软件定义网络一致性协同更新算法

为实现软件定义网络的一致性更新，本文提出一种协同利用分段路由、顺序更新、两步复制三种机制的更新算法.算法首先启用分段路由机制，尝试用现有路径规则拼接待更新数据流的最终路径，并根据最终路径是否能由现有规则拼接，将数据流分为可拼接与不可拼接两种.对于可拼接流，分段路由可将最终路径信息封装入数据包包头，使得数据包能立即沿最终路径转发.对于不可拼接流，算法计算最长一致性更新序列，并按照此序列依次更新节点，最后利用两步复制机制来完成剩余未更新节点的更新.并且经实验验证，算法比之前研究提出的算法不仅消耗更少的三态内容寻址存储器的空间资源，并且有更好的适用性与稳定性.

Synergetic Consistent Update Algorithm for SDN Networks

To achieve consistent update in software defined network,a consistent update algorithm which combines segment routing,two-phase commit and node scheduling mechanism is proposed in this work.The algorithm first leverages segment routing mechanism,which attempts to splice the final path with existing paths.According to whether the final path can be spliced by the existing paths,the algorithm divides flows into either segmentable flows or flows that are not segmentable.For the segmentable flow,segment routing mechanism can encapsulate the final path information into the packet header so that packets can be forwarded immediately along the final path.For the flows not segmentable,the algorithm calculates the longest consistent update sequences for them,and updates nodes in accordance with these sequences.Finally,the algorithm uses the two-phase commit mechanism to complete the update of the remaining nodes.We verified its performance by experiments and the outcome illustrates that our algorithm not only requires less additional ternary content addressable memory resources but also has better performance stability and applicability than prior techniques.