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Network Working Group M. Taylor Request for Comments: 1674 CDPD Consortium Category: Informational August 1994

                  A Cellular Industry View of IPng

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 memo is a response to RFC 1550, "IP: Next Generation (IPng)
 White Paper Solicitation".  The statements in this paper are intended
 as input to the technical discussions within IETF, and do not
 represent any endorsement or commitment on the part of the cellular
 industry, the Cellular Digital Packet Data (CDPD) consortium of
 service providers or any of its constituent companies.

Introduction

 This is a draft of the requirements for IPng as envisioned by
 representatives of the Cellular Digital Packet Data (CDPD) consortium
 of service providers.  As the leading service providers for this
 nascent technology, which will provide the capability for mobility of
 native mainstream connectionless network layer-based applications it
 is our intention to support whatever form IPng takes.  However, there
 are several requirements which we feel IPng must meet.

Mobility

 Since we will offer mobile services, our primary requirement is that
 IPng not inhibit our support of mobility.  IPng must not impede
 devices from being able to operate anywhere anytime.  Applications on
 these mobile devices must look and feel the same to the user
 regardless of location.  NPDUs should be self-contained and not
 disallow the redirection inherent to our mobility solution, i.e.,
 IPng must be connectionless.

 Further, since IPng provides an opportunity for design enhancements
 above and beyond IPv4, we propose that native support for mobility be
 regarded as an explicit IPng requirement.  Local area and wide area
 wireless technology creates new opportunities for both TCP/IP and the
 Internet.  Although the capability for mobility is orthogonal to the
 wired or wireless nature of the data link in use, the rapid

Taylor [Page 1]  RFC 1674 A Cellular Industry View of IPng August 1994

 deployment wireless technology amplifies the requirement for
 topological flexibility.

 As a by-product of mobility, the significance of "occasionally-
 connected hosts" increases.  The ability to accommodate
 occasionally-connected hosts in IPng is a requirement.

Scale

 In terms of scale, we envision some 20 to 40 million users by the
 year 2007.  In this context a "user" can be anything from a vending
 machine to a "road warrior".  These numbers are for North America
 alone.  Worldwide, we anticipate that IPng should be able to support
 billions of "users".  Of course, the sparseness of network address
 assignments which is necessary for subnetting, etc., dictates that
 IPng should support at least tens or hundreds of billions of
 addresses.

Addressing

 In terms of addressing, we would expect addresses to be hierarchical.
 In addition, a node with multiple links should require only a single
 address although more than one address should also be possible.  The
 mapping of names to addresses should be independent of location; an
 address should be an address, not a route.  Variable-length
 addressing is also required to ensure continued protocol (IPng)
 extensibility.  Administration of address assignments should be
 distributed and not centralized as it is now.

Security

 IPng should also support security mechanisms which will grow
 increasingly important on the proverbial "information highway" for
 commercial users.  Security services which may optionally be expected
 from a Layer 3 entity such as IPng include peer entity
 authentication, data confidentiality, traffic flow confidentiality,
 data integrity and location confidentiality.

Accounting

 The ability to do accounting at Layer 3 is a requirement.  The CDPD
 specification can be used as a model of the type of accounting
 services that we need.

Taylor [Page 2]  RFC 1674 A Cellular Industry View of IPng August 1994

Route Selection

 In the voice communications arena, "equal access" and choice of an
 "interexchange carrier (IXC)" are issues that must be addressed.
 Similar requirements for data may also exist.

 Source- and policy-based routing for inter-domain traffic can address
 this requirement.  IPng must allow the selection of at least the
 first transient network service provider based on the source host.

Data Efficiency

 The bandwidth of wide area wireless networks is a precious resource,
 the use of which must be optimized.  IPng must allow optimal use of
 the underlying Layer 2 medium.  Layer 3 Protocol Control Information
 (PCI) should be as condensed as possible.  The protocol should be
 optimized for data efficiency.

 Packet prioritization must also be supported by IPng in order to
 optimize the use of low speed networks.  This requirement includes
 both class and grade of service definitions for flexibility.

Transition

 The final requirement for IPng is that it must interoperate with IP
 for the foreseeable future.  Bridging mechanisms must be supported
 and a strategy for the transition from IPv4 to IPng must be defined.
 Use of options fields, etc., are one mechanism to support the
 requirement for IPng protocols to support IP addresses and headers.

Security Considerations

 See section on Security.

Author's Address

 Mark S. Taylor
 Director of System Development
 McCaw Cellular Communications, Inc.
 Wireless Data Division
 10230 NE Points Drive
 Kirkland, WA 98033-7869 USA

 EMail: mark.s.taylor@airdata.com

Taylor [Page 3]