A Novel Direct Upper Approximation for Workload Loss Ratio in General Buffered Systems

The workload loss ratio (WLR) is a key quantity from the point of Quality of Service (QoS) provisioning in packet-based communication, hence it’s estimation is an important issue. The existing results in the area of WLR approximation usually interpret the workload loss as a product of some well assessable quantities. We call this approach as the indirect approximation of the WLR. The drawback of this approach is that each estimation has an error and the product of these errors could result in a highly inaccurate bound. This work deals with the upper approximation of the workload loss ratio based on it’s original definition and proposes a new direct bound on the WLR applicable in general service curve network element. Extensive and systematic performance analysis of the formulae have been done, in which we found that the direct approach gives more accurate bound in several cases. We illustrate this analysis through some numerical examples.