High Attenuation

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musnit

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About 2 months ago my attenuation spiked to 59.0 down/31.5 up. My Noise margin still seems fine at 26.4 down/8 up (Up is low though). I logged queries with telkom and they supposedly checked the exchange etc, but found nothing, and refuse to fix it or try anything else because my line still runs semi-stably since they have limited it to 1meg. Anything higher and it just gets too inconsistent.

I know that tons of people have had the same problem, so has there been any progress with finding out a way to convince Telkom to fix it or finding out what the source of the problem is?

(Don't think my problem is the same as in the old 17 page thread - I think mine is just because of the attenuation?)
 
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Hmmm, your attenuation should at best be below 50db for downstream. It sounds like noise. Phone the normal telkom helpdesk and complain about noise on your 'normal' telephone line and you would just like it fixed.

Keep it simple and modular and then telkom has a better chance of understanding whats going on.

EDIT: Ok dumbass moment, wasnt thinking....Its not your noise. It would seem you are too far away from your exchange. Your best bet to see if this is true is to ask a neighbour or someone nearby if their ADSL has the same stats. If yes then unfortunately you too far, if not give telkom a nice warm hard time to fix it.
 
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59 dB line attenuation!?
That's extremely high.

You can be happy that you have ADSL at all.

From our Telekom you wouldn't get any ADSL at this line attenuation. :D (too risky)

So be happy to have 1 mpbs. ;)
 
hehe I live with 60dB down and 31.5dB up get nice speeds on my 2mbit profile. My noise is even worse up and down below 9dB. I am hoping that the upgrading they are currently busy with in my area might alleviate the problem.
Attenuation is mostly to do with distance though...the way I understand it after 4km ADSL1 performs really badly and I am apparently on that limit.
 
yeh i know its mainly distance etc, but my attenuation was always low and just suddenly went up 2 months ago, so im wondering what could have caused the sudden change.
 
aborg said:
Attenuation is mostly to do with distance though...the way I understand it after 4km ADSL1 performs really badly and I am apparently on that limit.
Click to expand...

The attenuation depends on line length AND on the diameter of the copper cable.

You can calculate it:
Ø 0,35 mm: 14,0 dB/km
Ø 0,4 mm: 12,0 dB/km
Ø 0,5 mm: 8,5 dB/km
Ø 0,6 mm: 7,5 dB/km
Ø 0,8 mm: 5,7 dB/km
 
aborg said:
hehe I live with 60dB down and 31.5dB up get nice speeds on my 2mbit profile. My noise is even worse up and down below 9dB. I am hoping that the upgrading they are currently busy with in my area might alleviate the problem.
Click to expand...

Busy?
What are they doing exactly?
Is your Telkom using Outdoor-DSLAMs? (picture: http://de.wikipedia.org/w/index.php...LAM_Endstufe.JPG&filetimestamp=20051105235822 )

Until Jan/2008 i had a attenuation of ~60 dB (line length: ~10km) and i didn't get any ADSL. (not even 384 kbps)
Then our Telekom upgraded my village with Outdoor-DSLAMs.
Now my line length is 360m. :)

My router says: 1 dB for download / 3 dB for upload :D
 
@Wurschtler: Are you subscribed to an ADSL2 service or a VDSL one? How much do you pay monthly and what kind of download limits does DT enforce? How much faster in practice is the VDSL service in relation to an ADSL2 one? Does DT still have the largest number of broadband customers in Germany? Are the independent ISPs now allowed to offer VDSL or only ADSL2 services via LLU?

You also previously mentioned the availability of high speed fibre connections. Are these being provided by private companies? Is this completely independent infrastructure or does it share the current DT ducting etc. Is the fibre being installed underground or aerially? How much do such services cost including installation charges? How long did it take for commercial services to be launched after construction of the network began?
 
What I understood from the area supervisor is that they are upgrading the infrastructure in our area. That could mean several things, from new cabling / equipment to upgrading all the local boxes on the poles, my local junction box was changed yesterday and I am seeing some improvement in the noise margin 2-3dB. IF they keep there promise and replace the old equipment, most from around 1959 to 1965 I am sure things will be much better, but by that time I might have Neotel fibre to my house....hehe
 
Yotch said:
@Wurschtler: Are you subscribed to an ADSL2 service or a VDSL one? How much do you pay monthly and what kind of download limits does DT enforce? How much faster in practice is the VDSL service in relation to an ADSL2 one?
Click to expand...

It's only ADSL2+ (17696 kbps download / 1180 kbps upload).
But I hope Telekom will upgrade our DSLAMs with VDSL2-linecards soon. :)
Big cities already have been upgraded in 2006/2007.
I'm paying 50€ for my ADSL2+ line.
But it's a bundle price with phone flatrate, internet flatrate, wlan hotspot flatrate, 10x free movie downloads per month, etc.
A naked ADSL2+ line with flatrate I would get for 30€ from competitors.

And there are not any limits for download or upload.
It's not necessary for Deutsche Telekom, because they have a powerful backbone-network of many Terabit/s to provide VDSL2 and IP-TV-services.

There are 2 offers for VDSL2 from DT:
25 mbps download / 5 mbps upload -> 60€ per month
50 mbps download / 10 mbps upload -> 65€ per month
(big bundle like mine + IP-TV flatrate)

There are no unbundled VDSL2-offers from DT.
50 mbps are great in practise. You can download with fullspeed from many european servers.
HDTV over IP is nice too.

Yotch said:
Does DT still have the largest number of broadband customers in Germany? Are the independent ISPs now allowed to offer VDSL or only ADSL2 services via LLU?
Click to expand...

Yes, they still have the most customers, but they have lost MANY customers.
ADSL & ADSL2+ is regulated by government, so competitors are allowed to resale it. (30€ for ADSL2+...)
VDSL2 is not regulated yet. Telekom has an investment protection for some years. (VDSL2 investment did cost at least 3 billion € until now)


Yotch said:
You also previously mentioned the availability of high speed fibre connections. Are these being provided by private companies? Is this completely independent infrastructure or does it share the current DT ducting etc. Is the fibre being installed underground or aerially? How much do such services cost including installation charges? How long did it take for commercial services to be launched after construction of the network began?
Click to expand...

ALL internet connections are provided by private companies. ;)
Deutsche Telekom doesn't offer fibre-connections to the homes, because VDSL2 (copper) is still enough for up to 100 mbps.
Some other ISPs are building its own independent fibre-optics-infrastructure, but until now it's very rare. (only bigger cities like Munich, Hamburg, Cologne...)
And the FTTH/C intrastructure is not finished yet!
Fibre & copper lines are 99,9% installed underground. (so streets must be torn open)
It takes while and it is very expensive...
M-net will develop 60% of Munich in 2011. (start: 2007)

Costs for customer?
Installation is usually for free.
Monthly fee.... depends on ISP.
M-net (in Munich) is the cheapest ISP with only 40€ for a 100/10 mbps line. (but without extras)

I think I will never get fibre to my home in my one horse town. :(
But I hope, that I will get VDSL2 soon.
50 mbps are enough for me. :D
 
aborg said:
What I understood from the area supervisor is that they are upgrading the infrastructure in our area. That could mean several things, from new cabling / equipment to upgrading all the local boxes on the poles, my local junction box was changed yesterday and I am seeing some improvement in the noise margin 2-3dB. IF they keep there promise and replace the old equipment, most from around 1959 to 1965 I am sure things will be much better, but by that time I might have Neotel fibre to my house....hehe
Click to expand...


My junction box is from ~1980.
But our old copper cables are ironically better than the new.
reason:
New copper cables have a smaller diameter and so the line attenuation is higher. :D
 
yeah ;) ...is it possible to test your ADSL at a neighbour to check if they got the same problems?
BTW I found out that we still have old paper covered copper cables on our area, that must have been before plastic became the standard?!? Weird.
 
i'll try find out from a neighbour...

The problem can't be anything to do with distance from the exchange, or type of cabling or anything like that i doubt, because it always worked fine at 4megs until about 2 months ago. What things could've caused the sudden change?
 
@Wurschtler: Many thanks for taking the time to post that information. I have a few other questions regarding broadband in Germany that I'll post in the next few days.

@musnit: Sorry to hijack your thread. It might be a good idea to get Telkom to do an LTS test on your line. Here is some information that Leftfoot and Dosti posted previously. If you post the results somebody may be able to help you further.

OK.....as an ex Telkom technician I can tell you the following:

If your DSL modem disconnects (or loses sync) on a regular basis....insist on a line test......in fact insist on the results of that line test (even though it might not make any sense)

Most modern cables in Telkom are PVC but can be influenced by moisture or other systems that carry higher voltages.

The test should reflect:
-absolutely no Earth potential
-no more than 12v contact (foreign -ve)
-also watch out for how many phones are connect to your line at any stage - The more phones, the higher the line capacitance.....the easier it it for your modem to lose sync by not understanding the incomming carrier signal.

I too have a 4meg line and had frequent disconnects at a stage.....insisted on a line test (through the supervisor as the "Kelly personel" operator insisted that because I could browse the net all was Cool)......The test result showed a -38v contact that went to -49v when it rained. note: Audibly I could not hear any problem during normal conversation......somtimes you can here a slight "cross-line" with this type of condition.

A line fault was reported and a spare pair of wires was used to bypass the fault......then the "Kelly personel" chic phoned me back to write the fault off.....once again....insist on the results of a second test....if all is clear then allow them to write the fault off

These people are stats driven.....so its important not to allow them to write the fault off if it is not clear.....you will get higher priority on the system a more people will try to resolve your problem

Incidently.....The testing system (LTS) CANNOT perform a test while you are talking on the line, they have to tell you to put the phone down then ring you back with the results.

Hope this is of help to you guys!


Good chance that if you had a lightning strike on the line that there will be problems elsewhere ie. other lightning protection on phones/faxes etc, poles or the exchange itself degraded. Insulation in cables blown through and perhap touching a tree. "Kelly temps" at Telkom do the line testing most of the time and they ignore some fault conditions. Its a time consuming exercise that they dont like to do on the LTS system. A telkom line test should be no worse that these limits:

Foreign earth - 10M? (line touching the greater mass of the earth through trees, wet soil, nests etc)
Foreign contact or negative (-ve) - <12v (line touching another line through low insulation, dampness, etc.
Line capacitance - more that 8µF on the line indicates too many phones and as such has been known to weaken analogue data signals.

Anything other than this....the line is faulty. I always insist on these results from the "Kelly temp" and if they cant supply it, they have not tested the line. They cannot test the line while you are talking on it, they have to ring you back. If they cant help you with the results immediately, demand to speak to an operator. Do not accept a reference number until the results are given to you.

A standard cable cable pair has:
- an E-SIDE (from Exchange to SDC-Street distribution cabinet
- a V-SIDE (from SDC-Street distribution cabinet) to the terminal equipment

The E-side is usually pressurised to resist water penetration
The V-side is not pressurised an has many connect points and potential problem sources. (trees rubbing through insulation, animals eating insulation, bats urinating and corroding connections...the list goes on)

9 times out of 10 the problem will be on the V-SIDE

In order to change your pair the whole way the tech needs to divert in at least 3 places (the Exchange -MDF, the street box -SDC, and the Local Distribution Point - DP).....can also be as much as ten points if your line in aerial cable fed.
Click to expand...

http://mybroadband.co.za/vb/showpost.php?p=1777488&postcount=6
 
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Yotch said:
@Wurschtler: Many thanks for taking the time to post that information. I have a few other questions regarding broadband in Germany that I'll post in the next few days.
Click to expand...

No problem.
But why is it such interesting for you?
 
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