[comp.sys.mac] Are Modems >$ Voice?

kassover@minerva.crd.ge.com (David Kassover) (04/10/90)

In article <40835@iuvax.cs.indiana.edu> harlan@silver.ucs.indiana.edu (Pete Harlan) writes:
...
>Do any readers know if calls really are broken up like that, or if
>there is just an unbroken connection from one end to the other that is
>left in place regardless of what is transmitted or not.
>

The technology exists to do this.  It is commonly done in
satellite links, and also, I believe, for cellular
radio/telephony.

Whether any particular phone call does or does not pass through
some instance of this technology is difficult to tell.

Basically, statistical multiplexers that have been tweaked for a
"typical" voice call to Aunt Grunaldehyde or your broker don't
perform so well when passing many many kilobytes at 1200 baud.

On the other hand, if you tweak them for data transmission (or go
straight time division multiplex), a conversation is hard to
have.

It seems like we're going to have the old data vs voice channel
problem again...

rich@aoa.UUCP (Rich Snow) (04/11/90)

In article <40835@iuvax.cs.indiana.edu>, harlan@silver.ucs.indiana.edu (Pete Harlan) writes:
> In the suggested letter for battling the [fictitious] FCC legislation
> regarding modems, there is written:
> 
> | [...]  Calls placed using modems require no special telephone
> | company equipment, and users of modems pay the phone company for use
> | of the network in the form of a monthly bill. In short, a modem call
> | is the same as a voice call and therefore should not be subject to any
> | additional regulation.
> 
> As I understand it, the phone system can break up calls into discreet
> digital packets and send them out over the lines.  Thus it is not
> more than a voice line.  If this were the case, then the phone company
> would be justified in charging more for modem use than voice use.
> 
> Specifically, they should charge by the 'packet' rather than by the
> length of time spent on the line (well, a base charge per minute plus
> a per-packet charge.)
> 
> Do any readers know if calls really are broken up like that, or if
> there is just an unbroken connection from one end to the other that is
> left in place regardless of what is transmitted or not.
> 
> Pete Harlan
> harlan@silver.ucs.indiana.edu
> "You look bad, Seth."

Yes, most phone service in the US is provided by multiplexing the
voice data after it has been digitized. In general this is true of areas
where the central office has electronic switching, so if you have
a touch tone phone service and call waiting - forwarding etc. you
probably don't have a dedicated line. I believe that all long distance
voice services are digital at this point.

The question of what they should base charges on is interesting...
Since the system is infrastructure, it is regulated heavily, and
the issues and the technology are so complex that basing a charge
"directly" on usage out of some sense of fairness is bound to be
a big mistake. A per usage charge is dependent on whose analysis
is applied to the problem - it's statistical.

The usage question is probably irrelevant anyhow since the primary
cost of the system is installation and maintenance - which are
only indirectly related to usage.

Note: be careful of the term 'packet' since in telecommunications
"packet networks" refer to something different than the regular
phone system.

This is kind of a general discussion for the Mac group, perhaps
we should continue it in another newsgroup?

Cheers,

	Rich Snow  AOA-----------------*
	...!{decvax,linus,ima,ihnp4}!bbncca!aoa!rich

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