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[guest]

I'm afraid I disagree kitz - as you know I have local noise "issues" at night so I've been here and tweaked that SRA means I don't have to now but I spent a LONG time getting this "just right" on Be.

I would initially set it to 9dB and see what speed that gives. I would do this at night as that's when the worst of the noise is likely to occur. If it results in too much of a drop in speed then take it down to about 7.5dB. The aim (IMHO) is to set a margin that is as fast and as stable as possible and you can only do this when noise is at its worst. As I understand it, if the line does not resync (other than when modem/router is turned off) then DLM should never come into play? If that is correct then setting the noise margin high and then tweaking it down under worst case scenarios is the way to go.

I'm more than willing to be corrected on this as I have no experience of BT's DLM systems.

Edit - eg on Be I regularly had a 9.5-10.5dB margin on downstream during the day which would fall to about 7dB at night. Swings and roundabouts really but most people aren't at home during the day so there's no "loss" of speed then anyway.

[PortyAL]

Hi Guys

Alot of what you are saying is a bit over my head, but I'll try to answer some of your questions. The disconnects now appear to be less frequent. There was one today between 3 and 4 pm. Up until then I had gone nearly a day and a half without interruption. The previous 2 disconnects took place sometime during the night on consecutive days. My line stats after I connected this afternoon are:

Line Rate 5312 Kbps 448 Kbps 
 Noise Margin 6.1 dB 21.0 dB 
 Line Attenuation 50.0 dB 30.5 dB 
 Output Power 19.6 dBm 12.0 dBm 
 K (number of bytes in DMT frame) 167 15 
 R (number of check bytes in RS code word) 0 0 
 S (RS code word size in DMT frame) 1 1 
 D (interleaver depth) 1 1 
 Super Frames 349811  349809   
 Super Frame Errors 650  0   
 RS Words 0  0   
 RS Correctable Errors 0  0   
 RS Uncorrectable Errors 0  0   
 HEC Errors 434  0   
 OCD Errors 9  0   
 LCD Errors 0  0   
 ES Errors 0  0 

As regards Plusnet, I did mention to them before Christmas re the higher sync rates and random disconnects, but I got a response saying that to wait 10 days due to line training. I have not contacted them since. My max download speed as per Plusnet is now 4500k which is much higher than it has ever been before.

Don't know what you mean by "DLM". If this does "kick in" how much do you think my speeds will reduce?

I suppose the DMT tool is worth a try as long as any changes can be undone. In any case I'm getting much higher speeds that I used to so a small decrease won't matter. Although I'm a bit apprehensive about fiddling with something I know nothing about 

If I can stop the disconnects during the night I'd be more than happy as I would sometimes schedule downloads for the "wee small hours".

Thanks again for your help and advice.

AL

[guest]

It's a bit late tonight (for me anyway as I have some odd stuff going on in the next day or so) to start sorting this but fear not for we're not going to leave you with a dodgy connection. The DMT tool is the antithesis of that

Kitz said earlier that you needed version 8 of the DMT tool so go to this link and read more :

http://www.kitz.co.uk/tute/voyager2100_DMT.htm

Please download the DMT tool and see if you can get it to connect. Please DON'T try tweaking yet as I'd like to see a screenshot of your stats as reported by the DMT tool. If you could take a screenshot every few hours between tonight and tomorrow around the same time  that would be SUPERB.

You seem to have a quite exceptionally good line now - in fact I don't think I've ever seen one better given how far you must be from the exchange. I know people who would almost kill for a line like that

Listen to kitz or Eric if they tell you to do something. For the love of gods do NOT do anything that might make BT look at your line for it can't get better in physical terms

Edit - your line is so good that when BT rollout ADSL2+ then you will get the full Annex M upload rate - 1.6Mbps up! Really. I suspect given the noise levels on your line that you'll get 10Mbps down too. Your stats are so remarkable that I'm suspecting the router isn't being entirely honest. I have my fingers crossed for you as you have a line that will actually increase the value of your home were you to sell it - I kid you not.

[PortyAL]

Please download the DMT tool and see if you can get it to connect. Please DON'T try tweaking yet as I'd like to see a screenshot of your stats as reported by the DMT tool. If you could take a screenshot every few hours between tonight and tomorrow around the same time  that would be SUPERB.

You seem to have a quite exceptionally good line now - in fact I don't think I've ever seen one better given how far you must be from the exchange. I know people who would almost kill for a line like that

I live about 1 - 1.5 miles from the exchange "as the crow flies". Please follow the link below for a screen shot from the DMT tool at 8.05pm this evening.

http://www.cassells.plus.com/01Jan08%208-00pm.jpg

Thanks

Edit: Stats at 22.45 now attached:



AL

[guest]

Can you post the stats this evening after running the line flat-out for an hour or so - assuming that doesn't kill your usage allowance. The reason is that I want to see how bad those error counts get and the only way to do that is to put heavy traffic load on the line.

kitz/Eric/Chris - can you remind me what the profile intervals are please? Eg - if sync drops below 5Mbps what does the profile do? I'd check myself but as kitz knows I have other things on my mind today

Back later.

[PortyAL]

Stats at 7.56 this morning. Connection has been up all night. Currently downloading via P2P.

AL

[kitz]

>> I'm afraid I disagree kitz - as you know I have local noise "issues" at night so I've been here and tweaked that  SRA means I don't have to now but I spent a LONG time getting this "just right" on Be.

You are probably right rizla.   
Because I didnt know how much the line drops and at what time, nor by how much it fluctuates - I think I was going to "see if at first" it could handle it and just to see if the larger SNR would be sufficient.
I was perhaps approaching it from another angle, I did wonder when typing it and probably by saying "starting" I didnt make it clear enough where I was coming from, nor why.

>> Alot of what you are saying is a bit over my head,

Dont worry about that AL - some of us just chucking ideas and thoughts around, some of it was just me "musing" since we dont have full access to what happening on your line and by how much it drops.

Just going to have a look now at all the stats you've kindly provided since last night - and then I'll type some more

[kitz]

Woahhhhhhhhh


Ive just been looking at the stats provided - and noticed the CRC errors slowly clocking up whilst downloading, which specifically then made me go look for this...

D (interleaver depth) 1 1

Interleave depth 1 = Fast path. ..   and DMT also shows that line as being on FAST!!!
  
Why on earth hasnt the DLM kicked in interleaving first in an attempt to stabilise that line?
PN by default also normally now request that Interleaving is applied on all new lines (with the option to opt out).  So why isnt interleaving on?
This goes back to the thought earlier about why the DLM hasnt already adjusted the target SNR.



---
AL

are you a gamer? Is latency (ping times) important to you? 
Have you  ever specifically requested Plusnet to get BT to turn Interleaving off?

[PortyAL]

AL

are you a gamer? Is latency (ping times) important to you? 
Have you  ever specifically requested Plusnet to get BT to turn Interleaving off?

Hi

The answer to all 3 questions is no. With 2 young children I haven't time to play online games!! I've heard of Interleaving but don't know what it is. I was happy enough with my speeds prior to BT disconnecting my line. It was more that ample for what I use broadband for, i.e. internet, e-mail and occasional P2P downloads. As stated earlier I would do most of my downloading overnight - therefore disconnects during that period are the most annoying. In saying that I was downloading last night and the connection stayed up. All in all I don't need lightning speed broadband, but now that it appears I have a better line than I used to it would be nice getting a faster stable speed.

Thanks

AL

[kitz]

Explanation of Interleaving

If your line is particularly susceptible to bursts of noise then interleaving should improve your adsl experience simply because if you lose a whole batch of data then this could cause your modem to loose sync with the exchange.

I cant help but wonder why the DLM process hasnt even attempted to put interleaving on your line, its normally one of the first things to kick in, I cant see any reason why it hasnt already been automatically turned on... hence me asking if you'd ever asked for it to be turned off.

Since you're not a gamer then you shouldnt notice any difference if interleaving is applied.  It will reduce the amount of CRC errors that are being racked up, and may help resolve the problem you are seeing.

Plusnet should be able to get BTw to put Interleaving on your line if you ask them

* kitz is still puzzled why it hasnt already kicked in.

[Azzaka]

There may be an exchange fault and hence the disconnections and the fact that interleaving has not been turned on. Something to look for when calling.

[chrisparr]

I've had a look through this thread and the first thing I'd suggest is to try interleaving on the line, I'd be more than happy to place this order manually from here if you want to try this.

The stats for your line look remarkably good for the length of line too.

Code: [Select]

Loop Loss 50
SNR Margin 7
Speed 5312
 

[PortyAL]

Thanks Chris.

Please go ahead and place the order for interleaving.

My Plusnet user name is "cassells". Do you require any additonal information?

Thanks

AL

[kitz]

tbh it looks to me like chris has perhaps already sussed out your account - although not sure how (not guilty).
Unless Im wrong, from his last post it looks like he's already performed an xdsl check (woosh test) on your line.

Good luck with the interleaving - lets see how that goes.
Fingers crossed it may do the trick.


---
Chris
- any idea why the DLM stuff doesnt appear to have kicked in on this line?

[chrisparr]

There was a post earlier in the thread linking to PN webspace I figured out the username from there.

I'll go place the interleaving order now, it should hopefully complete tomorrow morning.