Network element

The invention relates to a network element, comprising at least one input, to which an optical signal can be fed, at least one output, which is equipped to emit an optical signal, a first coupler having an input and a first and a second output, wherein the first input of the network element is linked to the input of the first coupler, an optical receiver, which comprises at least one input and at least one output, wherein the second output of the first coupler is linked to the input of the optical receiver, an optical sender, the at least one input of which is linked to the output of the optical receiver, wherein a signal processing device is arranged in the signal path, a second coupler having a first input, which is linked to the first output of the first coupler, a second input, which is linked to the output of the optical sender, and an output,; which is linked to the first output of the network element.