Quality-of-Service (QoS) becomes a vital requirement in MPSoCs with NoCs. In order to serve them NoCs provide guarantees for latency, jitter and bandwidth by virtual channels. But the allocation of these guaranteed service channels is still an important question. In this paper, the authors present and evaluate different realizations of a central hardware unit which allocates at run-time guaranteed service virtual channels providing QoS in packet-switched NoCs. They evaluate their performance in terms of allocation success, compare it to distributed channel setup techniques for different NoC sizes and traffic scenarios and analyze the required hardware area consumption.