Emulating of Output Queueing using a Novel 3D-VOQ Switch

This study proposes a novel Three-Dimensional Virtual Output Queue (3D-VOQ) switch architecture to emulate an output-queued switch operating only at the line speed. The 3D-VOQ switch needs no speedup, and emulates an output-queued switch precisely with a broad class of service scheduling algorithms irrespective of its incoming traffic pattern and switch size. An N×N 3D-VOQ switch is first proposed. In this architecture, input queues were designed with a few virtual output queues (VOQ) to avoid Head-Of-Line problems, and the output sides of switch have sufficient separate queues. This scheme creates an input/output contention-free architecture. Next, a Small Time-to-leave Cell First (STCF) algorithm, which can generate a stable many-to-many assignment, is proposed. The proposed 3D-VOQ switch can also be applied to mimic a specific OQ switch. Finally, analysis and simulation are used to verify the performance of 3D-VOQ and to support high/low QoS requirements.