摘要:
The invention relates to a method of providing protected transmission between two nodes (1, 2) of a wavelength-division multiplexed network. The invention proposes to have loss of signal over the main line (3) detected by a node, and then to interrupt transmission of data over the main line by said node. By interrupting transmission, it is thus possible to force loss of signal on the other node: the other node then switches its transmission of protected data over to the backup line (4). Interrupting the transmission of data can be achieved by switching off the laser of said node. The invention also describes a method of testing with a view to re-using the main line (3). The invention provides means for switching the protected data over to the backup path that are particularly simple in terms of protocol.