Avoiding Speedup from Bandwidth Overhead in a Practical Output-Queued Packet Switch

We study a time-slotted and synchronous output queued switch that uses packet concatenation to reduce band width overhead, or CS-OQ switch. The CS-OQ switch avoids memory speedup through the use of dedicated optical lines connecting inputs to outputs. The dedicated lines are combined with virtual input queues (VIQs) at the outputs and segmentation queues at the inputs. The segmentation queues are used for packet concatenation. We show that the performance of the CS-OQ switch approaches that of an ideal output queued switch, or asynchronous OQ (A-OQ) switch by selecting a suitable segmentation length in combination with packet concatenation.