PERFORMANCE MODELING OF PARTIAL PACKET DISCARDING USING THE END-OF-PACKET INDICATOR IN AAL TYPE-5

The ATM adaptation layer type 5 (AAL5) is an adaptation layer protocol for the ATM layer of broadband integrated services digital networks ( BISDN's), which targets connection-oriented services. Among several fe atures, it is unique in the sense that it includes an end-of-packet (E OP) indicator in the header of the ATM cell (the ATM-layer-user-to-ATM -layer-user (AUU) parameter in the payload type (PT) field). It was su ggested that the use of this indicator may be used to provide a means by which buffer occupancy can be reduced by selectively dropping cells from already incomplete packets [1]. The objective of this paper is t o study the performance of this layer and the effectiveness of the EOP indicator, The performance measures of interest are the probability o f packet loss and the mean packet delay, An approximate analytical mod el is constructed in which the blocking of a tagged source is kept tra ck of in an exact manner. The rest of the sources are modeled approxim ately, The accuracy of the model is enhanced through an iterative appr oach, A simulation model is also constructed to assess the accuracy of the approximate model.