星载IP交换机中基于流的变长调度机制的设计和实现

Design and Implementation of Folw-based Variable-length Scheduling Scheme for Satellite Onboard IP Switch

当调度器面对数量众多的流进行队列选择时,使用传统的轮询方式依次检测队列状态会耗费大量时间。本设计在队列管理器与调度器之间的接口处使用出发队列,有效降低了调度过程中的延时。同时,为了降低硬件复杂度,节约硬件资源,本设计采用了基于DRR的变长调度机制。通过在Xilinx xc6vlx240t的FPFA上进行综合实现,电路占用了882个Slice寄存器、804个Slice查找表和36个块RAM/FIFO,有利于满足三模冗余的要求。

When the scheduler performs queue selection among massvie flows, a considerable amount of time would be expanded to detect the status of each queue in traditional round robin manner. The design adopts departure queue as the interface of between queue manager and scheduler, this could effectively reduce the delay time during the scheduling process. Meanwhile, in order to reduce the complexity of hardware resources, the design adopts DRR（deficit-round-robin） based variable-length scheduling scheme. The whole design is implemented in Xilinx xc6vlx240t FPGA,the circuits occupy 882 Slice Registers,804 Slice LUTs and 36 Block RAM/FIFO, meeting requirements of the triple modular redundancy.