This interface converter is based on FPGAproviding one framed E1 interface and one Ethernet interface to achieve 10/100base-T Ethernet data transmission on the E1 channel. It is a high performance self-learning Ethernet bridge. This device is the extension device of Ethernet using network (PDH/SDH/Microwave) that provide E1 channel to achieve local and remote Ethernet interconnecting with serial interfaces at a lower cost. The device has inter-set loop test function to facilitate the project launching and daily maintenance.