Efficient scheduling using adaptive packing mechanism for network apparatuses

A scheduler in a network device serves ports with data units from a plurality of queues. The scheduler implements a scheduling algorithm that is normally constrained to releasing data to a port no more frequently than at a default maximum service rate. However, when data units smaller than a certain size are at the heads of one or more data unit queues assigned to a port, the scheduler may temporarily increase the maximum service rate of that port. The increased service rate permits fuller realization of a port's maximum bandwidth when handling smaller data units. In some embodiments, increasing the service rate involves dequeuing more than one small data unit at a time, with the extra data units temporarily stored in a port FIFO. The scheduler adds a pseudo-port to its scheduling sequence to schedule release of data from the port FIFO, with otherwise minimal impact on the scheduling logic.