A solution for handling hybrid traffic in clustered environments: the MultiMedia Router MMR

The primary objective of the MultiMedia Router (MMR) project is the design and implementation of a compact router optimized for multimedia applications. The router is targeted for use in cluster and LAN interconnection networks, which offer different constraints and therefore differing router solutions than WANs. One of the key elements within the router are the algorithms used to decide the forwarding order of the information that traverses it: the link and switch scheduling algorithms. They help greatly to determine the QoS guarantees delivered to the application flows. Also, conventional best-effort traffic should be seamlessly integrated by scheduling algorithms, in such a way that link bandwidth is efficiently used, but without degrading the QoS guarantees of the multimedia connections. In this paper, two solutions for switch scheduling are thoroughly evaluated with mixed workloads (i.e., composed of multimedia and best-effort traffic), and their is performance compared to another well-known approach for switch scheduling, that does not consider QoS requirements when performing scheduling decisions. Results show that, when a QoS-aware switch scheduler is used, the QoS received by the multimedia flows is not affected by the presence of best-effort traffic.