Reliability-aware ring protection link selection in Ethernet ring mesh networks

Ring topology is an appropriate solution to be applied on the carrier Ethernet networks due to its high switching speed when one of the links fails. Meanwhile, the ITU-T G.8032 Ethernet ring protection (ERP) recommendation was developed to compete with the switching speed of synchronous digital hierarchy (SDH)/synchronous optical networking (SONET) rings. Nevertheless, ERP has emerged some new optimization issues that the most important of which is to find the ring protection link (RPL). In addition, this issue should also satisfy the network reliability requirements as a key performance parameter. To cope with this problem, in this paper, a new approach is proposed. The main idea behind the proposed approach is to analyze the impact of network links on the overall network reliability. In this regard, the proposed approach consists of five steps: (1) computing the reliability equation for the network through the spanning tree set method, (2) calculating the reliability importance for each link through the Birnbaum importance measure, (3) sorting links based on reliability importance by investigating numerical results, (4) selecting the most appropriate links as RPL per ring by taking into account two modes of working and protection, and finally (5) choosing a ring hierarchy based on the selected RPLs. Performance evaluations demonstrate that the proposed approach provides significant improvement in network reliability compared to the representative approaches.