Abstract: A network multiple physical layer interface connected to a first communications network physical layer and through a MODEM to a second physical layer wherein the interface includes circuitry for selecting transmission and reception frequency bandwidths for the MODEM and also includes a first transceiver circuit for receiving data from the first physical layer and transmitting this data through the MODEM to the second physical layer and a second transceiver circuit for receiving data from the second physical layer through the MODEM and retransmitting the data on the first physical layer. The interface further includes user selectable modes to enable this interface to provide a communications connection to only the first physical layer or to both physical layers. Still further, the interface includes collision avoidance circuitry to prevent any transmissions onto the network through this interface when information traffic is present on either physical layer.