Transmission network in which a communication path is automatically restored in accordance with occurrence of a failure in a distributed way

摘要

For enabling automatic restoration of a path in a transmission network including a plurality of crossconnect systems and a plurality of communication routes, a unit specifying circuit specifies, as a first and a second specified unit, two of the crossconnect systems in accordance with a particular route which is selected as the path. It will be assumed that a failure occurs in a particular point of the path. In this event, the first specified unit executes a predetermined operation in cooperation with the second specified unit. When the predetermined operation finishes, each of the crossconnect systems is operable to select, as the path, another one of the communication routes. It is preferable that the failure is detected in accordance with a path alarm indication signal which is surely supplied from the particular point to each of the first and the second specified units.