Method and apparatus for wfq scheduling using a plurality of scheduling queues to provide fairness, high scalability, and low computation complexity

Abstract

A method and apparatus is provided for scheduling access to a common resource for a plurality of objects queued in a plurality of connection queues. Tokens associated with the connection queues are stored in scheduling queues. Each scheduling queue has a scheduling weight assigned thereto. Each connection queue has a connection weight value assigned thereto. A serving value is used to determine which scheduling queue to select. When a scheduling queue is selected, an object stored in a connection queue having an associated token stored in the selected scheduling queue is provided to the common resource. Tokens are moved among the scheduling queues as a function of the connection weight values, scheduling weights, and serving value. The objects queued in the connection queues may be fixed length cells or variable length packets. When the objects are variable length packets, a residual weight value is also maintained for each connection queue, the residual weight values being useful to prevent the connection queues from receiving an undue amount of service relative to their connection weights during each serving cycle.