Abstract: A network element includes a data transfer interface for connecting to a data transfer network, a data-plane section for managing data to be forwarded, and a control section for configuring the data-plane section in accordance with configuration data carried by control-plane messages received from the data transfer network. The control section controls the data transfer interface to send one or more overload messages to the data transfer network in response to an overload situation where the workload of the control section impairs the ability of the control section to react to the control-plane messages. Thus, other network elements know that the network element that does not respond to the control-plane messages and thus appears to be non-working may still forward data even though its ability to react to the control-plane messages is, at least temporarily, impaired.

Abstract: A software-defined network includes a database (105) that is accessible to a controller system (108, 109) of the software defined network and also to network elements (101-014) of the software defined network. The controller system determines configuration data and delivers it to the database. Each network element retrieves its part of the configuration data from the database and implements the retrieved part of the configuration data into its own configuration system that enables the network element to operate as a part of the software-defined network. The commonly used database facilitates maintaining the congruence between the network elements and the controller system of the software-defined network.

Abstract: A network element includes a data transfer interface for connecting to a data transfer network, a data-plane section for managing data to be forwarded, and a control section for configuring the data-plane section in accordance with configuration data carried by control-plane messages received from the data transfer network. The control section controls the data transfer interface to send one or more overload messages to the data transfer network in response to an overload situation where the workload of the control section impairs the ability of the control section to react to the control-plane messages. Thus, other network elements know that the network element that does not respond to the control-plane messages and thus appears to be non-working may still forward data even though its ability to react to the control-plane messages is, at least temporarily, impaired.

Abstract: A network element (201) for a data transfer network comprises functional entities (221-226) each being adapted to maintain an entity-specific configuration system which comprises configuration entries with the aid of which the functional entity under consideration is able to co-operate with the other functional entities so that the network element is capable of operating as a part of the data transfer network. The network element maintains a database that is writeable and readable by the functional entities. At least one configuration entry related to one or more of the functional entities is composed of data items written by many functional entities to the database, and thereafter the relevant one or more functional entities read the configuration entry from the database. The database that is commonly used by the functional entities facilitates maintaining the congruence between the functional entities and reduces the amount of configuration data traffic between the functional entities.

Abstract: A software-defined network includes a database (105) that is accessible to a controller system (108, 109) of the software defined network and also to network elements (101-014) of the software defined network. The controller system determines configuration data and delivers it to the database. Each network element retrieves its part of the configuration data from the database and implements the retrieved part of the configuration data into its own configuration system that enables the network element to operate as a part of the software-defined network. The commonly used database facilitates maintaining the congruence between the network elements and the controller system of the software-defined network.