Thanks to whoever fixed my broadband!

[Bat]

Hi,
I've no idea, but I like the look of this! 


Cheers,
Gavin

[Sebby]

Are you referring to the drop in SNRM? It could be that you've maintained a stable connection for over 14 days and the DLM has dropped it, yielding you more speed. But it could also be that there's more noise around...

[Rik]

It looks like the target NM has been dropped, Seb, there appears to be a re-sync at a lower margin.

[Steve]

Worth keeping for the archives  Evidence of a  resync with a lower margin  after 14 days of stability . A rare event

[Rik]

I've already framed a print, Steve.

[Steve]

Already on the wall above the router

[Rik]

Quite.

[LadFromWales85]

So, the DLM will decrease the target SNRM, all on it's own, if your line demonstrates stability over a 14 day period?

Due to a line fault on 12th Dec, rendering my line dead on the voice side, apparently one core of my pair severed at the pole, my modem kept syncing up as I wasn't home to notice, it ended up at something like 800/64!  Since been repaired, but the target SNRM is still sitting at 15dB despite being 400m from the exchange and having a 21dB attenuation.
I bought a Draytek Vigor 100 as my D-Link DSL-300g+ doesn't show linestats on either the web or cli, and with that was able to sync at 76xx kbps with the 15dB margin.  Not happy with just 76xx, I bought a Netgear DG834gV4 which managed around 6mbit...I was disappointed, as everyone seems to rave about how well the Netgears hang on to the line down to 0dB, so I installed the DGTeam firmware and tweaked its SNRM slider down to 1%...8128 sync!  Margin is 10.1dB at the moment, been synced since I installed the firmware happily, so I am happy with it for now   Just need the DLM to put me back to 6dB so that I don't need to tweak the target SNRM!

Simon has had a go at getting BT to lower the target manually, but they are reluctant to, due to the instability caused by a fault on their own network!  But of course, BTw are not going to know this, as it's unlikely BT's own faults team will inform BTw of the fault...left hand right hand!

[Rik]

Twas ever thus with BT sadly.

The speed should recover on its own though, but sometimes needs a helping hand.

[LadFromWales85]

heh my speeds are fine now, well a bit wobbly this evening, prob a bit of exchange contention!
Am now on interleaving opt-out so it shouldn't come back to haunt me...syncing at the full 8128/832 with the help of the Netgear being able to somehow lower the target SNRM.
Just want BT to lower the target at the dslam so that I can go back to using my Vigor 100, as the latency with that modem is a steady 17ms rather than the 23ms on the Netgear

[Sebby]

Netgears (those with the AR7 chipset) seem to negotiate a sync rate that's too high, and it ends up achieving an SNRM short of the target.

The DLM should drop the target SNRM automatically following 14 days without a re-sync, but it rarely happens.

[LadFromWales85]

I've got a DG834G version 4, so it has a Broadcom chipset.
As standard, it actually syncs slower than both my Draytek and D-Link (Globespan) modems, achieving only 6meg while reporting a 15dB margin, whereas both the Draytek and D-Link sync at at least 7648 while reporting 15dB!

This leads me to believe that the DG834G (version 4 at least) reads the downstream SNRM incorrectly, lower by a few dB at least, which would explain why some people manage to keep sync at 0dB and below.  Not important to me though, I'm only on ADSL1 and could happily sync at 8128 with any modem if BT put the damn target margin back where it should be!  For now though, the Netgear with DGTeam firmware with its tweakable margins allow me to sync up at 8128...as soon as the margin is lowered I'll likely go back to the Draytek as the latency to first hop is 17ms rather than 23ms.

I'll badger Simon on Monday to badger BT to lower the margin manually!

[Rik]

I have heard that, if you manually adjust the target NM from your end, the automatic system will no longer work (because the BT software is seeing a lower NM than the current target).

[Steve]

That's is correct as far as I know,you can't have it both ways.

[Rik]

Though I have tried.

[LadFromWales85]

But as the system rarely works, as has been said in this forum, I may as well tweak the target SNRM on the modem, and get it lowered manually at the dslam.
It's either that, or syncing at sub 8128 with one of my other modems and just hoping the system will lower it on its own within 14 days, which it may not do anyway, as the margin will drop below the target at points throughout the day anyway.
The modem has been synced up for over 72 hours now, so I'll leave things as they are for the timebeing

[Rik]

The problem is that BT will often refuse to manually intervene, unless they have a record of a fault being cleared. Let's hope Simon can work his magic though. 

[Sebby]

Fingers crossed for you. BT should reset it if there was work on their network, but their policies are far from uniform.

[LadFromWales85]

The problem is that BT will often refuse to manually intervene, unless they have a record of a fault being cleared. Let's hope Simon can work his magic though. 

Yep, my account shows two PSTN faults, both marked successful (first engineer was rubbish, did nothing, left my line broken, blaming my phone!), and an ADSL fault, marked as successful, apparently my connection at the exchange 'fell off' (his words!) as soon as he touched it.

I've no clue what the snrm's were like on my line prior to the fault, as my old modem didn't show statistics, but kept sync indefinately.  This Netgear DG834Gv4 appears to report the margin as being lower than it does on the Draytek and my Linksys ADSL2MUE (when it works, psu fault ) which means it syncs lower than both of them when not applying the SNRM tweak!  Think that explains how people report keeping sync with a Netgear reporting -2dB where others kick the bucket below 3dB or so...!

But this is BT we're talking about, don't know their arm from their elbow...I just hope Simon can coerce them to click a few buttons to reduce my margin so I can go back to using a modem I can trust!   Gotta love the Netgear for getting me back to 7150k though!

[Rik]

Different modems seem to manage the NM in different ways. The Netgears have always swung wildly in my experience, but have maintained sync at <0db, usually to -2db for me. OTOH, my 2-Wire 2700 rarely moves by more than 2db from target.

[LadFromWales85]

Everyone raves about this 2-wire on here!  What's so special about it?  Good at obtaining sync on long lines or something?  I'm close to the exchange, so naffed up DLM profiles aside, I get full sync with any modem.

Yeah the margin on the Netgear does seem to swing wildly, but I'm unsure it's the Netgear showing interference on the circuit somewhere or it just being, well, a Netgear!  The important thing is that the connection hasn't dropped for 60 hours so far
Does the 2-wire show margins at a higher resolution than whole dB or can it show it to one decimal place like the Netgears?  Could explain the differing appearance of margin on your line maybe?

[David]

  Im not up on all of this but  for Bat and the Lad 

[LadFromWales85]

lol cheers

Though I've been an IDNet subscriber (twice!) and have been registered on these forums for ages, but never really posted much...never had anything to post about, heh!

[David]

lol cheers

Though I've been an IDNet subscriber (twice!) and have been registered on these forums for ages, but never really posted much...never had anything to post about, heh!

You mean we need a reason  god I have it all wrong   

[Sebby]

The 2700 seems to be good on long lines. It usually yields higher sync whilst maintaining a more solid SMRM. And it's cheap.