SAIX & IS ADSL architecture clarification

[Need4Speed]

Can someone in the ISP/Network business please clarify the current ADSL architecture we have in South Africa.

Here's how I understand it: Telkom (SAIX) owns the infrastructure (DSLAMS) and basically sells PPPoE usernames and passwords to VISPs. I'm not sure whether the VISPs run their own RADIUS servers which get queried by Telkom's RADIUS server or whether all PPPoE sessions are directly authenticated by Telkom, but after authentication you get assigned a SAIX IP and from then on you use SAIX, and your ISP doesn't feature further.

Now what confuses me is the new IS ADSL offerings. As I understand it IS now has access to Telkom's ATM backbone, and once you logon with IS, you are assigned an IP in IS's range, and you are routed through IS's international bandwidth.

Is this summary correct? Is there some website where SA's ADSL (and other) backbone infrastructure is documented?

Just curious......

 

[sburrell]

From what i know, all dsl users connect to there exchanges thru a dslam at there local exchange which allows data to pass onto the local atm network. This data is then passed thru onto a DSL Cloud network, which is seprate from isdn and dial up traffic. All data in this cload is then terminated and peered in Rosebank, onto designated loops such as IS and UUnet

Thats my understadning of it all.

 

[Need4Speed]

This raises 2 questions in my mind:

1. If SAIX is congested/down wouldn't it be better to be on dialup/ISDN? Because you dial directly into the ISP's POP, the ISP can choose contention ratios themselves? (if they have a fixed slice of SAT3)
2. What incentive is there for choosing a well known and trusted, yet expensive ADSL ISP like MWeb over a "cheap and nasty" ISP. Apart from the "value added services" like online encyclopedias etc, the service will be exactly the same!

 

[Ktech]

telkom is the only tellykoms in SA that has access to the SAT3 cable. untill a second telko comes into SA that has access to the SAT3 cable we can than get better pricing and internet connections from telkom and all other ISP's.

yes your statement is correct about the connection from any other ISP's ADSL running through Telkoms SAIX network.....