Higher values represent higher Priority. Once a flow was admitted, the preemption priority becomes irrelevant. Instead, its defending priority is used to compare with the preemption priority of new flows. For any specific flow, its preemption priority must always be less than or equal to the defending priority. This provides a mechanism for balancing between order dependency and priority.
Denial of service is virtually the inverse of the free-rider problem.
Participating priority elements are selected. The highest priority of all participating priority elements is computed. The reasoning for this approach is that the highest QoS flow is the one dominating the merged reservation and as such its priority should dominate it as well. This approach is the most amiable to the prevention of priority distortions such as free-riders and denial of service. This is a recommended merging strategy.