Goals for Internet Messaging to Support Diverse Service Environments
RFC 4416

Network Working Group                                       J. Wong, Ed.
Request for Comments: 4416                               Nortel Networks
Category: Informational                                    February 2006

    Goals for Internet Email to Support Diverse Service Environments

Status of This Memo

   This memo provides information for the Internet community.  It does
   not specify an Internet standard of any kind.  Distribution of this
   memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2006).

Abstract

   This document is a history capturing the background, motivation and
   thinking during the LEMONADE definition and design process.

   The LEMONADE Working Group -- Internet email to support diverse
   service environments -- is chartered to provide enhancements to
   Internet mail to facilitate its use by more diverse clients.  In
   particular, by clients on hosts not only operating in environments
   with high latency/bandwidth-limited unreliable links but also
   constrained to limited resources.  The enhanced mail must be
   backwards compatible with existing Internet mail.

   The primary motivation for this effort is -- by making Internet mail
   protocols richer and more adaptable to varied media and environments
   -- to allow mobile handheld devices tetherless access to Internet
   mail using only IETF mail protocols.

   The requirements for these devices drive a discussion of the possible
   protocol enhancements needed to support multimedia messaging on
   limited-capability hosts in diverse service environments.  A list of
   general principles to guide the design of the enhanced messaging
   protocols is documented.  Finally, additional issues of providing
   seamless service between enhanced Internet mail and the existing
   separate mobile messaging infrastructure are briefly listed.

Wong                         Informational                      [Page 1]
RFC 4416                     LEMONADE Goals                February 2006

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4
   2.  Conventions Used in This Document  . . . . . . . . . . . . . .  6
   3.  Messaging Terminology and Simple Model (Client-to-Server
       Aspect Only) . . . . . . . . . . . . . . . . . . . . . . . . .  6
     3.1.  Messaging Transaction Models . . . . . . . . . . . . . . .  6
     3.2.  Mobile Messaging Transactions  . . . . . . . . . . . . . .  7
       3.2.1.  Submission . . . . . . . . . . . . . . . . . . . . . .  7
       3.2.2.  Notification . . . . . . . . . . . . . . . . . . . . .  7
       3.2.3.  Retrieval  . . . . . . . . . . . . . . . . . . . . . .  8
   4.  Profiles . . . . . . . . . . . . . . . . . . . . . . . . . . .  8
     4.1.  Existing Profiles  . . . . . . . . . . . . . . . . . . . .  8
       4.1.1.  Voice Messaging (VPIMv2) . . . . . . . . . . . . . . .  8
       4.1.2.  iFax . . . . . . . . . . . . . . . . . . . . . . . . .  9
       4.1.3.  Internet Voice Mail (IVM)  . . . . . . . . . . . . . .  9
     4.2.  Putative Client Profiles . . . . . . . . . . . . . . . . .  9
       4.2.1.  TUI  . . . . . . . . . . . . . . . . . . . . . . . . .  9
       4.2.2.  Multi-Modal Clients  . . . . . . . . . . . . . . . . . 11
       4.2.3.  WUI  . . . . . . . . . . . . . . . . . . . . . . . . . 11
   5.  General Principles . . . . . . . . . . . . . . . . . . . . . . 13
     5.1.  Protocol Conservation  . . . . . . . . . . . . . . . . . . 13
       5.1.1.  Reuse Existing Protocols . . . . . . . . . . . . . . . 13
       5.1.2.  Maintain Existing Protocol Integrity . . . . . . . . . 13
     5.2.  Sensible Reception/Sending Context . . . . . . . . . . . . 13
       5.2.1.  Reception Context  . . . . . . . . . . . . . . . . . . 13
       5.2.2.  Sending Context  . . . . . . . . . . . . . . . . . . . 13
     5.3.  Internet Infrastructure Preservation . . . . . . . . . . . 14
     5.4.  Voice Requirements (Near Real-Time Delivery) . . . . . . . 14
     5.5.  Fax Requirements (Guaranteed Delivery) . . . . . . . . . . 14
     5.6.  Video Requirements (Scalable Message Size) . . . . . . . . 14
   6.  Issues and Requirements: TUI Subset of WUI . . . . . . . . . . 14
     6.1.  Requirements on the Message Retrieval Protocol . . . . . . 14
       6.1.1.  Performance Issues . . . . . . . . . . . . . . . . . . 15
       6.1.2.  Functional Issues  . . . . . . . . . . . . . . . . . . 16
     6.2.  Requirements on the Message Submission Protocol  . . . . . 18
       6.2.1.  Forward without Download Support . . . . . . . . . . . 18
       6.2.2.  Quota by Context Enforcement . . . . . . . . . . . . . 19
       6.2.3.  Future Delivery Support with Cancel  . . . . . . . . . 19
       6.2.4.  Support for Committed Message Delivery . . . . . . . . 20
     6.3.  Requirements on Message Notification . . . . . . . . . . . 20