Scalable network assessment for IP telephony

Multimedia applications such as IP telephony are among the applications that demand strict quality of service (QoS) guarantees from the underlying data network. At the predeployment stage it is critical to assess whether the network can handle the QoS requirements of IP telephony and fix problems that may prevent a successful deployment. In this paper we describe a technique for efficiently assessing network readiness for IP telephony. Our technique relies on understanding link level QoS behavior in a network from an IP telephony perspective. We use network topology and end-to-end measurements collected from the network in locating the sources of performance problems that may prevent a successful IP telephony deployment. We present an empirical study conducted on a real network spanning three geographically separated sites of an enterprise network. The empirical results indicate that our approach efficiently and accurately pinpoints links in the network incurring the most significant delay.