PERFORMANCE EVALUATION OF ATM MULTIPLEXING SCHEMES FOR BURSTY TRAFFIC SOURCES IN LOSSY ATM NETWORKS

Two new service disciplines in an ATM Multiplexer or a Multiplexer based ATM switch for connectionless services are presented. Their main advantage is to avoid or minimize a fragmentation process that a frame undergoes when applying commonly used ATM Multiplexing disciplines. This is especially important when the data sources are applications running on Local Area Networks and generating frames, and the Multiplexer is an access unit in the BISDN ATM based Public Network used for a public LAN -WAN -LAN interconnection service. The disciplines proposed offer several advantages, namely they facilitate the reassembling of cells into frames and offer an overall better frame error rate performance, if similar strategies are carried out throughout the ATM network, when the network is lossy in terms of cells, and the cell loss tends to occur in bursts, as it is the case when by overloading, some buffers overflow. This is particularly likely to happen when the ATM network is operated not in connection oriented mode, or when resource allocation cannot be done effectively due to the impossibility to know in advance the bandwidth requirements of the connectionless sources, and where, as the case will be, one wants to obtain statistical gains in the network. This paper presents the new disciplines, simulate the performance against other disciplines already proposed for ATM Multiplexers, and compares their performance and the complexity for their hardware implementation.