OpenFlow中基于精确时间戳的延迟测量方法

New delay measurement method based on accurate timestamp in OpenFlow

目前的OpenFlow延迟测量方法占用较多的网络资源,且测量精度较差。根据SDN集中控制的特性,在OpenFlow网络中设计一种基于准确时间戳的延迟测量方法。使用控制器动态计算出任意2个交换机之间的多条可达路径,只需发送一个探测分组就可以测量出多条路径上的延迟,减少了网络资源的消耗。同时,为了提高准确性,将时间戳的获取从控制器转移到OpenFlow交换机中。仿真实验证明,与其他测量方法相比,该方法的测量精度与稳定性都有较大提升。

At present, delay measurement methods in OpenFlow network have the disadvantage of excessive network re-sources and poor measurement accuracy. DeMon, an active mechanism to measure the delay of multiple paths between any two switch based on the controllable feature of individual traffic flow provided in OpenFlow was proposed. DeMon required only one probe packet to be send from controller, which was excepted to reduce the operational cost. Moreover, DeMon used OpenFlow switch instead of controller to get the timestamp of probe packet, making the measurement accu-racy and stability have been greatly improved compared with other monitoring techniques in the OpenFlow network.