Targeted Distribution of Resource Allocation for Backup LSP Computation

Under the hypothesis of single failures in the network, some backup paths cannot be active at the same time because they protect against the failure of different components. Hence, share the bandwidth between such backup paths is central to optimize the bandwidth allocated in the network and to decrease the bandwidth wasting. In this paper, we propose a novel algorithm, based on targeted distribution of resource allocation (TDRA), to compute the backup label switched paths (LSPs) in a distributed multiprotocol label switching (MPLS) environment. Our algorithm is scalable, efficient and capable to protect against the three types of failure risk: node, link and shared risk link group (SRLG). Indeed, the TDRA algorithm decreases the quantity of information (resource or bandwidth allocation) transmitted in the network with the selection of nodes to be advertised (with the selection of recipient nodes). Furthermore, bandwidth availability is increased by sharing bandwidth between backup LSPs as long as possible. Simulations show that the ratio of rejected backup LSPs obtained with the transmission of a small quantity of information in the network is low.