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