基于联合备份的服务功能链可靠性保障的部署方法

在网络功能虚拟化(NFV)环境中，针对服务功能链(SFC)部署时的可靠性问题，该文提出对备份虚拟网络功能选择、备份实例放置和服务功能链部署的联合优化方法。首先，定义一个单位开销可靠性提高值的虚拟网络功能衡量标准，改进备份虚拟网络功能选择方法；其次，采用联合备份的方式调整相邻备份实例之间的放置策略，以降低带宽资源开销；最后，将整个服务功能链可靠性保障的部署问题构建成整数线性规划模型，并提出一种基于最短路径的启发式算法，克服整数线性规划求解的复杂性。仿真结果表明，该方法在优先满足网络服务可靠性需求的同时，优化资源配置，提高了请求接受率。

A Reliability-guarantee Method for Service Function Chain Deployment Based on Joint Backup

In the Network Function Virtualization (NFV) environment, for the reliability problem of Service Function Chain (SFC) deployment, a joint optimization method is proposed for backup Virtual Network Function (VNF) selection, backup instance placement and service function chain deployment. Firstly, the method defines a virtual network function measurement standard named the unit cost reliability improvement value to improve the backup virtual network function selection method. Secondly, the joint backup mode is used to adjust the placement strategy between adjacent backup instances to reduce bandwidth resources overhead. Finally, the reliability-guarantee problem of the whole service function chain deployment is modeled as integer linear programming, and a heuristic algorithm based on the shortest path is proposed to overcome the complexity of integer linear programming. The simulation results show that the method optimizes resource allocation while prioritizing the network service reliability requirements, and improves the request acceptance rate.