Dynamic Core Provisioning for Quantitative Differentiated Services

Abstract

Efficient network provisioning mechanisms that support service differentiation are essential to the realization of the Differentiated Services (DiffServ) Internet. Building on our prior work on edge provisioning, we propose a set of efficient dynamic node and core provisioning algorithms for interior nodes and core networks, respectively. The node provisioning algorithm prevents transient violations of service level agreements (SLA) by predicting the onset of service level violations based on a multiclass virtual queue measurement technique, and by automatically adjusting the service weights of weighted fair queueing schedulers at core routers. Persistent service level violations are reported to the core provisioning algorithm, which dimensions traffic aggregates at the network ingress edge. The core provisioning algorithm is designed to address the difficult problem of provisioning DiffServ traffic aggregates (i.e., rate-control can only be exerted at the root of any traffic distribution tree) by taking into account fairness issues not only across different traffic aggregates but also within the same aggregate whose packets take different routes through a core IP network. We demonstrate through analysis and simulation that the proposed dynamic provisioning model is superior to static provisioning for DiffServ in providing quantitative delay bounds with differentiated loss across per-aggregate service classes under persistent congestion and device failure conditions when observed in core networks.