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Network Working Group                                          M. TaylorRequest for Comments: 1674                               CDPD ConsortiumCategory: Informational                                      August 1994A Cellular Industry View of IPngStatus 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 toRFC 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 rapidTaylor                                                          [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 1994Route 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.comTaylor                                                          [Page 3]