Control system, network control method and program
In a control system for controlling a network providing a service by using a virtual network function, the control system includes: a QoS estimation unit configured to estimate QoS at a current time of each flow in the network on a basis of observation information of the network; a QoS degradation detection unit configured to determine whether or not there QoS degradation flow is present on a basis of an estimation result by the QoS estimation unit; and a control determination unit configured to determine a control content and an execution timing thereof by solving an optimization problem with minimizing a total of degradation amounts in a time range from the current time to future for all flows as an objective function when the QoS degradation flow is determined to be present by the QoS degradation detection unit.
1 . A control system comprising a control determination unit configured to determine, when a flow in which quality of service is degrading is present, at least one of a control content and an execution timing thereof, based on amounts of quality-of-service degradation in all flows, wherein the amount of degradation is calculated based on respective control contents of resource control and routing control, and a model that is based on an execution time of each control content.
2 . The control system according to claim 1 , wherein the control determination unit determines the control content and the execution timing thereof by solving an optimization problem about the amounts of quality-of-service degradation in all flows in a predetermined period of time.
3 . The control system according to claim 2 , wherein, in the optimization problem, an objective function is set such that a total amount of quality-of-service degradation in all flows is minimized.
4 . The control system according to claim 2 , wherein the predetermined period of time is from a current time to a future time.
5 . A control system for controlling a network that provides a service by using a virtual network function, the control system comprising:
a quality-of-service estimation unit configured to estimate quality of service of each flow at a current time in the network, based on observation information of the network;
a quality-of-service degradation detection unit configured to determine whether or not a flow in which the quality of service is degrading is present, based on a result of estimation by the quality-of-service estimation unit; and
a control determination unit configured to determine a control content and an execution timing thereof by solving an optimization problem, in which an objective function is set such that a total amount of quality-of-service degradation in all flows in a time period from the current time to a future time is minimized, when the quality-of-service degradation detection unit determines that the flow in which the quality of service is degrading is present.
6 . The control system according to claim 5 , wherein the quality-of-service estimation unit estimates a delay time of each flow as the quality of service, the delay time being a total of a processing delay in an instance of a virtual network function that is used by each flow, and a transmission delay between servers on which the instance of the virtual network function used by each flow operates.
7 . The control system according to claim 5 , wherein the quality-of-service degradation detection unit determines that a flow in which the delay time exceeds a threshold value is the flow in which the quality of service is degrading.
8 . The control system according to claim 5 , wherein the amount of degradation is calculated based on respective control contents of resource control and routing control, and a model that is based on an execution time of each control content.
9 . A network control method to be executed by a control system, the network control method comprising determining, when a flow in which quality of service is degrading is present, at least one of a control content and an execution timing thereof, based on amounts of quality-of-service degradation in all flows, wherein the amount of degradation is calculated based on respective control contents of resource control and routing control, and a model that is based on an execution time of each control content.
10 . A non-transitory computer-readable recording medium storing a program that, when executed on a computer, causes the computer to function as each unit of the control system of claim 5 .