Several router mechanisms have been proposed to achieve fair rate allocations. However, most of them require the proposed mechanisms to be deployed at all routers within an autonomous domain in order to achieve the desired, or any appreciably improved, quality of service. In this paper, we present an incrementally deployable QoS architecture called iQ. iQ consists of a set of core- and edge-router mechanisms that allow for changing one router at a time, improving the rate fairness provided by the network gracefully, for each additional iQ router deployed. We use simulations to compare the incremental deployability of the iQ architecture with that of existing approaches.