Pipelined heap (priority queue) management for advanced scheduling in high-speed networks

Abstract

Quality-of-service (QoS) guarantees in networks are increasingly based on per-flow queueing and sophisticated scheduling. Most advanced scheduling algorithms rely on a common computational primitive: priority queues. Large priority queues are built using calendar queue or heap data structures. To support advanced scheduling at OC-192 (10 Gbps) rates and above, pipelined management of the priority queue is needed. We present a pipelined heap manager that we have designed as a core integratable into ASICs, in synthesizable Verilog form. We discuss how to use it in switches and routers, its advantages over calendar queues, and we present cost-performance tradeoffs. Our design can be configured to any heap size. We have verified and synthesized our design and present cost and performance analysis information.