基于分组优先级的队列管理与自适应丢包机制

Packet priority-based queue management and adaptive packet drop mechanism

提出了一种基于应用类别和分组优先级的队列管理与自适应丢包机制,用于路由器内因特网拥塞控制。模仿积极的队列管理优化问题,并为不同类型的数据流提供拥塞控制与公平性机制。相同类型应用的数据包进入同一队列,在队列内部按分组的优先级分成不同的逻辑子队列。把保持相对较短的队列总长度和较小的包丢失率作为最优控制目标,计算出不同队列最优的包丢失率,然后按照得到的包丢失率,将逻辑子队列中的分组按优先级从低到高的顺序,在拥塞产生之前丢失。仿真结果表明,该方案提供了一种队列长度变化更加平滑的管理机制,并且能改善图像的跳跃度和模糊度,可以保证不同类别、不同等级多媒体应用的服务质量。

An application class and packet priority-based queue management and adaptive packet drop mechanism in the routers for Internet congestion control is put forward. Active queue management is modeled as an optimization problem,congestion control and fairness are provided for different types of traffic flows. The packet of same application class come into the same queue,and then are divided into different logical sub- queues by packet priority in the queue. By holding relatively short length of queue and relatively small ratio of packet drop,the optimal ratios of packet drop of the different queues can be calculated. According to the calculated ratios of packet drop,the packets are dropped one by one from low to high of packet priority. The simulation results demonstrate that this scheme provides a queue management mechanism of queue length changing more smoothly,and can improve the jump and faintness of picture,guarantees QoS of different class and level multimedia applications.