Communications Project

Document Type:Dissertation
Name:David C. Lee
Title:Active Library Resolution in Active Networks
Degree:Doctor of Philosophy
Department:Electrical and Computer Engineering
Committee Chair: Scott F. Midkiff
Committee Members:James D. Arthur
Nathaniel J. Davis, IV
F. Gail Gray
Charles E. Nunnally
Keywords:Library Resolution, Active Networks
Date of defense:February 20, 1998
Availability:Release the entire work for Virginia Tech access only.
After one year release worldwide only with written permission of the student and the advisory committee chair.


An active network is a computer network in which new protocols can be installed at run-time in any node within the network. For example, the deployment of Internet multicast technology has been slow because service providers have been reluctant to upgrade and reconfigure their routing nodes. Under the active network scheme, users who desire multicast services can have the service automatically installed without any direct intervention by the user or the provider.

One major question in realizing active networks is how the code for the new active library can be found, or resolved, and retrieved. A model of the resolution and retrieval mechanisms is the major focus of this research. To validate the model, a proof-of-concept experimental system that realizes a simple active network architecture was developed. An active library resolution service model, suitable for a global Internet, was investigated using this experimental platform and a simulation system. The two protocol components that were built and studied are the active transport protocol and the active library resolution protocol.

The experimental and simulation systems were used to evaluate the extensibility, overhead, resolution time, scalability, and policy constraint support of the service. Extensibility and policy constraint support are an integral part of the proposed design. For libraries located on servers that are at most ten hops away from the requesting source, the resolution time is under 2.6 seconds. Simulations of networks of different sizes and with different error rates exhibit linear resolution time and overhead characteristics, which indicates potential scalability. Behavior under high loss rates showed better than expected performance. The results indicate that the library resolution concept is feasible and that the proposed strategy is a good solution.

List of Attached Files


At the author's request, all materials (PDF files, images, etc.) associated with this ETD are accessible from the Virginia Tech network only.

The author grants to Virginia Tech or its agents the right to archive and display their thesis or dissertation in whole or in part in the University Libraries in all forms of media, now or hereafter known. The author retains all proprietary rights, such as patent rights. The author also retains the right to use in future works (such as articles or books) all or part of this thesis or dissertation.