Abstract: A parameter adjustment device (100) for a network device testing system (10) having a head-end device (102) and a central office device (104) includes a data collection module (1001), a data parsing module (1003), and a data management module (1009). The data collection module is used for collecting connection data on the head-end device and parameters on the central office device. The data parsing module is used for parsing the connection data on the head-end device and the parameters on the central office device to determine whether the head-end device has new connection data indicating a new established connection associated with the head-end device. The data management module is used for adding a set of new parameters associated with the new connection data to the central office device data if the head-end device has the new connection data.

Abstract: A test system for testing a network device is provided. The test system includes a control device and a cable group. The control device receives a user instruction, generates a test instruction according to the user instruction, and includes a control board and a relay board. The control board parses the test instruction, and generates a control signal. The relay board is connected to the control board, and comprises a plurality of switches, various of the switches are switched on or off according to the control signal. The cable group includes a plurality of cables with different lengths, the cables electrically connected to the switches, for forming a test line with a required length according to the control signal. A system and a method for automatically adjusting a length of a test line are also provided.