Abstract: A directional coupler includes: a main line connecting an input port and an output port; first to third subline sections each of which is formed of a line configured to be electromagnetically coupled to the main line; a first matching section provided between the first subline section and the second subline section; and a second matching section provided between the second subline section and the third subline section. The first and second matching sections are configured to cause changes in phase of high frequency signals passing therethrough, and have mutually different characteristics so as to create two attenuation poles in the frequency response of the coupling of the directional coupler.

Abstract: A communication system includes: a plurality of communication nodes; and a control apparatus that controls packet processing of the plurality of communication nodes. The control apparatus further includes: a virtualization unit that configures a virtual node(s) from a plurality of communication nodes among the plurality of communication nodes; a control unit that sets a processing rule for a packet in at least one communication node of the plurality of communication nodes included in the virtual node(s), so that the at least one communication node executes packet processing corresponding to an operation of the virtual node(s); and a path calculation unit that calculates a forwarding path of a packet, based on a virtual network topology including the virtual node(s). The plurality of communication nodes process a packet corresponding to the forwarding path, in accordance with the processing rule.

Abstract: A communication system including: a plurality of communication nodes that process received packets on the basis of a packet handling operation for processing packets; and a control apparatus that sets the packet handling operation in the plurality of communication nodes; wherein, in response to setting a first packet handling operation for changing header information of a packet(s) in a first communication node, the control apparatus sets a second packet handling operation for processing the packet(s) including the changed header information in a second communication node.

Abstract: A communication system comprises: a node that requests a processing rule for processing a packet; a control apparatus that notifies a processing rule to the node in response to the request; and a plurality of path calculation apparatuses that calculate a forwarding path of the packet received by the node. The plurality of path calculation apparatuses calculate the forwarding path based on at least one policy for calculating the forwarding path, and notifies the calculated forwarding path to the control apparatus. The control apparatus generates based on one of a plurality of the notified forwarding paths the processing rule for forwarding the packet received by the node.

Abstract: A communications system includes: a first node device provided in a first network; a first controller controlling the first node device; a second node device provided in a second network and connected to the first node device; and a second controller controlling the second node device. The first controller sets the first node device with a processing rule according to which packets transferred between the first and second controllers are processed. The second controller sets the second node device with a processing rule according to which the packets are processed. The first and second controllers exchanges the packets each other through at least the first and second node devices.

Abstract: A communication system includes: a plurality of communication nodes; and a control apparatus that controls packet processing of the plurality of communication nodes. The control apparatus further includes: a virtualization unit that configures a virtual node(s) from a plurality of communication nodes among the plurality of communication nodes; a control unit that sets a processing rule for a packet in at least one communication node of the plurality of communication nodes included in the virtual node(s), so that the at least one communication node executes packet processing corresponding to an operation of the virtual node(s); and a path calculation unit that calculates a forwarding path of a packet, based on a virtual network topology including the virtual node(s). The plurality of communication nodes process a packet corresponding to the forwarding path, in accordance with the processing rule.

Abstract: A communication system includes a first switch that refers to a first processing rule included in a packet and processes the packet in accordance with the first processing rule; a second switch that includes a table associating and storing an identifier and a second processing rule for a packet, refers to an identifier included in a packet, and processes the packet in accordance with a second processing rule associated with the identifier; and a control apparatus that stores the first processing rule and the identifier in a packet, associates and stores, in the table of the second switch, the identifier and the second processing rule.