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Low SNR figure since upgrade to MaxADSL?

hmburg52
Grafter
Posts: 35
Registered: 11-08-2007

Low SNR figure since upgrade to MaxADSL?

I noticed last week that my connection dropped a couple of times, I checked the figures on my Draytek 2600 Plus and noticed the SRN was only 6-8db. It used to be mid 20's. I was told today I was upgraded to MaxADSL on the 14th June. My download speed test is just over 1Mb, used to be 1.7-1.8Mb ( was on the 2Mb service) While I understand speed variations for a while after the upgrade could the change affect the SNR figure? I'm concerned that with the low figure BT will limit my speed to less than it was before the change.
12 REPLIES
N/A

Low SNR figure since upgrade to MaxADSL?

Yes, Max is very sensitive to noise and so your SNR will reduce.
It sounds as though you are still in the training period, so you should see improved figures after a while.
It seems that BT starts everyone on the fastest their line can support, then starts increasing SNR, and possibly turning on interleaving, in order to get a stable connection.

I used to be on 1 mb/s but now I have a stable rate of 2.5 and my stats are terrible on max. 4.8 to 7 SNR and 62 attenuation. I dropped to under 900 kb/s at one point early on, and was disconnected every evening, but now, six weeks on, everything is stable and faster than ever before.
chymorva
Grafter
Posts: 275
Registered: 29-08-2007

Re: Low SNR figure since upgrade to MaxADSL?

Quote
While I understand speed variations for a while after the upgrade could the change affect the SNR figure?

Most definitely, yes.
MaxDSL works by increasing the speed of your line to the maximum stable rate. The faster the connection the lower the SNR becomes until the connection is lost. A minimum figure of approx 6dB is needed for a stable connection. Eventually MaxDSL will find the highest speed without losing connection (so either approx 6dB for SNR, or maximum line speed [8128 at the moment]).
It's rather like trying to listen to someone speaking - the faster they talk the quieter the surroundings need to be to be understood.
hmburg52
Grafter
Posts: 35
Registered: 11-08-2007

Low SNR figure since upgrade to MaxADSL?

Thanks for the help, I will see if I can improve the SNR by removing the ring wire or another faceplate.
namtab
Grafter
Posts: 50
Registered: 14-04-2007

Low SNR figure since upgrade to MaxADSL?

Hi, I have a SNR of 13 this has been stable for around 6 weeks but my speed has been set at 3mb, should BT not increase my speed and lower my SNR to the recomended min of 6 ? confused.
chymorva
Grafter
Posts: 275
Registered: 29-08-2007

Low SNR figure since upgrade to MaxADSL?

@ hmburg52:
No problem. Let us know how you get on with the removal of the ring wire.

@ stainer:
Hi,
When you say your speed has been set at 3Mb, is that the sync speed or a speed test result ?
namtab
Grafter
Posts: 50
Registered: 14-04-2007

Low SNR figure since upgrade to MaxADSL?

Hi chymorva, my sinc speed is 3700,the 3000 is the speed set by p/net,
https://portal.plus.net/my.html?action=stable_rate
hmburg52
Grafter
Posts: 35
Registered: 11-08-2007

Low SNR figure since upgrade to MaxADSL?

ok, took the faceplate off what I thought was the master socket in my study upstairs and found the phone extensions downstairs still worked! When tracing BT wiring back it turns out the bloke who came in Feb who was meant to move the master socket upstairs didn't, just fed an extension! I didn't realise at the time as I hadn't even moved in then and assumed he had done the neccessary. Back to BT! Why can't people do what you askHuh!
N/A

Re: Low SNR figure since upgrade to MaxADSL?

Quote
I noticed last week that my connection dropped a couple of times, I checked the figures on my Draytek 2600 Plus and noticed the SRN was only 6-8db.

I had the same issue when my line was upgraded, SNR went from high 20's to 6-9dB although I had no stability problems.

However, as VOIP seemed to be becoming more prominent I I wanted to try it and and upgraded my Draytek 2600's to 2800V's about 5 weeks ago and my SNR jumped up to 13dB and has remained at this rate (+/-0.5dB) since then.

Might be worth trying another router if you have one or can borrow one from somewhere.

Just out of interest, how much do BT charge to move a master socket, I'm wanting mine moved?
hmburg52
Grafter
Posts: 35
Registered: 11-08-2007

Low SNR figure since upgrade to MaxADSL?

They charged me about £80 to ( supposedly ) move the master socket and reconnect 2 extension points to it. Spoke to BT today, got a very polite and helpful chap and he has arranged an engineers visit for tomorrow so see what he says. I dont think they will try and charge me again as I made a point about paying for work to be done and it wasn't!
hmburg52
Grafter
Posts: 35
Registered: 11-08-2007

Low SNR figure since upgrade to MaxADSL?

ok, had the chap from BT and the sockets are now wired correctly. SNR has improved a bit, from 6-7Db to 8-9Db. Did 2 speed tests today, at 1.00pm I got 3147.1 but at 10.00pm it has dropped to 2051.3. When I get time I will take the faceplate off the box and try the router in the test socket, if this makes an improvement I'll get an ADSL faceplate.
N/A

Low SNR figure since upgrade to MaxADSL?

Hey guys

dumb question SNR is that the same as noise margin? if so mine is 15.1/22db down/upstream and line attenuation 30/15db down upstream. My connection speeds are 8096/372. Can anyone enlighten me whether that is good or bad.

Thanks
N/A

Low SNR figure since upgrade to MaxADSL?

Looks good, jalopeno.

You should get fairly fast speeds with that, and your router is syncing at the max for download. Attenuation isn't bad, and it doesn't matter as much with Max as with fixed speed products.