An asynchronous router for QNoC (Quality-of service NoC) is presented. It combines multiple service levels (SL) with multiple equal-priority virtual channels (VC) within each level. The VCs are assigned dynamically per each link. A different number of VCs may be assigned to each SL and per each link. The router employs fast arbitration schemes to minimize latency. Asynchronous circuits for VC and SL arbitration, as well as detailed overall architecture, are presented and analyzed. NOTE TO REVIEWERS: We are presently porting the design to a 0.18u technology (the most advanced one for which we have sufficient process data). In the final paper, if accepted, we will replace the 0.35u results with 0.18u results. In addition, the text here is arranged into one column for a more convenient reading and will be organized into two columns IEEE format in the final version.