RFC 2126 (rfc2126) - Page 2 of 25

ISO Transport Service on top of TCP (ITOT)

RFC 2126              ISO Transport on top of TCP             March 1997


   3.2.3.1 Network Connection Establishment........................8
   3.2.3.2 Network Data Transfer...................................9
   3.2.3.3 Network Connection Release.............................10
   4. Transport Protocol Specification............................10
   4.1 Class 0 over TCP...........................................10
   4.1.1 Connection Establishment.................................11
   4.1.2 Data Transfer............................................11
   4.1.3 Connection Release.......................................11
   4.2 Class 2 over TCP...........................................12
   4.2.1 Connection Establishment.................................12
   4.2.2 Data Transfer............................................13
   4.2.3 Connection Release.......................................15
   4.3 TPKT Packet Format.........................................15
   5. Address representations.....................................16
   5.1 String representation of ITOT access point addresses.......17
   5.2 OSI Network Address encoding...............................17
   6. Notes to Implementors.......................................17
   6.1 TCP Connection Establishment...............................17
   6.2 TCP Data transfer..........................................17
   6.3 Class negotiation..........................................18
   6.4 Default maximum TPDU size..................................18
   6.5 Class 0 TPDU bit encoding..................................18
   6.6 Class 2 Options............................................19
   6.7 Class 2 Expedited Data Acknowledgement.....................21
   6.8 Class 2 Normal Data and Expedited Data handling............21
   6.9 Class 2 Forward Connection procedure.......................22
   6.10 TPKT......................................................22
   7. Rationale - Interoperability with RFC 1006...................22
   8. Security Considerations.....................................23
   Acknowledgements...............................................23
   References.....................................................23
   Authors' Addresses.............................................25

1. Introduction, Motivation

   There are two basic approaches which can be taken when "porting" ISO
   applications to TCP/IP ([RFC 793],[RFC 791]) and IPv6 [IPV6]
   environments. One approach is to port each individual application
   separately, developing local protocols on top of TCP. A second
   approach is based on the notion of layering the ISO Transport Service
   over TCP/IP. This approach solves the problem for all applications
   which use the ISO Transport Service. This document describes the
   second approach.

   The protocol described in this memo is based on the observation that
   both the Internet Protocol Suite and the ISO Protocol Suite are
   layered systems.  A key aspect of the layering principle is that of
   layer-independence.  The concept of layer-independence means that if



Pouffary & Young            Standards Track