Speculation: ADSL over ISDN...

[ic]

...
NOTE: You will need one micro filter for every telephone socket connected to the ADSL line on your premises, even if there is no equipment connected to that specific socket.

These micro filters are not required when you have an ISDN line, as Telkom will supply a splitter for the ISDN line. (*ADSL over ISDN is not yet available.) If you purchase a Telkom modem you will receive 2 micro filters in the box, and only need to buy additional micro filters if you have more than 2 telephone sockets on your premises.

What does it mean? - Telkomonopoly have secret plans to provide ADSL over ISDN? I saw something today when googling telkom.co.za - Telkomonopoly had a webpage saying that ISDN is the latest technology...

 

[sybawoods]

Yeah, I remember speculating about this a while back (on the old forum, I think) - I saw that Marconi had ADSL over ISDN modems mentioned in their product range - goto http://www.marconisa.co.za/adslisdn.htm

ADSL over ISDN is widely available in Germany, where ISDN was also heavily promoted prior to their broadband roll-out. South Africa has a somewhat similar ISDN profile, so this would be quite likely.

When ADSL was first launched, the TELKOM ADSL pages even had diagrams for hooking up ADSL over ISDN - they have since been removed.

 

[sybawoods]

Interesting article here - BT says ISDN over ADSL "impossible"

BT's asynchronous digital subscriber line (ADSL) will be sold in the UK requiring new lines at an extra cost to customers, despite the fact that its German rival Deutsche Telekom is offering the same service over existing ISDN lines.

BT claims that the two services operate on overlapping frequency spectrums which prevent their concurrent use...

AVM, however, a leading German manufacturer of DSL interfaces, has refuted BT's claim. Kai Allais, international sales director at the company, said: "That is absolutely not true. You can run ISDN and ADSL over the same pair. The Deutsche Telekom service is always over the same pair."

The frequency levels of the two services are configurable by the operator, so it is the operator's decision as to whether any two services overlap, Allais added. "ADSL is a transmission-oriented technology; it is simply a decision of where you split the frequency spectrum between the services," he said.

 

[Edinetz]

When Deutsche Telekom launched ADSL they said it was only possible over ISDN and shortly thereafter it was availble on analogue. When DT introduced ISDN there aim was to convert all telephones to ISDN so they tried to accelerate the acceptance of ISDN by only offering ADSL over ISDN. Now we have BT saying it doesn't work over ISDN. It seems all telkoms just tell you what they want to sell you.

 

[caroper]

When I got ADSL I had to pay to have my line downgraded to analogue then upgraded to ADSL and was told that ADSL over ISDN would be availlable in six months at an additional upgrade cost. That was two years ago and I am still being billed for services that cant be inplemented over adsl (CLI, Multi numbers, Voice mail, etc.) that I was advised to keep pending the upgrade. Telcon as usual.

 

[Edinetz]

... billed for services that cant be inplemented over adsl (CLI, Multi numbers, Voice mail, etc.)

Did you mean analogue because CLI, Multi numbers (available as MyRing - different ring pattern) and Voicemail are all available on a normal phone line.

 

[caroper]

No, I had it all setup on ISDN with an ISDN modem that acted as a mini PABX.
4 seperate numbers, 1 per extention plus CLI and Voice mail. The latter have never worked since I got ADSL, and my mini PABX is sitting idle waiting for the upgrade.