拖图题

QoS

traffic policing：
causes TCP retransmissions when traffic is dropped导致TCP重传时流量下降
introduces no delay and jitter引入无延迟和抖动
drops excessive traffic减少过多的流量
traffic shaping：
buffers excessive traffic缓冲过多的流量
introduces delay and jitter引入延迟和抖动

QoS

QoS

applied on traffic to convey Information to a downstream device：Marking
应用于流量，将信息传递给下游设备：做记号
distinguish traffic types：Classification
区分交通类型：分类
process used to buffer traffic that exceeds a predefined rate：shapping
用于缓冲超过预定义速率的流量的进程：定型
permits traffic to pass through the device while re