Subject: What is ISDN Good For?

From: mkapor (Mitch Kapor)
Date: Tue, 10 Dec 1991 18:34:55 -0500

[email-masked] (Harry Shapiro) writes:

"What applications that require ISDN can't already run with existing
products like switched 56 kbit, and 14,400 modems?"

Switched 56 kilobit service has the same order of bandwidth as 64 kbit
ISDN, but its availability is strikingly different.  Switched 56 is not
intended to be a residential service.  Our vision of ISDN is that you
simply order it the way you order an additional voice-grade phone line.
Further, we believe ISDN must be priced like voice telephone service.
Switched 56 is not priced like voice service.  It is much more
expensive.  ISDN must be ubiquitous and affordable.  Switched 56, while
useful for businesses which can afford expensive installation and fees
is not.

The ISDN rate of 64 kb is at the critical threshold which will permit
interactive multimedia using video and audio compression.  14.4 is
simply too slow, even with compression, for videotelephony, much less
other more demanding forms of video.  Before it is argued that the
effective rate of a V.32bis modem is not 14.4 kb, but 14.4 kb plus
compression effects, let me point out that the same compression
techniques can and will be applied over 64 kb ISDN lines, boosting its
effective rate by an equivalent factor of two to four.

While it is still considered heretical in some quarters to assert that
VHS-quality video will be possible over a 64 kb line, there is a growing
consensus among researchers at the cutting edge of work in this area
that that is exactly where we are headed.  In such a scenario, using
desktop personal computers of the year 1995 as video production studios,
everyone with access to a PC and ISDN potentially becomes a video
producer, with ISDN as the switched distribution network providing video
dial-tone.  This will open the floodgates of innovation in video,
acheiving the richness of video (not passive, but interactive) with the
type of diversity heretofore associated only with print.

Beyond ISDN are other protocols which can run over copper-pairs, such as
ADSL, which runs at 300 kb /second.  More on that later.

Mitchell Kapor
Electronic Frontier Foundation

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From: <[email-masked]> (by way of [email-masked] (Mitch Kapor))
Date: Fri, 13 Dec 1991 15:17:35 -0500

It seems that the main attribute of interest in ISDN is the (relatively)
high 
bandwidth.  Actually, this it is modest compared with other media (such as 
cable TV and newspapers), but still better than standard phone lines.

But there are other aspects that I'm more concerned about including:

* Ideally, ISDN should provide peer protocols between my premises equipment

and the central offices in terms of controlling connections and accessing 
network resources.  I should also be able to provide services.  A simple 
example is call forwarding -- I should be able to implement this locally.  
One advantage of a local implementation is the ability to add policies.  
These protocols should support queries about pricing and other service 
aspects.

* For data transmission I need to be able to connect to multiple services 
using either a datagram capability or multiple virtual circuits.  This
should 
be a standard offering so that I can build software that takes advantage of

it.

* Addressing (phone number) issues should be cleaned up over the current 
system so that I have a uniform way of addressing resources on the network.
 
I.e., no dial "9" for an outside line.  But this should be extended to 
subaddressing as in specifying an extension number, a person or service.  
This is similar to DID but universal without the high costs of a DID trunk.

This is extending the view of what ISDN is.  For example, I should be able
to 
use standard ISDN protocols to pass the additional data bits to a pager. 
(Of 
course, the character set should be Unicode and not just digits).

* Of course, pricing should be such that casual connection to network 
services for many hours should be comparable to the price for an unmeasured

service line.  The current message unit pricing assumes that the use of the

phone is an unusual event.  If it is our connection to the communications 
infrastructure then the default is to be connected and use of a modest size

information pipe should be negligible  Perhaps a better price comparison 
would be to the newspaper.  Getting the newspaper delivered via ISDN should

not cost more than getting some ink laden woodpulp hand carried to my
house.

In reading the notes about the physical wiring for ISDN, I'm concerned
about 
ISDN being an MIS manager dream and an end user's Procrustean bed.