This presentation will describe the design and implementation of a middleware. It is a real-time fault-tolerance message-passing service provider in an industrial control system. The selection of the fundamental method for fault-tolerance in redundant LAN environment will be discussed. The author brings forwarded the Concurrent Transmission Method for fault-tolerance in the middleware, and will evaluate its performance in this presentation. Besides fault-tolerance, different issues that solved during design and implementation will also be covered to form a complete image of this middleware.