Posted Stats and Noise Margin

These stats are from last night after putting v6.1.4.3 firmware on my Speedtouch which resolved the incorrect modulation issue on my line.

How do these stats look?

Link Information

Uptime: 1 day, 1:22:33
Modulation: G.992.1 Annex A
Bandwidth (Up/Down) [kbps/kbps]: 448 / 1,600
Data Transferred (Sent/Received) [MB/MB]: 34.89 / 327.78
Output Power (Up/Down) [dBm]: 11.5 / 16.5
Line Attenuation (Up/Down) [dB]: 31.5 / 63.5
SN Margin (Up/Down) [dB]: 6.0 / 12.0
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): 0 / 0
FEC Errors (Up/Down): 32 / 2,020
CRC Errors (Up/Down): 2 / 89
HEC Errors (Up/Down): 2 / 83

Snapshot of SNR

Today I've used the DMT Tool to cause a decrease in target SNR Margin and achieved a sync of 1856kbps.

I guess the acid test will be tonight when the noise on the line increases?

Regards

Looking good, although the power is a bit low.

What did you reduce the SNR Margin to?

Just a couple of clicks on the scale. Currently SNR Margin is 10.5dB. Just seen a big spike down to 7.5dB at 12:34 though.

Something switched on or off? 6dB is probably the lowest

Just about the time I was switching HiFi/DAB radio on so quite possibly. tx

Ah ok.

Sorry I wasn't too clear - 6dB is probably the lowest standard Target margin you can set to achieve the best speed without too many disconnections.

BTW raised my target SNR from 6-9-12db during the recent 10 day training period. What I don't know is whether this was due to too many errors or multiple resyncs. I was monitoring the link during that period and didn't see multiple resyncs or millions of errors, so none the wiser there really, actually the stats looked quite good. Trouble is I gather the link will have to be *very* stable for quite a lengthy period before DLM will drop the target SNR back down again without manual intervention, hence using DMT tool. If I can get some data that suggests that the link will survive a drop in target SNR then I'll badger my ISP to move it down again.

Does this make sense?

Ah yes, BT's profiling nightmare. Be aware if you lower the margin too much, BT will put you on a banded profile from which you may never recover.

I'm only going down a small amount at a time and will monitor performance to see if errors/instability start to appear. I'm *hoping* that a combination of past line faults, an exchange fault and crashy router were responsible for all my problems in the past.

As I think I said in my previous posts, my neighbour gets a very good link (for a not/slow spot) and up until May last year my sync was 2048 and bRAS 1750 - I managed a throughput of 1600ish according to the speed tests, which I was quite happy with. Then the line problems started...

I have a contact at BT (a customer services manager), who has promised to put his best BB engineer on it if I log another fault with my ISP (if problems continue).

Regards