Abstract: A method controls resource allocation in a data center. The method comprises identifying a first computational task to be transferred from a first set of one or more servers. The method also comprises identifying a second set of one or more servers to which the first computational task may be transferred, by using the respective current computational load of the second set of servers to determine that the second set of servers has sufficient available computational resources to implement the computational task and identifying network links for transferring the computational task and using the respective transmission loads of the identified links to determine that there is sufficient network capacity to transfer the computational task from the first set of servers to the second set of servers. The method then comprises transferring the computational task from the first set of servers to the second set of servers.

Abstract: A polarization controller is configured to control polarization of an optical signal. The polarization controller includes a first polarization rotator and a second polarization rotator controllable by control settings. The polarization controller includes a monitor unit configured to generate a monitoring value indicating a performance of the polarization controller. The polarization controller is configured to determine from the monitoring value if the polarization controller is operating in a selected one of a plurality of optimal performance states. If operation is not in an optimal performance state, the polarization controller is further configured to select different control settings to select an alternate one of the plurality of optimal performance states for the polarization controller.

Abstract: A data center network node (28) comprises one or more switch (18,19,22,23) configured to link an optical transceiver (16,17) to an optical connection comprising a multi-core optical fiber (30) having a plurality of cores (31). For each core (31), the one or more switch (18,19,22,23) is configurable between a first configuration in which an optical signal on a said core (31) of the multi-core optical fiber bypasses the optical transceiver and a second configuration in which the optical transceiver is optically linked to the said core (31) of the multi-core optical fiber (30).

Abstract: Resource provisioning in a virtualized network Within a network comprising a plurality of domains, an end-to-end route for a required service is computed by setting a respective parameter value for each of a plurality of paths in a domain. Each parameter value is based on resources that are available for the required service, and the parameter value is dependent on a priority given to said service. The end-to-end route for the required service is selected based on said parameter values.

Abstract: A data center network node (28) comprises one or more switch (18,19,22,23) configured to link an optical transceiver (16,17) to an optical connection comprising a multi-core optical fiber (30) having a plurality of cores (31). For each core (31), the one or more switch (18,19,22,23) is configurable between a first configuration in which an optical signal on a said core (31) of the multi-core optical fiber bypasses the optical transceiver and a second configuration in which the optical transceiver is optically linked to the said core (31) of the multi-core optical fiber (30).

Abstract: A polarization controller (10;40) is configured to control polarization of an optical signal. The polarization controller comprises a first polarization rotator (18) and a second polarization rotator (28) controllable by control settings. The polarization controller comprises a monitor unit (34) configured to generate a monitoring value indicating a performance of the polarization controller. The polarization controller is configured to determine from the monitoring value if the polarization controller is operating in a selected one of a plurality of optimal performance states (52). If operation is not in an optimal performance state, the polarization controller is further configured to select different control settings to select an alternate one of the plurality of optimal performance states for the polarization controller.

Abstract: A method of controlling resource allocation in a data center, the data center comprising a plurality of servers connected by a plurality of network links.

Abstract: Resource provisioning in a virtualized network Within a network comprising a plurality of domains, an end-to-end route for a required service is computed by setting a respective parameter value for each of a plurality of paths in a domain. Each parameter value is based on resources that are available for the required service, and the parameter value is dependent on a priority given to said service. The end-to-end route for the required service is selected based on said parameter values.