Using Object - Oriented Techniques

Appropriate use of object-oriented programming mechanisms in the implementation of communication architectures results in a type structure that reflects the architectural model and increases the run-time performance of the protocol machines at each layer. This result is important since it contradicts the assertion by some that layered protocol architectures, such as the ISO Reference Model, necessarily suffer in performance because of layering, thus forcing implementors to violate the layering principle in search of efficiency. The result substantiates the experience of others, notably Clark, that sound network programming methodology leads to efficient implementations that are also understandable. In this paper, elements of an object-oriented implementation of the upper layer OSI protocols are presented. The purpose of the paper is two-fold: first, to communicate to software engineers, particularly those developing systems software, that object-oriented programing techniques facilitate and enhance the implementation of layered architectures; second, to convey to language designers that object-oriented language features are useful in building communication protocols. The focus is on the requirements for the upper layer OSI protocols and how inheritance, subtyping, and polymorphic functions effect their implementation. Paper Category: Experience CHRIS J. TOMLINSON MCC 3500 W. Balcones Center Dr. Austin, TX 78759-6509 512.338.3765 [email protected] R. GREG LAVENDER MCC 3500 W. Balcones Center Dr. Austin, TX 78759-6509 512.338.3252 [email protected] DENNIS G. KAFURA Department of Computer Science 562 McBryde Hall, Virginia Tech Blacksburg, VA 24061-0106 703.231.5568 [email protected]