面向多播请求的虚拟网络嵌入保护算法

针对弹性光网络(elastic optical networks，EONs)中提高虚拟请求的生存性问题，提出一种基于节点关联度的双树嵌入保护DEP-NCD(dual-tree embedding protection based on node correlation degree) 算法.该算法采用预先规划的方法为工作树分配链路分离的保护树，在发生故障时，能够尽快利用网络中的空闲资源，为中断的请求重新选定路径，保证请求能够不间断传输，减少因故障造成的损失，避免对用户造成严重的影响.仿真结果表明，该算法能最大限度地减少资源的使用，避免冗余多播请求在底层光网络中的传输.

Virtual Network Embedding and Protection Algorithm of Multicast Requests

To improve the survivability of virtual requests in elastic optical networks(EONs)， a dual-tree embedding protection based on node correlation degree(DEP-NCD) algorithm was proposed， which uses a pre-planning method to assign link-separated protection trees to the work tree. When a failure occurs， DEP-NCD algorithm can make use of the idle resources in the network as soon as possible to reselect the path for the interrupted requests. The newly selected path ensures that the requests can be transmitted uninterruptedly， reducing the losses caused by the failure and avoiding serious impacts on users. The simulation results indicated that the proposed algorithm can minimize the use of resources and avoid the transmission of redundant multicast requests in the substrate optical network.