IP电话数据包优先级设置及对QoS影响的研究

Setting priority for data packets and QoS of IP telephone

为改善IP电话的QoS ,将语音、普通IP和系统控制 3种不同的分组数据包设置成不同的优先级 ,其中控制分组优先级最高 ,话音分组次之 ,普通数据分组最低 ,使得控制分组和话音分组数据包的平均等待时间从 14 0ms缩短到 30ms左右 ,为原来值的 1 4 ;而普通IP分组数据包的平均等待时间增加 1 5 ,仍在可以忍受的范围之内 ,从而在很大程度上改善了IP电话的QoS .研究结果表明 ,对IP网络不同数据包进行优先级设置是改善IP电话QoS的可行方法之一 .

Different priority levels are set according to the kinds of the data packets in order to improve the IP telephone system's QoS. The system controling data packet's priority is topmost, the voice data packet's priority is lower, and the normal data packet's priority is lowest, This can lower the mean waiting time of the system controling data packet and the voice data packet from 140 ms to 30 ms which is a quarter of the former waiting time. And the normal IP data packet's waiting time gets a 20% increase which is also in the allowable tolerance. The research result indicates that to set different priority to the data packets is one of the feasible ways to improve the IP telephone system's QoS.