3-Tier Service Level Agreement with automatic class upgrades

Tremendous efforts have been spent on devising mechanisms that would provide quality of service (QoS) needed by various applications, and network operators have spent a lot of resources trying to fit their networks with differentiated services capabilities. One of the service level agreements (SLA) promising to sell these QoS services is the "triple play" SLA, bundling 3 classes of services targeting voice, video, and data. In this paper, we propose a "3-tier SLA with automatic class upgrades", an enhancement to the triple play SLA, in that it automatically upgrades lower classes' packets to fill the unused reserved bandwidths in the expensive, better quality upper classes. The enhancement incorporates a scalable solution to the reordering problem caused by the upgrades, which does not require per flow state information. We provide an analysis of the QoS performance and show that the enhancement maximizes the customer's usage of the reserved and paid-for bandwidths by maximizing the utilization of the most expensive QoS classes.