This paper presents a new fault tolerance control unit model in call-based architecture. The main feature of the model is that a control unit is able to individual repair that uses to improve system reliability in case of control units are failure. In the approach considered a cell to be multi-layers that separate repairing and detecting of each layer, and also used to support repair and detect faults between layers. This paper shows how the model can be used to repair cover a single fault and multiple faults. The reliability analysis shows the improving fault-tolerance of this model.