Efficient interface scheduling that maintains fairness among the scheduled interfaces and remains efficient even when scheduling large numbers of interfaces and even when implemented in software. Systems for scheduling interfaces through a physical port are provided that utilize a bit-mask. Each bit-mask has a bit-mask-level-1 having a plurality of bits, each bit in the bit-mask-level-1 represents a unit of bandwidth with the total number of bits in the bit-mask-level-1 representing the port's line speed, each bit in a bit-mask-level-1 is associated with an interface, and the number of bits associated with each interface determines the bandwidth for that interface. Methods of scheduling interfaces are provided that utilize one or more bit-masks to determine an order in which interfaces are scheduled. The present invention can efficiently implement versions of the dual-token-bucket algorithm.