
9	Locked	40.3	26	0
10	Locked	40.3	21	0
11	Locked	40.9	17	0
12	Locked	38.9	23	0
13	Locked	37.6	54	0
14	Locked	37.3	287	0
15	Locked	35	4406	0
16	Locked	32.2	10081716	0
17	Locked	28	2064973020	1288372
18	Locked	31.9	19689367	5
19	Locked	35	3086	0
20	Locked	37.3	247	0
21	Locked	38.6	95	0
22	Locked	38.6	25	0
23	Locked	40.3	20	0
24	Locked	40.3	30	0

Upstream bonded channels

Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID

1	49600000	42.5	5120	64 qam	1
2	36600262	42	5120	64 qam	3
3	30100064	42	5120	64 qam	4
4	43100000	42.3	5120	32 qam	2
5	23599898	42	5120	16 qam	5

Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1	ATDMA	0	0	0	0
2	ATDMA	0	0	1	0
3	ATDMA	0	0	0	0
4	ATDMA	0	0	0	0
5	ATDMA	0	0	0	0

[Tudor]

I would guess your hub needs replacing unless it’s an amplifier fault in the street cabinet, although other users would also have problems. You need a technician visit to rectify. 

[Ashleigh_C]

Hi there @i_saw_drones 

Thank you so much for your post and welcome back to the community forums, it's great to have you here.

I am so sorry that you have faced these issues with your service and thank you to our community for their advise here. 

I have taken a look and can see there is currently a SNR (Signal to Noise Ratio) outage in the area that may be causing these issues, this is due to be resolved December 4th at 9am. 

Are you able to let us know how things are looking after this time? 

[jpeg1]

It's extremely unlikely that your faults are all caused by an area SNR problem, but I suppose you'll have to wait until they have fixed it before you will get the site visit you need.

[i_saw_drones]

Hi Ashleigh,

Thank you for your reply and warm welcome back!
Thank you for the investigation on this, I tried the status checker before posting but could not see any local issue.

Sure thing, I will wait until later in the day on the 4th and reply back then.

[Tudor]

Check with Area faults on 0800 561 0061 If you have a VM landline 150 this goes down to post code level. You could also try the web page status, but this is not recommended as it only covers issues that affect a very large number of customers.

[i_saw_drones]

Hi there,

I decided to give this a couple of days to let it settle, but unfortunately, it doesn't seem to have done anything much 😞 Please could you let me know what are the next steps?

Please find below my latest stats as of just now (hub has been up for around 10-15 mins as I had to restart it):

Downstream bonded channels

Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID

1	235000000	0.4	36	256 qam	13
2	243000000	-2.4	34	256 qam	14
3	251000000	-6.2	31	256 qam	15
4	259000000	-11.7	26	256 qam	0
5	267000000	-11.7	26	256 qam	0
6	275000000	-5.2	31	256 qam	18
7	283000000	-1.5	35	256 qam	19
8	291000000	0.7	37	256 qam	20
9	299000000	2.7	37	256 qam	21
10	307000000	4	38	256 qam	22
11	315000000	5.4	40	256 qam	23
12	323000000	6.1	40	256 qam	24
13	331000000	6.8	40	256 qam	25
14	339000000	7	40	256 qam	26
15	347000000	7	40	256 qam	27
16	355000000	7	40	256 qam	28
17	363000000	6.9	40	256 qam	29
18	371000000	6.5	40	256 qam	30
19	379000000	5.5	40	256 qam	31
20	387000000	4.4	38	256 qam	32
21	395000000	3	38	256 qam	33
22	403000000	1.5	37	256 qam	34
23	411000000	-0.4	36	256 qam	35
24	419000000	-3.2	34	256 qam	36

Downstream bonded channels

Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors

1	Locked	36.6	1	0
2	Locked	34.9	45	0
3	Locked	31.6	258492	0
4	Locked	26.4	3266907	10016865
5	Locked	26	282738	12999734
6	Locked	31.4	411195	0
7	Locked	35	43	0
8	Locked	37.3	6	0
9	Locked	37.6	2	0
10	Locked	38.9	4	0
11	Locked	40.3	5	0
12	Locked	40.3	4	0
13	Locked	40.9	5	0
14	Locked	40.3	4	0
15	Locked	40.3	0	0
16	Locked	40.3	5	0
17	Locked	40.9	5	0
18	Locked	40.3	4	0
19	Locked	40.3	6	0
20	Locked	38.9	5	0
21	Locked	38.9	20	0
22	Locked	37.6	5	0
23	Locked	36.6	1	0
24	Locked	34.9	57	0

Upstream bonded channels

Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID

1	49600000	42.8	5120	64 qam	1
2	36600000	42.8	5120	64 qam	3
3	43100000	42.8	5120	64 qam	2
4	23600020	42.5	5120	64 qam	5
5	30099937	42.5	5120	64 qam	4

Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1	ATDMA	0	0	0	0
2	ATDMA	0	0	0	0
3	ATDMA	0	0	0	0
4	ATDMA	0	0	0	0
5	ATDMA	0	0	0	0