I. Introduction
Thanks to the wavelength-division-multiplexing (WDM) technology, today's optical networks provide a transport infrastructure with very high capacity. This huge capacity requires efficient survivability mechanisms in order to avoid that the failure of a network element (typically a link or a node) can cause a large amount of data loss. Recently, new techniques have been proposed to efficiently deal with this problem in mesh networks. Among them, Segment Protection (SP) is a promising candidate for protection in WDM/MPLS networks because of its desirable resource efficiency, and for its ability to limit the signalling delay for recovery.