From: Bob_Frankston@frankston.com
Newsgroups: comp.dcom.telecom
Subject: Thoughts About ISDN
Date: 12 Apr 92 19:11:00 GMT
Organization: TELECOM Digest
X-Submissions-To: telecom@eecs.nwu.edu
X-Administrivia-To: telecom-request@eecs.nwu.edu
X-Telecom-Digest: Volume 12, Issue 312, Message 1 of 7

Prescript: I've been putting these comments together for a while, but
at some point, I've got to ship the product even if it is not perfect
nor complete.  With that caveat in mind, I'm submitting this
commentary on ISDN and the rest of the universe.

I've just read through D.P.U. 91-63-B of the Commonwealth of
Massachusetts Department of Public utilities which is the response to
the ISDN filings.  I've already Prodigy's briefs on the subject.
Though the language was a bit long winded, it was, to my surprise,
fascinating.  I don't know how these compare to what the situation is
in other states, but there is some spirited opposition to NET's
attempt to sell ISDN services at a high rate.  The Prodigy filing also
incorporated some of Mitch Kapor's research.

I should also strongly emphasize that I am not a lawyer, I'm not well
versed in regulatory law.  I'm more a dabbler/kibbitzer in these
matters, then an expert.  Given all that, I'll attempt to give a
biased summary of the filings and my reactions.  More my reactions
than summary.

The basic position of NET is that ISDN is an optional offering that
should be priced at competitive rates.  Where competitive means "what
the market will bear".  Prodigy's position is that ISDN should be a
basic part of the communications infrastructure and should be priced
at a rate that would encourage its use, or at least, not discriminate
against its use.  NET referred to Prodigy's view as a "field of
dreams" wherein Prodigy expects that if ISDN were available, people
would flock to it.  NET claimed its studies showed that there are
people who would pay high rates for ISDN and thus it should be priced
for the known customers.  I call this "railroad pricing" referring to
the days when the railroads were in decline and kept increasing their
rates to get the same return from fewer passengers and thus reduced
the number of passengers etc.  Even worse, for communications
offering, providing only one hand so that people can experiment with
clapping has its limits.

There is much discussion on what the actual costs of ISDN deployment
are.  This gets complicated because the costs of ISDN components vary
due to accounting considerations as well as purchase price variations
due to one time offers, quantity discounts and startup costs.  The
distinction between hardware, software and other components is not
clear, so I resort to the technical term "stuff".  The fact that these
are not broken out makes it hard to evaluate some of the claims.

The DPU seems to be caught in the middle.  It seems to buy into the
infrastructure argument but is very conservative on limiting NETs
rates since NET must be allowed to recover its costs.

Now a word from our sponsor -- me.  I had a number of disparate
(knowing how bad spelling is on the net, I should point out that that
is not a typo for desperate) reactions to reading these filings.

One question is whether ISDN is the right service for data.  Some of
the DPU discussion was on the relationship of ISDN as a data transport
with switched 56KB (an example of high priced service).  But there was
no discussion on how to provide a connectivity other than point to
point bulk data transfer.  I realize the advantage of concentrating on
ISDN issues is that there is at least some agreement on what ISDN is
 -- a necessary prerequisite for rational debate.  Given the grief that
NET is giving over ISDN deployment, asking for really different
services seems to be an uphill battle.

Which brings us to NET as a consumer buying merchandise off the shelf.
It seems that once they've bought into an exchange (often the DMS-100)
they are captives of their maintenance plan with the exchange.  I
can't imagine them buying anything nontrivial from anyone but
Northern-Telecom for its DMS-100 COs.  It doesn't seem they have much
negotiating leverage.  It would be nice to see the CO become a more
distributed entity that allowed more mixing and matching from
different vendors.  For now, at least, it is not clear how to build
such a system.  This further concentrates debate on off-the-shelf ISDN
because alternatives are problematic.

NET whines about the difficulty of providing ISDN, yet they seem to
have no problems if you want Intellipath and Centrex, both of which
are ISDN-based services.  This seems to be far from a level playing
field.  I'd like to see a situation in which NET couldn't base any of
its services on ISDN unless others gain the same access.  Of course,
the fact that the ISDN services seem to run in the same switch as ISDN
itself means that they can provide the services without the
complexities of providing ISDN to third parties.  This goes back to
the issue of the monolithic CO.  Perhaps ISDN can be a mechanism for
brining CO capabilities outside the physical (or even logical) machine
so that the protocols necessary for these services are provided at
arms length and thus provide a mechanism for a marketplace.

This issue of ISDN as a set of protocols for implementing a
marketplace is an interesting one but not fully fleshed out in the
current ISDN protocols.  It should receive explicit attention in its
own right. Given all this, it still galls me to see NET refer to
capabilities by their service product names rather than the generic
features.  It also recalls the problems that "good' COCOTS have in
trying to compete with NET in the pay phone business since NET gives
itself a great deal on the costs of phone calls (of course, the fact
that Massachusetts still mandates $.10 for NET pay phones is probably
also a factor -- something that bespeaks a strong DPU which might make
the state a good place for ISDN advocacy).

The cellular phone network offers an interesting case study.  In
following the discussions of features of the cellular phone network,
it feels like amateur night wherein features are cobbled together by
kludging together disparate systems.  A lot of the feature set depends
on whether one happens to have an Ericsson or Motorola switch and what
sort of jumpers have been placed between them.  I get the impression
that many features are implemented by placing a PC (personal computer)
offnet and having it send back DTMF codes.  I see this a symptom of
the complexity of making any changes in the network.  At least, in the
network as currently architected

The ISDN and cellular problems illustrate the problem of what happens
when one buys a complete service from a monopoly.  Unlike the PC world
of mix and match, you get all or nothing.  A long term agenda should
be to go beyond simply breaking of ATT to architecting a communications 
infrastructure that consists of components.  This is very very
difficult, especially when coupled with requirements for reliable and
predictable service.  It is less clear that the current approach is
more amenable to graceful evolution.

A more modest approach is to encourage competition on the local loop.
Perhaps the RBOCs should be divested of their control of the right of
way and instead, all parties would have equal access to the
communications right of way at a physical level.  Access at a logical
or signal level is more complicated.  We'll see some of this in action
now that Cable companies are becoming more of a force for loop
competition.  Cable company monopolies are anther topic I won't get
into here.

Back to my Ox.  The current network is designed for voice
communications with services like switched 56KB being viewed as
expensive premium services.  But the reality is just the opposite.
Voice is very demanding of the network whereas data communications is
very forgiving of delays and can recover from errors (OK, voice can
tolerate many errors that give data fits).  So why is voice cheap and
data expensive?  There are some answers in the current network
architecture but these are not intrinsic.

The other aspect is the circuit switched model for data
communications.  Admittedly it is possible to get an X.25 connection
that does provide a switched service but I'm not confident that it is
sufficiently standard for me to assume I can make a very cheap quick
connection to a service and be charged accordingly.  If I want to get
one stock price, how much overhead is involved?  If I want to keep
simultaneous connections to multiple services is there a holding
charge?  I realize that there is a contradiction between my asking for
a raw service from telco and the ability to then buy enhanced services
from other parties.  But is the raw service copper to the CO and a
voice path or is it a datapath.  If a third party provides the packet
service, do all messages have to travel through the network and then
get redispatched?  Are there sufficient standards for things to "just
work"?

This brings us to the concept of intra CO tariffs. These do exist for
Centrex and might exist for early ISDN capabilities which can be
supported within a switch but which must await protocol upgrades
(SS7?) in order to communicate with other exchanges.  I can image that
a call within the exchange being essentially free but having a
significant charge to call the next town.  Or should social policy
minimize this?  We already have the example of cable TV systems where
I simply cannot get broadcasts from the next town -- a very bad
precedent but something we accept as if it were natural rather than a
kludge while we await BISDN (where BISDN is a code word for switched
video but not limited to ISDN protocols).

Postscript.  I've seen mention that NET has adopted ISDN pricing that
is akin to standard message unit service but haven't seen the details.
I've also received a brochure from Nynex touting Basic Exchange
Service which seems to be their ISDN Centrex replacement that lists a
menu of features that you can select 3 of plus optional features.  Of
course, it is these services that are being offered, not "raw" ISDN.