Bidirectional transmission of electrical power along with data over a wired telecommunications network

A network interface apparatus comprises: a communication portion (4, 6) adapted to connect the interface apparatus to a wired telecommunications network; a rectifier (8) connected to the communication portion; a power distribution bus (14) connected to the rectifier; a first power controller (10); a second power controller (12); a first switch (SW1) coupled to the first power controller (10) and configured to selectively prevent electrical currents from flowing between the connection portion and the power distribution bus, and a second switch (SW2) and a third switch (SW3) each respectively coupled to the second power controller (12) and configured to selectively prevent electrical currents from flowing from the power distribution bus to the connection portion, wherein the second switch (SW2) is connected in parallel with a rectifier element (D3) of the rectifier (8) and the third switch (SW3) is connected in parallel with a second rectifier element (D1) of the rectifier (8).