Introduction        iii
 1     Scope
 2     Normative references
        2.1     Identical Recommendations | International Standards
        2.2     Paired Recommendations | International Standards equivalent in technical content
 3     Definitions
        3.1     Reference Model definitions
        3.2     This Recommendation | International Standard uses the following terms defined in CCITT Rec. X.290 | ISO/IEC 9646-1:
        3.3     Additional definitions
 4     Abbreviations
        4.1     Data units
        4.2     Types of transport-protocol-data-units
        4.3     TPDU fields
        4.4     Parameters
        4.5     Miscellaneous
 5     Overview of the transport protocol
        5.1     Service provided by the Transport Layer
        5.2     Service assumed from the Network Layer
        5.3     Functions of the Transport Layer
        5.4     Model of the Transport Layer
 6     Protocol mechanisms
        6.1     Transport-protocol-data-unit (TPDU) transfer
        6.2     Transfer over the connectionless-mode network service
        6.3     Transfer over the connection oriented network service
        6.4     Checksum
 7     Encoding of the unit data (UD) TPDU
        7.1     General
        7.2     Unit data (UD) TPDU
 8     Conformance
Annex A – State table
Annex B – PICS proforma
        B.1     Introduction
        B.2     Abbreviations and special symbols
        B.3     Instructions for Completing the PICS Proforma
        B.4     Identification
        B.5     Base Standard/Recommendation Conformance
        B.6     General Statement of Conformance
        B.7     PICS Proforma
Annex C – Checksum algorithms
        C.1     Symbols
        C.2     Arithmetic conventions
        C.3     Algorithm for generating checksum parameters
        C.4     Algorithm for checking checksum parameters