topic Re: DLM Reset / Line Cap in Broadband

DLM Reset / Line Cap

Icipher — Thu, 19 May 2022 12:53:55 GMT

Hi there,

I had some issues with my line just over 3 months ago resulting in a slight speed decrease due to multiple resyncs, which an engineer visit resolved, he said at the time I should be syncing at 80Mbps but was only syncing at 76Mbps and DLM should sort it out in the coming weeks.

Well it's been 3 months and nothing has happened yet, would it be possible for someone to request a DLM reset on my line please if it's possible, I know I'm only a few Mbps lower than it should be but as you can see from the stats the line is more than capable of the full 79,999 it used to sync at.

Much appreciated, thank you.

Re: DLM Reset / Line Cap

adamwalker — Fri, 20 May 2022 09:45:56 GMT

Hi there! I've just checked and there's no banding in place and the line is syncing at 79.9mbs so a DLM reset won't do anything I'm afraid.

Have you been connected by WiFi or ethernet when testing the speeds? I ask as the former will always be a few mbps slower by design.

Re: DLM Reset / Line Cap

Icipher — Fri, 20 May 2022 11:15:42 GMT

Hi Adam

It's the Plusnet router that's syncing at 76.3 as per my screenshot, it isn't syncing at 79.9 despite what the Plusnet portal is saying.

It definitely used to sync at 79,999 for years before the issues with the line?

Thanks

Re: DLM Reset / Line Cap

jab1 — Fri, 20 May 2022 11:41:08 GMT

@Icipher Have you tried a single reboot?

Re: DLM Reset / Line Cap

Icipher — Fri, 20 May 2022 14:17:38 GMT

Hi,

Yep, capped at the exact same rate. (see attachment)

I'm sure a DLM reset will resolve this, as the router is definitely not syncing at 79.9

Re: DLM Reset / Line Cap

jab1 — Fri, 20 May 2022 14:21:44 GMT

Not doubting you, but what does BTW Performance Tester say if you run the 'Additional Diagnostics'?

Re: DLM Reset / Line Cap

Icipher — Fri, 20 May 2022 14:46:17 GMT

Hi John

Good idea, see below - that's confirmed my line does have a lower profile applied and I will not be able to get back to 79.9 like it was without some intervention?

Re: DLM Reset / Line Cap

jab1 — Fri, 20 May 2022 15:19:14 GMT

Yep, for some reason, PN's is set at 73.9 - only they will be able to tell you why.

Re: DLM Reset / Line Cap

RealAleMadrid — Fri, 20 May 2022 15:36:56 GMT

@jab1 IP Profile is perfectly correct at just under 97% of the sync speed. The problem is the sync speed looks like it is banded, it should not re-sync at the same speed.

I wonder why @adamwalker thinks it is syncing at 79.9Mbps.🤔

Re: DLM Reset / Line Cap

jab1 — Fri, 20 May 2022 15:40:49 GMT

Oooops - done it again- sorry @Icipher . Yes, would be good to see where that info came from.

Re: DLM Reset / Line Cap

Icipher — Fri, 20 May 2022 15:44:12 GMT

It's ok. As long as we are all in agreement it is being capped hopefully Adam or someone can address it.

Thanks both.

Re: DLM Reset / Line Cap

Gandalf — Fri, 20 May 2022 15:52:09 GMT

I've been looking into this for you and our tests are 100% showing your line's in sync at 79998 kbps.

Retransmission though is enabled in a high state which can affect your speeds, particularly throughput.

I've done a DLM reset anyway which should take effect within an hour or so. I'm not confident it'll help, but we shall see.

Let us know how it goes.

Re: DLM Reset / Line Cap

RealAleMadrid — Fri, 20 May 2022 17:26:01 GMT

@Gandalf Are you sure you are looking at the right line? The router is syncing at 76.34Mbps and the IP profile is 73.9Mbps which is 96.8% of the sync speed, which is the correct value for retransmission low. Something fishy going on here, your figures are not correct.

Re: DLM Reset / Line Cap

Gandalf — Mon, 23 May 2022 11:52:39 GMT

@RealAleMadrid, I am indeed and I agree that it's odd. I'd done the DLM reset anyway though, so hopefully that's improved the speed and sorted the discrepancy out.

Re: DLM Reset / Line Cap

Icipher — Mon, 23 May 2022 12:31:01 GMT

The line did drop around the time you said you did the reset @Gandalf but nothing has changed speed wise as of yet, it just synced straight back as it was.. my understanding which of course may be wrong is that DLM sets the line back to it's max then daily during the night drops it down to what is stable based on the days stats so still not quite sure why the modem in the Hub is only able to sync at 76.34Mbps and your systems seeing 79.99Mbps 🤕

Re: DLM Reset / Line Cap

Gandalf — Mon, 23 May 2022 12:50:37 GMT

Genuinely is a weird issue, but the line's not banded and well within speed estimates, so not sure what more we can do.

I'll attach below a full copy of the testing which I can see. To start with, a GEA Service Test:

GEA Test Detail
Circuit ID	NA	Service ID	[redacted BBEU]


Test Outcome	Pass
Test Outcome Code	GTC_FTTC_SERVICE_0000
Description	GEA service test completed and no fault found .
Main Fault Location	OK
Sync Status	In Sync
Downstream Speed	76.3 Mbps
Upstream Speed	20.0 Mbps
Appointment Required	N
Fault Report Advised	N
NTE Power Status	PowerOn
Voice Line Test Result	Not Run - Unable to run
Bridge Tap	Not Detected
Radio Frequency Ingress	Not Detected
Repetitive Electrical Impulse Noise	Not Detected
Cross Talk	Not Detected
Estimated Line Length In Metres	-47.8
Upstream Rate Assessment	Very Good
Downstream Rate Assessment	Very Good
Interference Pattern	Not Detected
Service Impact	No Impact Observed
Home Wiring Problem	Not Detected
Downstream Policing Discard Rate	0.0
Customer Traffic Level	Upstream and Downstream traffic detected
Technology	VDSL
Current 15Min Bin Retrains	0
Last 15Min Bin Retrains	0
DP Type	External
Profile Name	0.128M-80M Downstream 5dB, Retransmission High - 0.128M-20M Upstream, Error Protection Off
Time Stamp	2022-05-10T13:45:00

Parameters	MIN	MAX	AVG
Down Stream Line Rate	79.9 Mbps	79.9 Mbps	79.9 Mbps
Up Stream Line Rate	19.9 Mbps	19.9 Mbps	19.9 Mbps
Up Time	900.0 Sec	900.0 Sec	900.0 Sec
Retrains	0.0	0.0	0.0

Current and Last 15 Minute Bin Performance
Parameters	Last Traffic Count(Upto 15 mins)	Current Traffic Count(Upto 15 mins)
Start Time Stamp	2022-05-23T12:16:15Z	2022-05-23T12:31:15Z
Ingress Code Violation	1	2
Egress Code Violation	0	0
Errored Seconds	0	0
Severely Errored Seconds	0	0
Unavailable Seconds	0	0

The downstream speed here is showing 76.3mbps as this can take into account the lower than normal IP profile, if retransmission is enabled, in this case in a high state.

For good measure, I've also run a line test separately as "Voice Line Test" didn't run as part of the GEA. Line tests passed.

Looking at what we call RRT data is showing the raw sync rate at 79998.

I wonder if the Hub calculating the data rate in the same way which a GEA does? Seeing as it's exactly the same figure.

Re: DLM Reset / Line Cap

Icipher — Mon, 23 May 2022 13:01:55 GMT

Yep, very weird.

I do have a billion router somewhere if I can find it to see what that syncs at as the hub's modem is really that is only thing left?

The openreach engineer did say he was getting 80 on his test equipment when the fault was fixed a few months back.

Re: DLM Reset / Line Cap

Gandalf — Mon, 23 May 2022 13:12:24 GMT

Yeah maybe. I'd bet that this is all caused by retransmission, which should hopefully be automatically removed soon as your line looks to be in excellent shape. Definitely worth giving your Billion modem a go if you can find it.

Re: DLM Reset / Line Cap

goldenfibre — Mon, 23 May 2022 19:44:58 GMT

@Icipher My fave router is Billion. Very good router cos it got broadcom chipset as I do know the FTTC cabinet from Huawei 288 will love that Billion router!

Good luck if you find your billion router and worth a try out. Remember to powered down for 30 minutes to avoid DLM.

Re: DLM Reset / Line Cap

Icipher — Tue, 24 May 2022 07:17:26 GMT

Good news @Gandalf DLM resynced the line during the night - getting very close to where it was before.

Going to leave it alone as far as the Billion is concerned for another week, as I have a feeling it may sync again in another few days at 79,999

Thanks again everyone for the help and input, will mark it as resolved 👍