Multiple Mode Protection Switching Failure Recovery Mechanism under MPLS Network

In order to solve the problem of constrained routing algorithm without capability of dealing with failures, this paper proposes a failure recovery method based on multiple mode protection switching including global protection???segment protection and local protection. This method quantifies the performance of three protections switching styles as a protection metric, making use of this metric to computer the optimal protection style for the working path. This paper put this failure recovery method into constrained routing algorithm to enhance the invulnerability of the algorithm