Abstract: A device, to which an RPR setting instruction is input by a network administrator, comprises an RPR controller and information (RPR information) that the RPR should be set is transmitted to all devices in the established network. In a SONET device at the gateway to a path where the RPR network uses the SONET ring, a NUT controller is comprised. The NUT controller, which received the RPR information, notifies all devices in the SONET ring of information instructing the NUT setting. All of the devices in the SONET ring, which receive the information, perform the NUT setting automatically.

Abstract: A cell switch module having a unit cell switching function and placeable in either an active state or a standby state. The module comprises a plurality of input ports for inputting cells thereto, a plurality of output ports for outputting cells therefrom, and a cell switching controller to execute such control that, in response to an active/standby switching instruction, a decision is made as to whether the input cell is a specific first cell or not, and if the input cell is detected to be the first cell in the active state, any subsequent cell inputted thereafter is not switched, but if the input cell is detected to be the first cell in the standby state, any subsequent cell inputted thereafter is switched.

Abstract: The transmitter comprises: a detection part for detecting an identifier (CI-ID) for identifying a band use to be received; an identifier setting part for previously setting the identifier (CI-ID) for identifying the expected band use; and a control part for monitoring the detection part and identifier setting part in each minimum unit of a line, wherein the control part periodically monitors the identifier for identifying the band use to be received in the previously defined band, and when the identifier is different from the identifier for identifying the expected band use, the identifier for identifying the expected band use is re-established as the identifier for identifying the band use to be received.

Abstract: A cell switch module having a unit cell switching function and placeable in either an active state or a standby state. The module comprises a plurality of input ports for inputting cells thereto, a plurality of output ports for outputting cells therefrom, and a cell switching controller to execute such control that, in response to an active/standby switching instruction, a decision is made as to whether the input cell is a specific first cell or not, and if the input cell is detected to be the first cell in the active state, any subsequent cell inputted thereafter is not switched, but if the input cell is detected to be the first cell in the standby state, any subsequent cell inputted thereafter is switched.

Abstract: A cell switch module having a unit cell switching function and placeable in either an active state or a standby state. The module comprises a plurality of input ports for inputting cells thereto, a plurality of output ports for outputting cells therefrom, and a cell switching controller to execute such control that, in response to an active/standby switching instruction, a decision is made as to whether the input cell is a specific first cell or not, and if the input cell is detected to be the first cell in the active state, any subsequent cell inputted thereafter is not switched, but if the input cell is detected to be the first cell in the standby state, any subsequent cell inputted thereafter is switched.

Abstract: The transmitter comprises: a detection part for detecting an identifier (CI-ID) for identifying a band use to be received; an identifier setting part for previously setting the identifier (CI-ID) for identifying the expected band use; and a control part for monitoring the detection part and identifier setting part in each minimum unit of a line, wherein the control part periodically monitors the identifier for identifying the band use to be received in the previously defined band, and when the identifier is different from the identifier for identifying the expected band use, the identifier for identifying the expected band use is re-established as the identifier for identifying the band use to be received.

Abstract: An optical multiplexing transmitter having functions for dropping or demultiplexing an optional time slot of a channel of a high-ordered group to optional channels of a low-ordered group channels and adding and multiplexing optional time slots of a low-ordered group to a channel of the high-ordered group in the reversed direction also referred as to an add/drop cross connect function. The optical multiplexing transmitter further, for may loopback optional time slots of the low-ordered group to optional channels of the low-ordered group also referred to as a hair pin cross connecting function.

Abstract: An optical transmission system includes a plurality of nodes connected via optical transmission lines in a ring form. When an optical transmission line is disconnected or a fault is found on the optical transmission device of a node, a transmission line is switched over to another transmission line by a line switching system which includes optical transmission lines of a working line for transmitting optical data signals and a protection line for transmitting APS (Automatic Protection Switch) bytes. Each of the nodes has a comparing and detecting unit for receiving the APS bytes sent from an adjacent node and comparing a fault pattern indicated by the APS bytes with a fault pattern stored in advance, and a processing unit which determines a line switching route, based on the result of comparison in the comparing and detecting unit.