Solid 8128 for 3 years now stuck lower

It's been a while since I had to browse these excellent forums - a recent issue has brought me back.

For 3 years, I achieved a good solid 8128000 sync speed with interleaving off. My SNR Margin reported 12-13db with loop attenuation at 9db.

On the 1st of June this year my router lost sync and re-synced at 7360000. I noticed the SNR Margin had increased a bit (weeks) before this to 15db. I finally managed to get the sync up to 7584000 but cannot for the life of me understand why for 3 years+ I NEVER synced below 8128000 and now I'm stuck at 7584000.

I guess I probably really am splitting hairs but it's frustrating not knowing/understanding why this has happened. Been throught the ISP/BT mill with the usual apathy from both - short of sitting on the steps of the local exchange (2 minute walk) I'm at a loss.

Here's the current stats from my router:

> show adsl ?
  --------------------------- ATU-R Info (hw: annex A, f/w: annex A) -----------
   Running Mode            :    G.DMT       State                : SHOWTIME
   DS Actual Rate          :  7584000 bps   US Actual Rate       :   832000 bps
   DS Attainable Rate      :  7584000 bps   US Attainable Rate   :  1324000 bps
   DS Path Mode            :        Fast    US Path Mode         :        Fast
   DS Interleave Depth     :        1       US Interleave Depth  :        1
   NE Current Attenuation  :        9 dB    Cur SNR Margin       :       15  dB
   DS actual PSD           :    17. 9 dB    US actual PSD        :    12. 5   dB
   ADSL Firmware Version   : 232201_A
  -------------------------------- ATU-C Info ---------------------------------
   Far Current Attenuation :        4 dB    Far SNR Margin       :       18  dB
   CO ITU Version[0]       : 00005453       CO ITU Version[1]    : 00005443
   DSLAM CHIPSET VENDOR    : < TI >
>
> show status
<snip>
ADSL Information:      ADSL Firmware Version:232201_A
Mode:G.DMT             State:SHOWTIME   TX Block:12937479 RX Block:291268337
Corrected Blocks:18    Uncorrected Blocks:24
UP Speed:832000     Down Speed:7584000    SNR Margin:15  Loop Att.:9
>

No amount of usual tests from end makes any difference - I did try a BT Business Hub (2wire) but that synced at 7000000 ... done all the usual stuff, remove faceplate use test socket etc. - nada, no different.

Can anyone shed some light on my numbers above, the margin increasing from 12 to 15 is significant? Should I consider turning interleaving back on?

I know there are many people here happy to get something above 1Mbit/s so I apologise in advance for appearing so pedantic but it's a question of needed to know more than anything.

Ta.

Odd considering the line stats. Have you tried a different router, could be yours has developed a fault.

Yes, I tried a BT Business Hub and a DLink wireless router - both gave lower than the Draytek 2820 (for which I posted the stats).

It is very strange and I've drawn a blank with BT / ISP - not unsurprisingly.

We've a very similar issue on one of our test lines.

It's around 250 meters from the exchange, 4db loss and normally a 12db profile. It went up to 15db for no reason that we could work out and there were no errors on the line.

So, we arranged for BT to set the SNR margin back to 12db, which corrected the issue, only for it to get bumped upto 15db again.

Maybe ask your service provider to arrange for BT to lower it to see if it stays put!

Matt

Thanks for that. Trouble is, the ISP (Entanet) refuses or states that BT will NOT reset it. I'm really stuck, I have an ISP that's not bothered (because it's < 1Mbps reduction) and I have no way of talking to BT Wholesale directly - most frustrating.

OK - so I dug out my DSL-2740B and hooked it up and it synced at 6300!

So I issued: adsl configure --snr 6 and it resynced at 8128. In 8 hours I've had 1 HEC upstream 0 downstream and a solid connection.

If I reboot then again it syncs at around 6300-6400. Does this indicate far end configuration, e.g. SNR margin set by BT?

I put the Draytek back on and it syncs again 7584 - sadly, no way to force the margin on the Draytek.

So, do I hold my breath for 14 days and hope that it gets reset proper at t'other end or what?

yes, the target SNR margin has got stepped up perhaps due to an odd wobble in the past. It should in principle come down after a couple of weeks or so of stability, otherwise needs a manual intervention to correct the profile on the DSLAM.

Thanks yarwell - patience is not in my nature, especially when I know there are those with powers to intervene but choose not to - c'est la vie. I'll sit tight...

C.

just run it with adsl configure --snr 6 ?

Sadly no because I am having to use the Draytek router, the DLink doesn't have the flexibility, wireless sucks and does not handle multiple IP addresses very easily. Otherwise I would....