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