Communication network and method for operating a communication network

Communication network, comprising a plurality of communicating nodes that are enabled to request the establishment of flows among each other, a plurality of switches that support the routing of said flows, means for intercepting requests for flow establishment, at least one calculation module being configured to preselect for each flow a set of possible network paths that are compliant with said flow's performance requirements and/or quality constraints, wherein each network path includes a specific set of switches said flow has to traverse, and at least one selection module being configured to apply a selection algorithm that analyses the load of switches that are contained in any network path of said preselected set of network paths for determining a single network path from said preselected set of network paths that is most suitable in terms of energy efficiency, wherein, said selection module is configured to perform said selection algorithm as follows:

• Create the set of switches that contains all switches that are part of any network path of said preselected set of network paths and annotate each of the switches with a utilization metric, unmark all switches in all network paths, select a switch from the set created with the highest value of its utilization metric, remove the selected switch from the set created, mark the selected switch in all network paths that contain it, and if all switches in a network path are marked, output that network path, otherwise, select a switch from the set created with the highest value of its utilization metric.