My DLM is not working

I upgraded from ee�s 40/10 fibre to 80/20. Their �fibre plus� service went liven last Thursday (06/07/2018).
Right now, I�m in 10-day line training period. So, I should be syncing at max possible speed, and if noise margin goes too high it should dial back a bit. right? DML should be testing different speeds and setting to determine best possible speed for me. Right?

Well� DLM is not doing anything. At exactly 3 am last Thursday my sync speed went from 40/10 to 63/20. And it is syncing at the same speed since. (no change in speed: no increase, on decrease).

Noise margin hasn�t changed either. It�s been exactly 6.2(db) up and 6.3(db) down since Thursday. (this also shows the speed is not increasing or decreasing).
I live 334m meters from my fibre cabinet and about 350 to 400 meters from local exchange point. Line Attenuation is 0.0 (dB) up and 14.3 (dB) down.

I should be syncing close to 80mbps. I know my line is good, we had it installed a few a years ago (2 years ago when I had standard ADSL2 over copper, I was getting close to 22mbps to the router on this line).

does anyone know why am I syncing at 63mbps instead of close to 80mbps.

Also, my ping doubled which I think is normal as it should go back to 10ms after the training period.

Edited by deleted (Mon 09-Jul-18 22:35:44)

DLM does not work like you suggest i.e.

No 10 day period on VDSL2
DLM does not test all different speeds

The line will be open and the usual sync negotiation i.e. that minute or two between modem being turned on, booting and showing sync does the testing and determines what speed you will connect at based on some rules, which is usually a 6dB target margin. The lowering to 3, 4 or 5dB and increased speeds will happen over a number of weeks or months if you have a Huawei cabinet, and it may be a week or more if the DSLAM and DLM end up offering G.INP

In short while the DLM starts with an open range of settings, over time on some lines you may see further improvements these days and may even seen the latency lower again.

On a good line of around 350m and 14dB attenuation, which roughly correspond, you could get a max achievable of maybe 90Mbps. However, if there is a high level of noise then the achievable speed will drop off.

Going by your 6.3 dB SNR and the speed you are seeing at 63Mbps points towards a noisy local environment which may be due to factirs in your house or outside.

Similarly with upstream - a good low noise line of that length would see maybe 25Mbps and the 6.2dB SNR points to a max achievable of possibly 20.5 ... so again potentially a noise problem.

thanks for your reply,

so, there is no training/stabilisation period on G.993.2 (VDSL2)? I been seeing that all over the internet. and I contacted my ISP several times and they said I am on 10 day stabilisation period.

I am aware of Openreach lowering its noise margins to 3db. but I should still be getting much better speeds then 63mbps. To me it looks like my speed is somehow capped to 63mbps.

that 6.3 db is not SNR, it's noise margin.
my router doesn't show signal to noise ratio.


DEFECT/FAILURE INDICATION
Operation Data Upstream Downstream
Noise Margin 6.2 (dB) 6.3 (dB)
Line Attenuation 0.0 (dB) 14.3 (dB)

Actually it is the SNR Margin - I know the differences between all of them (having worked in the communications filed for 40 years. I just use the term that most people use without thinking as trying to define/describe them time and again gets tedious, much the same as reminding people it should be 6.2dB not db or Db or D, or speeds in Mbps not mbps - millibits persecond, or MBps, or mBps, or Mbs ...

Your SNR Margin at just over 6 is very close to the target and will have been negotiated at 6 before moving slightly.

Edited by MHC (Mon 09-Jul-18 23:12:35)

10 days relates to an old figure recorded against ADSL2+ lines, but many ISP keep the 10 day story as DLM is usually fairly settled by then, but it does react to changes forever, i.e. after 10 days things are not fixed

The line may be suffering lots of cross talk, or you may have less then optimal wiring in the home, or was sync and dB figures from the test socket already.

Speeds may go up if the router is super stable and left alone. They may also go down.

i don't know, that could be SNR. I did the noise test on my line and there is no noise. that makes me believe that 6dB is just the level of background noise.

The noise test is about noise in the audible range.

VDSL2 is in the 2 MHz to 17 MHz range so well outside of the range you will hear, as is much of the noise that affects it.

The standard setting for SNRM is 6dB, both up and down. It is quite common for it to end up +/- 0.2dB by the time the sync process has completed.

As has been said already, you may have a constant high level of background noise, hence a low SNR. Such noise may be external, or may be a sub-optimal setup in your home. Such things as star wiring, or the modem being close to something like the electricity meter. An always on, even on standby, PVR or satellite TV receiver?

Is your modem connected to a filtered faceplate at the master, or on a dangly filter at an extension?

These are all factors that might not affect a 40/10 connection, but have a considerable effect on an 80/20 one.

I think I have this NTE5c mk4 master socket which was installed in 2017. We just have a master socket, no extentions.
As I already mentioned I was getting 22mbps to the router on standard broadband.(where theoretical maximum speed is 24mbps). So my line can't be noisy.
Is there a way I can check if my line is noisy?

Noise can come and go as can other customers which affects sync speed. My speed just inexplicably dropped from 80 to 66.

As ADSL2+ is using a different spectrum of frequencies performance on that does that have a linear relationship to performance on VDSL2

i.e. almost max ADSL2+ speeds does not mean you will see almost max VDSL2 speeds

Every line has noise on it - it comes from many many sources almost all of which are outside your control.

Examples: Radio transmissions, cross talk, electric motors, PCs, televisions, traffic lights, central heating, fridge freezers,, and te frequency of the noise will be from DC to light!

Look at any DSLstats bit loading graph and there will be dips where radio transmissions occur - 720 kHz, 909kHz, 1215kHz, 1440 kHz, &c. Other sources may be wideband and may not be as easily noticeable of may have just a small effect - 1 or 2 bits per tone compared to 10, 12 or more for radio transmissions

In reply to a post by Customer69:

i don't know, that could be SNR. I did the noise test on my line and there is no noise. that makes me believe that 6dB is just the level of background noise.

SNR is indeed what is important. That is what determines the maximum possible speed on a line. However it makes no sense to let a line connect at its maximum, as the moment a noise impulse occurred the connection would drop. SNRM(argin) is therefore applied by the system, reducing the sync so that when such extra noise happens it is accommodated in that stability margin.

SNR and SNRM vary together. If the noise increase is greater than the margin set at sync time then the connection will fail, and reconnect at whatever speed it can. Depending on what noise then exists, but with a full margin.

See this page for more detail of how it works.

thanks for your help guys,
It looks like DLM is sort of working. Almost a week into training period DLM finally did something. The noise margin is reduced by 0.1 dB both ways and speed is also reduced.

here are the new DSL stats.

DATA RATE INFORMATION
Upstream 18702 (Kbps)
Downstream 57468 (Kbps)

DEFECT/FAILURE INDICATION
Operation Data Upstream Downstream
Noise Margin 6.1 (dB) 6.2 (dB)
Line Attenuation 0.0 (dB) 14.3 (dB)

In case someones interested in the ping:
ping to google.co.uk:
before training period: 11 - 13 ms
1st day of training period: 19 - 20 ms
5th day of training period: 26 - 27 ms

where ping to 192.168.1.1 was <1ms.

DSl status page on this router hardly shows any info. Does Bright box 2 router support telnet.

That looks a bit as though Interleaving has been applied due to high error rates. On its initial application a latency increase of a minimum of 8ms is usual, with a sync speed reduction of 6-8Mbps.

I should also be getting close to the max. speed but get 62 Mbps or thereabouts.

I am close to my cabinet which is also close to the exchange.

OR has tested and tell me that there is some ally cable somewhere in the system that supplies me and that is why I will never get the full speed. This only showed up when I got the speed boost.

Just a thought but may explain your speeds.

In reply to a post by Customer69:

Almost a week into training period DLM finally did something.

There Is No Training Period!

here is an update to my situation.

someone else had the same issue as me, they lived really close to the fibre cabinet with a really good line but the sync speed was no where near 80 mbps. so, they had open-reach guy come in and change their line over to another spare port in the fibre cabinet. And the issue was solved for them.

so, I also called my provider and asked for a check. Open-reach guy comes, checks the speed at fibre cabinet and everything is fine. then checks the speed at my master-socket and I'm only getting around 67mbps. So I tell him about switching my line over to new port. he goes back to the fibre cabinet and 30 mins later I'm syncing at 77mbps. here are my new dsl stats.
STATUS
********************Configured*****Current
Line Status********--***************UP
Link Type**********--***************Fast Path
Operation Mode**Automatic******G.993.2 (VDSL2)
DATA RATE INFORMATION
Upstream 20000 (Kbps)
Downstream 77375 (Kbps)
DEFECT/FAILURE INDICATION
Operation Data*******Upstream*****Downstream
Noise Margin*********9.8 (dB)********6.3 (dB)
Line Attenuation******0.0 (dB)*******13.5 (dB)

Indicator Name****Near End Indicator****Far End Indicator
Output Power******4.7 (dBm)**************13.6 (dBm)

Only problem now is ping:
when the guy first came in to checked the speed at master socket my speed jumped from 57mbps to 67 mbps. and ping droped from around 30ms to 10ms. (no idea how that happened. I think when he plugged in his meter, DLM just went away; I started getting the max possible speed which was 67mbps. also Interleaving went away which cause to ping to drop back to 10 ms.)
but when he switched my line to a different port at fibre cabinet, ping went form 10 ms to 19 ms. (DLM probably applied Interleaving to my line)

also my ping is not just high it's not even stable, in game it does not feel responsive. game play is smooth but everything is delayed. I kill the guy, game stutters for a bit and kill is registered 2 seconds later. In game ping this 40 to 50 ms which is decent, game lags because ping is not stable. When DLM went away for abit, ping was perfect and really responsive.

what's causing the high/unstable ping? is it the DLM?

Some people saying that I should get get rid of ISP provided router and get a proper router. I have ee router which has build in modem for VDLS fiber, do I have to get a separate modem as well. Or can I just get a good modem for reliable speed and ping and leave the routing tasks for ee router?

Edited by deleted (Tue 17-Jul-18 16:36:12)

The router component is what responds to pings. Not the modem. Modems just pass a string of bits in both directions between your box's router component and your modem connection at the DSLAM. At exactly your sync/connection speed (data rate).

http://tbb.st/1531842069702298655
http://tbb.st/1531842125695135455
http://tbb.st/1531842484389248755

Believe these are your recent speed tests, and notice how the single thread test takes time to reach maximum speeds, suggesting something is not perfect.

Ruling out the EE router is worth doing at this point, since EE customers seem to have this pattern and often worse to the point it impacts the multiple thread.

Edited by MrSaffron (Tue 17-Jul-18 19:57:54)

Is there a missing "router" there please Andrew?

I think those are my results but I'm not 100% sure.
I did more tests and single threaded performance is much worse.

https://www.thinkbroadband.com/speedtest/15318521071...
https://www.thinkbroadband.com/speedtest/15318522736...
https://www.thinkbroadband.com/speedtest/15318523101...
https://www.thinkbroadband.com/speedtest/15318523663...
https://www.thinkbroadband.com/speedtest/15318524155...
https://www.thinkbroadband.com/speedtest/15318524531...
https://www.thinkbroadband.com/speedtest/15318525971...
https://www.thinkbroadband.com/speedtest/15318526932...

can you tell anything from these results?

Rooted around and found the missing router

Either the ee router is a bad device or there is some heavy congestion or screwball management

EE records poorly on our quality scoring system each month, but speeds overall don't reflect that.

Change router and if no effect change sip

+1 - wanted to chip in

replace the word sip with sip in the above post

In reply to a post by MrSaffron:

replace the word sip with sip in the above post

Seems your autocorrect is working overtime

Have checked, and yes if I type I S P it gets auto corrected to sip