Hybrid Optimization for QoS Control in IP Virtual Private Networks

A multiservice IP Virtual Private Network is considered, where Quality of Service is maintained by a DiffServ paradigm, in a domain that is supervised by a Bandwidth Broker (BB). The traffic in the network belongs to three basic categories: Expedited Forwarding (EF), Assured Forwarding (AF) and Best Effort (BE). Consistently with the DiffServ environment, the Service Provider's Core Routers (CRs) only treat aggregate flows; on the other hand, the user's Edge Routers (ERs) keep per-flow information and convey it to the BB. The latter knows at each time instant the number (and the bandwidth requirements) of flows in progress within the domain for both EF and AF traffic categories.