In digital networking, an active device, having multiple input/output (I/O) ports, in which a signal introduced at the input of any port appears at the output of every port. Note 1: A multiport repeater usually performs regenerative functions, i.e., it reshapes the digital signals. Note 2: Depending on the application, a multiport repeater may be designed not to repeat a signal back to the port from which it originated.

In an optical communication system, an optoelectronic device or module that receives an optical signal, amplifies it (or, in the case of a digital signal, reshapes, retimes, or otherwise reconstructs it), and retransmits it as an optical signal.

A device that interfaces concatenated E&M signal paths. Note 1: A PLR converts a ground, received from the E lead of one signal path, to -48 Vdc, which is applied to the M lead of the concatenated signal path. Note 2: In many commercial carrier systems, the channel bank cards or modules have a “PLR” option that permits the direct connection, i.e., concatenation, of E&M signaling paths, without the need for separate PLR equipment.