Multicast switches have found many applications in communication networks. A common design of multicast switches is a tandem of a copy network and a point-to-point routing network. The occurrence of overflow is an inherent problem in copy networks. The authors study overflow control mechanisms in copy networks and present a novel copy-network architecture, which is based on T.T. Lee's design (1988). The network consists of three parts: an input cell-splitting stage, a shared-memory buffering stage and a copy distribution network. The proposed design provides a maximum throughput for the copy network with FIFO capability. A queueing model is also presented, to evaluate and compare the performance of this architecture with other previous work.