Soft Protocols research in the FAN Club

Overview

The research is founded on a component-based view of computer communication protocols, in which we have identified a dozen largely-orthogonal underpinning principles that lead in turn to corresponding protocol techniques. This gives a horizontal perspective on communication systems, in contrast to the vertical perspective encouraged by the OSI reference model of ISO. Systems are still implemented in a layered manner, but there are no preconceptions about which functions are handled in which layers. The work blends ideas from human communication, from formal methods and from novel system architectures. The new perspective is explained and justified in extended form (470 pages) in the book "Computers in Communication" which was published by McGraw-Hill in 1997.

This research has application in our flexible architecture for networking applications research.


Areas of investigation

Active protocols

Active protocols are soft protocols used in an active network setting. Active protocols are defined, constructed and used dynamically, perhaps very dynamically on a per-connection basis. In general, active networks allow arbitrary (safe) computation at network nodes. Active protocols make use only of domain-specific computation - the domain being communication protocols - and so enhance reliability and safety. A prototype active protocol system is being constructed, using implementation over an "ABone" - an active protocol backbone.

Theory of soft protocols

This involves the specification and verification of soft protocol behaviour, using the Calculus of Communicating Systems (CCS), augmented by a new addition operator over actions. This allows soft protocol components to be specified, and their behaviour analysed. The longer-term aim is to mechanise the analysis in a "protocol workbench" - a tool for analysing communication protocol behaviour.

Modelling and simulation of soft protocols

This involves hierarchical methods that model system components at the coarsest level of detail adequate to obtain valid results, together with improved simulation algorithms and the use of supercomputers to assist with brute-force simulation. Validation is carried out as an interative process, to find the most efficient hierarchical model structure for production-run simulations.
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Gordon Brebner, questions to <gordon@dcs.ed.ac.uk>, 26 March 1999