Kitz Forum

Broadband Related => ADSL Issues => Topic started by: tickmike on November 17, 2006, 12:04:00 PM

Title: Tests I have been doing to try to get a better sync speed.
Post by: tickmike on November 17, 2006, 12:04:00 PM
Hi All.
I've just gone on Broadband (6 weeks ago) and because I did not know in time about turning off your router/modem to (hopefully) get a better sync speed during the 10 day training period.
My ISP has my speed set at 3424Kbps, So now my 10 days has gone, I'm trying a test were my router is turned off for *2 hours* in the 'wee small hours' every night. (with a time switch).

The results if I do not turn it off = 3424Kbps.
With router turned off each night = 4320 to 5540 Kbps

Although my exchange (3.5kl away ) is showing red I will have to wait until it's fixed to do any serious speed tests.

*2 hours* Do not turn off only for a few minutes because the exchange will think there is a fault and may drop your speed .

From Michael.
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: alanbo on November 24, 2006, 09:08:04 PM
I did not know in time about turning off your router/modem to (hopefully) get a better sync speed during the 10 day training period.

Hi Michael

What is the source of this advice to turn off the router regularly during training? I'm having trouble with a low BRAS profile, and also found this advice referred to here - http://www.upstreaminter.net/fm/viewtopic.php?t=724&sid=ca89e50c73ac757f7a9fe5111f2b7eeb - I can't find it on the Kitz site. My ISP and advice on other forums suggest the router should be left on 24/7, even if your'e away on holiday for 2 weeks.

Alan
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: kitz on November 24, 2006, 10:00:13 PM
Hi and welcome :)

I think youll find that several have us have discussed this in the forums several times.
My own personal advice is keep the router up and running for as long as possible.

However, there are some exceptions when I would recommend reboots..  and that is if you know your router can sync at higher speeds and are trying to increase your bRAS profile.  You do have to time the reboot carefully though to make sure you get a decent speed.  Mornings normally give you the best chance of syncing at a higher speed.
But there is a downside to that - sync at too high a speed in the morning, then you run the risk that in the evening when SNR margin falls, then your connection may drop out..  in which case you will resync at a lower speed... 
However it should then hopefully settle down and find its own level.

The original advice that came out was leave connected.. many ISPs still recommend this.
The reboot once a day theory first came from the BT video which you can download from the link at the top of this forum
http://forum.kitz.co.uk/index.php?topic=83.0


I certainly dont recall ever saying "turn OFF the router for 15 minutes a day during training".
Ive said in the past that turning off the router shouldnt do any harm if you leave it off overnight etc. 
Once thing I dont recommend is turning off the router too often.  Constantly turning the router on and off can fool the dslam into thinking that you are struggling to maintain sync and can have the adverse effect of decreasing your speeds.
If you are going to turn it off... then if possible leave it off for at least 15 mins to avoid this happening.

Hope that clarifies a few things :)


Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: tickmike on November 24, 2006, 11:22:31 PM
Hi Alan.
Being an Ex Scientist I like to try different things to get the best performance out of my 3.5Kl long line as I live in the 'sticks', so I read on another site that you could sometimes sync at (Hopefully) a higher speed if you disconnect and reconnect.
 
Note, I'm out of my 10 day line leaning time for the exchange when I did test tests.

My exchange was on Red so I will repeat the tests again soon and publish any results.

Regards Michael.
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: mr_chris on November 25, 2006, 01:47:10 AM
To be honest, I have seen suggestions to reboot your router once a day. However this is only likely to kick the data rate profile into updating faster. There's no magic that will actually increase the speed of your line beyond that which it syncs at.

Sync speed is all to do with the target SNR margin. This is set by default at 6dB which means at sync time, your modem and the DSLAM in the exchange will negotiate the best sync speed they can, whilst maintaining 6dB of SNR margin. Since SNR fluctuates during the day due to environmental changes, you may well find that the SNR is better in the morning, therefore you get a better sync speed when you turn your router on in the morning.

However during the day, your line may be such that the SNR drops so low that it forces a resync later in the day. Therefore you're not really gaining anything.

If you disconnect and reconnect too often, trying to get a better sync speed, this may flag up to BT that you've got an unstable line, and their DLM may push your SNR margin up, therefore making you sync slower than you used to, every time. It's hard (impossible?) to get BT to reset your target SNR margin back down to 6dB.
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: tickmike on November 25, 2006, 07:21:35 PM
Thanks for that explanation Chris....
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: alanbo on November 27, 2006, 01:22:57 PM
Hi Kitz, Michael and Chris

Thanks for your full replies to my post. I've been on Max ADSL with Newnet for over six months now, and have never had speeds above 2500, even though I have sync'ed at c.7000 for several days at at time before dropping to anywhere between 240 and 3200. Newnet advised me to buy a new router when I first went on Max. I had a 3-4 year old Linksys WAG54G. I bought a Netgear DG834G v.2, and now they are advising me to try a different router to eliminate that as an (unlikely) cause. However, I am unable to borrow a router so I may have to buy another one.

At the moment I have the Netgear plugged directly into an NTE5 ADSL faceplate. I am 393 metres from the exchange, Palmers Green N13, which is capable of 5.5-8Mbpsand whose VP status is red but was supposed to be upgraded on 22nd November. My noise margin downstream is 12db and upstream is 13db, attenuation down is 7db, up 1db, I am syncing at 2112, and getting actual speeds of c.130 (average of various speedtesters: bbmax, btspeedtester, giganews, adslguide). I've had visits from three BT engineers over the last six months but none of them can understand why I am not getting faster speeds, nor could a person at the exchange who was telephoned by the last engineer. The last engineer reported the fault as cleared because I was getting speeds of 7000 - this was wrong - I was sync'ing at 7000 but only getting speeds of 130.

Kitz,  I'm thinking of using your draft letter at http://forum.kitz.co.uk/index.php?topic=213.0 , but can you explain what the ECO system is and if I need to refer to it.

Thanks,

Alan
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: mr_chris on November 27, 2006, 01:30:17 PM
Quote
However, I am unable to borrow a router so I may have to buy another one

I believe Argos (http://www.argos.co.uk) has a 16 day money back guarantee ... ;)
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: kitz on November 27, 2006, 02:36:50 PM
Hi alan

Your line stats look good - very good. The sync speed just doesnt seem to match those stats. In particular the attenuation. I would expect you to be syncing at either 8128 or 7616 kbps

>> before dropping to anywhere between 240 and 3200.
It would be interesting to see if your line stats change any.

If youre syncing at 2112 then actual speeds of around 130 KB/Sec (1040 kbps) is possible on a RED exchange during peak. However, I would expect that speed to fluctuate and you at least see some decent speeds in the early hours when things should be less busy.  I suspect however that its actually your bRAS profile that is actually stopping you acheive the higher speeds.  Your bRAS profile will be limit your actual throughput speed regardless of your sync speed and continue to do so for several days. More info http://www.kitz.co.uk/adsl/maxdsl2.htm

Details how to check your bRAS (IP rate). http://www.kitz.co.uk/adsl/btwperformancetest.htm

Since you are already plugged into an  NTE5 faceplate, then the problem could be your router.. 
or probably some sort of interference which is causing low SNR Margin... in turn keeping your sync speed down.
In view of the fact that you can on occasions get 7000 syncs..  I would be more looking at seeing if there was a pattern to the lower sync speeds.
Does this occur at a particular time of day?  Does it co-incide with lights being turned on etc.
Theres many things that can cause electrical interference which could be causing your problem, and because of this possibly one of the hardest things to diagnose.

-------------

eCo (http://whitepapers.zdnet.com/casestudy.aspx?&scname=Transaction+Processing&sortby=comp&docid=86802) is BTs electronic ordering system, which the ISPs use to automatically make amendments to your adsl line such as upgrade your speed etc.

TBH that letter doesnt apply in your particular case - you are already on MAX and your line should easily be able to support the higher speeds, and it certainly wouldnt appear that the BT database is whats causing your problems.

Once youve eliminated the router being the cause then... I think the culprit is probably going to be "Noise" from interferance.
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: tickmike on November 27, 2006, 11:30:04 PM
Hi Alan .
If you have no one you could borrow a router from you could try what 'chris' said to get a good one from Argos and be careful how you unpack it, set it up and see what through put you get and if its the same then you know its not your router you can take it back to Argos !.
Try and do what 'Kitz' says about doing some readings (and what I try to do) is take readings from your router and do a 'Speedtest' and log them all (I use MS Excel ) then you can do a graph.

Did the BT chaps use there own PC and router/modem to do there test at your end ?

can you copy and paste your routers details on to this forum ?.

Is there anything in your routers log ?.

Is your router connected 24/7 ?.

Does your router re sync a lot ?.

Is there any noise on your phone or can you hear any other people in the back ground (cross talk).

From Michael.
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: alanbo on November 28, 2006, 11:33:33 AM
Did the BT chaps use there own PC and router/modem to do there test at your end ?

can you copy and paste your routers details on to this forum ?.

Is there anything in your routers log ?.

Is your router connected 24/7 ?.

Does your router re sync a lot ?.

Is there any noise on your phone or can you hear any other people in the back ground (cross talk).
BT used their own router and laptop with the same results. The router is a Netgear DG834G v.2. firmware v4.01.06, PPoA, wireless 54Mbps connection. There's nothing in the log that shows a problem - I've pasted the log at the end of this post. The router is on 24/7 usually, except this weekend I tried turning it off overnight as advised in the BT video, even though the line finished training months ago, supposedly. It usually only resync's a few times after rebooting - starts to sync at c.7000 and comes down to c.2000. There's no crosstalk on the phone. BT engineer checked this, and I wouldn't expect any with the router plugged into the faceplate and therefore isolated from the internal wiring - cordless phone base station is plugged into an internal extension.


bRAS (IP rate). http://www.kitz.co.uk/adsl/btwperformancetest.htm


Does this occur at a particular time of day?  Does it co-incide with lights being turned on etc.


Here are a couple of BRAS profiles from recent BT tests:

06.51 20061123
IP profile for your line is - 1500 kbps
DSL connection rate: 448 kbps(UP-STREAM) 2144 kbps(DOWN-STREAM)
Actual IP throughput achieved during the test was - 1291 kbps
08.55 20061126
IP profile for your line is - 135 kbps
DSL connection rate: 448 kbps(UP-STREAM) 7104 kbps(DOWN-STREAM)
Actual IP throughput achieved during the test was - 84 kbps

The sync rate and speed do not drop at any particular time of day. If I reboot the router, it will usually sync at c.7000 for a few days with speeds of no more than 2500, sync will then drop to c.3000, speed c.2500 for a few more days. Over the weekend it went right down - see second BRAS profile above, and this morning it's gone up to 2112, with speed c.1300, where it has in the past stayed for days, weeks at a time. Changes don't coincide with use of electrical equipment - at the moment the router is in a completely empty room (it's being redecorated) with no electrical equipment at all.

Once youve eliminated the router being the cause then... I think the culprit is probably going to be "Noise" from interferance.

Does this mean low SNR - currently 12db up and down? Does it mean interference on the phone line between the master socket and the exchange? Or does it mean interference from electrical equiment inside the house, which I thought has been eliminated. I managed to sync for months at 3200, speeds c.2500 with the router plugged into an extension socket beside the computer, and surrounded by a mass of mains and other wiring behind the computer desk.

Alan

Log from Sunday to today - I've deleted my IP address:

Sun, 2002-09-08 12:00:43 - Initialize LCP.
Sun, 2002-09-08 12:00:43 - LCP is allowed to come up.
Sun, 2002-09-08 12:00:51 - CHAP authentication success
Sun, 2002-09-08 12:00:54 - Send out NTP request to time-g.netgear.com
Sat, 2006-11-25 10:29:06 - Receive NTP Reply from time-g.netgear.com
Sat, 2006-11-25 10:31:01 - Administrator login successful - IP:
Sat, 2006-11-25 10:28:12 - Router start up
Sat, 2006-11-25 15:34:32 - Administrator login successful - IP:
Sat, 2006-11-25 17:22:49 - Administrator login successful - IP:
Sat, 2006-11-25 21:33:11 - Administrator login successful - IP:
Sun, 2006-11-26 08:46:23 - Administrator login successful - IP:
Sun, 2006-11-26 09:02:16 - Administrator login successful - IP:
Sun, 2006-11-26 09:02:34 - LCP down.
Sun, 2006-11-26 09:02:35 - Initialize LCP.
Sun, 2006-11-26 09:02:35 - LCP is allowed to come up.
Sun, 2006-11-26 09:02:41 - CHAP authentication success
Sun, 2006-11-26 09:05:56 - LCP down.
Sun, 2006-11-26 09:05:57 - Initialize LCP.
Sun, 2006-11-26 09:05:57 - LCP is allowed to come up.
Sun, 2006-11-26 09:06:01 - CHAP authentication success
Sun, 2006-11-26 09:07:50 - LCP down.
Sun, 2006-11-26 09:07:51 - Initialize LCP.
Sun, 2006-11-26 09:07:51 - LCP is allowed to come up.
Sun, 2006-11-26 09:07:57 - CHAP authentication success
Sun, 2006-11-26 09:14:58 - LCP down.
Sun, 2006-11-26 09:15:02 - Initialize LCP.
Sun, 2006-11-26 09:15:02 - LCP is allowed to come up.
Sun, 2006-11-26 09:15:06 - CHAP authentication success
Sun, 2006-11-26 09:18:14 - LCP down.
Sun, 2006-11-26 09:18:15 - Initialize LCP.
Sun, 2006-11-26 09:18:15 - LCP is allowed to come up.
Sun, 2006-11-26 09:18:20 - CHAP authentication success
Sun, 2006-11-26 11:32:19 - Administrator login successful - IP:
Sun, 2006-11-26 15:38:38 - LCP down.
Sun, 2006-11-26 15:38:39 - Initialize LCP.
Sun, 2006-11-26 15:38:39 - LCP is allowed to come up.
Sun, 2006-11-26 15:38:47 - CHAP authentication success
Sun, 2006-11-26 15:39:03 - Loss of synchronization :1
Sun, 2006-11-26 16:55:27 - Administrator login successful - IP:
Sun, 2006-11-26 23:08:58 - Administrator login successful - IP:
Mon, 2006-11-27 07:43:55 - Administrator login successful - IP:
Mon, 2006-11-27 12:43:46 - Administrator login successful - IP:
Mon, 2006-11-27 15:00:04 - Administrator login successful - IP:
Mon, 2006-11-27 15:00:54 - LCP down.
Mon, 2006-11-27 15:00:55 - Initialize LCP.
Mon, 2006-11-27 15:00:55 - LCP is allowed to come up.
Mon, 2006-11-27 15:01:01 - CHAP authentication success
Mon, 2006-11-27 15:08:02 - LCP down.
Mon, 2006-11-27 15:08:06 - Initialize LCP.
Mon, 2006-11-27 15:08:06 - LCP is allowed to come up.
Mon, 2006-11-27 15:08:10 - CHAP authentication success
Mon, 2006-11-27 15:08:18 - LCP down.
Mon, 2006-11-27 15:08:18 - Initialize LCP.
Mon, 2006-11-27 15:08:18 - LCP is allowed to come up.
Mon, 2006-11-27 15:08:23 - CHAP authentication success
Mon, 2006-11-27 23:00:21 - Administrator login successful - IP:
Tue, 2006-11-28 07:15:30 - Administrator login successful - IP:
Tue, 2006-11-28 08:29:06 - Send out NTP request to time-g.netgear.com
Tue, 2006-11-28 08:29:09 - Receive NTP Reply from time-g.netgear.com
Tue, 2006-11-28 09:23:38 - Administrator login successful - IP:
Tue, 2006-11-28 11:04:38 - Administrator login successful - IP:
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: kitz on November 28, 2006, 01:20:25 PM
>> The router is a Netgear DG834G v.2. firmware v4.01.06,

Something thats occured to me..  that Ive heard elsewhere...

Chris

Can you remember what it was that Peter and his dad were reporting to Netgear about a particular problem where they were saying that sync seemed to drop down over a period of time?


(Im hoping chris may remember more about this since iirc he has a Netgear DG834Gv2 and his memory is better than mine :D )


Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: alanbo on November 28, 2006, 01:40:51 PM
Thanks Kitz

Newnet have arranged for a 4th BT engineer to call - so any suggestions about what I should ask him and get him to check?

Alan
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: mr_chris on November 28, 2006, 02:13:30 PM
kitz, I'm not sure to be honest...

Peter's SNR bug on the netgear meant that over time, the SNR would deteriorate to the point whereby it would get so low as to force a resync. This isn't through quality of the line, just an apparent bug in the firmware.

So yes, this might be related - who knows what's really going on inside the router. I'd seriously consider trying to get a different router or a modem on loan for a few days and trying it out to see. For instance, you can pick up voyager 105s on ebay (http://search.ebay.co.uk/search/search.dll?cgiurl=http%3A%2F%2Fcgi.ebay.co.uk%2Fws%2F&fkr=1&from=R8&satitle=voyager+105&category0=) for practically peanuts and see if that makes any difference.

You really need to eliminate your own equipment first, or else if BT find fault with your equipment, and the engineer's feeling particularly harsh, he may slap the ?50 charge onto Newnet, who will, I think, pass it onto you.
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: tickmike on November 28, 2006, 04:36:35 PM
Hi Alan.
Have you tried resetting your router to the 'factory default' setting by using the reset button, if not give that a try But make sure you have all your details to re-enter on the router again.
can you copy and paste the routers other details, 'dsl connection link information' eg.sync speed, errors etc.
From Michael.

Edit... have you upgraded the firmware to the latest one.?.  edit end
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: alanbo on November 28, 2006, 10:46:46 PM
Sorry all - it's v.3 of the DG834G I'm using, and the firmware is up to date according to the Netgear site.

I'l lleave resetting the router until BT have been on Thursday.

Attached file is further router stats.

Alan

[attachment deleted by admin]
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: tickmike on November 30, 2006, 02:14:39 PM
How did you get on with BT ?.
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: alanbo on November 30, 2006, 03:18:55 PM
Hi Michael

Here are the notes I submitted to Newnet Online Support:

notes on the BT engineer's visit:

1. BT engineer plugged his laptop and router into master socket - sync'ed at 190

2. When reconnected I sync'ed at 7200, speed 1300

3. BT engineer disconnected BT line and checked cables in a junction box outside the property then plugged his laptop and router into the junction box - sync'ed at 5500

4. When reconnected I sync'ed at 160, speed 130

5. BT engineer plugged his laptop and router into master socket - sync'ed at 6800

6. When reconnected I sync'ed at 6816, speed 130

7. Reconnected automatically at 7296 about 15 mins later

8. BT Performance test 11.56 20061130:

IP profile for your line is - 135 kbps
DSL connection rate: 448 kbps(UP-STREAM) 7296 kbps(DOWN-STREAM)
Actual IP throughput achieved during the test was - 86 kbps

9. BT speed test logged into speedtest@speedtest_domain

The speed test has completed on test server speedtester1.nat.bt.com for user [phone no removed by mod] and you have downloaded a 1.7Mb file at a speed of 129 kilo bits per second (Kbps), your service bandwidth will have been quoted to you in kilo bits per second.

Your IP address is **, your browser is reported as being Mozilla 5.0 and is running on Windows XP


10. BT engineer said these results were inconsistent and the connection was unstable. Said he would check exchange equipment. Said he could not ask exchange to reset the BRAS profile, Newnet would have to do that.

Rang back later to say that he had checked and replaced filters at the exchange and checked connections and there were no problems. Had tested my line from the exchange to the router and said it was capable of 7.2Mbps - i.e my current sync rate. He could not explain why my speed logged into the BT speed test domain was only 129, as above. He said the MSR was set at 2.8Mbps, but could not explain why it was not higher. He said that the line was not capped, but did not check this with anyone at the exchange, and said the profile was set automatically. He said he would have to refer these matters to the "IT people" at Broadband Control who would take it up with Newnet.

So I'm currently back to sync'ing at 7296 but having a speed of 130 again, having sync'ed stably for several days at 2112, and having a speed around 1300.


Since then I've resync'ed at 160, with speed about 90.

 :wall:  Alan
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: tickmike on November 30, 2006, 09:29:19 PM
Hi Alan .

First Edit your phone and IP Numbers out of the above post before you get spammed.!   ;)

Well it looks like its not your end, I think its about time you give your ISP 28 days to get it sorted and ask for your Mac code and go to another ISP.

I went from BT dial-up (9Kbps) to 'Eclipse' and they said I would be connected in 5 Days, it was 4 days only and I've had no problems at all with them, With my line being 3.5kl today the BT tester gave me 3.5Mb which is not bad, I found "Eclipse" very helpful (with help centre in the uk Not India ).
Dan Hall is my contact at 0800 915 5999    daniel.hall@kcom.com  and he's been very helpful.

From Michael.
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: kitz on November 30, 2006, 10:05:43 PM
Hi

The ISP cant reset the BRAS profile - unless its a stuck bRAS. 
The DLM at the exchange is in control of that, and unfortunately you have no option really but to wait for a stable connection for 3 days before it will increase again.
Even if it was reset, it would only take one poor sync and youd be back where you started.

>> He could not explain why my speed logged into the BT speed test domain was only 129,

The reason for that is because your IP profile (read bRAS) is set as 135 kbps.
Until you get a stable line for 3 full days of higher speeds then that isnt going to increase Im afraid.
I cant believe this is happening on a 7dB line - something is very wrong somewhere.


>>> He said the MSR was set at 2.8Mbps

Thats because during your 10 day training your lowest speed would have been somewhere around that mark.  TBH the MSR doesnt really mean too much in the day to day running of adsl.  That is the least of your worries right now and isnt anything to do with what you are seeing.

>> I'm currently back to sync'ing at 7296 but having a speed of 130 again, having sync'ed stably for several days at 2112, and having a speed around 1300.

Damn..  it would seem that the 160 sync today has immediately affected your bRAS profile and thats whats now limiting your speeds.. and will do for a few days.
Which is a shame because it was just creeping back up again.


>> replaced filters at the exchange

Good call by the engineer, although normally unlikely, it is a possible reason for your symptoms.
This isnt an ISP problem - its something wrong with your particular line, or a local noise problem.


If I were you and you are now syncing at 7296  Id do all I could to make sure that your router doesnt get switched off.
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: kitz on November 30, 2006, 09:09:25 PM
Quote
Since then I've resync'ed at 160, with speed about 90.

Sorry just seen that bit.

nooooooooooooooooooooooooooooo :wall:

Needs to go back to BT again :( :(

>> He said he would have to refer these matters to the "IT people" at Broadband Control

Needs further investigation..  its possibly something locally that is causing a huge burst of noise for it to vary so much between so good and so poor.
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: alanbo on November 30, 2006, 10:20:10 PM
Sorry about the phone number and the IP address - bad form - but I was too busy  :wall: . I was logged into speedtest@speedtest_domain at the time - doesn't that mean that my IP address wasn't my normal one, as I was logged in to a different server?

I think its about time you give your ISP 28 days to get it sorted and ask for your Mac code and go to another ISP.
Newnet seem to have been as frustrated by BT as I am. Their support centre is in England and over problems like this they phone you, which is a good personal touch.

The ISP cant reset the BRAS profile - unless its a stuck bRAS.
I meant the BT engineer can't ask BT to reset the profile, Newnet have to ask BT.

This isnt an ISP problem - its something wrong with your particular line, or a local noise problem ................. its possibly something locally that is causing a huge burst of noise for it to vary so much between so good and so poor.
- but I get good noise margin readings even at these low levels.

I rebooted the router a couple of times and it's now sync'ing at 6144, but speeds are still about 130, so presumably, Kitz, don't reboot while I've got this sync rate.

 :wall: Well I like playing squash. :wall:

Alan

PS - went down to 1344 a couple of  hours ago:

IP profile for your line is - 135 kbps
    DSL connection rate: 448 kbps(UP-STREAM)  1344 kbps(DOWN-STREAM)
    Actual IP throughput achieved during the test was - 99 kbps


Should I reboot?


Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: kitz on December 01, 2006, 01:24:05 AM
>> doesn't that mean that my IP address wasn't my normal one, as I was logged in to a different server?

Yep..  its a BT domain one irrc assigned by the BT RAS - and why I didnt bother removing it when I took your phone no out.


>> The ISP cant reset the BRAS profile - unless its a stuck bRAS.

Understood what you meant..  The ISP cant ask BT to reset the bRAS profile unless its stuck - the bRAS profile is dynamic and can change (as you are finding out) every time you sync at a different speed.
By the time it will have been processed.. it will have probably been changed by the DLM anyhow.
It takes the DLM 3 days for upwards and 75mins to go downwards.

>> but I get good SNR even at these low levels.

But how good is good?

The higher the speed you sync at the less your SNR is.
Each time you resync with MAX, the product is designed to run with a target SNR and a margin.
Depending on the target SNR set on your line (default is 6dB), then the DLM will always try and give you the highest sync speed it can whilst maintaining a margin.

Its a bit hard to explain.. but take for eg my own line

I also have a 7dB attenuation line which is close to the exchange.

Im currently syncing at 8128kbps with an SNR Margin of 14dB.

When I synced at 2272kbps my SNR Margin was 31dB
When I synced at 1152kbps my SNR Margin was 35dB
iirc when sync at 512kbps my SNR Margin was 39dB

My target Margin is (default) 6dB..  which means that on this line I have an additional 8dB to "play with" so if I wasnt restricted by 8128 being the max speed then the line would be able to handle even higher speeds.

However, for some reason your line is being problematic..  the DLM will have therefore increased your Target SNR to either 9, 12 or 15 dB.

At a guess your Target SNR is 12dB.. therefore every time you resync..  your router will negotiate the highest line speed it can whilst still having an SNR Margin in the region of 12dB.
This happens each time you (re)connect.

The SNR Margin will then be subject to variations once you are connected because thats what it is supposed to be - a safety margin. Once that margin drops too low then you loose connection.

Hope this makes sense.

Have a read of An explanation of SNR and SNR Margin
http://www.kitz.co.uk/adsl/linestats.htm

Roseway has also written some very good info here
http://forum.kitz.co.uk/index.php?topic=147.0
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: kitz on December 01, 2006, 12:31:28 AM
>> I rebooted the router a couple of times and it's now sync'ing at 6144, but speeds are still about 130, so presumably, Kitz, don't reboot while I've got this sync rate.

Yeah..  but looks like your line isnt playing ball, and its dropping out on its own accord.  >:(

~ High burst of noise..  and bam your connections gone.
~ Your router tries to resync
~ Noise is still there and the highest speed it can get for your target SNR is say 300 kbps.
~ DLM records that you can only sync at 300 and sets that on your profile

~ After a while the external noise stops..
~ and then your SNR Margin will show on your router as being high..
~ At this point you can reboot your router

~ It will stay like this until the next burst of noise.
~ Only thing is your IP profile has now been set to 300kb and this is going to be the highest throughput speed you can get from speedtesters. :(


Unfortunately because of the way the DLM sets the IP rate (3days up 75mins down) you are going to be continually stuck with a throughput speed based on your lowest sync speed.

You need an engineer to investigate what is causing so much noise on your line.
There is supposedly a trick you can do yourself and thats by using an old MW AM radio..  I dont know much about that Im afraid - that area is more in prof roseways realm. ;)

But the theory being that AM radio signals are on a similar frequency to adsl - infact AM radio signals are one of the culprits for a drop in SNR.  Ive known someone even report problems from what was coming from a taxi-radio.
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: tickmike on December 01, 2006, 02:10:45 PM
Alan, looking at your location, do you by any chance live near an electrified railway line ?.
Also do your neighbours have any problems with BB ?.
From Michael.
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: roseway on December 01, 2006, 03:54:42 PM
There is supposedly a trick you can do yourself and thats by using an old MW AM radio..  I dont know much about that Im afraid - that area is more in prof roseways realm. ;)
Flattered though I am, I don't think I can add much I'm afraid. :( It's certainly the case that medium wave radio signals propagate further during darkness, and this can be one of the causes of lower noise margins at night. But I don't think that this is likely to be the cause of such dramatic drops in sync speed. That sounds more like local electrical interference, such as you might get from an exercise treadmill. Have a quiet word with the neighbours perhaps?

Eric
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: alanbo on December 01, 2006, 08:38:56 PM
You need an engineer to investigate what is causing so much noise on your line.
Do you mean a 5th BT engineer, or somebody higher up the pecking order? The one who came last week reported back that "there was a problem with my equipment which had not been resolved". Newnet were going to give BT a roasting for this.

do you by any chance live near an electrified railway line ?.
The exchange is 393 m away as the crow flies and just the other side of the exchange from me there is a railway line with overhead electric gantries in a cutting.

Also do your neighbours have any problems with BB
I haven't asked them yet.

I haven't had time to digest all the arguments about noise yet, but it looks like I'm facing the weekend with a down speed of 130.  :no:

Alan
Title: Re: Tests I have been doing to try to get a better sync speed.
Post by: tickmike on December 02, 2006, 12:11:39 AM
Hi Alan.
I was a scientist with British Railways Research Dept.and one of the jobs we investigated was lots of Television interference (TVI)  with a group of house's near Cricklewood electrified railway line.
After spending Many hours setting up a on site monitoring lab,we did hours of recording because the residents had this problem for a long time and blamed the railway .
Well one day I decided to have a walk around the area and the first thing I came across was a small building with a aerial on it, It was a for pumping waste water and it was this the automatic monitoring equipment that sent information back to control centre  via a radio link that was interfering with all the televisions and not the railway.
Michael
But in your case the interference  ( across many frequencies ) from the overhead electrified lines could in theory cause problems with broadband signal, but it would not only affect you, it would affect a lot of people,ask about see if anyone else has problems near you, and I'm sure that BT would be aware of the problem but may not admit it.!.