[Gllug] ADSL modem -- WTF?

John Hearns john.hearns at clustervision.com
Tue Jul 20 09:39:25 UTC 2004

On Tue, 2004-07-20 at 10:30, Richard Jones wrote:

> Actually it's worse than that.  Underneath ATM is another layer called
> SDH which adds even more cruft.  I have some 155 Mbps ATM cards around
> here which I've never managed to get to transmit TCP/IP data at a
> higher rate than 77 Mbps.  Basically around half the advertised speed.
I know. But you should put this into the context of the time.
100Mbps Ethernet wasn't common - heck 10Mbps ethernet on UTP wasn't

Lots of projects, unis and companies went for ATM to the desktop as it
was the fastest thing around, and the plan was for the same technology
to go on the backbone at 622Mbps - and then higher mupltiples.
Sadly the 622Mbps cards never really took off, and prices stayed high.
Cue gigabit ethernet, lurking in the wings.

Remember at the time a fast campus backbone would have been an FDDI
ring. We had an existing 2Mbps datastream at the hospital I worked for.
The 155Mbps circuit I put in was like something out of Buck Rogers.

Some markets always demand what the fastest is at the moment.
When I went to Framestore, they had an internal ATM backbone,
ATM links to several workstations 155Mbps laser link across the roofs of
Soho and a 155Mbps link to Sohonet. 
SGI not providing the drivers for Irix 6.5 was really the deathknell for
ATM there (sniff). Cue implementation of a gigabit backbone,
and finding 100Mbps cards for the SGI Indigos.

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