On Mon, 11 Dec 2000, Don Stokes wrote:

> a lab floors) was that ADSL borrowed the idea of QAM modulation from
> the modem world..

Some varieties, yes.

> (ADSL was being pushed to carry video via a 6Mbps downlink; nobody
> much was talking about other kinds of DSL.

At that time Murray Hill way (Bell Labs) it was being investigated as a
T1/E1 replacement. Greater range over fewer pairs.

> Using the technology for packet data (let alone IP packets) seemed to
> have escaped them;

There was no need to; you had the "who you gonna call" problem that ISDN
had. Worse, the technology's limits weren't understood in the practical
world (and still aren't).

> expected that the ADSL kit would then be attached through ATM, and
> circuit switched to whatever broadband service provider you wanted --
> one service at a time. Very typical of telco thinking at the time.

Actually, this is how it's still being sold, and it's a good thing. I use
a frame relay over DSL interworked to an ATM connection back to my office
at home. Much more simple, much more reliable, than IP + MPLS (or
whatever) can be for awhile yet; no authentication, or routing problems
for me!

--
Josh Bailey (josh@vandervecken.com - Berkeley, CA, USA)
This message is part of the NZ ADSL mailing list.
see http://unixathome.org/adsl/ for archives, FAQ,
and various documents.
To unsubscribe: send mail to majordomo@unixathome.org
with "unsubscribe adsl" in the body of the message