Abstract: A switching method in a bidirectional line switched ring includes the steps of performing span switch by one node of the ring for getting rid of a fault detected by the one node, changing the span switch into ring switch when the span switch could not be performed normally, and performing the ring switch, and holding the ring switch request as an internal request of the one node when a span switch request, higher in priority than the ring switch, generated in another node is received by the one node.

Abstract: A ring configuring method configures a network in which a plurality of nodes are connected linearly, and performs topology construction for the ring by circulating topology data through the respective nodes and collecting connection information of the respective nodes. The method includes the steps of providing in the topology data a flag indicating whether the connection information is collected in each node; inverting the flag at a terminal station which is an end node of the open ring, and turning the topology data there; causing the topology data to passing through a node other than any terminal station as it is; and adding the connection information to the topology data in each node according to the flag, and performing topology construction.

Abstract: The invention concerns a system configuration setting method and a transmission apparatus, and simplifies system reconfiguration operations. The transmission apparatus comprises an HMI control block 1, a main control block 2, a line connection block 3, high-speed units 4 and 5, low-speed units 6 to 8, and a power supply unit 9, wherein the high-speed and low-speed units are managed by the main control block 2, whose management information is also stored in the HMI control block 1. A system reconfiguration command associated with a unit insertion, removal, etc. is entered into the transmission apparatus from a terminal 10.

Abstract: A transmission device including an advanced security system is provided to specify an illegally operated device, inhibit the illegal operations, prevent from forgetting to unlock a log-in status by a maintenance operator, and set permitted user level for each command. The security system for a transmission device in a network is formed with plural transmission devices each including, at least, a port for a control terminal, which controls the transmission devices, when a cable disconnection is detected in a port of one transmission device, a log-in status is unlocked for the one transmission device or the other transmission devices through the port.

Abstract: A transmission device including an advanced security system is provided to specify an illegally operated device, inhibit the illegal operations, prevent from forgetting to unlock a log-in status by a maintenance operator, and set permitted user level for each command. The security system for a transmission device in a network is formed with plural transmission devices each including, at least, a port for a control terminal, which controls the transmission devices, when a cable disconnection is detected in a port of one transmission device, a log-in status is unlocked for the one transmission device or the other transmission devices through the port.

Abstract: When an unauthorized log-in is attempted from a maintenance terminal (18) physically connected to one of transmission apparatuses (20, 22, 23, 25, and 27), a log-in process block (34) incorporated in the transmission apparatus (for example, 25) on which the log-in has been attempted counts the number of attempted log-ins (60), and when the number of attempted log-ins reaches a predetermined number, a message reporting the occurrence of an unauthorized log-in attempt is sent to a monitoring terminal (28) for display thereon, together with the network addresses of the transmission apparatus (25) and the transmission apparatus (20) to which the maintenance terminal (18) is physically connected.

Abstract: A ring configuring method configures a network in which a plurality of nodes are connected linearly, and performs topology construction for the ring by circulating topology data through the respective nodes and collecting connection information of the respective nodes. The method includes the steps of providing in the topology data a flag indicating whether the connection information is collected in each node; inverting the flag at a terminal station which is an end node of the open ring, and turning the topology data there; causing the topology data to passing through a node other than any terminal station as it is; and adding the connection information to the topology data in each node according to the flag, and performing topology construction.