Performance Guaranteed Single Link Failure Recovery in SDN Overlay Networks
Lilei Zheng, Hongli Xu, Suo Chen, Liusheng Huang · 2020
An SDN overlay network is a legacy network improved through SDN and overlay technology. It has some traits including the cheap upgrade cost, flexible network management and the sharing of physical network resources which has brought huge benefits to the multi-tenant cloud platform. Link failure is an important issue that shoulde be solved in any large network. In SDN overlay networks, link failure recovery brings new challenges different from the legacy network, such as how to maintain the performance of overlay networks in the post-recovery network. Thus, in the case of single link failure, we devise a recovery approach to guarantee the performance of overlay networks by the coordination between SDN switches and traditional switches. We formulate the link failure recovery (LFR) problem as an integer linear program and prove its NP-hardness. A rounding-based algorithm with bounded approximation factors is devised to solve the LFR problem. The simulation results show that the devised scheme can guarantee the performance of the overlay network after restoration. The results also show that, compared with SPR and IPFRR, the designed method can reduce the maximum link load rate by approximately 41.5% and 51.6%.