Example methods and system to validate proper network connections between a digital subscriber line (DSL) access multiplexer (DSLAM) and the subscriber loop to a customer location are disclosed. A disclosed example device includes first and second nodes to electrically couple the device to a port of a DSLAM and to a first end of a communication circuit, the communication circuit to facilitate electrical coupling of the port of the DSLAM to a central office (CO) switch at a second end of the communication circuit, and a signature circuit electrically coupled between the first and second nodes to generate a signature signal in response to a test signal injected onto the communication circuit at a second end of the communication circuit, the signature signal having a magnitude substantially proportional to the test signal.