Network Working Group J. Curran
Request for Comments: 1669 BBN
Category: Informational August 1994
Market Viability as a IPng Criteria
Status of this Memo
This memo provides information for the Internet community. This memo
does not specify an Internet standard of any kind. Distribution of
this memo is unlimited.
Abstract
This document was submitted to the IETF IPng area in response to RFC
1550. Publication of this document does not imply acceptance by the
IPng area of any ideas expressed within. Comments should be
submitted to the big-internet@munnari.oz.au mailing list.
Introduction
In an open marketplace, adoption of new technology is driven by
consumer demand. New technologies that wish to succeed in the
marketplace must provide new capabilities or reduced costs to gain
consumer confidence. Internetworking technologies can be
particularly difficult to deploy and must provide a correspondingly
high return on investment. In order to determine market viability of
new internetworking technology, it's necessary to compare the
required deployment effort against the potential benefits as seen by
the customer. "Viability in the Marketplace" is an important
requirement for any IPng candidate and this paper is an attempt to
summarize some important factors in determing market viability of
IPng proposals.
"Pushing" Internetworking Technology
It has been asserted by some that the adoption of a single IPng
protocol by the computing industry would generate general acceptance
in the networking industry. There is ample evidence to support this
view; for example, some of the today's more prevalent networking
protocols gained initial market acceptance through bundling with
computer operating systems (e.g. IP via UNIX, DECNET via VMS, etc.)
It should be noted, however, that this approach to technology
deployment is by no means assured, and some of today's most popular
internetworking software (Novell, etc.) have thrived despite
alternatives bundled by computing manufacturers. Given that IPng
will have to compete against an well established and mature
internetworking protocol (IP version 4), promotion of an IPng
solution by computer system manufacturers should be recognized as
highly desirable but not sufficient on its own to ensure IPng
acceptance in the marketplace.
Can IPng compete against IPv4?
Given the large installed base of IPv4 systems, computer system
manufacturers will need to continue to provide IPv4 capabilities for
the foreseeable future. With both IPng and IPv4 support in their new
systems, users will be facing a difficult choice between using IPv4
and IPng for internetworking. Existing IPv4 users will migrate to
IPng for one of three possible reasons:
New functionality not found in IPv4
IPng needs to provide functionality equivalent to that currently
provided by IPv4. It remains to be seen whether additional
functionality (such as resource reservation, mobility,
autoconfiguration, autoregistration, or security) will be included in
the base specification of any IPng candidate. In order to provide
motivation to migrate to IPng, it will be necessary for IPng
proposals to offer capabilities beyond those already provided IPv4.
Reduced costs by using IPng
It is quite unlikely that migration to IPng will result in cost
savings in any organization. Migration to IPng will certainly result
in an increased need for training and engineering, and hence
increased costs.
To gain connectivity to otherwise unreachable IPng hosts
For existing sites with valid IPv4 network assignments, connectivity
is not affected until address depletion occurs. Systems with
globally-unique IPv4 addresses will have complete connectivity to any
systems since backwards-compatible communication is required of new
IPng hosts.
From the perspective of an existing IPv4 site, IPng provides little
tangible benefit until IPv4 address depletion occurs and
organizations reachable only via IPng appear. Given the absence of
benefits from migration, it is uncertain whether a significant base
of IPng sites will be occur prior to IPv4 address depletion.
Sites which are not yet running IP have little motivation to deploy
IPng for the immediate future. As long as IPv4 network assignments
are available, new sites have an choice to use IPv4 which provides
the sufficient internetworking capabilities (measured in
functionality, cost, and connectivity) for many organizations today.
Given the parity in IPng and IPv4 capabilities, IPv4 (as a more
mature internetworking protocol) is the more probable choice for
organizations just now selecting an internetworking protocol.
Once IPv4 address assignments are no longer available, sites wishing
to participate in the global Internet will have a very difficult
decision in selection of an internetworking protocol. The current
suite of IPng proposals cannot provide complete internetworking
between IPng-only sites and IPv4-only sites since (by definition)
there will be insufficient space to map all IPng addresses into the
IPv4 address space. As none of the proposals currently call for
dynamic network address translation (NAT), it is inevitable that
IPng-only sites will have access to a partial set of IPv4 sites at
any given moment.
Internetworking services which do not allow complete access to the
global Internet (IPv4 and IPng in the post-IPv4-address-depletion
world) are clearly not as valuable as services which offer complete
Internet access. Sites which are unable to obtain IPv4 network
assignments will be seeking Internet services which can provide
complete Internet service. Additionally, some sites will have
"privately numbered" IPv4 networks and will desire similar Internet
services which provide transparent access to the entire Internet. The
development of network address translation devices and subsequent
services is highly likely under these market conditions.
Summary
No internetworking vendor (whether host, router, or service vendor)
can afford to deploy and support products and services which are not
desired in the marketplace. Given the potential proliferation of
network address translation devices, it is not clear that IPng will
secure sufficient following to attain market viability. In the past,
we have seen internetworking protocols fail in the marketplace
despite vendor deployment and IPng cannot succeed if it is not
deployed by organizations. As currently envisioned, IPng may not be
ambitious enough in the delivery of new capabilities to compete
against IPv4 and the inevitable arrival of network address
translation devices. In order to meet the requirement for "viability
in the marketplace', IPng needs to deliver clearly improved
functionality over IPv4 while offering some form transparent access
between the IPv4 and IPng communities once IPv4 address depletion has
occurred.
Security Considerations
Security issues are not discussed in this memo.
Author's Address
John Curran
BBN Technology Services, Inc.
10 Moulton Street
Cambridge MA 02138
EMail: jcurran@near.net