Tweaking SNR

Does anyone know whether manually tweaking the SNR on the router stops BT's DLM from automatically reducing it after the two week period of stability?

In theory the best way to get your Target SNR reduced automatically is to run your line with as few errors as possible. So if tweaking your SNR to lower your target means your line's error counts rise it could affect things.

That makes sense. You'll need to help me out here then. How do I check my errors? I'm using a DG834G v4 with DGTeam firmware.

Cheers

In reply to a post by dicko1975:

Does anyone know whether manually tweaking the SNR on the router stops BT's DLM from automatically reducing it after the two week period of stability?

The easiest way to do that would be to get your ISP to get BT to lock the SNR margin - this can be done.

I can recommend RouterStats

It seems most ISPs have trouble getting BT to reduce Target SNR never mind locking/pinning it!

So many people may struggle with this...

OK. I'll have a look this evening. I've used RouterStats Lite to monitor my DS noise margin when I had trouble with the line. That's all sorted now, so I just want to see if the target SNR should be down to 6db, rather than the 12db it currently wants to be at. Got it tweaked down 9db at the mo, and never seen it dip below 8.3db. From memory current downstream stats are : -

DS att 63.5db
DS sync 1344kbps
DS noise margin 9db

OK. I've gone into the advanced diagnostics on my DG834G, and found the following: -

Total time = 6 hours 32 min 27 sec
SF = 1377822
CRC = 7866
LOS = 0
LOF = 0
ES = 759

For some reason, the router rebooted itself around midday. Had been up for almost 400 hours last night.

Is 7866 CRC errors good or bad in 6.5 hours?

In reply to a post by dicko1975:

Does anyone know whether manually tweaking the SNR on the router stops BT's DLM from automatically reducing it after the two week period of stability?

I can tell you that many moons ago a duff router resulted in my target margin being raised. By the time I realised and got a better (and tweakable) router my target margin rose to 12dB. I manually tweaked it back to 6dB and as it happens my line was a natural 8Mbps @ 6dB margin so I just left the tweak in place. Much later I wanted to try a later firmware which did not support tweaking and found that the BT system had reverted to a 6dB target.

The way I think tweaking worked for me (DMT on a 585) was to reduce the target margin rather set a value so assuming your line isn't a convenient 8Mbps @ 6dB as mine was you'd need to check it regularly so that you didn't over compensate and get problems.