RFC 1698 (rfc1698) - Page 2 of 29


Octet Sequences for Upper-Layer OSI to Support Basic Communications Applications



Alternative Format: Original Text Document



RFC 1698             ThinOSI Upper-Layers Cookbook          October 1994


    4.3 Encoding methods and length fields ..........................14
    4.3.1 Session items .............................................14
    4.3.2 ASN.1/BER items (Presentation and ACSE) ...................14
    4.4 BER Encoding of values for primitive datatypes ..............15
    4.5 Unnecessary constructed encodings ...........................16
   5. Notation ......................................................16
   6. Octet sequences ...............................................17
    6.1 Connection request message ..................................17
    6.2 Successful reply to connection setup ........................20
    6.3 Connection rejection ........................................22
    6.4 Data-phase TSDU .............................................23
    6.5 Closedown  - release request ................................24
    6.6 Closedown - release response ................................25
    6.7 Deliberate abort ............................................25
    6.8 Provider abort ..............................................27
    6.9 Abort accept ................................................27
   7. References ....................................................27
   8. Other notes ...................................................28
   9. Security Considerations .......................................29
   10. Author's Address .............................................29

1.  Introduction

   The upper-layer protocols of the OSI model are large and complex,
   mostly because the protocols they describe are rich in function and
   options. However, for support of most applications, only a limited
   portion of the function is needed. An implementation that is not
   intended to be a completely general platform does not need to
   implement all the features. Further, it need not reflect the
   structuring of the OSI specifications - the layer of the OSI model
   are purely abstract.

   This document presents the protocol elements required by the OSI
   upper layers when supporting a connection-oriented application with
   only basic communication requirements - that is to create a
   connection, optionally negotiate the data representation,
   send/receive data, close a connection and abort a connection.
   Optionally, data may be sent on the connection establishment, closing
   and abort messages.

   In this document, the protocol elements needed are given in terms of
   the octet sequences that comprise the 'envelope' around the
   application data. The envelope and its enclosing data form a
   Transport Service Data Unit (TSDU) that can be passed via the OSI
   Transport Service [ISO8072] (which in turn may be supported as
   specified in [RFC 1006] or any class of the OSI Transport Protocol
   [ISO8073]).




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