RFC 1693 (rfc1693) - Page 2 of 36


An Extension to TCP : Partial Order Service



Alternative Format: Original Text Document



RFC 1693       An Extension to TCP: Partial Order Service  November 1994


   The authors envision the use of a partial order service within a
   connection-oriented, transport protocol such as TCP providing a
   further level of granularity to the transport user in terms of the
   type and quality of offered service.  This RFC focuses specifically
   on extending TCP to provide partial order connections.

   The idea of a partial order service is not limited to TCP. It may be
   considered a useful option for any transport protocol and we
   encourage researchers and practitioners to investigate further the
   most effective uses for partial ordering whether in a next-generation
   TCP, or another general purpose protocol such as XTP, or perhaps
   within a "special purpose" protocol tailored to a specific
   application and network profile.

   Finally, while the crux of this RFC relates to and introduces a new
   way of considering object ordering, a number of other classic
   transport mechanisms are also seen in a new light - among these are
   reliability, window management and data acknowledgments.

   Keywords: partial order, quality of service, reliability, multimedia,
   client/server database, Windows, transport protocol

Table of Contents

   1. Introduction and motivation ..................................  3
   2. Partial Order Delivery .......................................  4
   2.1 Example 1: Remote Database ..................................  4
   2.2 Example 2: Multimedia .......................................  8
   2.3 Example 3: Windows Screen Refresh ...........................  9
   2.4 Potential Savings ........................................... 10
   3. Reliability vs. Order ........................................ 12
   3.1 Reliability Classes ......................................... 13
   4. Partial Order Connection ..................................... 15
   4.1 Connection Establishment .................................... 16
   4.2 Data Transmission ........................................... 19
   4.2.1 Sender .................................................... 22
   4.2.2 Receiver .................................................. 25
   5. Quantifying and Comparing Partial Order Services ............. 30
   6. Future Direction ............................................. 31
   7. Summary ...................................................... 32
   8. References ................................................... 34
   Security Considerations ......................................... 35
   Authors' Addresses .............................................. 36








Connolly, Amer & Conrad