In this paper, we propose a path-computation algorithm for a dynamic virtual network topology (VNT) configuration. We focus on a multi-layer network formed by a connection-oriented Ethernet over a wavelength-switched optical network under the framework of a unified generalized multi-protocol label-switching control plane. The algorithm chooses the route depending on the current state of the network resources, favoring the usage of virtual and forwarding adjacency (FA) traffic engineering (TE) links over a new lambda switching capability (LSC) label-switched path (LSP) establishment. The performance evaluation of the proposed algorithm is conducted through simulations according to three different operational scenarios for the VNT configuration: dynamic, in which all LSC LSPs are established and released dynamically, semi-dynamic, in which a set of FA LSC LSPs is pre-established and advertised by a routing protocol as FA TE links, and virtual, in which a set of FA TE links is pre-defined, but not established. Two different topologies are used: NSFNET and Pan-European. It is shown that the proposed algorithm significantly reduces the connection-blocking probability compared to the algorithms found in the literature, providing an efficient collaboration between the switching layers involved.
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