The results of a simulation study undertaken to evaluate a high-performance packet-switching fabric supporting point-to-point and multipoint communications are presented. This switching fabric contains several components, each based on conventional binary routing networks. The most novel element is the copy network, which performs the packet replication needed for multipoint connections. Results characterizing the performance of the copy network are presented. Several architectural alternatives for conventional binary routing networks are also evaluated. For example, the performance gains obtainable by using cut-through switching in the context of binary routing networks with small buffers are quantified. One surprising result is that networks constructed from nodes with more then two input and output ports can perform less well than those constructed from binary nodes. This result is quantified and explained. >