RFC1216

Network Working Group Poorer Richard Request for Comments: 1216 Almanac Institute

                                                          Prof. Kynikos
                                                  Miskatonic University
                                                           1 April 1991

            Gigabit Network Economics and Paradigm Shifts

Status of this Memo

  This memo proposes a new standard paradigm for the Internet
  Activities Board (IAB) standardization track.  Distribution of this
  memo is unlimited.

1. Introduction

  The history of computer communication contains many examples of
  efforts to align the capabilities of processors to that of
  communication media.  Packet switching is the classic case of a
  careful tradeoff between the costs of memory, processing, and
  communications bandwidth.

  With all of the attention and publicity focused on gigabit networks,
  not much notice has been given to small and largely unfunded research
  efforts which are studying innovative approaches for dealing with
  technical issues within the constraints of economic science.  This
  memo defines one such paradigm.

2. Contemporary Network Economics

  Recent cost estimates predict a continuing decline in the cost for
  processing, memory, and communication.  One recent projection put the
  decline for $/bit and $/MIP at 99% per decade and put the decline for
  $/bps at 90% per decade.  Scalable parallel processor designs may
  accelerate the cost declines for CPU and memory, but no similar
  accelerated decline should be expected in the cost of communications.
  Such a decline would imply eventual declines in the cost of 56Kbps
  service used for voice, resulting in a negative rate of return for
  telecommunications carriers, an unlikely eventuality even if free-
  market forces are carried to their logical extreme.

  Increases in processing power create additional demand for
  communications bandwidth, but do nothing to pay for it.  While we
  will sell no paradigm before its time, the 9% difference,
  particularly after compounding is taken into account, will bankrupt
  the internet community unless a paradigm shift takes place.

RFC 1216 Gigabit Network Economics and Paradigm Shifts April 1991

3. The ULS Paradigm Shift

  The ULS paradigm shift breaks the downward spiral by concentrating on
  end-to-end datagrams and virtual circuit services operating in the
  .01 uGbps region, namely Ultra Low Speed networking.

  However,

  "The worlds best technological paradigm shifts are useless unless
  they (a) are economically viable, (b) have clear applicability, (c)
  are technically feasible."

          --Milton John in "Paradigms Lost"

3.1 Economic Viability

  Cost projections indicate that individual ULS circuits can be
  provided at a cost of <$.03/month due to the unusually high
  multiplexing that will be possible on Gbit links.  The 10 THz
  bandwidth of existing optical fibers will be able to support on the
  order of 1 TUser, handling population growth, and even internet
  growth, for some time.  Moreover, if $.03/month is a significant
  barrier to entry, substantial discounts appear to be economically
  feasible.

3.2 Clear Applicability

  A fundamental principle of networking is that network speed must
  match the application.  We have identified a number of critical
  applications that are matched to ULS technology.  Below we itemize a
  few of these, but we provide a brief description for only the first;
  the match for the others should be equally obvious.

  - Low priority facsimile: A large percentage of documents and letters
    are sent via facsimile not because they need sub-minute delivery,
    but because they carry signatures or graphics.  In these cases, a
    three-hour delivery (comparable to the value reliably achieved on
    many of today's packet-based email systems) is sufficient.  With
    proper compression, this delivery time can be achieved over a
    ULSnet.

  - Real time data (e.g., tracking glaciers)

  - US postal service

  - Contracting for research

  To be truly viable, ULS networking must scale, and indeed it does.

RFC 1216 Gigabit Network Economics and Paradigm Shifts April 1991

  With some effort, we envision extending the technology to the
  extremely-low-speed regime.  Applications that scale from the ULS
  applications above are:

  - Real time data (e.g., gravity wave detectors)
  - Italian postal service
  - Congressional budget process

3.3 Technical Feasibility

  The hardware issues are well in hand.  The remaining issues are
  protocol related.  To examine them, we must extrapolate backward from
  some well known networking principles.

  "Gigabit networks require new protocols."

  The clear inference here is that ULS will require old protocols, so
  as we recede into the future, we should expect the following:

  ULS will require minimal development.  Although we may need research
  in storage technology to recover the software from old media such as
  decayed magnetic dump tapes, paper tape, and partially recycled card
  decks, this effort will be more than offset by the savings.

  ULS protocols will be well documented, amenable to verification, and
  suitable for MSI implementation in Silicon, or even Germanium or
  relays.  In particular, the alternating bit protocol [1] is a leading
  contender.

  "Bad news travel fast."

  Therefore, ULS gives preferential treatment to good news.  While this
  will delay the delivery of bills, notices from timeshare
  condominiums, and contest announcements, it will also produce
  immediate productivity gains on several mailing lists.

3.4 Problems Requiring Work

  ULS is not without problems.

  Some other well-known protocol suites are well ahead of ULS in
  exploring the desired performance operating point.  We note our
  concern about the dearth of domestic (U.S.-based) research and
  development in this important area.  This is particularly disturbing
  in light of the level of work now underway in other countries.

  Efficiency is a problem:

RFC 1216 Gigabit Network Economics and Paradigm Shifts April 1991

  - All ULS protocols incorporate slow-start.

  - Lower data rates mean fewer errors.

  - Whereas modern protocols use 32 bit sequence numbers,
    acknowledgment fields, etc., ULS headers can be quite small (1 bit
    sequence numbers for the alternating-bit protocol).  Thus the
    header/data ratio shrinks.

  The net result is "creeping efficiency" which tends to push us away
  from the proper ULS operating point.  While we have no definitive
  solution, there are several promising palliatives:

  - Forward Error Insertion (FEI)

  - Negative window scaling factors

  - New protocol layers

  - Multiple presentation layers

4. Conclusions

  The road to Ultra Low Speed (ULS) technology is long, slow, and easy.

REFERENCES and BIBLIOGRAPHY

  [1] Lynch, W. "Reliable full-duplex file transmission over half-
      duplex telephone lines", CACM, pp. 407-410, June 1968.

Security Considerations

      Security issues are not discussed in this memo.

Authors' Addresses

      Dr. Poorer Richard
      Almanac Institute
      Center against Misoneoism
      Campo Imperatore, Italy
      EMail:  none

      Prof. Kynikos
      Miskatonic University
      Arkham, MA.
      Email: [email protected]