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Author Topic: MY BT Broadband Struggles, help needed please.  (Read 4924 times)

JimmyW77

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MY BT Broadband Struggles, help needed please.
« on: April 14, 2011, 02:30:44 PM »

Hi All,

First post here, am after some advice, guidance and hopefully some info to help me tackle an issue with BT Broadband. When I speak to BT shortly I want to guarantee that I am providing them with enough information to get a satisfactory resolution. After reading through multiple forums a full-on approach seems necessary.
The basic details.
1.   BT BB option 2.
2.   Best sync speed (Downstream) 1834k (Monitored over 9 months, didn’t know about IP Profile or BRAS till about a month ago)
3.   Best recorded speedtester.bt.com overall result  over 9 months was 1456 kbps

Present results (I know the profile is low part of the issue I think and will come to that later)

Test1 comprises of Best Effort Test:  -provides background information.
   Download Speed
   446 Kbps
   

0 Kbps   500 Kbps
Max Achievable Speed

Download speed achieved during the test was - 446 Kbps
For your connection, the acceptable range of speeds  is 50-500 Kbps.
Additional Information:
Your DSL Connection Rate :1792 Kbps(DOWN-STREAM), 448 Kbps(UP-STREAM)
IP Profile for your line is - 500 Kbps

I’ll keep it short but will give some background. Over the last 9 months. The BT  Broadband Option 2 has been slow, intermittently slow speeds and just generally poorer than expected.
My expectations for this connection are for a connection of around 2 mb.  (Give or take the variations due to  Attn and SNR, length i am form the exchange etc) Think broadband has people only a couple of streets away with connections of around 6mb

I’ve had 1 visit form a BT engineer following a 2 week period of sub 500k speeds. Unfortunately I don’t know what my IP Profile was set to at that time as I have been on a learning experience trying to get to the bottom of it and didn’t know to look for that previously.  The sync speed was about 1700 kbps then though.
He replaced the main faceplate on the master socket  with an openreach one (has the inline filtering as far as I know). He had the line re-profiled and all was well for another couple of months.
My present  stats are  (Via the test socket)
ADSL Link   Downstream   Upstream
Connection Speed   1792 kbps   448 kbps
Line Attenuation   63.0 dB   31.5 dB
Noise Margin   12.5 dB   17.0 dB

I noticed that it was slowing again about 3 weeks ago and since then I have tried to be methodical in my troubleshooting.  (Knowing it can take 5 days for the IP Profile to stabilise)  I have done the following in this order:
1.   Reset the BT HH (It’s a HH1)
2.   Removed additional peripherals form the extension lines (Skybox and extensions)
3.   Swapped Microfilters on extension socket where router was seated
4.   Changed routers to a DGN2000
5.   Move it to the Test socket in the master socket.  New Microfilter (Up for 48 hours, will leave it up to hopefully improve the IP Profile, so probably still reprofiling that atm.)

They are all new D-Link Microfilters. These were changed at the last call out 2 months ago.

So after lots of reading in the last week on Kitz, SamKnows, digitalspy and the Openworld forums.  I have drawn these conclusions on my present connection stats.
My Line Attn is high. According to samknows, I am 1.69km from the exchange (as the crow flies). 

http://www.kitz.co.uk/adsl/max_speed_calc.php
With a line attenuation of 63.0 db that would have a cable length of 4.6km this seems crazy to me, is it possible that my cable length could be so long?  (I understand some give and take but that is nearly there and back again and then there again)
My SNRM seems low, should be at least 6 dB? Am I correct and have I worked that out correctly?
I’ve been running  RouterStats –lite for 2 days and have had a couple of drops, though the router has a 48 hour uptime after its most recent move (i.e. no physical connection drop according to the router).  My Speed has been  1792kbps (Via the test socked) Noise 12.8 dB constantly for both without the 2 drops. Which seem instantaneous.

So in conclusion can anyone point out where to start with BT? Are my expectations reasonable?  Theory seems to suggest I could get up to 4mb.  Dependant on copper quality etc.

Thanks in advance and I hope that that’s not too much info.  All suggestions welcome.
James
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Oranged

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Re: MY BT Broadband Struggles, help needed please.
« Reply #1 on: April 14, 2011, 04:35:30 PM »

Was the data (BT speedtest and router's stats) that you have posted taken from the test socket ?

If not then can you do that with no other item of telephony connected ?

Have you changed the ADSL lead from socket to router....it looks like you've changed everything else.
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roseway

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Re: MY BT Broadband Struggles, help needed please.
« Reply #2 on: April 14, 2011, 04:44:19 PM »

Hi James, and welcome.

If the new master socket faceplate is the type with two sockets on the front, one for the router and one for the telephone, then you should be able to forget about your extension wiring as a possible cause of the problem. The one proviso on this is that there shouldn't be any extensions wired directly into the back of the socket, they must be wired into the faceplate only. (I would hope that the BT engineer checked this.)

It's probably better to leave the Sky box unconnected, but if you do need it to be connected, then use a filter at the extension socket even though the extensions are already filtered by the master socket faceplate. Sky boxes are notorious for causing trouble, and double filtering is a good precaution.

If your line attenuation is reported as 63 dB, then it's most probably the case that your line takes a circuitous route to the exchange, or possibly includes aluminium cable. It's hard to think of a fault which would cause the attenuation to rise but remain stable. I'm afraid you're probably stuck with speeds not greater than 2Mbps, unless the line fails altogether and has to be changed.

If the connection is now stable at its present speed, it may be that there was previously a problem with your wiring that's been eliminated by the new faceplate and/or connecting to the master socket. Or there may be an intermittent fault with your line, or some intermittent high level interference. You need to continue to monitor it with Routerstats (-Lite) to see how it progresses.

Sorry if I haven't been very encouraging. Hopefully someone else will be along with some better ideas.

(I see Oranged has posted some ideas, but I'll send this anyway).
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JimmyW77

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Re: MY BT Broadband Struggles, help needed please.
« Reply #3 on: April 14, 2011, 05:20:34 PM »

Hi, thanks for the welcome.

@Oranged, yes that was via the test socket.

Yes that is also a new cable. Sorry forgot to mention that previously.

@roseway

Many thanks. I think BT call it a type 3 plate, it only has one socket but it is filtered.  I am goign to leave it the router connected via the test socket for at least a week, with as little down time as possible. I am really keen to see if the profile improves. I'll continue to monitor RSL and see what happens. SKY is staying dc'd - those boxes are the devils work.  I do find a couple of things worrying.

1. The intermittent nature of the speed decreases.
2. That there could be a cable run as long at 4.5km to an exchange that is 1.69 km away LoS, can i check the cable length (I think you used to be able to do this via 17070 but its now protected) 2mbps would be better if i can achive it. Am toying with the BT enginer visit for £90 or free if they can't eek 500k speed increase out of their visit, first things though is getting a stable connection.

Thanks again to you both for your quick responses. Much appreciated.

James

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jeffbb

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Re: MY BT Broadband Struggles, help needed please.
« Reply #4 on: April 14, 2011, 06:05:44 PM »

Hi
quote : Noise Margin   12.5 dB   17.0 dB

Your noise margin is higher than the ideal . Normally it should be around 6db . It seems that your line was unstable at sometime nad the so your target has been raised to 12db . That can cost up to 120kbps per 3db above the norm of 6db. That of course is dependant on bit loading .In your case with your attenuation ,with lower bit loading you could eventually get some improvement to your synch rate of say between 200 and 400Kbps . That is providing your line remains stable . One thing to remember is that you must NOT reboot too often .

Regards Jeff
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JimmyW77

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Re: MY BT Broadband Struggles, help needed please.
« Reply #5 on: April 14, 2011, 06:14:45 PM »

Thanks Jeff,

I have been very deliberate in my troubleshooting and have only rebooted when absolutley required. (I have a feeling as already mentioned that SKY HD box might be the noisey culprit) Thats been unplugged for sometime. I think BT reset the SNR over a 30 day period if what i have read elsewhere is correct? True?

1 or 2 roads/streets away - people are getting 4-6 mbps. That bothers me. But need a stable line first i guess as going LLU probably won't benefit me if its a line length thing, or am i mistaken?

Thanks again

James
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jeffbb

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Re: MY BT Broadband Struggles, help needed please.
« Reply #6 on: April 14, 2011, 07:16:10 PM »

Hi
quote I think BT reset the SNR over a 30 day period if what i have read elsewhere is correct? True?
its supposed to be every 14days but in practice Who knows ?.
Its not BT resetting its automatically done by the system(DLM) . I have been waiting for about 18 months to get back to 6db I am now at 9db from 15. There are all sorts of conditions on how the system decides on the easing of the target SNR .

very heavy information here  
see table 1 down the page
Regards Jeff
« Last Edit: April 14, 2011, 07:19:10 PM by jeffbb »
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jeffbb

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Re: MY BT Broadband Struggles, help needed please.
« Reply #7 on: April 14, 2011, 07:22:36 PM »

Hi again
quote : 1 or 2 roads/streets away - people are getting 4-6 mbps.
Their connection must be routed totally differently to yours . If you still connect to the same exchange using the same route then you will not benefit from LLU.
Regards Jeff
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JimmyW77

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Re: MY BT Broadband Struggles, help needed please.
« Reply #8 on: April 14, 2011, 07:45:22 PM »

Thanks Jeff, v.helpfull answers.

Its hard to draw firm conclusions. So good to get these answers. IMHO cable routing should be public access. To much resting on laurels.

I'll keep the forum updated of progress.

James
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JimmyW77

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Re: MY BT Broadband Struggles, help needed please.
« Reply #9 on: April 18, 2011, 06:55:09 PM »

Latests Speedtester results in.  (This was done peak time)

Test1 comprises of Best Effort Test:  -provides background information.

 Download  Speed
 1379 Kbps
   
0 Kbps 2000 Kbps
Max Achievable Speed

 Download speedachieved during the test was - 1379 Kbps
 For your connection, the acceptable range of speeds is 400-2000 Kbps.
 Additional Information:
 Your DSL Connection Rate :1792 Kbps(DOWN-STREAM), 448 Kbps(UP-STREAM)
 IP Profile for your line is - 1500 Kbps

At least the profile is reasonable now. I'll continue to monitor, though i still want to get my SNRM sorted. I need also to see what happens with my Line Attn at 63dB is to high i think. I'll hope that thats comes down soonish.  Thanks for the advice all!

 

James
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waltergmw

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Re: MY BT Broadband Struggles, help needed please.
« Reply #10 on: April 18, 2011, 11:29:47 PM »

Hi James,

Line attenuation usually remains nearly constant. Although this is over-simplifying it, you might perhaps think of it as a measurement of a sort of line resistance which varies with the signal frequency.
Furthermore there is a fair chance that your attenuation is higher than 63 dB as that is the maximum allowed within the ADSL specification, so is often limited to that figure by the modem firmware.
If you put 64 dB into the this link

http://www.kitz.co.uk/adsl/max_speed_calc.php

you will see it provides an accurate estimation of your line speed and it shows your line length as 4.6 km. Apart from the discrepancy you have observed nearby, it shouldn't be too much of a cause for concern. I am regularly dealing with lines of up to 8 km, but naturally at much slower speeds than you have.

I don't think you are likely to achieve much, but if you were to obtain a 2Wire 2700HGV modem from e-bay or amazon, you can connect it without entering your username and can obtain more accurate figures from its diagnostics page.
Even better if you have a friendly neighbour in the better performing area and can obtain comparison figures. However attempting to change cable routing is a very difficult task indeed. Every line is slightly different but the 2700 is known to perform marginally better than most other modems particularly on longer lines, but there's no absolute guarantee that would be so in your case.

Kind regards,
Walter
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JimmyW77

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Re: MY BT Broadband Struggles, help needed please.
« Reply #11 on: April 19, 2011, 11:19:03 AM »

Walter,

That’s great advice thanks a lot. I've got friends in  most parts of town so I will see if i can get some figures.

FTTC in September as well according to one of the engineers who visited. If i can achieve an IPProfile between 1500k and 2000k for the reaming 5 months then I'd be content enough (Mainly as the risk vs rewards and battling BT doesn't seem that feasible, as an aside, it is a rather frustrating situation)

Thanks again all, fingers crossed that things stay stable.

James
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