Abstract

In this paper an understanding of the configuration and performance of a Differentiated Services (DS) network is presented. Strong emphasis is placed on the configuration of the quality of service (QoS) dynamics of expedited forwarding (EF) and assured forwarding (AF) per-hop behaviour (PHB) class types that are required to allow an Unspecified Bit Rate (UBR) application to function effectively - in particular, the configuration of the AF features that mark non-conformant packets with a lower drop priority DS Code Point (DSCP). The usability of these mechanisms is then evaluated in a real, testing environment. DS edge and core routers are configured in a testbed that has been created to emulate a multiple-domain network. Data was then collated from a diverse range of testing procedures and then analysed to allow the authors to draw their conclusions that increased their understanding how a DS network operates.