topic Re: SNR reset please? in Broadband

SNR reset please?

AMC1973 — Mon, 07 Mar 2022 09:35:12 GMT

Hi,

Would a kind member of the team reset my line please? The DLM appears to have banded it, possibly due to a router reset, followed a couple of hours later by a power interruption. I'm still synching slower than I would expect, after a thorough investigation by Plusnet - I've had two engineers out to my house, and they've confirmed that the connection into the house, and inside the house is spotless, and tests from your side have found no fault. Looks like I may just have to except slower speeds until Plusnet rolls out FTTP! I just want to start the line from scratch - now the router has been reset, and hopefully no more power cuts - and see if it performs any better than previously.

Thanks

AMC

Re: SNR reset please?

SammyM — Tue, 08 Mar 2022 12:05:23 GMT

Hiya @AMC1973,

I have checked the connection from our side and the line is not banded as the profile shows up to 40Mbps as well as the speed being 33Mbps going down the line.

What is the speed you are seeing on a wired connection?

Re: SNR reset please?

AMC1973 — Tue, 08 Mar 2022 12:54:13 GMT

Hi Sammy,

Thanks for the reply,

My throughput is almost always excellent - in the context of my sync speed (see below). Over wireless, my download is always a meg or two below my sync speed - can't complain about that! After having a fault cleared on my line, and being told that my line is in excellent shape, it's just a bit frustrating that I'm synching at 33 rather than the 38 I'd gotten used to. I would just love to know why my line only seems comfortable at a noise margin of 9, when it used to be happy at 6. Still, if you're sure I'm not banded, I'll take your word for it. Would you still be kind enough to reset my line? If it drops back down to 33, I'll humbly except defeat, and live with my new slower speed - until PN goes FTTP!

Thank you kindly

AMC

5. DSL uptime:	0 days, 10:43:28
6. Data rate:	7834 / 33478
7. Maximum data rate:	7834 / 42202
8. Noise margin:	6.0 / 9.2
9. Line attenuation:	31.3 / 22.2
10. Signal attenuation:	30.8 / 20.5

Re: SNR reset please?

RealAleMadrid — Tue, 08 Mar 2022 14:48:25 GMT

@AMC1973 From those stats I would definitely say the line is banded at 35Mbps. You could try a single reboot of the router, if it comes back at the same sync speed it's banded.

@SammyM Have you possibly looked at an out of date profile from a GEA test because the router shows almost certain symptoms of banding, why else would the SNRM be 9dB?

Re: SNR reset please?

AMC1973 — Tue, 08 Mar 2022 15:48:44 GMT

Thanks RealAleMadrid,

Tried the reboot router a few days ago, no difference; I always try this whenever I suspect banding - and it always turns out to be banding. Had two Openreach guys out, they couldn't locate a problem. My fault ticket is due to close soon. I'm no closer to establishing why my "excellent" line (three green stripes on the Openreach guys scanner!) keeps getting banded to 35mbps. Sammy, didn't you confirm my line wasn't banded? Are you sure? If it is, that suggests my line is unstable; if that's the case, surely my line wouldn't keep passing GEA tests with (almost) flying colours. Something is going wrong somewhere. This is why I want a line reset; then I can monitor the situation, see if the DLM bands my line again. If it does, then I know there must be an issue somewhere.

Re: SNR reset please?

BobR1 — Wed, 09 Mar 2022 06:58:05 GMT

Interesting... I have exactly the same issue; a much higher downstream SNRM than I would expect and a good connection after an OpenReach engineer checked it.

I have been an Plusnet customer for quite a while and for long periods my downstream SNRM was in the range 5.5 to 6.5 dB with significantly better speeds. It feels to me like the SNRM is being manipulated to throttle speeds. Plusnet deny this and I have no reason to doubt them. Is it OpenReach playing around I wonder.

Re: SNR reset please?

AMC1973 — Wed, 09 Mar 2022 10:14:11 GMT

Hi Bob,

Sorry to here you're in the same boat. Yeah, it's really frustrating; my router makes it quite clear what I'm capable of achieving - and that seems spot on, when I look at the BT Broadband Availability Checker. I have a clean, impact free line, my router shows my max sync at 42, as you can see, that's slightly nearer the low end, but I'm almost 10mbps below that! The fact is, as RealAleMadrid pointed out, my 9dB SNRM is a clear sign of banding. To be honest, I think in both our cases, there is an issue, either in the DP, the cabinet or the exchange - obviously not at our end. Like you, I find it difficult to believe that we can have long periods of downstream SNRM at 6, then suddenly up to 9.

I shall carry on pushing till I get this sorted.

Featured Products	Downstream Line Rate(Mbps)		Upstream Line Rate (Mbps)		Downstream Handback Threshold(Mbps)	WBC FTTC Availability Date	WBC SOGEA Availability Date	Left in Jumper
Featured Products	High	Low	High	Low
VDSL Range A (Clean)	50.5	35	10	7	32.4	Available	Available	--
VDSL Range B (Impacted)	49	32.4	9.8	6.5	27.4	Available	Available	--

Featured Products	Downstream Line Rate(Mbps)	Upstream Line Rate (Mbps)	Downstream Range (Mbps)	Availability Date	FTTP Install Process
WBC FTTP	Upto 1000	Upto 220	--	Available	1 Stage

ADSL Products	Downstream Line Rate (Mbps)	Upstream Line Rate (Mbps)	Downstream Range(Mbps)	ADSL Availability Date	Left in Jumper
WBC ADSL 2+	Up to 5	--	4 to 6	Available	Yes
WBC ADSL2+ Annex M	Up to 5	Up to 1	4 to 6	Available	Yes
ADSL Max	Up to 4	--	2.5 to 7	Available	--
WBC Fixed Rate	2	--	--	Available	Yes
Fixed Rate	2	--	--	Available	--

SOADSL Products	Downstream Line Rate (Mbps)	Upstream Line Rate (Mbps)	Downstream Range(Mbps)	WBC SOADSL Availability Date	Left in Jumper
WBC SOADSL 2+	Up to 5	--	4 to 6	--	Yes
SOADSL Max	Up to 4	--	4 to 6	--	--
SOADSL Fixed Rate	Up to 2	--	2.5 to 7	--	Yes

Observed Speeds	VDSL	ADSL
Max Observed Downstream Speed	34.99	7.35
Max Observed Upstream Speed	7.87	1.08
Observed Date	2022-03-03	2020-12-14

Other Offerings	Availability Date
VDSL Multicast	Available
ADSL Multicast	Available

Premise Environment	Status
Bridge Tap	U
VRI	N
NTE FacePlate	N
Last Test Date	18-02-2022

Exchange Product Restrictions	Status
FTTP Priority Exchange	N
WLR Withdrawal	N
SOADSL Restriction	Y

Re: SNR reset please?

Gandalf — Wed, 09 Mar 2022 11:44:53 GMT

Hi @AMC1973

I'm really sorry for the confusion.

I've done some digging and I can see as of yesterday the banding on your line is showing as "Downstream: 0.128M-35M with Retransmission (Low). Upstream: 0.128M-10M with no error protection" and a sync speed of 34998. Interestingly, your router stats is showing a sync of 33478, so it doesn't actually appear to be banded.

I've however added to the caution counter reset tracker to request the banding is lifted for your line, which should go through within the next 3 working days. Let me know how it goes.

@BobR1, I'm aware of your connection issues and someone should be getting in touch with you shortly about them.

I would like to say though that there isn't anybody at Plusnet or Openreach who throttles your speeds.

I haven't arranged for your line to be reset, because you are already on the highest profile "Downstream: 0.128M-80M with Retransmission (Low). Upstream: 0.128M-20M with no error protection"

Re: SNR reset please?

AMC1973 — Wed, 09 Mar 2022 14:58:00 GMT

Hi @Gandalf,

Thanks very much, I appreciate that,

Actually, my router was syncing at 34998, but overnight the DLM dropped it slightly to 33478. I'm not certain, but it's my understanding that within banding, the sync speed can move down slightly - as mine did - but the noise margin remains the same.

Anyway, thanks again, and I'll keep you posted.

Re: SNR reset please?

BobR1 — Wed, 09 Mar 2022 15:17:24 GMT

@Gandalf

I note your comments but the fact remains that the downstream SNRM on my connection has been running at a higher level than was the case in the past and so the speed is reduced. I would be delighted to park this issue and move on if someone would simply provide a straight forward explanation of that changed circumstance.

Re: SNR reset please?

Gandalf — Wed, 09 Mar 2022 15:21:07 GMT

Hi @AMC1973

No problem, aye keep me posted on how it goes.

@BobR1

It's hard to provide an explanation, because our tests aren't showing any causes for this.

We've already arranged an engineer to check things out from their side but it looks like they've not been able to figure it out either and have been unable to investigate further as your speeds are within expectations.

Re: SNR reset please?

AMC1973 — Thu, 10 Mar 2022 12:04:44 GMT

Hi @Gandalf

It looks like the reset went through a 9am - that was quick! Out of curiosity, I decided to take a look through my routers event log - to see if the DLM had touched my line in the early hours, and it had. As you can see, it reduced my downstream further, from 33 to 31!

02:21:57, 10 Mar.

(482441.130000) PPPoE is up - Down Rate=31008Kbps, Up Rate=7856Kbps; SNR Margin Down=10.1dB, Up=5.9dB

There's a clear pattern here; after my line is reset, my downstream is 38181, a day or two later, the DLM then bands my line to 35, two or three days later, down to 33; a couple more days late, down to 31, and so it goes on. I think we can both agree, that is not what you'd expect from a good line, but it is what you'd expect from a significantly unstable line - or a connection that has a fault lying on it somewhere. As you know, GEA tests from your end show no fault, but do show my downstream to be 'reasonable', when it should be 'good'. Openreach have twice confirmed that everything is in top condition at my end. I have noticed a couple of oddities that may offer some insight - although they probably don't - I'll run them by you anyway. The maximum data rate on my router fluctuates somewhat - anywhere between 42600 and 38100. Is that normal? Just a few months ago it would drop right down to 33000, and always after 3pm. It hasn't dropped below 38 for months now though. Is it normal for a max sync speed to fluctuate? Could this be linked to the following point? That point being, ever since I've had this slow sync issue, I've never been able to 'Run Diagnostic' on the BT Wholesale speed test (see below). Could either of these issues be evidence of a fault? Is my hub one somehow to blame? Do I need a new router? Am I clutching at straws? I shall monitor my router over the next couple of weeks, My guess is, in two weeks time, my downstream will be 31000, and a 10dB SNRM. Hopefully I'll be wrong...

Summary of Performance Test

Timestamp

Thursday 10 March 2022 | 11:54:39

Ping

15 Ms

Download

35.30 Mbps

Upload

8.04 Mbps

Advance Test

Download Test

Download speed achieved during the test was 35.30 Mbps

Upload Test

Upload speed achieved during the test was 8.04 Mbps

Summary Advanced Test

Your speed test has completed and the results are shown above, however during the test an error occurred while trying to retrieve additional details regarding your service. As a result we are unable to determine if the speed you received during the test is acceptable for your service. Please re-run the test if you require this additional information.

Re: SNR reset please?

Gandalf — Thu, 10 Mar 2022 15:19:30 GMT

Hi @AMC1973

Thanks for the insight!

I'd personally take "Downstream Rate Assessment" on a GEA test with a pinch of salt as a more advanced diagnostics tool we have also shows the line's in good condition over the last week, albeit the data is back from the <8th March.

I agree with what you've said and I don't think it's normal for your speeds to fluctuate like that.

It's tricky because with FTTP available, engineers may not be too inclined to do any major work on the copper infrastructure, but if your speed drops further I'd say we should replace the router as the next step, and if you still have issues, depending how much your speeds drop by, it may be worth calling out an engineer to take another stab at the problem.

On the FTTP front, it's in our sights and the good news is that the finish line may be near... I can't give a date though.

Let me know how things go over the next week or so.

Re: SNR reset please?

Gandalf — Thu, 10 Mar 2022 16:41:45 GMT

I went to the effort of taking a screenshot of the diagnostics tool and blurring out account details then forgot to attach it.

Here you go

Re: SNR reset please?

AMC1973 — Thu, 10 Mar 2022 16:57:48 GMT

Thanks @Gandalf

I do agree with you, and I take your point about engineers not being inclined to get their hands dirty on the copper infrastructure. I'm starting to suspect the router, it certainly handles the WiFi brilliantly, but as you say, the max speed fluctuations are suspect.

I must admit, I don't see much point in calling out another engineer to the house, there's no reason to believe another engineer is going to find a problem, when two others haven't.

Great news about FTTP though - the sooner the better! I've already had to listen to my neighbour, boasting about his 500mbps! I can get just over 35 at the minute over wireless, can't complain about that - if only it would stay that way! And yes, I'll look at replacing the router as the next step if speeds drop again.

Cheers for the info

Re: SNR reset please?

AMC1973 — Thu, 10 Mar 2022 17:14:36 GMT

That's very interesting, The red definitely explains the noisy line that was fixed. Seems from the 5th March, things were consistently pretty good. Very interesting indeed! I think I need to get out more!

Re: SNR reset please?

Gandalf — Thu, 10 Mar 2022 19:34:25 GMT

Yup makes sense. Soon you'll be able to have an FTTP-off (Similar to a bake off) with your neighbour.

On the topic of getting out more, I'm off to see the new Batman now at the Odeon.

Keep me posted on how things go.

Cheers

Re: SNR reset please?

AMC1973 — Fri, 11 Mar 2022 09:18:20 GMT

Yeah, I here it's pretty good - according to Mark Kermode! Hope you enjoyed it. I think I'll try and catch it next week.

Yep, I'll keep you updated...

Re: SNR reset please?

Gandalf — Sat, 12 Mar 2022 01:05:28 GMT

Aye, it was awesome.

Not sure if Robert Pattinson playing the part is better than Christian Bale though.

Still a genuinely good film!

Re: SNR reset please?

AMC1973 — Sat, 12 Mar 2022 11:07:05 GMT

Forget Robert Pattinson or Christian Bale, I refuse to see another Batman film until Adam West reprises the role!

I'm not going to get my hopes up, but my latest router stats look quite encouraging! So the line was reset at 9am on the 10th, and the DLM intervened on the line at 11pm - but not as I expected. As you can see, it slightly reduced my downstream, but it was happy with a 6dB SNR - and no intervention last night. I'm more than happy with that! Looking back at the RRT you uploaded, it's a bit concerning seeing all that red. In the LINE_ASSESMENT_RATE column, my line goes from 'Bad' to 'Very Good' in the space of a day - now that's an unstable line! I thought that was down to my noisy line issue, but looking back, that was the early Feb, so I wonder what could account for all that red? Also, if you look at the DLM intervention after the reset, you can see that my max data rate would have been very close to that downstream of 37806kbps given the 6dB SNR, And yet, as you can see, it's now at 41839, and the SNR is now at 6.9dB. Could that be a router fault do you think?

5. DSL uptime:	1 days, 10:56:12
6. Data rate:	7838 / 37806
7. Maximum data rate:	7838 / 41839
8. Noise margin:	6.1 / 6.9

09:09:09, 10 Mar.

(506872.900000) PPPoE is up - Down Rate=38171Kbps, Up Rate=7785Kbps; SNR Margin Down=6.9dB, Up=6.0dB

23:05:10, 10 Mar.

(557033.290000) PPPoE is up - Down Rate=37806Kbps, Up Rate=7838Kbps; SNR Margin Down=6.0dB, Up=6.1dB