Abstract: A divided hierarchical network system based on software-defined networks, the divided hierarchical network system including: an edge controller configured to: generate forwarding information in response to a flow forwarding inquiry from a lower level and respond to the request with the forwarding information; generate mapping information such that each of a plurality of edge ports of each of a plurality of switches that form the lower level corresponds to each of a plurality of virtual ports of one virtual switch; if it is not possible to generate forwarding information in response to a request received from a lower level for forwarding a flow that comprises edge ports, query forwarding information to an upper level regarding a flow in which the edge port is converted into a corresponding virtual port based on the mapping information.

Abstract: A method for providing service chaining in a software-defined network (SDN)-based network system, the method including: receiving, at a controller, a first packet-in message from a first switch of a plurality of switches, which has received a service request packet from a user, to indicate that the first switch does not have a corresponding entry in a field extracted from the service request packet; extracting from the packet-in message both a service identifier that identifies a type of a service requested through the service request packet and a user identifier that identifies the user; and searching an entry database for an entry list that enables the service request packet to be forwarded to a network function list that corresponds to the service identifier and the user identifier, with reference to a service table, a user table, and a network function table which are associated with one another.

Abstract: A divided hierarchical network system based on software-defined networks, the divided hierarchical network system including: an edge controller configured to: generate forwarding information in response to a flow forwarding inquiry from a lower level and respond to the request with the forwarding information; generate mapping information such that each of a plurality of edge ports of each of a plurality of switches that form the lower level corresponds to each of a plurality of virtual ports of one virtual switch; if it is not possible to generate forwarding information in response to a request received from a lower level for forwarding a flow that comprises edge ports, query forwarding information to an upper level regarding a flow in which the edge port is converted into a corresponding virtual port based on the mapping information.

Abstract: A divided hierarchical network system based on software-defined networks, the divided hierarchical network system including: an edge controller configured to: generate forwarding information in response to a flow forwarding inquiry from a lower level and respond to the request with the forwarding information; generate mapping information such that each of a plurality of edge ports of each of a plurality of switches that form the lower level corresponds to each of a plurality of virtual ports of one virtual switch; if it is not possible to generate forwarding information in response to a request received from a lower level for forwarding a flow that comprises edge ports, query forwarding information to an upper level regarding a flow in which the edge port is converted into a corresponding virtual port based on the mapping information.

Abstract: An integrated routing method in an integrated routing system based on a software-defined network (SDN), including: obtaining information regarding a plurality of edge switches that are SDN-based switches and belong to a switch group that establishes an independent network; and setting the independent network as at least one virtual router, based on the obtained information regarding the plurality of edge switches, such that the independent network is treated as at least one legacy router by a plurality of legacy networks that are connected to the independent network.

Abstract: A divided hierarchical network system based on software-defined networks, the divided hierarchical network system including: an edge controller configured to: generate forwarding information in response to a flow forwarding inquiry from a lower level and respond to the request with the forwarding information; generate mapping information such that each of a plurality of edge ports of each of a plurality of switches that form the lower level corresponds to each of a plurality of virtual ports of one virtual switch; if it is not possible to generate forwarding information in response to a request received from a lower level for forwarding a flow that comprises edge ports, query forwarding information to an upper level regarding a flow in which the edge port is converted into a corresponding virtual port based on the mapping information.

Abstract: A method for providing service chaining in a software-defined network (SDN)-based network system, the method including: receiving, at a controller, a first packet-in message from a first switch of a plurality of switches, which has received a service request packet from a user, to indicate that the first switch does not have a corresponding entry in a field extracted from the service request packet; extracting from the packet-in message both a service identifier that identifies a type of a service requested through the service request packet and a user identifier that identifies the user; and searching an entry database for an entry list that enables the service request packet to be forwarded to a network function list that corresponds to the service identifier and the user identifier, with reference to a service table, a user table, and a network function table which are associated with one another.