High SNR Margin

W00dy

W00dy

W00dy

Associate
Joined
17 Nov 2003
Posts
1,586
Location
Beside the Seaside !
Just got hold of a D-Link 624 router as a replacement to the Home Hub.

Got a rock solid connection now with no line drops but only connected at 576kbps (IP Profile set at :500)

My SNR Margin is very high - up and down is both 30, with Line Attenuation at 31/47.

Any ideas how I can reduce the SNR Margin which would increase speed?

Or does the ISP have to set the SNR Margin? If so, will they adjust it automatically ( I, for my sins, are with BT :o )

Thanks
 
What is your upstream sync?

That SNR is way too high even for the maximum target setting.

It looks more likely to me that you have a capped profile intended to emulate a fixed speed 512Kb line.

If that is the case then your upload will be set lower than max as well.
 
Yep upload speed was set at 288kbps, so slower.

I say was because this morning woke up to find no ADSL sync at all :mad:

I have now tried 2 routers, 3 filters and changed the cabling numerous times - do you think I have now elinimated everything bar a line fault?

I suppose it better have a stiff drink before calling the BT Help Desk tonight - I just hope they dont tell me to clear out my cookies again :mad:
 
Your SNr is excellent your Att is somewhat higher. However, you should on adsl max be hitting something above 4000 with a good router such as the Speedtouch 780WL or bretheren with Broadcom chipset
Something aint cosher if you aint getting something much more realistic check with your ISP they are doing or indeed not doing! With the 780 on an SNR of 6 and Att of 42 I am hitting 8000 down/768 up (ukonline)
Your best if not only option to improve your figures is to use a filtered face plate ( I have the competitor £12 excellent) on the master socket and run a sheilded adsl cable to your modem
This site gives some good info:
http://www.kitz.co.uk/adsl/maxdsl.htm
The SNR changes during the day and usually increses negatively during the evening (it goes down) The Attenuation stays much the same.
 
Thanks for the info Marmalade.

I am already bypassing any wiring issues as I am plugged directly into the test socket :(

The SNR Margin did drop during the evening from 30 to 19 at about 11.00pm when I logged off last night. I can only assume the SNR margin dropped too low and hasn't recovered.

Hope BT can sort this thing out it is driving me nuts :(
 
Given those figures you are definately on a capped profile which means that all the usual automatic controls that will increase your sync while reducing the SNR to a target (usually 6dB) are turned off.

In theory the capped profile is used to stabilise a line that otherwise wouldn't be usable but given your stats that doesn't look likely.

Complain long and loud till this gets fixed.

If anyone tries to tell you that 'this is all your line can support' then insist on being escalated to a higher authority as your stats don't suggest that at all.
 
OK thanks for the advice will get on to BT - hope the Call Centre staff are a bit more switched on this time.
 
W00dy said:
Yep upload speed was set at 288kbps, so slower.
Click to expand...

You are not on a adsl max service, the 576 down and 288 up is the classic 512k service, not adsl max. If it was max you should see 448kbps upload and a lot higher download. Need to get onto bt about that, probably wont get much sense from the indian call center but the higher teir support should get it sorted.
 
That isn't strictly true any more.

A while ago BT added the ability to mimic the old fixed rate profiles on the Max product.

If, as seems likely from what has been posted, the BT Speed Tester is showing a 500Kb profile and you have 288kb upload speed then he is on a capped profile.

I'll link the BT documentation here shortly.

Edit: go to http://www.sinet.bt.com/ and navigate to Sin 386 then read page 6 and 7.
 
Last edited:
Thanks Teal mate for taking the trouble to post that link - very interesting.

I have just got off the phone to BT India - I am sorry to say they are next to useless - asked me AGAIN to delete cookies :mad: god that makes my blood boil.

Anyway no-one had a clue what I was going on about so it is being escalated to the fault team :rolleyes: also they are switching interleaving off to see if it improves the speed.

I wait with baited breath.

If I wanted to cancel BT could I get out of the contract, as I have only been with them for 6 grief-ridden weeks, and haven't had a decent connection yet :confused: :(
 
Nothing is going to improve until someone accepts your profile is capped and that needs to be raised with BTW as your line stats simply don't justify that.

Hopefully the fault team will spot what has happened and do something about it.

If you do not get a good response within a couple of days I'd be inclined to start talking about cancelling on the basis of failure to deliver the service you should expect to get as you did not order a 512Kb connection I presume :)

Expect to be told the service is 'up to 8Mb' and that speed is not guaranteed etc. so you will have to argue the point again that the line has been set up incorrectly for your current line stats.

Without knowing the history of your problems I can't be certain, but if the Home Hub was faulty it is entirely possible that they frequent line drops and instability has convinced the BTW systems that your line quality is very poor, hence the capped profile.

The trick is getting it looked at again now the router has been changed.
 
Nice link but if w00dy upgraded to option 3 or similar from a 512k package there is a chance that he still had the ipstream service. Either way its a hard one to get fixed, try emailing [email protected] explaining your problem and asking for them to sort it.

You can also get out of contract pretty easy by emailing them, also mention the appauling speeds!
 
Agreed, it was this bit though that led me to the capped profile conclusion -

Got a rock solid connection now with no line drops but only connected at 576kbps (IP Profile set at :500)
Click to expand...

You wouldn't see a profile on a non-Max line.

If that didn't come from the BT Speedtester though I'd agree it could just be an old standard fixed product.
 
Just a quick update.

BT have ran tests for the past several days and cannot get Max stable anywhere substantially over 512kbps, so are going to leave me on a fixed IP profile, of 576kbps up and 288kbps down. :(

Attenuation is OK where I am (47) and my friend 150m away can get 2mbps, so I am at a loss as to the speed difference. :(

At least the line is now stable and doesn't disconnect.

Thanks again for all your help :)
 
With a 30dB SNR margin at 512kbps? Are they smoking something?

They're fobbing you off - at the very minimum, it should do the same 512kbps you've already got...
 
You must log in or register to reply here.
Back
Top Bottom