Help,is this DLM? fluctuating Attenuation?

In march this year I migrated bb only from be, left landline with BT.

I was about to go for fibre with plusnet, but sky have me free landline for a year and my bb for £5 a month. So decided to go ahead. Now during speed checks it's always said still I'm on o2/be,, and I spoke to tech about this before I signed asking if I was still on the old o2/be, which he said yes, and over never had DLM on the line as bb migrators didn't. I said well that change is I put my line with you, he said no.

Anyway, on the 1st of Dec my line went active with sky, immediately I checked my speed, and WOW it was high, 12.7mb/1119mb.. The most I've ever had ever, and strangely my my attenuation had gone from 34db to 33.5db ,OK only half, but it lowered just connecting to sky's line.

Anyway the high sync speed is short lived and my line resynced about 1am tonight and it's gone to just 8mb/0.5mb and the DSL type changed to G.992.1? Is this normal, And my attenuation has dropped to 31db.

I'm still using the technicolor 582n router from be, should I plug the sky hub in if it is DLM?

Also now I do a speedtest it says my ISP is sky, so they have moved me when 2 tech told me I would stay on the old infrastructure. Which was the selling point for me..

Any help is be so grateful

Edited by deleted (Tue 02-Dec-14 02:42:01)

Just as I typed this out, my line disconnected and went back to this.

DSL Type: ITU-T G.992.5

Bandwidth (Up/Down) [kbps/kbps]: 1.023 / 12.544

Full stats below
Link Information

Uptime: 0 days, 0:20:58

DSL Type: ITU-T G.992.5

Bandwidth (Up/Down) [kbps/kbps]: 1.023 / 12.544

Data Transferred (Sent/Received) [GB/GB]: 2,33 / 1,86

Output Power (Up/Down) [dBm]: 12,1 / 19,6

Line Attenuation (Up/Down) [dB]: 16,8 / 33,5

SN Margin (Up/Down) [dB]: 13,9 / 5,8

System Vendor ID (Local/Remote): TMMB / ----

Chipset Vendor ID (Local/Remote): BDCM / BDCM

Loss of Framing (Local/Remote): 44 / 0

Loss of Signal (Local/Remote): 5 / 0

Loss of Power (Local/Remote): 0 / 0

Loss of Link (Remote): -

Error Seconds (Local/Remote): 283 / 28

FEC Errors (Up/Down): 2 / 181

CRC Errors (Up/Down): 0 / 58

HEC Errors (Up/Down): 159 / 0

Yes, this looks like Sky DLM. It really does test your line over the first few days and try to find the optimum connection speed/SNR margin. Generally it will resync at around 2am every night; once it stops doing this it's complete. In my experience it does a pretty good job, but the speed can fluctuate a lot during this time.

I also see my attenuation varying by 0.5dB from time to time. I don't think it's anything to worry about.

Edit: sorry, I missed the bit about the DSL type changing, and the attenuation change being to 31dB. I can't explain that.

Edited by ip75 (Tue 02-Dec-14 09:29:07)

Given most routers only have a resolution of 0.5dB in the display of the attenuation it is nothing to worry about

Thanks for the help. I read on sky forum that the drop in attenuation to the 31db is prob due to it changing me to ADSL-1 , is really odd that the DLM even tests this option.

Must checked my stats and it is still connected at the speed from last night.


EDIT**Line testing is not currently in progress on your telephone line.**- Odd?

Edited by deleted (Tue 02-Dec-14 12:31:56)

Thanks, do you think if would be worth plugging the sky router in during this DLM time,as I'm still using the old o2 Tg-582n?

In reply to a post by craggs:

EDIT**Line testing is not currently in progress on your telephone line.**- Odd?

My Sky is often out of date as far as the DLM line testing information goes.

Don't switch off, reboot or change your router during line testing.

Yeap with Sky their DLM is one where the less interference from the end-user the better.

Usually it starts at around 4 Mbps for ADSL2+ lines and works its way up, so you have done better than some people who panic on the first morning the service is live.

I don't think it works this way any more. I joined back in January and it started off fairly high (around 6.5Mbps) and never went below 5.5 during the DLM period. Ended up at around 6, which isn't too different to what I had with Eclipse before.

Only issue I can see is I installed an phone extension of the master with proper BT wire, and a proper BT box about 3yrs ago.it has the open reach fibre faceplate on it, from my master socket, I've not got fibre but an sfi engineer fitted it as I had a line fault.

Anyway I put a socket of that and put the faceplate on my detention. Now it is in line testing im concerned I should put the router into the main socket at least to get better results.. Though it's been connected with be on the extension with no issues for Yeats.

I not sure that what I did counts as moving the master socket?

So long as the master socket is still there and you only wired stuff up to the rear of the removable faceplate then you should be fine.

BUT testing back at the main test socket in the property is needed to rule out a wire break/loose connection

Ok thanks!

It dropped again last night,and sky say line testing is not in progress still,but I know assume that it's infact delayed.

I've left my technicolor router plugged in as advised and not put the sky router on.

Fingers crossed my technicolor doesn't start to 'Kernel warm start' a few times during testing and look at it as a disconnection.

Currently my line is showing after last nights disconnection

Uptime: 0 days, 13:01:42
DSL Type: ITU-T G.992.5
Bandwidth (Up/Down) [kbps/kbps]: 1.256 / 13.029
Data Transferred (Sent/Received) [MB/GB]: 167,36 / 1,99
Output Power (Up/Down) [dBm]: 12,0 / 19,2
Line Attenuation (Up/Down) [dB]: 17,0 / 33,5
SN Margin (Up/Down) [dB]: 6,2 / 3,0

Which is better than I have ever had,but I appreciate it is maxing my line out and when it's finished it will drop somewhat as I am about 2.5Km away from the exchange and I have ever only had about 10-11mb max

Quick update,my line was dropping a lot on Wednesday night from about 9pm and midnight.it dropped about 7 times,3 of which seemed to be in a row.

Now that night the DLM did not reset the line in the night,and it did not do it the next night.its only been running since the 1st dec,So I was wondering if because of the line drops the DLM is assessing things.The other problem is my router has warm restarted a couple of times which is annoying.

So today I decided to run router stats on my line for a few hours.

My downstream SNR is perfect straight line but my upstream is having around 1db spike's,is this normal,i've tried to included a graph of the spikes but not sure how to do it?

You right click the pane and then select save from the menu.

This is mine:-

http://s5.postimg.org/cirbstah3/routerstats_image.jpg

Thanks, sorry I meant how to display the link on the forum. Think I've worked it out now using photo bucket.

Can I ask if you see any changes to the up/down SNR when you make a call?

Quick update,my line was dropping a lot on Wednesday night from about 9pm and midnight.it dropped about 7 times,3 of which seemed to be in a row.

This is unlikely to be DLM. It is likely Sky are trying fast speeds to assess if the line can handle it and the lines dropping.

Now that night the DLM did not reset the line in the night,and it did not do it the next night.its only been running since the 1st dec,So I was wondering if because of the line drops the DLM is assessing things
Ω

. It often will not do anything for multiple days, what it's looking for here is if the line can sustain that speed.

E.g. it will set the line to 13Mbps speed. It may then wait 72 hours before doing anything. WHY? It wants to see that there were 1) no drop outs in that 72 hours and 2) no big errors built up in that period.

DLM is quite extensive, it literally wants reliability and the aim is to set a speed where the line does not drop out. It's reliability over speed. If DLM made changes every few hours, it wouldn't be able to establish if there was stability, that takes days of monitoring.

The other problem is my router has warm restarted a couple of times which is annoying.

If this is happening, take your router, find the nearest bin and replace it. It's going to have a bigger impact on your line keeping this faulty router connected than just changing it immediately to the Sky hub. Pop the Sky hub in, also I have found it syncs higher than these speedtouch routers.

If your speeds end up poor, that's fine, ring sky and explain old router kept overheating and rebooting they can re-run DLM and start over the process.

Also key to note, DLM never really stops running, say you were not in the master socket and had poor wiring to the extension socket, and also turned off the router all the time during initial DLM, you may only sync at say 5Mbps.

If you then moved to the master socket and never turned the router off, DLM would notice the improvement in conditions, after a month or so of the better conditions DLM would re-run automatically and give you better speeds.

So today I decided to run router stats on my line for a few hours.

May as well post them up

My downstream SNR is perfect straight line but my upstream is having around 1db spike's,is this normal,i've tried to included a graph of the spikes but not sure how to do it?

That's fine.

It dropped again last night,and sky say line testing is not in progress still,but I know assume that it's infact delayed.

I've left my technicolor router plugged in as advised and not put the sky router on.

Fingers crossed my technicolor doesn't start to 'Kernel warm start' a few times during testing and look at it as a disconnection.

As already said...
Plug in Sky hub. We all assumed the technicolour router was fully working and would not keep rebooting itself. Just change it ASAP.

Sky Hub may sync a bit better too

It has set a noise margin of 3db so it's clearly thinking it's not a bad line.

MySky is VERRRYYYYYYY delayed as suggested.

Thank you for your help on all my questions,it is really appreciated

Here is the links to my upload SNR from router stats,all the drops in noise correspond to when I have used the phone.

Today has been the most dramatic,,I can't hear any noise on the line,and the internet connection does not drop whilst on the phone.I had a major issue years ago where the line kept dropping when the phone was used,back then the SNR would drop to -100.and drop the line.So I guess i'm just a little paranoid as it was a journey to track the corroded joint by the SFI.

Hope these links work,,

yesterday

http://i175.photobucket.com/albums/w151/craggle_rock...

Today

http://i175.photobucket.com/albums/w151/craggle_rock...

R.E plugging the sky hub in,I actually forgot to say it's not here yet,I thought it would be by now,but sky say it will be here next week.

And my router stats

Uptime: 2 days, 0:33:40
DSL Type: ITU-T G.992.5
Bandwidth (Up/Down) [kbps/kbps]: 1.308 / 11.872
Data Transferred (Sent/Received) [GB/GB]: 1,71 / 3,21
Output Power (Up/Down) [dBm]: 12,1 / 19,2
Line Attenuation (Up/Down) [dB]: 17,1 / 33,5
SN Margin (Up/Down) [dB]: 4,6 / 4,2
System Vendor ID (Local/Remote): TMMB / ----
Chipset Vendor ID (Local/Remote): BDCM / BDCM
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 0 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): -
Error Seconds (Local/Remote): 120 / 5
FEC Errors (Up/Down): 0 / 328.546
CRC Errors (Up/Down): 738 / 332
HEC Errors (Up/Down): 1.182 / 0

All the disconnections/loss of signal has been reset when the router kernel warm restarted,which was when this last sync was.

Edited by deleted (Sun 07-Dec-14 17:01:16)

Nothing to be concerned about. I have seen ones which fluctuate A LOT, my line was far worse and would stay connected for months on end.

A key thing I have noticed is that these technicolour / speed touch routers (even for myself) seem to show a very stable noise margin. The Sky Hub and Netgear routers will show much more fluctuations. So it's one of those things don't get too worked up about

It's a shame that you have a faulty router during DLM, hopefully it won't affect things too much. It's not JUST disconnections it's also error build up.

IE lets of errors and a disconnection = bad
barely any errors and a disconnection = not so bad.

But disconnections do not help of course.
The Sky hub is decent, I've had it plugged in behind a fridge with uptimes of months on end without an issue.

Thanks for your help again

According to my sky page DLM completed in the 6th. It only took 5 days. It says line is set to 13.3/2.5mb,,I think the higher upload is a bug. So looks like the disconnections on the 4th didn't effect to much., it does seem to look like it's set a 3db line as the stats are around 4-5 dB up/down.,I think that's too low maybe

I'll not resync manually until the sky hub arrives , whenever that will be, should of been here by now really.

I'll not get to paronoid when running router stats with the new hub he he