A flexible soft DiffServ test-bed

This paper reports on a teaching and research SLA test-bed that we have constructed using specially developed soft DiffServ routing nodes operating in a Linux environment. The test-bed, and the associated tools, are intended for various levels of study of SLA translation and mapping algorithms. It is instrumented to provide considerable insight into the DiffServ behavior. The software is more modular, flexible and easier to configure than the "standard" Linux DiffServ offerings. This paper presents the architecture of our system, and reports on the proof-of-concept experiments that show that it can be used to implement a general Services Level Agreement (SLA) solution and study related issues. Initial empirical studies involve implementation of some of the quality of service (QoS) related IETF drafts and RFCs in a five-node test-bed, including an implementation and empirical evaluation of expedited forwarding (EF) PHB, assured forwarding (AF) PHB, virtual wire (VW) PDB, and of assured forwarding PDB.