Abstract: According to the present disclosure, provided is a network system including a plurality of devices and a network management apparatus connected to the plurality of devices by an IP transmission line, and the network management apparatus (100) includes a setting execution unit (116) configured to execute setting of a path to which the plurality of devices are connected, and setting of parameters for controlling the plurality of devices. With this configuration, it is possible to freely set a connection path and devices in a system in which a plurality of devices are connected.

Abstract: According to the present disclosure, provided is a network system including a plurality of devices and a network management apparatus connected to the plurality of devices by an IP transmission line, and the network management apparatus (100) includes a setting execution unit (116) configured to execute setting of a path to which the plurality of devices are connected, and setting of parameters for controlling the plurality of devices. With this configuration, it is possible to freely set a connection path and devices in a system in which a plurality of devices are connected.

Abstract: In a digital data communication network comprising digital data transmitting and receiving devices (111, 122) and first and second digital communication paths (16, 17) connected to each other and to the transmitting and the receiving devices, respectively, a stuffing circuit (23) is controlled by a control signal producing circuit (24) so as to stuff and not to stuff an input bit sequence when at least one of the first and the second digital communication paths has a restricted transmission characteristic and when both of the communication paths have an unrestricted transmission characteristic. Preferably, necessity and unnecessity of stuffing should be detected for a leading and a trailing part of each block with a shorter interval of time than for other parts of the block. More preferably, some of binary one bits placed at the beginnings of the respective blocks are used as a part of a multiframe synchronization pattern for a signal transmitted through the communication paths.