Enhancing ns-2 with DiffServ QoS features

In this paper, we present work that we have carried out in extending the ns-2 simulator in order to study and validate Quality of Service issues and related architectures. In the case of the DiffServ framework, simulation is valuable since an analytical approach of mechanisms and services is infeasible due to the aggregation and multiplexing of flows. This paper covers work in extending ns-2 functionality towards the direction of realistic traffic generation and a series of mechanisms defined by the DiffServ architecture. We have also extended ns-2 with the functionality of Bandwidth Brokers, which are entities for managing the resources and negotiating end to end resource reservations between domains. The Bandwidth Broker ns-2 implementation is useful for studying the related architectures and admission control procedures.