【Objective】

2

Natural disasters such as earthquakes have the characteristics of persistence and wide range. During the occurrence of disasters

the link resources of the optical network will be continuously damaged

resulting in the constant change of the link risk. In the face of constantly changing link risks

improper service recovery planning may cause service failures. From a service perspective

repeated faults will interrupt data transmission many times

and the subsequent link status damage may be aggravated after a disaster occurs. From the perspective of network management and control

repeated recovery wastes route calculation resources and occupies the recovery resources of other services. At the same time

different services have different requirements for transmission reliability because of the importance of the data to be transmitted. When a fault occurs

the high-importance services should be recovered first. Therefore

in the scenario of a large-scale persistent disaster

it is a problem worth studying to comprehensively consider the sustained impact of the disaster on link risk and the difference in path reliability requirements of different services for service recovery. To solve this problem

this paper proposes a link risk-aware service recovery algorithm-Dynamic Link Risk Reroute Algorithm (DLRRA) under persistent disasters.

【Methods】

2

Firstly

according to the service importance and link risk

we establish the service importance evaluation model and link risk evaluation model. Then we propose the optimization target route reliability. The DLRRA

combined with the optimization objective

fully considers the change of link risk degree caused by the impact of disasters on the continuity of links. By preferentially allocating low-risk recovery resources to the fault services of high importance

the risk of secondary failure of the same high-importance services is avoided during the continuous occurrence of disasters.

【Results】

2

The simulation results show that the second failure probability of DLRRA recovery is reduced by 11% compared with the traditional algorithm

and the average importance of DLRRA recovery under the high load is increased by 10%.

【Conclusion】

2

Therefore

the algorithm effectively avoids the loss caused by multiple service interruptions caused

and ensures the continuous and stable operation of important services in the disaster environment.