Upped to ADSL2+ and still on the dark age

[troesma]

Folks

Have requested IDNET to up me to ADSL2+ which is now available at my exchange. The folks, as usual, very helpful but I'm still where I was before the upping and this has not to do with the training period, me-thinks.

Run just now the BT Speed Test checker and found this

>>>

Test1 comprises of Best Effort Test:  -provides background information.
    Your DSL connection rate: 3483 kbps(DOWN-STREAM),  888 kbps(UP-STREAM)
    IP profile for your line is - 2500 kbps
    Actual IP throughput achieved during the test was - 2319 kbps

If you wish to discuss these results please contact your ISP.

>>>

Simply cannot get why my IP profile is STILL at 2500Kbps. Looking at my modem stats...

DSL Noise margin = 14.9db down / 8.0db up
Attenuation = 41db down / 23.4db up
DSL Transmit Power = 0db down / 12.8db up

Working out 41 / 13.81db/km ~ 2.9 Km from the exchange, which I believe is roughly right.

At 41db I guess should be in the 8 Mbps region, yet that would not be easy (!) if I'm profiled at 2.5 Mbps..!

Views..? have sent an e-mail to IDNET support and no reply so far today (maybe James is looking into this...)

Ed

[Rik]

WBC uses higher frequencies than Max, so I wouldn't have expected a huge gain on your line (mine's much the same). What's killing your speed is the target noise margin, which seems to be set at 15db, and is taking about 2M off your sync speed. Do you have lots of extensions or devices, eg Sky boxes, connected to the line? Have you removed the ring wire if you do have extensions?

[troesma]

WBC uses higher frequencies than Max, so I wouldn't have expected a huge gain on your line (mine's much the same). What's killing your speed is the target noise margin, which seems to be set at 15db, and is taking about 2M off your sync speed. Do you have lots of extensions or devices, eg Sky boxes, connected to the line? Have you removed the ring wire if you do have extensions?

Just the Sky Box on 1 extension, and yes, the ring wire is off from the BT master socket (dunno on the others, can check now...)

[troesma]

Just the Sky Box on 1 extension, and yes, the ring wire is off from the BT master socket (dunno on the others, can check now...)

Just as a sideline, BEFORE the upgrade the noise margin reported by the router was 12.1db, solid. In addition, transmit power was 18.8db down whereas since the upgrade is 0db.

[Rik]

Remove the ring wire at all sockets if you can, it will help. If you're not on multi-room with Sky, unplug the box except when you want to order PPV etc. After that, it's down to trying to locate the source of the noise or instability which has pushed the NM so high. Give support a ring and ask them to test the line, particularly the error count.

The NM has probably been changed by instability, it looks like your line suffers from noise. Don't worry about power - routers and MSANs seem to be inventing new rules.

[john]

I have to admit to not knowing about the technology in detail but it seems to me that though ADSL and particularly ADSL2+ is capable of much better speeds than what most people are experiencing it is constrained by an ancient infrastructure that was never designed for the purpose.

Although the technology is designed to provide broadband on the existing copper cables it's only ever going to reach its full potential under ideal conditions, i.e. short distances from the exchange and good wiring connections etc. We can do a limited number of things to optimise the wiring at home but ultimately we're dependent on BT's network much of which was only intended to provide low grade audio connections.

I think ADSL is merely a workaround to avoid the high cost of installing a new fit for purpose fibre network.

Together with the usual bottlenecks that comprise the internet it's no wonder it's often slow but then again it's a miracle it works at all.

[troesma]

Remove the ring wire at all sockets if you can, it will help. If you're not on multi-room with Sky, unplug the box except when you want to order PPV etc. After that, it's down to trying to locate the source of the noise or instability which has pushed the NM so high. Give support a ring and ask them to test the line, particularly the error count.

The NM has probably been changed by instability, it looks like your line suffers from noise. Don't worry about power - routers and MSANs seem to be inventing new rules.

Now this is peculiar...

Did remove the ring wire on 1 extension, nothing much changed.

Did unplug the Sky box... attenuation went up to nearly 45db..! Plugged it back in... now down to 40.5db. WTF is going on..? The Sky box is wired to an extension... 

[troesma]

Now this is peculiar...

Did remove the ring wire on 1 extension, nothing much changed.

Did unplug the Sky box... attenuation went up to nearly 45db..! Plugged it back in... now down to 40.5db. WTF is going on..? The Sky box is wired to an extension... 

BTW noise margin also went up on unplugging the Sky box, to 15.5db, on reconnecting it went down to 14.6db.

[troesma]

Update. Just got this message from James...

Hi Eduardo,

When the regrade takes place you are automatically put on a 2Mb profile
to start off the training period. Over the next 10 days the most stable
speed for your line will be calculated. It is normal to see 2Mb speeds
in the first few days.

Kind regards,

James
IDNet Support

Now, might that also explain the NM issue..?

[rireed3]

Now, might that also explain the NM issue..?

No that's just the original BT setup, before it even looks at your line.  Target noise margin is put up if you have a bunch of re-syncs.  Don't ever work on you phone wiring with the router on and connected, as the stupid Dynamic Line Management will punish you for weeks with a high target noise margin if you re-sync enough.

Two other things:

• I found that removing the ring wire on all extensions is best.  Even with the router one removed, with others connected there was still a noise effect.
• Sky boxes are notorious.  Usually you need one filter at every extension.  Most people recommend putting two filters in series in front of a Sky box.

Richard

[troesma]

No that's just the original BT setup, before it even looks at your line.

Two other things:

• I found that removing the ring wire on all extensions is best.  Even with the router one removed, with others connected there was still a noise effect.
• Sky boxes are notorious.  Usually you need one filter at every extension.  Most people recommend putting two filters in series in front of a Sky box.

Richard

Sure, BUT the effect of removing the Sky box was that NM and ATTN went UP, not down, suggesting the Sky box is acting as a filter. What you suggest (unless I'm getting it wrong) is that the Sky box introduces interference, whereas here seems the contrary..!

[rireed3]

No, that's actually backwards (I also edited my last post -- have another look)

Noise margin is not noise, it's the margin of clean DSL signal above a noise floor.  High noise margin means you have more clean signal to encode bits on.  Taking the noise source away makes the margin go up.  BT has your target at 15.  If it allowed a re-sync to a target of 6, you could get another 9 db worth of bits and corresponding speed increase, but they won't until your line proves it can hold the margin for 14 days.

Richard

[troesma]

No, that's actually backwards (I also edited my last post -- have another look)

Noise margin is not noise, it's the margin of clean DSL signal above a noise floor.  High noise margin means you have more clean signal to encode bits on.  Taking the noise source away makes the margin go up.  BT has your target at 15.  If it allowed a re-sync to a target of 6, you could get another 9 db worth of bits and corresponding speed increase, but they won't until your line proves it can hold the margin for 14 days.

Richard

OK, having disconnected the Sky box pumped the NM to 25.7db now. Let's see where it goes, but guess I'll need to wait for 48 hrs as James suggested above.

[Ted]

Have you tried connecting the router to the master socket behind the faceplate? That will eliminate all the potential wiring and device problems from your internal setup.

[troesma]

Nope, it's not connected to BT test socket, but from the outer one on the master box. Will try later on.

[Ted]

When you disconnect the router make sure you turn the power off first before removing the DSL line cable.

[rireed3]

pumped the NM to 25.7db now

That's very good.  The Dynamic Line Management (DLM) complicates what to do next, and Sky might wonder where their box went  

DLM is nearly the most annoying thing about BT packages sold by providers.  It punishes you for re-syncs when you're trying to fix your line.  And it punishes you for momentary noise like thunderstorms.

I would tell you to re-sync now, as that would get your noise margin back down to 15 and get some connection speed, but you've apparently angered the DLM god already, if your target is 15.  Also, you have to decide what to do with the Sky box, so don't re-sync any more than necessary.

When you figure out what wires to disconnect and what filters to buy and plug in, then turn your router off or unplug it from its filter and do all the wiring work.  Then plug in the router and turn it on.

Richard

[Ted]

If you're in the mood for spending  do yourself a favour and get one of THESE it will isolate your internal wiring and you no longer need any filters on any equipment.

[rireed3]

even the sky box?  

[Ted]

even the sky box 

Not in theory 

[Rik]

Did unplug the Sky box... attenuation went up to nearly 45db..! Plugged it back in... now down to 40.5db. WTF is going on..? The Sky box is wired to an extension... 

What did your sync speed do? Attenuation increases with speed on WBC. As Richard says, the increase in NM when the Sky box is unplugged is good, and a sign that the Sky box is part of your problem.

[Colin Burns]

if i was you i would disconnect the sky box untill sky start sending you letters if ever.

[Rik]

Which they will only do with a multi-room subscription.

[Gary]

Which they will only do with a multi-room subscription.

If you have a face plate Rik does that automatically remove a sky box from the equation?

[Rik]

Generally, I'd say yes, Gary, but Sky boxes are well known for getting through the filters.