SNR keeps dropping

[paulm34]

A strange thing happened this weekend my sync rate went from 4200kbps up to 6800kbps:confused: when i rebooted my router (st585 v6) .My SNR margin has been about 9dB for a month now but after this strange speed it is got as low as 2dB and has dissconected a few times. I used the DMT tool to get my SNR back to 6/7dB but its now back on 4dB. BT put my SNR up when i was with Aquiss to stop my dissconection (12dB) So why has it dropped so low please help this is very strange:rolleyes: , Thankyou:)

Here my stats(has my interleave been switched off as i have alot of errors)

Uptime: 0 days, 2:10:35

Modulation: G.992.1 Annex A

Bandwidth (Up/Down) [kbps/kbps]: 448 / 5,280

Data Transferred (Sent/Received) [MB/MB]: 35.71 / 835.06

Output Power (Up/Down) [dBm]: 11.5 / 19.5

Line Attenuation (Up/Down) [dB]: 28.0 / 47.0

SN Margin (Up/Down) [dB]: 19.0 / 4.0

Vendor ID (Local/Remote): TMMB / 

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): 834 / 0

FEC Errors (Up/Down): 4 / 20,913,984

CRC Errors (Up/Down): 0 / 9,940

HEC Errors (Up/Down): 0 / 8,289

[Ircsum]

One possibility is that, after a period of stable synch for a couple of weeks, DLM has dropped your target SNR by 3 dB, so you synch at a higher speed. This gets you back to the situation you were in before BT raised the target - instability.

Sounds like your line may be subject to big fluctuations in SNR - noise, from whatever source. So, if the target SNR is set high, the line can cope with those big fluctuations. If the target is too low then the drop in SNR is too much to maintain the connection and you disconnect. It's all a matter of balance, really.

If the disconnections happen during darkness, look to AM radio interference, street lights, your plasma T.V., etc. You didn't say if your line is overground or underground......if it's strung on poles you're much more liable to get noise interference, with a drop in SNR, than if it's underground. Have you disconnected the ring wire in all sockets?

Interleaving is ON at present, hence the FEC errors...this is nothing to worry too much about, just interleaving doing its job. The other error rates are high for the relatively short uptime, though. The lower the SNR the more errors you'll see.

Ircsum.

[paulm34]

Thanks for reply it has settled down a bit its now on 5556kbps and my snr is on 7dB. But i have had 2 down links in my router saved logs since last night. My ring wire is dissconected to all sockets. I had this trouble with Aquiss after the bad storms in the first part of the year. But my line was tested a few times with BT as my sync dropped into the 2000kbps But they ended up putting my snr up to stop the frequent dissconections which lowered my sync. My line is on a poles and i did loads of tests with Aquiss on my wiring eg master socket test but it made no difference. Bt are not really bothered unless you have no connection maybe its a loose connection somewhere to the exchange:rolleyes: