(single) Is the following description correct? The ADSL port can only allow further operations on the port after the port is unblocked.
(single) Is the following description correct? The process of voice fault location can be generally divided into: troubleshooting external devices, fault location to specific devices, and fault location to the board.
(multiple) Which of the following reasons may cause a voice user to pick up the phone without a dial tone?
(multiple) In the GPON network, which of the following reasons may cause the ONT to not be automatically discovered?
(multiple) In the GPON network, which of the following reasons may cause the ONU to fail to go online?