We consider a traffic model where a single source generates traffic having J (J/spl ges/2) quality of service (QoS) classes, QoS in this case described by a cell loss probability objective /spl epsiv//sub j/ for QoS class j. We assume that /spl epsiv//sub 1//spl ges//spl epsiv//sub 2//spl ges/.../spl ges//spl epsiv//sub J/, in other words, class J has the most stringent QoS requirements and class 1 the least. The traffic from K such independent heterogeneous Markov-modulated fluid sources is multiplexed into a single buffer of size B. There are J-1 thresholds.>

Traffic consisting of two classes (0 and 1) arrives at a buffer in a bursty fashion. The type-0 traffic is always admitted into the buffer (of size B/sub 0/) as long as there is space for it. Type-1 traffic is admitted to the buffer only if the buffer content does not exceed a threshold B/sub 1spl les/B/sub 0/. The authors develop an analytical model to determine the bandwidth allocation in order to ensure that the packet loss probability of type-i traffic does not exceed /spl epsisub i/, where 0>

The authors describe a technique for computing the distribution of the completion time of a program on a server subject to failure and repair. Several realistic aspects of the system are included in the model. The server behavior is modeled by a semi-Markov process in order to accommodate nonexponential repair-time distributions. More importantly, the effect on the job completion time of the work lost due to the occurrence of a server failure is modeled. They derive a closed-form expression for the Laplace-Stieltjes transform (LST) of the time to completion distribution of programs on such systems. They then describe an effective numerical procedure for computing the completion time distribution. They show how these results apply to the analysis of different computer system structures and organizations of fault-tolerant systems. Finally, they use numerical solution methods to find the distribution of time to completion on several systems.>