ADSL vs. ISDN - copper lines

[LandyMan]

I realised something very interesting last night. I was in the process of configuring my ISDN setup at home, MSN programming, etc etc. Went through alot of documents, and never even thought of this: ADSL runs over copper, ISDN runs over copper, HOWEVER, I was told by Telkom that I cannot get ADSL, as we are running fibre optic to the exchange. Then how come I was able to ISDN installed?

Any ideas as to what it might be?

 

[Borgir]

From what i understand it is distance to exchange, if enough ports aval etc. ADSL at exchange uses totally different system than ISDN. Any idea how far Exchange is? Or UMC ( i think it is called )

Some people call it a cigarette, other call it a cancer stick ... to me, it's a floating device

It does look indeed like a floating device

 

[Darth Garth]

BRI ISDN only uses a small chunk of the available frequency spectrum of twisted pair copper to carry it's signal so it can be packed along with a 100 other copper lines on a single fibre optic cable to the exchange.

DSL on the other hand needs much more.

Only solution is for Telkom to put a DSLAM (a mini) close to folks like you where your copper goes into fibre or run copper all the way for you to the exchange bypassing the fibre completely.

 

[mancombseepgood]

Are you in Centurion? It amazes me that you can get ADSL in King Williams Town but not in Centurion if that is the case... Where is Telkom investing their billions?

 

[Gambit]

ADSL requires that the exchange that houses the DSLAM for adsl have a fibre connection to the TELKOM ATM backbone. The problem that people seem to be experiencing (espescially in new areas) is that instead of copper coming out of the exchange and going to houses, fibre is used instead to cut costs. These fibres are going to distribution boxes in the street where they are converted to copper for the last couple of meters to the house. ADSL is a copper only technology so these people can't get it unless a mini dslam (quite expensive) is installed in the distribution box in the road. ISDN and normal analogue cards are interchangeable in the exchanges and distribution boxes so when you upgrade from analogue to isdn they just swap out the card in either the exchange or distribution box (if you have fibre to your road scenario).