Statistical delay guarantee of virtual clock

In this paper we derive a statistical delay guarantee of the generalized virtual clock scheduling algorithm. We define the concept of an equivalent fluid and packet source and prove a theorem that relates the departure time of a packet in a fluid FCFS multiplexor to its departure time in a packet multiplexor that uses generalized Virtual Clock algorithm for scheduling packets. This theorem enables us to use extant analyses of fluid FCFS multiplexors for providing statistical QoS guarantees in a network that employs the generalized Virtual Clock algorithm. We utilize the extant analysis of FCFS fluid multiplexors serving two-stare on-off sources with exponentially distributed on and off durations to evaluate the increase in utilization yielded by our analysis technique. Our experiments demonstrate that for one of the source models employed in the literature, our technique can increase utilization by up to 400% compared to previously know statistical analysis methods