US Patent 11792040 Communication system and control method

A communication system is a communication system connected to an upper network and a lower network, and includes at least one intermediate communication device including a plurality of upper ports for inputting and outputting optical signals to and from the upper network, and a plurality of lower ports for inputting and outputting optical signals to and from the lower network, the intermediate communication device being configured to relay communication between the upper network and the lower network, a switching device that is connected to the upper and lower networks and the plurality of upper and lower ports, switches a connection between the upper network and the plurality of upper ports, and switches a connection between the lower network and a plurality of lower ports, and a control device that outputs, to the switching device, an instruction to switch the connection by the switching device according to a communication status between the upper network and the lower network.