Estratégia híbrida de proteção dedicada e restauração dirigida por conexões de baixa prioridade com degradação diferenciada em redes EON para recuperação de desastres

Abstract

The rigidity of the spectrum of Wavelength Division Multiplexing networks does not allow them to accommodate requests in proportion to their bandwidth need, causing spectrum waste. Therefore, Elastic Optical Networks have been shown to be a solution for the future of optical transport networks, bringing flexibility and efficiency in the use of resources. The scalability provided by these networks proves to be an adequate paradigm for the bandwidth requirements for emerging Internet applications. Due to the volume of traffic supported by EONs, failure events can cause severe data loss. For this, protection and restoration schemes have been developed in order to minimize such damage. Service contract specifications (SLA) make it possible for applications to have their resources assigned appropriately and with their respective levels of tolerance for service degradation. Higher priority classes of service have greater restrictions to service degradation, while lower priority classes are more flexible to degradation. Therefore, the classification of connections and their respective SLA specifications must be taken into account when defining disaster recovery strategies in order to identify the best opportunities that increase the provisioning or reprovisioning capacity of the network. This work proposes a hybrid survival scheme (protection and restoration) with bandwidth degradation and restoration delay for low priority connections transmitted in the backup path of high priority connections. The proposed algorithm was compared with a dedicated backup path protection strategy. The results obtained demonstrate that restoration based on service degradation and the use of backup resources reduces the overall network blocking probability and the blocking probability by classes. Furthermore, the proposed strategy increases the ability to restore low-priority connections interrupted by the disaster while maintaining the ability to restore high-priority connections.