To reduce interoperability problems arising from ambiguous or incomplete web services protocol specifications, we have recently introduced a formal framework, which allows modelling and automatic verification of such protocols. However, interoperability problems can still occur due to incorrect implementations.
In this paper, we introduce a sniffer based approach to check the conformance of a protocol?s implementation to its specification; messages of the actual implementations are captured, processed and checked against the specification?s formal model. We also briefly illustrate the application of our framework using a version of the WSAtomicTransaction protocol.