A hardware approach to QoS support in cluster environments:: The multimedia router MMR

Over the past few years a dramatical increase in the use of multimedia applications has taken place, due mainly to the availability of fast processors and sophisticated peripherals at a low cost. Many of these applications either are inherently distributed, or need the resources of a cluster of computers. The traffic generated by multimedia applications has very different requirements than the best-effort traffic generated by conventional applications. Now, the network must deliver some sort of Quality of Service (QoS) to the flows that require it. The Multimedia Router (MMR) arises as a solution for providing such QoS support within a compact interconnection element, aimed for use in local and clustered environments. The particular needs for every kind of traffic, both multimedia and best-effort, are addressed in order to provide the multimedia flows the QoS guarantees they need, while still achieving high link utilizations. In this work, the Multimedia Router architecture is described, and some insight is given on its performance, specially regarding the interaction between buffer size and the algorithms used for link scheduling.