Evaluation and improvement of fault coverage for verification and validation of protocols

The paper analyzes the fault coverage of testing protocols using Unique Input/Output (UIO) sequences. UIO sequences can be efficiently employed in checking the conformance specifications of protocols for distributed systems by using transition testing. This process is based on finding the Rural Chinese Postman Tour of the state transition graph of a finite state machine. A new comprehensive fault model is developed and analytical expressions are given for the fault coverage. The conditions for undetectability are analyzed and a new algorithm is proposed. Simulation results and illustrative examples are presented. Overhead issues are discussed and significant improvements are shown for achieving 100% fault coverage. The major advantage of the proposed approach is that it provides the theoretical basis for fault coverage evaluation of protocol testing using UIO sequences