什么是主动队列管理：

In routers and switches, active queue management (AQM) is the policy of dropping packets inside a buffer associated with a network interface controller (NIC) before that buffer becomes full, often with the goal of reducing network congestion or improving end-to-end latency.

拆开来看，首先AQM具有以下几个特点：

• 集成于路由器或者交换机中；
• 与网卡协作，采用的动作大多是将包丢弃；
• 主要目标是降低网络的拥塞。

主动队列管理有哪些？

• Random early detection (RED);
• Random Exponential Marking (REM);
• Blue and Stochastic Fair Blue (SFB);
• PI controller;
• Robust random early detection (RRED);
• RSFB:
• RED with Preferential Dropping (RED-PD)
• Controlled Delay (CoDel)