[HARDWARE] Cost of crunching (was: Mac Questions)

John L. Bass jbass at dmsd.com
Sun Mar 17 19:42:07 EST 2002

George Mogiljansky <mogil_jan at sympatico.ca> writes on  Sun, 17 Mar 2002 19:45:07 -0500

	I'm using a 56k modem for several reasons, but mainly because the concept
	of an "always on" Internet connection using ADSL(regardless of whether or
	not I'm using it) seems wasteful. And there are security risks.
	Many thanks to those who participated in the debate.
	George M., Canada

The always on data services that are piggybacked on other mediums are actually
much less wasteful - which may seem counter intuitive.

Telephone cross bars are designed for a certain oversubscription level, typically
a factor of 8-10, so that only 15% of the subscribers can expect service at the
same time. Dialup modem service stresses this model, requiring more switching
resources and interswitch trunk lines. Carrying data on dedicated dual 64bkps voice
circuits isn't nearly as efficient as using aggregated packet switched data.

So, DSL and cable modem services are actually less wastefull - while the service
is "always on", it does not tie up 126kbps of continuous data like a full duplex
voice circuit does. Packets only flow while you are actually doing something on
the "always on" connection.

It is very important for our society to switch to non-dialup technologies, and
minimize the number of no-dial-tone events which might block a 911 call because
of high dialup internet use in certain areas.

John Bass
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