volt/amp readings using multimeter on ADSL line

O

[OUPA]MrNutz

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So i've been having this problem for years of unstable adsl - 384,512,1024..

SNR keeps stable for x min then just disconnects or goes 300% lower than it was originally.

as i said previously - tried TONS of filters - without any extras (just adsl) - 4 routers ect - so its not client side probs.

what kind of volt values should i expect from my line..

gonna get a multimeter today and take a few samples. I do realize that the line is analogue - thus normal fluctuations is to be expected.

if anyone can take a reading for me and post results here with approx distance from exch - that would be great!
 
[OUPA]MrNutz;1187771 said:
if anyone can take a reading for me and post results here with approx distance from exch - that would be great!
Click to expand...

You should measure approximately 50 VDC at about 2 to 3km from the exchange.
I'm sorry I can't provide more info than that but I don't own an oscilloscope.

The only reason why I know that off hand is because I've had to repair my ADSL line twice now. Telkom refuse to help me (even after talking to some managers).
 
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haha, whatever you do, don't just stick an ammeter in there :p

The phone line is should have about 48 VDC (like Paul S said) but, that wouldn't really help you in your investigation. The only thing i guess you could do with a (standard) multimeter is measure the resistance, since the rustier and more worn out the line is, the higher resistance it should give
 
you wont be able to check for resistance with the line connected though. you have to disconnect the line somewhere, but its not really going to help. you meter leads won't be long enough to check each end of the line.
even if you had a scope you will see a ton of signals which won't mean much.
 
If you're really getting desperate you could try to disconnect your house telephone wiring from the terminal block that connects it to the thick black Telkom cable and connect your router directly to this via a telephone extension cable. This may improve things if there are problems with the telephone wiring in your roof or the extension sockets. If not, then you will have to get Telkom to look at your line. Try to avoid using any unneccessary telephone extension cords, splitters, line filters, lightning protectors etc. Do you hear any noise on your telephone line after pressing a key to remove the dial tone? Any faint ticking or static noises could indicate a problem with lightning protection devices, line filters, faulty telephones/faxes or the line itself.
 
put it this way there is no way in hell you can do anything,First you will have to go to the exchange and measure there first ,but befor you do so you will have to get permission to disconnect the cables from the exchange,like in all electronic componets,No true value can be read without unplugging one side first.My 4 cents worth 2
 
Using millimetre on telephone line will be of no help.
We are talking here about values such as capacitance and impedance.
Let’s face it, ADSL in general is not the best technology and in fact very far from it.
You are limited by line condition, length, number of users at any given time and even weather.

My opinions only... give up and drop your sync rate.
 
thx for the inputs sofar boys.

this problem i am having is something like this:

-i've tried it at 384 ,512 and 1024 profiles...get EXACTLY the same bug.

-have 4 different brand filters
-have tried without filters in general

-have 4 different routers (5102g,mega100,netgear834,dlink300T)

-have used rj11 with and without surge protector provided by some of the routers
-running on APC line-interactive UPS
-have also run thru pure eskom power..

nothing i test makes a noticable difference.

so it must be upstream..

only thing i can do is play around with my wallbox and request that my line from the house to pole be made shorter (as i can do this with about 90m if it enters house from another angle).. 3.7km from exchange

classical behaviour:

http://i210.photobucket.com/albums/bb147/jannie40/20aug1014.jpg

after about 14 ref# from telkom they have given up - they dont know :)
 
@OMN: Problems with fluctuating noise margins are quite common with DSL. The Australians seem to think that the SpeedTouch modems perform best on noisy lines. I think that MWeb used to bundle certain models with their ADSL packages. As I mentioned before you need to carefully listen to your line - if you can detect something audible on the line then you have a good reason to get Telkom to investigate. If not, you may have to do the best that you can to get it to work reliably. Bad connections can occur anywhere along the line but Telkom will be reluctant to investigate unless there is a serious problem. If there is a lot of noise on the line then factors like the length of the internal wiring, the types of telephone sockets, extension cables may have a big influence. Take a look at these pages for more ideas. Search around yourself and let us know if you have any success. The shorter the wiring the better but it may be simpler to first try a SpeedTouch etc. Some reports would indicate that most of the routers/modems that you have tried do not perform well on noisy lines.

http://www.pcadvisor.co.uk/forums/index.cfm?action=showthread&threadid=289197&forumid=18

http://www.dslreports.com/comment/1215/31975

http://www.dslreports.com/forum/r18848278-Problem-with-PPPoE-disconnections

http://forums.whirlpool.net.au/forum-replies-archive.cfm/455852.html

http://forums.whirlpool.net.au/forum-replies-archive.cfm/603723.html

http://forums.whirlpool.net.au/forum-replies-archive.cfm/497854.html
 
Just to make thinks more complicated I found this on the net, quote:

"A critical component to your decision, which unfortunately may be difficult information to obtain, is what kind of hardware is on the other end of the DSL connection (commonly referred to as the DSLAM), and what type of DSL protocol is being used.

Knowing the type of DSL chipset in the DSLAM is useful, because interoperability between manufacturers can be a bit shaky. So, if you can get the telco to divulge to you that they the DSLAM you will be connecting to has a Broadcom chipset, you should seek out a Broadcom-based modem.

Knowing what kind of DSL protocol is being used is also important (there are many flavors), and you should make sure that whatever modem you buy supports the protocol the telco is using.

Most likely the telco is offering a version of asymmetric DSL, or ADSL. Standards within the ADSL family are G.Lite (1.5Mbps DS, 512kbps US), G.DMT (8.1Mbps DS, 1Mbps US), ADSL2 (faster still), ADSL2+ (faster still). Be warned that just because the telco uses a particular standard does not mean you will be getting that level of speed. The distance traveled between your home and the DSLAM affects the rate, and the telco will almost certainly rate-limit you, as this is how they structure their rate plans (and a big reason why DSL sucks over cable, but that's another story).

Some good ADSL modem brands: Comtrend, Westell, Actiontec, Netopia.

Also, in my own experience, the modem brand with the most problems is Visionnet".

But there's not specific unit to get?

There's no way to recommend a specific modem if you don't have the information stated above. I could recommend, for example, an excellent Conexant-based ADSL2+ modem, but that doesn't do you much good if your DSL connection turns out to be Broadcom-based SDSL. Also, a good TI-based ADSL modem might work fantastically with a TI-based DSLAM, but not a Broadcom-based DSLAM.

I wish it were easier, but it's not.

A different tack you might pursue-- ask the DSL provider you are going to use what kind of modem they recommend. They want your $$, and the more satisfied you are the more $$ they get...seems like it would be in their best interest to give you good advice.

A critical component to your decision, which unfortunately may be difficult information to obtain, is what kind of hardware is on the other end of the DSL connection (commonly referred to as the DSLAM), and what type of DSL protocol is being used.

Knowing the type of DSL chipset in the DSLAM is useful, because interoperability.
 
@voyt: Good point! I was under the impression that Telkom was using Marconi and Alcatel DSLAMS but it would be interesting to get feedback about this from Telkom themselves. The Speedtouch used to be manufactured by Alcatel and then the business was sold to Thomson so it's not impossible that one of these models would work better with an Alcatel DSLAM. Is there any way to determine the type of DSLAM that you are connected to while you are online?
 
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correct observation about the broadcom chipsets being compatible ect.

for example in my url provided - that was generated with a Telkom 5102G

Max SNR

5102G - 29/30
Mega100W - 14/15
Netgear 834 - 15/16 (resyncs the fastest)
Marconi 4 port wifi - 28/29
dlink 300T - 14/15

No audible noises when i pick up the telephone or when i press 0.

also doesn't happen alot - but it does : - when someone answers a ringing phone - it sometimes disconnects (please note - filters are correctly installed , and have many different types) - OR when picking up the phone to dail - ADSL can disconnect (drop sync) - or have a HUGE SNR spike on my graph..lower SNR

have also seen this on my setup :

when i take the phone off the hook - i get a MUCH higher SNR than when i would unplug that phone from the filter - or even unplug the phone AND filter.

but back to the broadcom chipset thing - it doesn't help my stability at all - it just is a case of having a higher SNR.

sigh..i dunno :?
 
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@OMN: You could ask Telkom to shield your telephone line but I doubt that they will be interested. You could even offer to pay but my guess is that it won't be cheap. Why don't you try one of the SpeedTouch modems that they mention in those threads. I'm sure that you could buy one on eBay in the UK for a few pounds. Take a look at the link below. I think that some of the SpeedTouch modems use an Alcatel chipset but I see that the later ones use a Broadcom one. In general Telkom's copper network seems to be in a dreadful state and I have to wonder if they will ever be able to upgrade to ADSL2 on a large scale as they have indicated.

http://www.dsldepot.co.uk/product_details.asp?idProduct=851

OK here is some info about the SpeedTouch chipsets. A Draytek router may also be worth considering. You can buy them in SA. Maybe you could get the distributor to give you a demo unit to test.

http://forums.whirlpool.net.au/forum-replies-archive.cfm/778646.html

http://forums.whirlpool.net.au/forum-replies-archive.cfm/417180.html
 
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Yotch said:
@OMN: You could ask Telkom to shield your telephone line but I doubt that they will be interested. You could even offer to pay but my guess is that it won't be cheap. Why don't you try one of the SpeedTouch modems that they mention in those threads. I'm sure that you could buy one on eBay in the UK for a few pounds. Take a look at the link below. I think that some of the SpeedTouch modems use an Alcatel chipset but I see that the later ones use a Broadcom one. In general Telkom's copper network seems to be in a dreadful state and I have to wonder if they will ever be able to upgrade to ADSL2 on a large scale as they have indicated.

http://www.dsldepot.co.uk/product_details.asp?idProduct=851

OK here is some info about the SpeedTouch chipsets. A Draytek router may also be worth considering. You can buy them in SA. Maybe you could get the distributor to give you a demo unit to test.

http://forums.whirlpool.net.au/forum-replies-archive.cfm/778646.html

http://forums.whirlpool.net.au/forum-replies-archive.cfm/417180.html
Click to expand...

nope - shielding not an option - 3.7km - which 3.2km is underground.

-cable is 40 years old
-runs past 2 security companies (dunno if that can have something 2 do)

Looks like a good router the Draytek - but i'm NOT forking out 1800 for a router..

have got 5 now - and if not 1 of them can give me a stable setup - it means problem is upstream.

its NOT a case of not having a service but as you can clearly see in my earlier posted URL - just a sudden loss of ADSL signal (the voice part however works 100% during that time)

so i just don't know...

have thought of posting on hellopeter and beeld's consumer forum - but if after 14 ref#'s and them not being able to solve it - i dunno.

i had a serious issue even with ISDN back in the days when it was avail.
LOTS of cutoffs (had a scratch noise even disconnecting the voice part then).
 
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@OMN: This software may also help. Apparently you can adjust various settings in your ADSL router. Take a look at some of the graphs etc. to get an idea. There seems to be a version for your Netgear. It may also give an indication of where the interference is coming from.

http://dmt.mhilfe.de/

A bit of help to set it up in English
http://www.kitz.co.uk/tute/voyager2100_DMT.htm
 
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thx 4 the info Yotch

unlucky me ...i only have the Netgear 834 model...not the G or GT (those work with that app) mine doesn't.

damn
 
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