Scalable network monitoring for multimedia applications in enterprise networks

Networked multimedia applications require stringent quality of service (QoS) guarantees from the underlying data network. Many techniques have been proposed at the network layer to deliver acceptable QoS for such applications. In this paper, we explore providing network monitoring support in the application layer for QoS policies. We study the feasibility of a scalable network monitoring service that real-time applications may access to gather network status information in order to adapt to changing network conditions and take actions such as making application level routing decisions. We propose a scalable, low probing overhead monitoring service based on monitoring utilization on network devices traversed by multimedia traffic. Our motivation is to take advantage of often intersecting end-to-end paths traversed by multimedia traffic in an enterprise setting. We empirically assess the QoS improvements resulting from a service that monitors network utilization for an application involving dynamic server selection on a real production network. Specifically, we compare the performance of various dynamic server selection strategies for multimedia streaming including random selection, round-trip time based selection, proximity based selection, and utilization based selection. Our results indicate that compared to random selection, server selection strategies that rely on our network utilization based monitoring scheme result in significantly lower end-to-end delay and packet loss in streaming sessions. Compared to round-trip time based selection, our scheme results in comparable end-to-end delay and loss figures while incurring significantly lower probing cost