||Advances in switching technologies are crucial to achieve the goal of current broadband ISDN. In my thesis, much work has been done on both electronic and photonic switching. In the photonic switching category, Log2(N,m,p) networks are examined and the methods to construct nonblocking multicast Log2(N,m,p) networks are discussed. The results presented allow the determination of the best design tradeoffs among some important parameters such as attenuation, crosstalk and the total amount of hardware, when used for directional-coupler-based photonic switching systems. In the electronic switching category, input organization and scheduling algorithm are our main focus to improve the performance of input-queued switches. A scheme with queue-splitting and random selection is deployed. Performance has been evaluated not only for single-stage and multi-stage switches with unicast traffic, but also for multicast switches. Simulation results show that great improvement in performance can be achieved if our approach is used. The most significant features of this scheme are that it can eliminate the degradation of traffic correlation and is applicable to both unicast and multicast traffic. Therefore, we conclude that this scheme is a good candidate for input-queued switch architectures.