EXFO America Inc. AXS-855-1-DS1 Ethernet 10/100/1000 Electrical and GigE Optical Test ModuleDual TX/RX DS1 interfaceEthernet testing including: - Single port 10/100/1000 Base-T Electrical and GigE optical interface - Supports BER, RFC 2544, and IP Connectivity testing up to Layer 4DS1