RFC 1861 (rfc1861) - Page 2 of 26

Simple Network Paging Protocol - Version 3 -Two-Way Enhanced

RFC 1861                   SNPP - Version 3                October 1995


   become even more realized when growing towards acknowledgment-based
   messaging such as ReFLEX paging--where it may be impossible to
   accurately predict costs associated with telco services such as 1-800
   numbers.

2. System Philosophy

   Radio paging is somewhat taken for granted, because of the wide
   availability and wide use of paging products.  However, the actual
   delivery of the page, and the process used (especially in wider area
   paging) is somewhat complicated.  When a user initiates a page, by
   dialing a number on a telephone, or entering an alphanumeric page
   through some input device, the page must ultimately be delivered to
   some paging terminal, somewhere.  In most cases, this delivery is
   made using TAP (Telocator Alphanumeric input Protocol, also known as
   IXO).  This protocol can be a somewhat convoluted, and complicated
   protocol using older style ASCII control characters and a non-
   standard checksumming routine to assist in validating the data.

   Even though TAP is widely used throughout the industry, there are
   plans on the table to move to a more flexible "standard" protocol
   referred to as TME (Telocator Message Entry Protocol).  The level two
   enhancements to SNPP (as described below) are intended for use with
   this forthcoming standard.

   The recently-added level three enhancements have been engineered for
   use, specifically, with acknowledgment-based paging.  With the recent
   advances in wireless technology, two-way paging is fast approaching
   reality--therefore creating a need for a workable end-to-end
   acknowledged protocol.  Two-way messaging, however, opens up several
   new areas of unpredictability.  The most pronounced is the subscriber
   response time.  Although deliveries from host to subscriber, and
   subsequent receipt-acknowledgments happen in a rather predictable
   manner, it is impossible to know when the subscriber will physically
   pull the unit out, read the message and respond to it.  Therefore, it
   could well be cost prohibitive to conduct such transactions online
   using a phone line as medium--especially an 800-number. This makes
   the Internet an extremely attractive alternative because of its
   (generally) usage insensitive nature.

   However, acknowledging the complexity of task, and flexibility of the
   current protocols (or the lack thereof), the final user function is
   quite simple: to deliver a page from point-of-origin to someone's
   beeper.  That is the simple, real-time function that the base
   protocol attempts to address.






Gwinn                        Informational