Max sync always 3776kbps / maybe noise issue

Hi everyone,

Been round at a mates house tonight trying to sort his woeful ADSL out.
He is on Plusnet with a 10Gb monthly download, he assumes its an "up to 8Mbit" service.

His stats are (Thomson 585v7 on Plusnet firmware);

Link Information

Uptime: 0 days, 0:09:49
DSL Type: G.992.1 annex A
Bandwidth (Up/Down) [kbps/kbps]: 448 / 2,208
Data Transferred (Sent/Received) [kB/kB]: 0.00 / 0.00
Output Power (Up/Down) [dBm]: 12.0 / 17.0
Line Attenuation (Up/Down) [dB]: 21.0 / 36.0
SN Margin (Up/Down) [dB]: 20.0 / 7.0
Vendor ID (Local/Remote): TMMB / TSTC
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): 0
Error Seconds (Local/Remote): 0 / 0
FEC Errors (Up/Down): 0 / 555,475
CRC Errors (Up/Down): 0 / 0
HEC Errors (Up/Down): 0 / 0

As you can see his sync is rubbish for a 36dB line attenuation so i suspected his wiring setup from the master socket.
Once i'd replaced the setup with a filtered faceplate (ADSLnation), left his phones unplugged and just connected up my Billion 7800N it synced at 3776kbps.....leads me to think dodgy cable.
OK its better but not perfect, on a 36dB (or 46dB as my 7800N misreports G.DMT connections) line attenuation he should be pushing between 7 - 8Mbit!
Looked at the Telnet stats in Routerstats and it was racking up the errors, errored seconds were shooting up as well as the other fields.....i didnt take a grab though.

Bit more messing later (including trying an old DG834 v2 i think it was, wouldnt report the line stats!) and i reconnected my 7800N and it synced again at 3776kbps exactly. Another reboot of the router and again a 3776kbps sync. Suspicious!

Anyone know of anything that would limit the sync to this 3776kbps value?

Logged the stats for 15 minutes on my 7800N;

SuperFrames: 54869
SF (CRC) Errors: 24
Reed Solomon: 1865558
RS Corrected: 1391553
RS Un-Corrected: 24
HEC: 17
Errored Seconds: 23
Severe ES: 0

Interleave Depth: 16
Bitswaps: 3

Does anything look out of place with those stats?

Tried listening for noise using his land line on 17070 but its only a normal wireless handset (no analogue wired one available) though saying that i could hear some slight noise and a faint electronic type noise....again this might be the fact its a wireless handset. He is going to try and get hold of a wired handset.

Sorry for the huge post but thought i'd try and get all the info in at the first attempt! Any help appreciated.

EDIT
Also when connected at 2208kbps on his Thomson the internet connection was extremely slow and intermittant and having to retry just pages like Google, the BBC homepage loading in all funnily arranged etc, almost like it there was loads of errors hampering his throughput.

Edited by deleted (Thu 02-Feb-12 22:15:37)

What's the SNR now?
The sync is probably capped.

In reply to a post by BatBoy:

What's the SNR now?
The sync is probably capped.

SNR is always around the 6-7dB mark.
Can an ISP cap your sync, it seems like an odd number to cap at?
He only knew that he was just out of the "tied" in contract period with Plusnet, didnt know what the actual package was.

Stick his phone number into samknows and give us the link please. We can check a couple of things about the exchange from that.

He is on the same exchange as me;

http://www.samknows.com/broadband/exchange/LCHOG

Plusnet has been having throughput issues today see our news, which may explain slow speeds for the sync you have.

On your service it can only be capped at 0.5 1 and 2Meg

So the cap looks to be a function of the router and how it is handling what looks like a lot of errors

In reply to a post by MrSaffron:

On your service it can only be capped at 0.5 1 and 2Meg

So the cap looks to be a function of the router and how it is handling what looks like a lot of errors

Thats what i thought, seemed an odd sync speed to be capped at.

Are the error 7800N stats then showing a definite problem?
This is plugged into the master socket via a filtered faceplate and just using a short (1m) normal adsl lead to the router....not much else that can be taken out of the equation. I couldnt see any other wiring connected to the back of the socket even where the drop wire came in so nothing somebody may have bodged into the BT side.

Andrew is right. Best to wait until Plusnet have given the all clear (see the Plusnet section's posts for more info), then reboot and start looking at the stats.

Yes, but where it is hard to say, and whether you'll get someone out to fix it and not charge you a lot is the key thing.

Hence being 100% sure, that you can show that its none of the wiring in your property

No apparent VP problems, but they should only affect throughput, not sync speed.

No WBC. Therefore he can't be on one of the "banded profiles" that provides, so I'm not aware of any way they could limit it to such a strange number. Maybe someone else will know of a way.

He has to be on either IPStream or IPSC. I don't know where Plusnet are up to with the transition from the first to the second. Yes it is an "up to 8Mbps" service.

Has it always been like this? You do know Plusnet have had a major incident starting last night? I haven't heard of it affecting sync speed though. Thread in the Plusnet forum, and a News Item with some useful info.

Edited by RobertoS (Thu 02-Feb-12 22:44:21)

In reply to a post by RobertoS:

You do know Plusnet have had a major incident starting last night?

Afaik, it was 8.25 ish this morning.

In reply to a post by camieabz:

Andrew is right. Best to wait until Plusnet have given the all clear (see the Plusnet section's posts for more info), then reboot and start looking at the stats.

How long has this been a problem for though? He has had issues for months and months from what i can tell. And Plusnet issues wouldnt affect sync especially as my 7800N didnt even have his ISP logon details entered!

Try a dangly filter straight into the test socket. Filtered faceplates can fail just like anything else.

Make sure no extensions work once the faceplate is removed. Does he have a phone-connected burglar alarm?

(Took me so long to write my previous post that all the others came in between ).

What we are saying is that while Plusnet is having its other problem, it will be hard to figure out if things are improving.

or an old phone bell as someone had on here recently

In reply to a post by RobertoS:

Try a dangly filter straight into the test socket. Filtered faceplates can fail just like anything else.

Make sure no extensions work once the faceplate is removed. Does he have a phone-connected burglar alarm?

(Took me so long to write my previous post that all the others came in between ).

I did try a dangly filter (i went prepared!) and there was no change. The filtered face plate works fine at my house.
There are no extensions into the removable faceplate, just his original extension from a normal plug in phone cable.

The only way a burglar alarm is connected is going to be at the back of the socket where it shouldnt be....ie BT side. Couldnt see anything but not 100%, just 99%!

In reply to a post by MrSaffron:

What we are saying is that while Plusnet is having its other problem, it will be hard to figure out if things are improving.

Yes but ISP throughput problems wouldnt affect sync on IPStream?

In reply to a post by MrSaffron:

or an old phone bell as someone had on here recently

Ooooo . I remember one of those reported here as a problem a few years ago. One of the loud add-on ones for the deaf, or keen gardeners. Caused mayhem to the ADSL.

In reply to a post by MrSaffron:

or an old phone bell as someone had on here recently

On the BT side of the master socket????

Correct, but I've learnt over the years to work on one problem at a time.

In theory you can fix the sync forgetting plusnet, but error counts will be a little false unless you can push data over the line properly

In reply to a post by InQ:

The only way a burglar alarm is connected is going to be at the back of the socket where it shouldnt be....ie BT side. Couldnt see anything but not 100%, just 99%!

He ought to know if he has one . Or there is one there from the previous owner. Such wiring has happened in the past, and these days they are supposed to have a filter inside the control box.

Not uncommon for alarms to be wired more oddly, if they have one you need to check.

Reason being they are wired so that someone does not just need to rip the faceplate off

It might be, they are pretty big so should be easy to spot

In reply to a post by MrSaffron:

Correct, but I've learnt over the years to work on one problem at a time.

In theory you can fix the sync forgetting plusnet, but error counts will be a little false unless you can push data over the line properly

Sorry are you saying "correct" as in bell wire on the BT side of the master socket?

I should also mention he lives next door to a sub station....

In reply to a post by MrSaffron:

It might be, they are pretty big so should be easy to spot

I think he did have a burglar alarm but never crossed my mind to check.

Sub station, mmm could mean lots of RF interference, is it a big one, or just a small local transformer?

I guess there could be an RF3 filter on the line.

In reply to a post by MrSaffron:

Sub station, mmm could mean lots of RF interference, is it a big one, or just a small local transformer?

Reasonable sized.....

His is the one with the bath outside it! The green cab is only at the end of the road there, about 20 meters from this house.

Edited by deleted (Fri 03-Feb-12 00:06:52)

LOL!

The phone line comes straight over the substation.

Yuk!

And there's a burglar alarm box on the wall.

Edited by RobertoS (Thu 02-Feb-12 23:11:26)

What's the wire to the chimney?

In reply to a post by BatBoy:

I guess there could be an RF3 filter on the line.

That's a possibility.

@INQ - look for strange junction boxes about the size of a Swan Vestas matchbox just inside the house where the line enters.

In reply to a post by RobertoS:

In reply to a post by BatBoy:

I guess there could be an RF3 filter on the line.

That's a possibility.

@INQ - look for strange junction boxes about the size of a Swan Vestas matchbox just inside the house where the line enters.

I have as i have an RF3 on my line at home so know what to look for. The line from what i can tell just comes direct into the back of the socket, looking on Google maps and following the line down the wall seems to show this is the case (his phone socket is behind the front door).

In reply to a post by RobertoS:

What's the wire to the chimney?

Its not going to the chimney, thats just Googlemaps tricking you! Seems like its next doors drop wire going to the front just under the gutter area somewhere.

Even so, his goes over the substation doesn't it?

As you have published the address, I suggest you delete the link now we have seen it. Or even the whole post.

Certainly do not answer any questions here about the alarm. PM it to those of us who have already posted here. Not to any "newbies".

RF3 filter should not have this level of impact, an RF2 might

In reply to a post by RobertoS:

Even so, his goes over the substation doesn't it?

As you have published the address, I suggest you delete the link now we have seen it. Or even the whole post.

Certainly do not answer any questions here about the alarm. PM it to those of us who have already posted here. Not to any "newbies".

It doesnt go directly over the top sub station, cuts the corner slightly of the plot the sub station is on.....still its near to the sub station in any case.

Other Post edited!

Shopping list:

6 x rolls tin foil
1 x ladder
1 torch (best to do it at night)


Joking aside, there could well be interference from that sub station. My last house had one about 20 feet away and it was impossible to get a mobile phone signal, although my BB speeds were fine, so maybe the substation won't be interefering after all. Even if it is, there would be little you can do, unless BT are willing to re-route the phone cable.

So from my first post, does the error stats look high for a 15 minutes period?

SuperFrames: 54869
SF (CRC) Errors: 24
Reed Solomon: 1865558
RS Corrected: 1391553
RS Un-Corrected: 24
HEC: 17
Errored Seconds: 23
Severe ES: 0

Interleave Depth: 16
Bitswaps: 3

Seems like a lot to me, but here's my router errors:

up 5 hours 51 minutes

Downstream :
FEC : 0
CRC : 380
HEC : 348
Upstream :
FEC : 0
CRC : 0
HEC : 0

...and that's on a bad Plusnet day. Hence why I recommended you wait a day or so until Plusnet get their end fixed, and you've done a reboot.

Remember that to reduce or eliminate errors, the ISP would reduce your speed. Errors are not a bad thing unless they're causing too much overhead (I'm sure someone with more experience of errors can put it more eloquently).

Was that 15 minutes from a resync or just 15 minutes during a long sync time?

In reply to a post by BatBoy:

Was that 15 minutes from a resync or just 15 minutes during a long sync time?

15 minutes from a resync or to be exact from power up the router from scratch.