基于最长有效功能序列的服务功能链部署算法

服务功能链的服务性能取决于功能的部署位置和数据传输路径的选择。针对资源有限的网络中的服务功能链部署问题，该文设计了一种基于最长有效功能序列(LEFS)的服务功能链部署算法，以功能复用和带宽需求联合优化为目标，在控制路径长度的同时根据LEFS逐步搜索中继节点，直至满足服务请求。仿真结果表明，该算法能够均衡网络资源，同时优化网络的功能部署率和带宽利用率，与其他算法相比，网络资源利用率降低了10%，可以支持更多的服务请求，且算法计算复杂度低，可以实现对服务请求的快速响应。

Service Function Chain Deployment Algorithm Based on Longest Effective Function Sequence

The efficiency of Service Function Chain (SFC) depends closely on where functions are deployed and how to select paths for data transmission. For the problem of SFC deployment in a resource-constrained network, this paper proposes an optimization algorithm for SFC deployment based on the Longest Effective Function Sequence (LEFS). To optimize function deployment and bandwidth requirement jointly, the upper bound of path length is set and relay nodes are searched incrementally on the basis of LEFS until the service request is satisfied. Simulation results show that, the proposed algorithm can balance network resource and optimize the function deploymen rate and bandwidth utilization. Compared with other algorithms, the utilization of network resource decreases 10%, so that more service requests can be supported. What is more, the algorithm has a lower computation complexity and can response to service requests quickly.