Upload/T3 problems (SNR?)

[cje85]

Hi,

My connection has been quite poor this week and a couple of times it has gone off completely. This afternoon has been particularly bad. It is barely working at all, with huge packet loss.

The problem seems to be with the upstream (channel ID 5)  which is showing a huge number of T3 errors, just minutes after rebooting the hub.

The service status shows no problems, but I ran the online test which displayed a message implying an SNR problem (something like "there's a problem with noise on the coax into your home").

What are the next steps? Is it an area fault?

Here are the stats and a BQM (Approx. 15 mins after a reboot)

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

1	331000000	7.4	40	256 qam	25
2	267000000	5	38	256 qam	17
3	275000000	4.9	38	256 qam	18
4	283000000	5.1	38	256 qam	19
5	291000000	6	38	256 qam	20
6	299000000	7.1	38	256 qam	21
7	307000000	7.4	40	256 qam	22
8	315000000	7.5	40	256 qam	23
9	323000000	7.4	40	256 qam	24
10	339000000	7.6	38	256 qam	26
11	347000000	7.8	40	256 qam	27
12	355000000	7.5	40	256 qam	28
13	363000000	7.5	40	256 qam	29
14	371000000	7.4	40	256 qam	30
15	379000000	7.4	38	256 qam	31
16	387000000	7.1	40	256 qam	32
17	395000000	7.1	40	256 qam	33
18	403000000	6.9	38	256 qam	34
19	411000000	6.5	38	256 qam	35
20	419000000	6.4	38	256 qam	36
21	427000000	6.3	38	256 qam	37
22	435000000	6.3	38	256 qam	38
23	443000000	6.4	38	256 qam	39
24	451000000	6.3	38	256 qam	40

Downstream bonded channels

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

1	Locked	40.3	2	0
2	Locked	38.6	6	0
3	Locked	38.9	3	0
4	Locked	38.9	0	0
5	Locked	38.9	5	0
6	Locked	38.9	5	0
7	Locked	40.3	7	0
8	Locked	40.3	5	0
9	Locked	40.3	4	0
10	Locked	38.9	7	0
11	Locked	40.3	5	0
12	Locked	40.3	7	0
13	Locked	40.3	5	0
14	Locked	40.3	6	0
15	Locked	38.9	7	0
16	Locked	40.3	22	0
17	Locked	40.3	7	0
18	Locked	38.9	8	0
19	Locked	38.9	19	0
20	Locked	38.6	15	0
21	Locked	38.9	4	0
22	Locked	38.9	10	0
23	Locked	38.6	7	0
24	Locked	38.9	2	0

Upstream bonded channels

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

1	46200000	43.5	5120	64 qam	3
2	32600000	43.5	5120	32 qam	5
3	39400000	43.5	5120	32 qam	4
4	53700000	43.5	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	52	0
3	ATDMA	0	0	0	0
4	ATDMA	0	0	0	0

Today's BQM

[Andrew-G]

Suddenness of onset at around 14:10 and severity tends to imply an equipment failure or cable damage, which would often be an area fault.  The preceding latency however looks like an unrelated case of over-utilisation, and you've probably read my views on that often enough.

I'd try calling it in as an area fault, telling whatever lies you need to in order to get past the crap chatbots and pointless and long winded fault-finding scripts, but bear in mind that any action by VM should fix packet loss, but is unlikely to address the apparent utilisation issues.

[cje85]

Finders crossed, the problem seems to have cleared up as ideally I don't want to call VM and subject myself to their torturous phone based customer service!

The sudden packet loss and upstream problem has happened a couple of times this week (I think it was Tuesday and Wednesday), but on those occasions it resolved quite quickly. Today was much worse.

I'm not sure if the peak time spikes are utilisation as generally I can still get full speed (or very close) at peak time. I think it may be down to noise on the upstream, that seems to be a long running problem in this area. I've had utilisation problems in the past and remember being concerned when the BQM started looking poor every night, but after posting about it on here, one of the team assured me it wasn't utilisation but just noise related.

I'll see how things go over the next few days and await the forum team to respond.

[Andrew-G]

Some internet use is not latency sensitive, and some people simply don't notice it even where it is impacting their connection.  If either applies to you, the utilisation issues can be ignored, and that avoids the time-wasting misery of the company's appalling telephone "support".  And if it all seems good, you can ignore my comments below.

Regardless of what VM staff might assure you, it looks pretty obvious to me that you have over-utilisation, which has a very distinctive pattern.  Sometimes it doesn't affect speeds, because queuing of data packets (if not long enough to timeout) won't materially affect a download if sequential delays only add a few milliseconds to a test that typically lasts for ten-twenty seconds, and as you observe, upstream over-utilisation can also exist separately from the downstream.  

Ignore the packet loss on your BQM, and compare the latency to mine (admittedly a good day):

If VM maintain it's "just noise related", then you should press VM to fix the noise source - it's either faulty equipment (VM's responsibility) or noise ingress through a poor joint or damaged cable (VM's responsibility).

[Akua_A]

Hi @cje85,

Welcome back to our forums.

Sorry to hear you have been have connection issues of late. We can understand this is not ideal and we want to best help.

I have been able to access your account using forum details. There is currently an SNR outage that may be causing the issues you are facing. Our engineers are currently aware of this and are working to resolve this. The current estimated fix time for this is 05 OCT 2021 18:00. Please do let us know if the issue persists after this and we will do our best to assist.

Thanks,

[cje85]

Is this still ongoing? The packet loss was back yesterday (it cleared up after a few hours) and today it's happening again.

Interestingly it started at around 8am on both occasions, I wonder if someone nearby is switching something on which is causing an SNR issue.

Friday

Today

Downstream stats

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

1	331000000	5.4	40	256 qam	25
2	267000000	3.2	38	256 qam	17
3	275000000	3.2	38	256 qam	18
4	283000000	3.7	38	256 qam	19
5	291000000	4.4	38	256 qam	20
6	299000000	5	38	256 qam	21
7	307000000	5.1	40	256 qam	22
8	315000000	5.4	40	256 qam	23
9	323000000	5.3	40	256 qam	24
10	339000000	5.5	40	256 qam	26
11	347000000	5.6	40	256 qam	27
12	355000000	5.4	40	256 qam	28
13	363000000	5.3	40	256 qam	29
14	371000000	5.3	40	256 qam	30
15	379000000	5.1	38	256 qam	31
16	387000000	5	38	256 qam	32
17	395000000	5	40	256 qam	33
18	403000000	4.6	38	256 qam	34
19	411000000	4.5	38	256 qam	35
20	419000000	4.4	38	256 qam	36
21	427000000	4.1	40	256 qam	37
22	435000000	3.9	38	256 qam	38
23	443000000	4	38	256 qam	39
24	451000000	4.1	38	256 qam	40

Downstream bonded channels

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

1	Locked	40.9	337	0
2	Locked	38.9	206	0
3	Locked	38.6	193	0
4	Locked	38.9	201	0
5	Locked	38.9	150	0
6	Locked	38.9	223	0
7	Locked	40.3	238	0
8	Locked	40.9	172	0
9	Locked	40.3	262	16
10	Locked	40.3	391	0
11	Locked	40.3	401	0
12	Locked	40.3	393	11
13	Locked	40.3	478	0
14	Locked	40.3	571	0
15	Locked	38.6	735	0
16	Locked	38.9	624	0
17	Locked	40.3	514	0
18	Locked	38.9	710	0
19	Locked	38.9	832	18
20	Locked	38.9	875	0
21	Locked	40.3	935	0
22	Locked	38.9	1112	0
23	Locked	38.9	1196	0
24	Locked	38.9	831	0

Upstream bonded channels

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

1	46200000	46.5	5120	64 qam	3
2	32600000	46.5	5120	32 qam	5
3	39400000	46.5	5120	64 qam	4
4	53700000	46.5	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	1	0
3	ATDMA	0	0	1	0
4	ATDMA	0	0	1	0

[Ashleigh_C]

Thank you for updating us @cje85 and I'm so sorry to hear that this has continued past the outage. 

I can see that there are a few issues showing on our side and for this reason, along with the evidence you've shared with us, I think it would be best to arrange for an engineer to come out and take a look at your equipment. 

I will send you a PM now so we can book this, please keep an eye out for the purple envelope in the top right corner of your screen alerting you to a new message. 

Thank you.