DSLAMS moving closer to you

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Leftfoot

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Just been chatting to a Telkom insider and it seems there are future plans afoot to bring DSLAMS closer to the end users with fibre. This still way in the future but it makes sense.....effectively halving the line attenuation in order to gain the full benefit of ADSL+2 (24000kbit/s):cool:

Perhaps in preparation for Telkom Media and tripple play?

http://www.internode.on.net/adsl2/graph/index.htm

Looking at most guys line attenuation figures in posts on this forum indicates to me that most people will gain very little when ADSL2+ is available.......lines simply have to be shortened to enable higher speeds.

Will we see these popping up on South African streets......hmmm, they might require 24hr security!! :eek:

http://www.nag.ru/2002/2309/img/dslam.jpg
 
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Ahhh! See in Richards bay we are always a little behind the major centres!:mad:
Well then I suppose its a good thing that upgrades are moving along then..:cool: Soon we will be right up there with Japan and China --- Not!:confused:
 
Telkom has been installing DSLAM / UMC and other equipment is street cabinet for quite sometime. If you look at some of the gated estates.
 
gregmcc said:
I want a DSLAM in my garden :)
Click to expand...
I've got a cylindrical thingy full of wires in my back garden and its a pain having it there. Every time they come around (unannounced) I have to put the dogs away.
 
!!DV!! said:
Telkom has been installing DSLAM / UMC and other equipment is street cabinet for quite sometime. If you look at some of the gated estates.
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Yep, we have a couple in our estate, and running fibre throughout
 
Here is an article on Telkom's rollout of mini DSLAMS.
http://mybroadband.co.za/nephp/?m=show&id=1914

Can somebody who is connected to a mini DSLAM post their linestats (i.e. down/up noise margins and attenuations) so that we can see how much better they are than those of the regular customers? If you are so close to the DSLAM you should get really low attenuations and high noise margins.
 
The gear in that picture does not look very Tsotsi-proof. I think they'll have to make a special SA version.:)
 
Daveogg said:
They already are. Not exactually as in the picture, but similar.
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Yes - We have just had one installed up the road by the Sherwood Hall... Had no idea what it was til you filled me in... many thanks...:D Would someone be kind enough to spell out what the acronym DSLAM stands for? Thanks....
 
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-toady- said:
Yes - We have just had one installed up the road by the Sherwood Hall... Had no idea what it was til you filled me in... many thanks...:D Would someone be kind enough to spell out what the acronym DSLAM stands for? Thanks....
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Digital Subscriber Line Access Multiplexer

EDIT - http://en.wikipedia.org/wiki/DSLAM
 
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Ace thanx bwana.....
*goes off muttering and mumbling and tries to memorize it...:D
 
@56kman: Line attenuation is related to the length of copper wire or distance from the exchange - typically it increases by 13.81dB per kilometer from the exchange. Any value less than 13.81dB would be excellent i.e. less than 1km from the exchange. In order to achieve fast ADSL line speeds (>10Mbps) the line attenuation must be low (<20dB) hence the long length of copper wire from the exchange to the distribution box is replaced with optical fibre that connects into a mini DSLAM which reduces the line attenuation significantly i.e. the DSLAM which is normally at the exchange is now relocated to a cabinet on the street much closer to the customer. Here is some more detailed information about line attenuation.
http://usertools.plus.net/tutorials/id/12
 
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Thanks Yotch! Didnt realise the role out was indeed underway.
When one thinks of the physical infrastucture required to bring these technologies to our doors......its actually a huge undertaking.
Neotel and the like must have huge financial resources, manpower....and genarally BALLS! to give it a fair go.

Yes, it would be interesting comparing attenuation stats with the MINI DSLAM units.....anybody know for sure that they are hooked up to one of these...post stats.

For 56kman -
Attenuation distortion is the distortion of an analog signal that occurs during transmission when the transmission medium does not have a flat frequency response across the bandwidth of the medium or the frequency spectrum of the signal.

Attenuation distortion occurs when some frequencies are attenuated more than other frequencies. When an analog signal of constant amplitude across its frequency spectrum suffers attenuation distortion, some frequencies of the received signal arrive being greater in amplitude (louder), relative to other frequencies.

To overcome the effects of attenuation distortion, communications circuits have special equalization equipment attached at the ends of the circuit or in between, designed to attenuate the signal evenly across the frequency spectrum, or to allow the signal to be received at equal amplitude for all frequencies. Attenuation distortion can still occur in a properly equipped circuit if this equalization filter is not properly maintained or adjusted.

In DSL circuits, echoes due to impedance mismatch often cause attenuation distortion so severe that some frequencies must be automatically mapped out and not used.
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http://en.wikipedia.org/wiki/Attenuation_distortion

Good or bad is relative and depends on how far you are away from the DSLAM - the links in my first post in this thead should give an indication of what should be expected for a given distance.
 
@Leftfoot: Thanks for the detailed explanation. The fact that you haven't seen any of the mini DSLAM cabinets in your area would suggest that it's more of a trickle than a rollout. I haven't seen one myself either.

In Germany the VDSL2 roadside cabinets are now within 300m of the customers and 700m in France. It would be interesting to get an idea of the distances to the mini DSLAMS in SA.
 
Yotch said:
@56kman: Line attenuation is related to the length of copper wire or distance from the exchange - typically it increases by 13.81dB per kilometer from the exchange. Any value less than 13.81dB would be excellent i.e. less than 1km from the exchange. In order to achieve fast ADSL line speeds (>10Mbps) the line attenuation must be low (<20dB) hence the long length of copper wire from the exchange to the distribution box is replaced with optical fibre that connects into a mini DSLAM which reduces the line attenuation significantly i.e. the DSLAM which is normally at the exchange is now relocated to a cabinet on the street much closer to the customer. Here is some more detailed information about line attenuation.
http://usertools.plus.net/tutorials/id/12
Click to expand...

Thanks :)
 
Leftfoot said:
When one thinks of the physical infrastucture required to bring these technologies to our doors......its actually a huge undertaking.
Click to expand...
I think many of those excited by the forthcomming LLU seriously underestimate just how large (read astonomically expensive) an undertaking it is.

Telkom have roughly 500+ exchanges nationwide, of which I believe roughly 80% are ADSL enabled (say 400 odd).

Guessing that each exchange services on ave. 25??? curb boxes (probably a gross underestimation), thats 10,000 mini-DSLAMs and associated backhaul fiber & power reticulation. Bit of a step up from the current situation (Telkom recently announced they have 2500+ DSLAMs deployed in the current exchanges).

I have yet to hear any 3rd party (incl. Neotel) commit to actually ustiling LLU facilities (in any wide scale sense) when they become avaliable.
 
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arent the blue and green telkom boxes the ones with dslams? there are only a few of them here and there..

if these dslams become full, then theyll most likely route all other customers to the main exchange, so there may be a dslam just down the road with no available ports and so instead you have to put up with 63db attenuation..
 
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