SNR issue, I guess.

[Icantcrabhere]

Hemel Hempstead(HP2)
Looks like the connection went down originally at around 12:30PM(ish) before coming back at just before 3PM.
Online fault checker is showing nothing wrong (currently).
Just posting so this can get potentially flagged up/noted.


Live Graph:

https://www.thinkbroadband.com/broadband/monitoring/quality/share/1700d27c199ce3ea214d66ce063ff9f395507b3e

Todays snapshot:

https://www.thinkbroadband.com/broadband/monitoring/quality/share/bd4c5b3ba711cd6c987a5b0314b71dd8761d746d-30-01-2023

Stats will be posted next:

as you can see: Only 1 upstream channel

upstream bonded channels

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

1

30100657

57

5120

32 qam

4

Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1

ATDMA

0

0

4

0

Downstream bonded channels

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

1	563000000	-9	37	256 qam	20
2	539000000	-8.4	37	256 qam	17
3	547000000	-8.7	37	256 qam	18
4	555000000	-8.7	37	256 qam	19
5	571000000	-9.2	37	256 qam	21
6	579000000	-9.5	37	256 qam	22
7	587000000	-9.5	37	256 qam	23
8	595000000	-9.4	37	256 qam	24
9	603000000	-9.4	37	256 qam	25
10	611000000	-9.5	37	256 qam	26
11	619000000	-9.7	37	256 qam	27
12	627000000	-9.7	37	256 qam	28
13	635000000	-9.5	37	256 qam	29
14	643000000	-9.2	37	256 qam	30
15	651000000	-9	37	256 qam	31
16	659000000	-8.7	37	256 qam	32
17	667000000	-8.9	37	256 qam	33
18	675000000	-8.9	37	256 qam	34
19	683000000	-9	37	256 qam	35
20	691000000	-8.9	37	256 qam	36
21	699000000	-8.9	37	256 qam	37
22	707000000	-8.7	37	256 qam	38
23	715000000	-8.7	37	256 qam	39
24	723000000	-8.9	37	256 qam	40

Downstream bonded channels

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

1	Locked	37.3	11	0
2	Locked	37.6	9	0
3	Locked	37.6	16	0
4	Locked	37.6	10	0
5	Locked	37.3	19	0
6	Locked	37.3	25	0
7	Locked	37.3	21	0
8	Locked	37.6	18	0
9	Locked	37.6	23	0
10	Locked	37.6	26	0
11	Locked	37.6	29	0
12	Locked	37.6	34	0
13	Locked	37.3	40	0
14	Locked	37.3	41	0
15	Locked	37.6	22	0
16	Locked	37.3	21	0
17	Locked	37.3	20	0
18	Locked	37.3	20	0
19	Locked	37.3	21	0
20	Locked	37.6	21	0
21	Locked	37.6	15	0
22	Locked	37.6	15	0
23	Locked	37.6	17	0
24	Locked	37.6	11	0

Gonna have to remove the 6DB attenuator to bring powers back into range at some point when I have the chance, too.
Kind of lucky I'm only using this as a backup connection/for family members now.. lol

[John_GS]

Hi Icantcrabhere

Thanks for coming back to the thread

I have checked the levels our side and still out of spec - were you able to remove the attuenator? 

If you need a tech visit to help, let us know and we can sort this.

Best,

[Icantcrabhere]

Hi John_GS!

Finally had time to try to remove it again,
unfortunately no luck, it's pretty firmly on there and refuses to undo(using a spanner, etc) - I didn't want to try further and damage the equipment/line.

Any help would be appreciated, cheers!

[Ashleigh_C]

Hi there @Icantcrabhere 

Thank you for popping back to us, I do think it would be best for us to get an engineer to take a look for you. 

I will pop you a PM across now, please keep an eye out for the purple envelope in the top right corner of your screen alerting you to a new message. 
 

[Ashleigh_C]

Hello again,

Thanks so much for your private message and confirming your address, I have now booked you a visit for your connection – you can check the date and time via your online account here. If you have any issues with accessing your online account or unable to see your visit, please do let us know and we’ll pop you a message to confirm.

There will be no charge for this visit unless:
• The technician diagnoses the faults as not being caused by our network/equipment 
• The technician discovers that the fault or problem relates to your equipment
• The technician discovers that the fault or problem relates to any system that we are not responsible for
 

The technician will confirm during their visit if any of these instances apply, and if so, a £25 charge will be applied to your account. 
 

Please ensure there is someone over the age of 18 present at the time of the visit. If you need to change or cancel your appointment you can do this online or via the My VM app by 4pm the day before the appointment.
 

If you do miss an agreed appointment for any reason, a £25 missed appointment charge will be applied to your account on the day of the appointment
 

[Icantcrabhere]

Okay so,
technician has been - power levels are back in spec.

HOWEVER, he as he mentioned too: Upstream QAM is still wrong.

I'll post stats now(after a hub reboot)

Upstream bonded channels

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

1	30100000	44.3	5120	32 qam	4
2	49600000	46.8	5120	32 qam	1
3	23600000	45.5	5120	64 qam	5
4	36599986	44.5	5120	32 qam	3
5	43100000	45.3	5120	64 qam	2

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

Downstream bonded channels

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

1	563000000	-4	38	256 qam	20
2	539000000	-3	38	256 qam	17
3	547000000	-3.2	38	256 qam	18
4	555000000	-3.5	38	256 qam	19
5	571000000	-4.4	38	256 qam	21
6	579000000	-4.5	38	256 qam	22
7	587000000	-4	38	256 qam	23
8	595000000	-3.4	38	256 qam	24
9	603000000	-3.2	38	256 qam	25
10	611000000	-3.5	38	256 qam	26
11	619000000	-4.4	38	256 qam	27
12	627000000	-4.5	38	256 qam	28
13	635000000	-4.5	38	256 qam	29
14	643000000	-4	38	256 qam	30
15	651000000	-3.4	38	256 qam	31
16	659000000	-2.7	38	256 qam	32
17	667000000	-2.7	38	256 qam	33
18	675000000	-3	38	256 qam	34
19	683000000	-3.5	38	256 qam	35
20	691000000	-3.5	38	256 qam	36
21	699000000	-3.5	38	256 qam	37
22	707000000	-3.2	38	256 qam	38
23	715000000	-3.2	38	256 qam	39
24	723000000	-3.2	38	256 qam	40

Downstream bonded channels

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

1	Locked	38.9	5	0
2	Locked	38.6	12	0
3	Locked	38.9	0	0
4	Locked	38.9	4	0
5	Locked	38.9	2	0
6	Locked	38.9	1	0
7	Locked	38.9	0	0
8	Locked	38.9	5	0
9	Locked	38.9	5	0
10	Locked	38.6	5	0
11	Locked	38.9	4	0
12	Locked	38.9	11	0
13	Locked	38.6	5	0
14	Locked	38.6	5	0
15	Locked	38.6	6	0
16	Locked	38.9	4	0
17	Locked	38.6	4	0
18	Locked	38.6	5	0
19	Locked	38.9	0	0
20	Locked	38.6	0	0
21	Locked	38.9	6	0
22	Locked	38.9	5	0
23	Locked	38.6	5	0
24	Locked	38.9	6	0

So yeah, definitely something not quite right.

Had issues with QAM for ages,
repull has already been done in regards to that too.

[David_Bn]

Thanks for coming back to us @Icantcrabhere.

Can you please provide us with any updates you have on the services performance?

Do you currently have a BQM running that we can refer to?

Looking into the local area, no faults appear the be present and a flow on the equipment suggests no issues present.

Kindest regards,

David_Bn

[Icantcrabhere]

Hi David_Bn,

Live graph.

https://www.thinkbroadband.com/broadband/monitoring/quality/share/1700d27c199ce3ea214d66ce063ff9f395507b3eL

 
the QAM is still out of spec on 4 of the 5 upstream channels.
This isn't normal in the slightest,

if you check my post history / previous PMs with staff members you'll see that this has been an issue for ages.
I've even had a repull done in regards to this.
In my previous reply, you can see the stats i posted, they're basically the exact same now.

So "No issues present" is a bit off, sadly.
I'm not sure why I've had so many issues getting this sorted, it's a bit disheartening.

[Kath_F]

Hi Icantcrabhere, 

Thanks for coming back to us on this. 

I'm afraid when checking the link you've posted, it's coming up with an error advising that the link has not been found. Can you double check this and repost the correct live URL link?

In terms of stats previously posted, we are unable to use these and instead need to look at the live stats which is what we do check before replying to you. The reason for this is because there may have been a previous open fault affecting your stats or even the uptime on your router may alter some things. 

We use the BQM graphs as further evidence as if something isn't quite right on your end but looks good this end, we can use the BQM to show there is an issue and this in turn allows us to investigate further. 

For now, as all looks good from this end, we need the working BQM link to help support you further. If you can post this, that would be great. 

Many thanks, 

[Icantcrabhere]

Hi there,
Live graph: this should 100% work.

https://www.thinkbroadband.com/broadband/monitoring/quality/share/1700d27c199ce3ea214d66ce063ff9f395507b3e

 As mentioned, if you were to currently check my current upstream QAM it's not staying at 64 like it's meant to.

Unfortunately this isn't my first rodeo, as they say.
I've made sure with each set of stats i've posted that it has been minimal router uptime. - as well as monitoring it myself before and after.

In regards to my previous posts/issues - I've had a repull done for this very same thing: Messed up QAM.
Which has clearly not helped.
My post history tells a story of this nightmare.

I appreciate your help, however - don't get me wrong 🙂
thank you!

[unisoft]

---

@Icantcrabhere wrote:

Hi there,
Live graph: this should 100% work.

https://www.thinkbroadband.com/broadband/monitoring/quality/share/1700d27c199ce3ea214d66ce063ff9f395507b3e

 As mentioned, if you were to currently check my current upstream QAM it's not staying at 64 like it's meant to.

Unfortunately this isn't my first rodeo, as they say.
I've made sure with each set of stats i've posted that it has been minimal router uptime. - as well as monitoring it myself before and after.

In regards to my previous posts/issues - I've had a repull done for this very same thing: Messed up QAM.
Which has clearly not helped.
My post history tells a story of this nightmare.

I appreciate your help, however - don't get me wrong 🙂
thank you!

---

That's a classic noise ingress issue causing your QAM on upstream to be wrong.

Networks Team should look at the cabinet level to see if others have it, and perhaps even a cable repull might need to be done depending on its age as that could have water ingress issues because of a rodent chewing it, though I'd normally expect SNR and downstream channels to be affected for water ingress and read that you've had cable repull anyway. If you are far from the green cabinet, they normally use a thicker cable to minimise attenuation but as your SNR looks healthy, whatever they used looks fine.

If QAM isn't 64 on your upstream channels, it's wrong. Its being negotiated to a lesser level which means less bandwidth on each channel.

Downstream SNR is good at 38 and power levels are within tolerance levels, though personally, if you had a forward path attenuator or equalizer fitted, I would remove them as I've generally found close to zero as possible is the text book result, but prefer + figures than - figures for power levels, and prefer not to go less than -3. That's just me as your levels are within specs of VM.

I did notice that went I went from HUB 3 to HUB 4 the figures were similar, but when I went to HUB5, the SNR shot up by 1-2db so assume the HUB5 has more sensitive components or ones that don't lower the SNR anyway. Mine went from 38db to 41db with no change to cabling.