DEVELOPMENT AND PERFORMANCE ASSESSMENT OF A DISTRIBUTED ASYNCHRONOUS PROTOCOL FOR REAL-TIME NETWORK RESTORATION

We describe the methodology used, and results obtained, in the computer-experimental development and verification of a new protocol for real-time network restoration. This protocol, called Selfhealing, relies on a combination of hardware and software features to achieve a dramatic advance in the speed of restoring network spans that have been cut. The hardware environment provides a new paradigm for heavily parallel, asynchronous, distributed interaction. This environment is uniquely suited to interactions between digital cross-connect switches (DCS) embedded in a high-capacity transport network. The goals of our study were: 1) to derive a very fast, distributed, database-free protocol for restoration which would exploit the proposed technique for distributed interaction; and 2) to verify the speed obtainable under realistic asynchronous conditions in models of the future Telecom Canada network. The speed determination was based on an implementation of the protocol exactly as it would exist in the target DCS host machine. This paper reports the results and problem-specific methodologies that were used both to derive and characterize this new protocol. We believe this is the first major study of a distributed protocol for this particular routing problem, and the first detailed emulation and mechanized tool set for modeling the communication networks which use this specialized protocol.