Design and implementation of a 320 Gb/s switch fabric

With fast development of the optical fiber technology, core routers face many great challenges, especially in the technology of switch fabrics. This paper mainly discusses the design of switch fabric in a gigabit core router named Tsinghua Core Router (TCR), which is our recent research project. This core router has 320 GB/s switch capacity, supporting 16 ports, each opening at 10 Gb/s (OC192c line rate). To achieve a high-speed and large-capacity switch fabric, this paper focuses on key technologies of supporting variable-length packets with a cell-based switch fabric, segmentation and reassembly, and multi-priority guarantee for various kinds of traffic with different QoS requirements. Through implementation and performance simulation, we demonstrate that the switch fabric can meet challenges of gigabit core routers, and provide better QoS control for Internet.