A method for communicating optically between nodes of an optical network, comprising: forming, between a first node and a second node of the network, a set of lightpaths, each lightpath comprising a set of optical links, defined by an optical fiber and a wavelength transmitted in the optical fiber, between end points of the lightpath, and each of the set of lightpaths having a respective configuration which specifies at least one setting for one or more elements (22, 24, 26, 28, 30) included in the lightpath; transferring (102, 104) communication traffic between the first and second nodes via the set of lightpaths; determining, for the set of lightpaths, that a communication traffic level associated therewith is less than a predetermined threshold; in response to the determining, removing (110, 112) at least one lightpath having a given configuration from the set of lightpaths to form a reduced set of lightpaths, by powering down the at least one lightpath; transferring the communication traffic between the first and second nodes via the reduced set of lightpaths, while reducing the level of power consumption in the at least one lightpath by the powering down and while maintaining the given configuration of the at least one lightpath; and wherein the first node comprises a first router and wherein the second node comprises a second router, and wherein removing the at least one lightpath comprises selecting the at least one lightpath so that reducing the level of power consumption of the at least one lightpath implements at least one of a group of actions comprising: providing a largest reduction in power consumption of the set of the lightpaths between the first and second routers; reducing an operational lifetime of an element in the at least one lightpath; and enabling a network interface card of the first router to be completely turned off. forming, between a first node and a second node of the network, a set of lightpaths, each lightpath comprising a set of optical links, defined by an optical fiber and a wavelength transmitted in the optical fiber, between end points of the lightpath, and each of the set of lightpaths having a respective configuration which specifies at least one setting for one or more elements (22, 24, 26, 28, 30) included in the lightpath; each lightpath comprising a set of optical links, defined by an optical fiber and a wavelength transmitted in the optical fiber, between end points of the lightpath, and each of the set of lightpaths having a respective configuration which specifies at least one setting for one or more elements (22, 24, 26, 28, 30) included in the lightpath; transferring (102, 104) communication traffic between the first and second nodes via the set of lightpaths; determining, for the set of lightpaths, that a communication traffic level associated therewith is less than a predetermined threshold; in response to the determining, removing (110, 112) at least one lightpath having a given configuration from the set of lightpaths to form a reduced set of lightpaths, by powering down the at least one lightpath; transferring the communication traffic between the first and second nodes via the reduced set of lightpaths, while reducing the level of power consumption in the at least one lightpath by the powering down and while maintaining the given configuration of the at least one lightpath; and wherein the first node comprises a first router and wherein the second node comprises a second router, and wherein removing the at least one lightpath comprises selecting the at least one lightpath so that reducing the level of power consumption of the at least one lightpath implements at least one of a group of actions comprising: providing a largest reduction in power consumption of the set of the lightpaths between the first and second routers; reducing an operational lifetime of an element in the at least one lightpath; and enabling a network interface card of the first router to be completely turned off. providing a largest reduction in power consumption of the set of the lightpaths between the first and second routers; reducing an operational lifetime of an element in the at least one lightpath; and enabling a network interface card of the first router to be completely turned off.