In general, in one aspect, a switching device is described that includes a segmentation unit to receive packets and divide packets having a length greater than a maximum segment length into multiple segments. A plurality of queues associated with a source and a destination stores the segments. A request generator generates requests that include external factors including amount of data contained in the queue and at least some subset of priority and age. A scheduler receives the requests and assigns the requests an internal priority based on the external factors. The scheduler processes the requests for the queues by internal priority in order to generate grants. A framer, responsive to the scheduler, aggregates a plurality of segments for the queues that received a grant to form a frame and to transmit the frame to an associated destination. The frame may contain segments associated with different packets.