(update) Loss of sync- Any reason you can see?

[#1]

Hi all, lost my lovely, consistent 8128 on sunday pm (3ish) and despite retrying frequently, changing routers (Dlink 2640b to Netgear 834gt <gt team>) plugged into test socket, going from wireless to ethernet, forcing SNR (which got me to 4100ish before switching to ethernet) I'm at less than half speed. No other devices connected. Dect phone (quiet line seems OK). I do use steamed music over LAN but that has run ok for months. The only unusual thing is my AM radio(s) are just total noise.
BT speed tests as follows and DMT attached
Many thanks. Rob

31-05-10 13.30pm
Test1 comprises of Best Effort Test:  -provides background information.
Download  Speed
2339 Kbps

0 Kbps 7150 Kbps
Max Achievable Speed
Download speedachieved during the test was - 2339 Kbps
For your connection, the acceptable range of speeds is 600-7150 Kbps.
Additional Information:
Your DSL Connection Rate :3264 Kbps(DOWN-STREAM), 448 Kbps(UP-STREAM)
IP Profile for your line is - 2500 Kbps

22,23pm

Test1 comprises of Best Effort Test:  -provides background information.
Download  Speed
2328 Kbps

0 Kbps 7150 Kbps
Max Achievable Speed
Download speedachieved during the test was - 2328 Kbps
For your connection, the acceptable range of speeds is 600-7150 Kbps.
Additional Information:
Your DSL Connection Rate :3776 Kbps(DOWN-STREAM), 448 Kbps(UP-STREAM)
IP Profile for your line is - 2500 Kbps


01-06-10 08-15am

Download  Speed
2149 Kbps

0 Kbps 7150 Kbps
Max Achievable Speed
Download speedachieved during the test was - 2149 Kbps
For your connection, the acceptable range of speeds is 600-7150 Kbps.
Additional Information:
Your DSL Connection Rate :3808 Kbps(DOWN-STREAM), 448 Kbps(UP-STREAM)
IP Profile for your line is - 2500 Kbps
netgear stats
Port   Status   TxPkts   RxPkts   Collisions   Tx B/s   Rx B/s   Up Time
WAN PPPoA 4802 5979 0 185 1137 01:21:57
LAN 10M/100M 36810 58485 0 1726 14197 01:22:30
WLAN 11M/54M 54625 29201 0 14013 449 01:22:25
ADSL Link Downstream Upstream
Connection Speed 3360 kbps 448 kbps
Line Attenuation 25.0 db 14.5 db
Noise Margin 12.3 db 23.0 db

[#2]

Quote

The only unusual thing is my AM radio(s) are just total noise.

Not quite sure what you mean by that ?
The bit loading graph is not good for a 25db attenuation line.

[#3]

Thanks Mr.W- regarding the radio when I turn it on to medium wave (AM) it is just very load, total interference throughout the whole spectrum. Tested with 2 radios, both on internal aerials. They were ok Friday, to my certain knowledge. I was wondering if there was a link between the loss of connection and  low resync and the interferance- some sort of REIN problem. My connection previously was 8128, with an snr of 6.8/7.2 and low errors. all was fine. I would eboot the router every 10 dys or so and had no problem getting the 8128 sync.
Rob

[#4]

Quote from: worcswizzard

I was wondering if there was a link between the loss of connection and  low resync and the interferance- some sort of REIN problem.

Very likely.
Try to "go walkabout" and rotate the radio/antenna to see if you can pin it down.

[#5]

If the radio is battery operated try turning house mains off, this will show whether interference is generated in the house or from neighbours.

[#6]

Thanks Hary and HP- same radio problem directly outside my flats with car radio, but not as I move away. Returns as I drive past. Comes directly from ny building!!! Enquired with neighbors. Radio ok in one but directly above me has phone problem and their sky is down. Engineers here at mo. We will see.
Cheers, Rob
update. radio back but snr up ( see attached)

[#7]

Hi all (again) It would seem that my neighbours sky was causing the problem :-\. just have to build my sync back up now. We will see
Rob

[#8]

Be interesting to see if the default noise margin has been affected.
I assume you have rebooted your router

[#9]

Quote

Hi all (again) It would seem that my neighbours sky was causing the problem

Any chance of posting another DMT screenshot so we can take a look at the Bit loading plot now its sorted...

[#10]

Hi Jim- I've not rebooted the router but used the netgear to force the snr. Its now at 12.4 with a sync of 7648 (dmt attached).
I deceided to leave it for now and reboot the router tomorrow and see if BT raise my profile. What do you think?
Rob
Mr.W .DMT attached after forcing. This is how its been for months. Yonks ago one of your regular posters (anotherone?) helped me get my sync up and remarked that I had BBc transmitter nearby (Droitwich) How did he know that?
Rob

[#11]

Using DMT has the same result - a resync with the exchange. I am surprised you could only force it down to 12dB - normally you can push it down 6dB and with the normal max default noise margin of 15dB that would get you down to 9dB and full speed.
First  - your IP profile will take about 3 days to improve
Second - the default noise margin will take several weeks to reduce.
If the default noise margin is indeed 18dB it might be worth asking for a retrain

[#12]

Hi Jim- not very experienced with this forcing. I was a bit tentative.I only went 50%. Usually I have 6.8/7.2 . Just tried again with same result (see attached) My interleaving is usually 64 down and 4 up.
OK. Just clicked the radio button at the top (ADSL mode) toADSLv1 and re-forced.  I'd not clicked those before. SNR now low 9s, interleaving at 64/4.
Piccies attached
Rob

[#13]

As you can get full speed you could let the automatic systems sort themselves out
Interleaving was put on because of the fault and you would need to request that it be removed so that you can get back to 8128kbps

[#14]

Cheers Jim- that's what I'd decided. A question, though, about the interleaving. Previously I used to get 8128 with the interleaving at 64/4 so I'm a bit confunded. Are you saying it should be lower? or not at all?
I'd be interested to know,as well, what would have happened if I had not been a radio user though. Would there have been anyway of discovering the answer to my loss of sync.
many thanks for the assistence of the forum'
Rob

[#15]

Personally I wouldn't force it as much, if at all - certainly not for a few days.
Give BT's system something to notice, react to and correct. 
Then once it's heading in the right direction ask for interleaving to be turned off.