The value of vRtrMplsLspFRMethod specifies the fast reroute method used. In the 'One-to-one Backup' method, a backup LSP is established which will intersect the original LSP somewhere downstream of the point of link or node failure. For each LSP that is backed up, a separate backup LSP is established. In the 'Facility Backup' method, instead of creating a separate LSP for every LSP that is to be backed up, a single LSP is created which serves as a backup for a set of LSPs. Such an LSP tunnel is called a 'bypass tunnel'.