Ok let me explain to you what is going on. In a normal exchange you have the ports where your tel no is working on. This is on a connection point called the main distrubution frame or MDF. Some where on the same MDF is the underground cables that goes out in all different direction to link up to clients premises. Normally a port is wired to a cable pair to provide service. When you apply for the line to be converted to ADSL the ADSL ports is also terminated on another place on the same MDF but with a in and out block. They now need to disconnect your cable side from the connecting wire and connect the telephone no port to the in of the ADSL block and from the out block they need to connect another wire to the cable again to reconnect your service.
On the mini exchanges it works a little bit different. They have two types of the mini exchanges. The older type that has a card with 6 users on in the exchange and a simillar card on the outside at the mini exchange. This card in the exchange get hard wired to telephone ports 1 to 1 on the MDF at the main exchange and their purpose is to convert the line to optics. On the outside the card do the reversal and from the mini exchange they run on copper to the house again. In this setup you have different cards ie for normal telephone line, ISDN, DAT cicuits for bussiness and ADSL cards. In the newer mini exchange you no longer have physical cards with 6 user on in the main exchange to link to the mini exchange. Certain position on the exchange equipment is now allocated to the different service types. On the outside you still have different cards for the different types of services.
This means in the normal exchange when you apply for a convertion someone just need to wire in the ADSL equipment. On the mini exchange however they need to move the wire in the older type to a new position inside the exchange as well as at the mini exchange side and for that they have to drive out to do it. On the newer mini exchange they have to remove your tel no from the old telephone port and reprogram your telephone number onto the ADSL card in the mini exchange and have to send someone out to that mini exchange to move the wire to the new port also. As self install is a way for them to save time and use a tech for something else and they cannot do it in this instance they don't allow a self install on this mini exchanges.
Another thing. This mini exchanges allow Telkom to provide service in areas where they never would be able to provide it due to distance constrains. They also now can provide higher speeds ADSL in this far of areas. I do however heard that currently they will not up the 4 megs services on this exchange to 10 meg even if the client is less than a kilometer from the mini exchange. This can only be due to the cards in the mini exchange that can not handle the higher speeds. Also be very carefull of the Billion 400 router of Telkom. It doesn't work on 4 meg profile on this mini exchanges. Most of the other router work perfect on a 4 meg profile but the 400 run so much errors that it refuses to verify the username and password although the line sync perfectly. Replace the modem with a private Billion or Netgear or Duoplus and it works a OK.
