A framework for providing differentiated QoS guarantees in IP-based network

The paper describes the traffic handling mechanisms implemented in the AQUILA pilot QoS IP network [AQUILA Project Consortium (2001)] [11]. The AQUILA architecture enhances the DiffServ concept [A Conceptual Model for DiffServ Routers (2000), An Architecture for Differentiated Services (1998), An Expedited Forwarding PHB (2001)] by adding new functionality for admission control and resource management as well as by defining new set of Network Services (NSs) [4,6,3]. Each NS is optimised for specific type of traffic (e.g. reactive and non-reactive) and has its own traffic handling mechanisms. The mentioned mechanisms operate at different time scales, ranging from long-medium term resources management (provisioning, resource pools) to flow level admission control, down to packet level scheduling and queuing management. Some of these mechanisms are related to NSs: in particular each NS is associated to a set of traffic handling algorithms at flow and packet level, collectively referred to as Traffic Classes (TCLs). This paper describes the set of traffic handling mechanisms defined in AQUILA, with a special focus on the implementation of TCLs, both at packet and flow level. In particular the scheduling/queuing and admission control schemes for each TCL are presented. Exemplary measurement results verifying the effectiveness of AQUILA approach for providing Quality of Service (QoS) guarantees and QoS differentiation are also included. (C) 2002 Elsevier Science B.V. All rights reserved.