Kitz Forum
Broadband Related => ADSL Issues => Topic started by: Kai Robinson on February 15, 2011, 09:36:33 PM
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Hi :)
Now, i realise this may not be the best place for it - as i'm an ex-pat, and the DSL service i get from France Telecom isn't quite the same system that's used in the UK, but hopefully someone will be able to help.
I've had DSL since 2006, when ReADSL (reach extended) became available as an option. It's expensive for what it is - €39 a month for 512k.
Now, for years, the sync speed has been 605kbps down, 157kbps up, and has been reasonably stable, despite me being exactly 5522 metres from the exchange in the middle of nowhere!
Problem is - the line quality is so poor for even phone calls sometimes, the DSL connection drops out. After changing from the supplied Speedtouch 510 to a proper router in 2008, and again last year when that one got hit by lightning, things were far more stable, and the sync was no longer lost when it rained a bit.
Now though - the problems are back. I have a DLink DSL-2640b router, running the latest firmware (v4.0), and it's been fantastically stable & reliable, and theres a version of DMT that'll work with it.
My line attenuation is the main problem. Most of the time it'll be between 71 and 73dB (never seen it any lower). I'm not surprised by this as if i make a phone call, or if someone calls me, they can hear themselves, and i can hear myself. Hang up, ring back a few times, and the echo has gone. In phone calls, the person at the other end is either too hard to hear, or comes through like a megaphone - there's no consistency at all. Crackle, hiss and what sounds like someone tearing velcro on in the background, to the point where you can't even hear the dialtone.
Things are worse in the wet - i have a feeling that the junction box on the telegraph pole is to blame, and the poor quality 1970's copper wiring that's used to hook my house to the pole. There's too much slack in it, it's covered in moss, and the exterior insulation looks dubious...oh and the junction box is all verdigris and 'orrid looking.
I realise i'll NEVER get more than 605kbps with line attenuation that bad, so there are two things i'd like to be able to ask France Telecom & Orange to do:
1) Is it possible for them to re-do the line to my house from the pole with a better quality cable that's less susceptible to interference & noise?
2) Can Orange set the tx power to a fixed amount, such as 17.5/18dB - instead of it constantly skipping around?
3) Can Orange set my sync speed from the fixed maximum of 605kbps to a floating 'whatever you can sync at' speed - as the DMT screenshot below proves that i can sync at higher speeds on good days - sometimes well over 1.1mbps, and always more than 768kbps.
According to the details i've been given, the theoretical MAXIMUM attenuation for my line is 71.174dB, and it's an Alcatel DSLAM that was installed in '04 supporting ADSL2/2+ & ReADSL.
This is a shot of DMT when it was up and down like a yoyo, and the worst attenuation:
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fkai.supramania.com%2Fcrapdsl2.jpg&hash=4b63a180c3ea55ae458e3486795e31f556e5e7d3)
And here, after someone had called me for 30 minutes:
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fkai.supramania.com%2Fbetterdsl2.jpg&hash=800f7217ffb0c0a605ef261302cbb54f8299c797)
Thanks in advance! :)
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Welcome to the forum Kai :)
It sounds like you've got a line fault, report it as a vioce fault and get that sorted first, then see if fixing that helps the broadband at all, if not, report a bb fault. You could try asking to come off a fixed connection, it may help.
Second, I use a 2640B with v4.01 f/w, so I know it's a good bit of kit and holds onto sync down below 2dB (mine was down to 1.5dB t'other evening :) ) so that may help you if you can get on an up-to 8meg service.
Thirdly, your DMT graphs are only monitoring over a very short period, and at (currently) around the worst parts of the day. It would be more representative if you alter the scale of the graphs to monitor over a 8 or 12 hour period, and will give you a better idea of how the line's behaving ( I set mine for 8 hrs @ 25 sec intervals). Also worth checking that the router is set to autosense (for type of modulation) and for bitswapping. edit- just spotted bitswap is on, sorry
See how you get on and report back :)
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There's hope for you yet mate.
It does indeed sound like you have a massive 'HR Fault' (High resistance), which is basically the wire/wires corroding somewhere in the network. As a result of this, your attenuation is reporting at 70+dB. Believe me, on a line-length of 5.5Km you should not have such a high attenuation unless you are connected to the exchange by 0.1mm wet string !!!
Definitely get a fault raised and I'm sure you will see a far better attenuation and a chance to switch products to a faster speed. I too don't know what France have to offer in the way of DSL speeds.
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your attenuation is reporting at 70+dB. Believe me, on a line-length of 5.5Km you should not have such a high attenuation unless you are connected to the exchange by 0.1mm wet string !!!
The further from the exchange you live then the higher the line attenuation.At 5.5km from the exchange a line attenuation of 70db is not far off the mark.
http://www.kitz.co.uk/adsl/linestats.htm
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your attenuation is reporting at 70+dB. Believe me, on a line-length of 5.5Km you should not have such a high attenuation unless you are connected to the exchange by 0.1mm wet string !!!
The further from the exchange you live then the higher the line attenuation.At 5.5km from the exchange a line attenuation of 70db is not far off the mark.
http://www.kitz.co.uk/adsl/linestats.htm
Well I hate to be the bearer of good news, but I can assure you (as I've just poured over my Field Repair log Book) I did a job as recently as last Thursday where the EU was 5.2Km from the exchange. His attenuation was 57dB, his SNR was 6dB and his immediate synch speed was 4.3Meg.
Not only is attenuation dependant on "The further you live from the exchange", it depends on the cable make up and poundage (ie, Copper or Aluminium --- 0.32mm/0.4mm/0.5mm/0.62mm/0.9mm) and also the product being pumped down the line (ie, the frequency bandwidth).
I honestly believe that, from the OP's comments, that he has a 'HR' fault which is reporting a higher attenuation than should be, or, he is the victim of internal 'Star-wiring' or otherwise, inside the premises. I'm not sure if the OP has stated he's testing from the 'Test socket' or even whether the French have a similar Master Socket to ours. Either way, at 5.5Km his attenuation should be less than 71-73dB unless he's on really, really thin Ali cable.
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Hi
quote : 5.5Km his attenuation should be less than 71-73dB unless he's on really, really thin Ali cable.
Well you may be right BUT for I believe that the figures calculated here (http://www.kitz.co.uk/adsl/max_speed_calc.php) are based on "normal" cabling .
Regards Jeff
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I'm not trying to be 'holier than thou' on this, I just know that that 'calculator' doesn't befit all real-life scenario's. I just tapped in 70dB and it gave me a line length of 5.1Km. As I've stated on this thread, I've very recently had an EU on a 5.2Km length with an attenuation of just 57dB. Thats 14dB less than the calculator for 1/10th Km more in length ??
All the cable poundages quoted by myself (again on this thread) are classed as 'normal'. The only abnormality to it (if you can call it that), is that the 0.63mm and 0.9mm poundages are only really used on D-side networks. I do know of one PCP that has 0.9mm E-sides to it, but this is not the norm where I live and work. It may be more common-place in the Highlands and Lowlands of Scotland, or in parts of Wales, but not in a roughly 50-50 Urban-Rural split !!
I don't know anything at all of France Telecoms (or any other French SP's) cable network, or indeed how 'they' go about their faulting processess, but I can quite catagorically state that 71-73dB attenuation is quite high for a bog-standard 5.5Km cable run.
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No one is doubting you Razpag,but the example you have posted is quite exceptional and in most cases 4.3mb is not achievable on that length of line.
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Thank you Uncle ...... I'm only a quarter of my way into my latest 'Repair Book' and have no other examples near to (or above) the distance the OP has mentioned, that I can bring to this forum.
I will make a mental note though, to share with you whatever I find around that distance in future. My memory may not be what it was, but I'm sure the example I've quoted is more the norm, than not. :)
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There's certainly considerable variation, but it's always been my understanding that the average attenuation in the UK is about 14 dB per km, and it's much same in other comparable countries. But I'm always prepared to be proved wrong (it happens fairly often). :)
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Hi Roseway .... do you know what poundage cable those figures are calculated over please ??
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I've had a look around and can see where you get the 14dB/Km, just as I can also see other figures of 11dB/Km and 10 dB/Km quoted. Even as low as 8dB/Km !!!
http://www.manxforums.com/forums/index.php?/topic/32235-adsl2/page__st__410
http://forums.thinkbroadband.com/btsupplier/3920607-line-length.html?fpart=2&vc=1
I've had a look at the Cabinet details of the job I mentioned on this thread, and there is nothing out of the ordinary in the cable sizes. In fact to be exact, the cable from the exchange to the cabinet (E-side) was made up of 0.045Km (0.4Cu) and 4.506Km (0.5Cu) cable. I don't know what the D-side cable was made up of, but I'm 99.999% sure it wouldn't be anything over 0.5mm Cu/Al. As I say, I got 4.3Meg instant synch speed. I luckily have the good fortune to see how DSL performs in the real-world as opposed to looking at 'Graph averages'. As I've previously mooted, I shall keep you informed if I come across any jobs that 'stick out' in relation to attenuation-speed. :)
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Hi Roseway .... do you know what poundage cable those figures are calculated over please ??
No idea, I'm afraid. It's just a figure which has been in my mind for a long time, but because actual line lengths aren't generally published it's hard to be certain. My own line fits that figure perfectly (42 dB, 3 km) if I assume that the line follows the road, which seems very likely when I look at the topography.
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Hi
Quote : My own line fits that figure perfectly (42 dB, 3 km)
At 30db by any route (really only 2 probable ) actual distance between 2.18 and 2.27 KM.
Regards Jeff
edit also just about spot on
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Its all to do with how good the copper is
we have 3 main lines going into our village
I stay miles away from the exchange and should have about 60 aut
but i am on the best line of copper in my village and this is how it looks for me
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fimg691.imageshack.us%2Fimg691%2F4528%2Fdmt201102182047.png&hash=ca0eb4d638d4210712e8a7508ac38ca33f3f6a03)
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Hey everyone - apologies for taking soooo long in getting back to you, but talking to France Telecom and having them admit any kind of fault, is like pulling teeth. In the dark. With a spoon.
I had an engineer come out and confirm that the internal wiring was new, and worked flawlessly, and that the problem was with the external cabling to the house.
He then said; "The wiring from your house to the exchange, as well as the junction box on the telephone pole, needs to be completely replaced, it's manky."
Then after a day at the exchange, he fiddled with something, and voila - the connection got a bit better...for about a week.
Last week, the line got SO bad, you could barely hear a dial tone. I reported a line fault, and later on that day, got a call back from an engineer who said 'i can't be bothered to come out, you live in a strange place, i don't know where you are'. Then, i lost all phones and DSL completely. Literally, you picked up the phone, and all you could hear was something akin to an asthmatic breathing into the other end, and any incoming callers were deafened by static.
At this point, i was at the end of my wick, and drove 70km round trip to the France Telecom office in St. Malo to demand that my line get fixed.
This morning, a van with a cherry picker turned up, and started testing the line from my pole, to the village. I didnt speak to them, except to confirm that my name was the reportee on their docket. when i got back, my line had not been replaced to the phone pole, nor the junction box. However, the dialtone on the phone was crystal clear, and the Router had effectively thrown a fit at having sync, probably surprised at actually having something to do, other than sit on the desk and look fancy...
Turns out that the phone line from the exchange passes along the side of the road, and a few trees had overgrown, and were only being held up by the phone cable in certain stretches - the whole side of the road looks like it's been a tree massacre, branches and piles of sawdust, new phone poles (4 of them) and at least 4 sections of new cable.
Now, i'm still reporting high attenuation, but, the quality of the line is much better, better than it's been in 10 years.
See this picture for all the details, but that looks much better to me...reckon i could let them bump me onto the 1 meg service, for a 400kbps speed boost?
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fkai.supramania.com%2Ffixeddsl.jpg&hash=d3498aa29c30c6bf0b60436f22a21b60255966b0)
I know, blistering speed, yo.
Although having read your comments - why is my attenuation STILL so high? Most people are in the 30 to 55dB range from my exchange, if degrouptest.com is to be believed...
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The attenuation is directly related to the length of your line, i.e. the cable linking you to the exchange. You unfortunately have a very long line, and it's never going to get any shorter. I'm afraid that the best you can hope is that the present quality improvement remains in place.
Sorry not to sound more encouraging.
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looks like if they have a 2meg service, it may be worth a try.....you've got a couple of dB snrm to spare if you need to tweak it. Give it a go and see how you get on :)
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Hmm...wondering about how long it takes for the DSLAM to update the statistics, as the line tester at degrouptest says i can still only support a download speed of 451kbps O.o
I'm going back to St. Malo today, and want to ask them to shove me on the 1mbps service, but....they might refuse, and say 'your line doesn't support it' :/
Edit: I did a 60 minute test using DMT - looks pretty stable to me, compared to the one on page 1
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fkai.robinson.free.fr%2Fdropbox%2Ffixeddsl2.jpg&hash=5a49765b335921272eece08aaca556c76361be19)
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Heyo - just thought i'd stop in to update...seems like i counted my chickens before they hatched. Despite working almost flawlessly for months, since they chopped tree branches and put new telephone poles in, in the last week, the service has been erratic, patchy and downright infuriating, whenever i've been trying to get any work done, or talk to my Fiancee over Skype.
SNRM's are usually pretty high, but with the rotten weather, rain, high winds, the SNRM's will suddenly drop to from say....16db (on ReADSL Mode) or 11dB (ADSL2 Mode), to around half that value, and then recover a bit, then drop to 0, then disconnect, then reconnect at a low SNRM, only to disconnect again a few seconds later. Can take me a DAY to reconnect. I did report a line fault and they confirmed one existed...and all was stable for an afternoon, SNRM's barely wavered and i thought all was fixed.
Now, however, the problem has resurfaced, there's crackle on the line, the router can't make up its mind whether to bother trying to sync DSL at all - and these are with supposedly NEW lines (at least until the telegraph pole over the road (500m away). I'm in two minds right now - it's either a) all down to the weather being so miserable - in which case, why is RAIN and no wind affecting the line, unless there's a leaky junction box somewhere? or b) France Telecom are entirely incompetent and have screwed something up at the exchange...again.
The question i also wanted to ask, is this; My router can connect via different modes, t1.413, G.dmt, G.lite, ADSL2/2+ and Annex L (ReADSL) but...is there any way i can FORCE the exchange to connect via one of those methods? I have Annex L selected on the routers Advanced Settings page, as when it does connect, by shoving everything under the 552kHz range, the SNRM is much higher, and the connection much more stable. Problem is, even with it selected in the router, DMT reports it connecting via ADSL2 pretty much all the time, and it can take multiple resyncs for the mode to change to ReADSL again.
Are any of you familiar with the adslctl command on Broadcom based routers? Or, is this the sort of thing that can be set/locked from the exchange side only, via a call to tech support (assuming i get an engineer, rather than a nose-picking moron with a phone)?
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I'm assuming that, irrespective of what you set in the router, the exchange will only sync at what it's capable of (in terms of modulation type), so unless FT enable or can supply the various modulation types, who knows :( Sorry not to be more positive, but I know less about FT than I do about UK (...and that ain't too much ;) )
I'm sure some of the more knowledgable peeps could help....but still sounds like your line has major issues :(