In this paper, we present a generic router and a tool that allow the designer to easily and quickly customise a NoC in order to meet the requirements of a set of applications. Our router addresses what we consider as the main features of a realistic and useful NoC. Firstly, it supports the management of different levels quality of service (QoS) allowing guaranteed throughput service in addition to the classical best effort service. Secondly, it is associated to a CAD tool, which can fully configure and generate the NoC VHDL code at the RTL level. The paper presents the router architecture and its various custom characteristics as well as their impacts on the performance of the system