Banyan networks and their improved switches such as 2-dilated banyan networks are usually constructed by a self-routing mechanism, and provide a high multiplexing transmission capacity to ATM networks. Due to cell blocking in the switching elements in these banyan networks, however, cell loss is occurred and then the throughput of each network is decreased. To improve this problem, we have introduced bypasses to the original and the 2-dilated banyan networks. This paper focuses on the position of the bypasses in these banyan networks and proposes the one-bypass-connection methods in order to minimize cell transfer delay caused by the bypasses. We also analyze output rate of each network and show that the bypass method gives network designers flexible selections for network performance and transfer delay.

Packet contention is one of the fundamental problems that must be overcome in designing packet switches. In banyan network, which has multistage interconnection structure of many small switch elements, we must be concerned with output port conflicts and internal collisions. Dilated banyan network which provides multiple path for internal link can reduce packet loss due to internal collisions in loss system. However, under hot-spot traffic higher packet loss probability is measured at the hot-spot port and the ports close to the hot-spot as coefficient h increases due to the heavy traffic to hot-spot port. In order to moderate the packet loss probability at the hot-spot port we propose the method to disperse the packets which concentrate on the hot-spot route by altering address field of a half of incoming packets. These packets are switched along detour routes. Thus, the traffic concentration toward hot-spot is mitigated and the packet loss probability at the hot-spot port is moderated.

Multicasting is an important feature for any switching network being intended to support broadband integrated services digital networks (B-ISDN). This paper proposes an improved multicast packet switch based on Lee's nonblocking copy network. The improved design retains the desirable features of Lee's network including its nonblocking property while adopting techniques to overcome the various limitations mentioned in various literature. The proposed network architecture utilizes d-dilated banyan networks to increase the amount of cells that can be replicated within the copy network. Cell splitting is used to optimize the utilization of the network's available bandwidth. Furthermore, the proposed architecture allows for the modular expansion in capacity to accomodate changing traffic patterns. The modular design of the proposed switch likewise offers easy handling and replacement of faulty modules.