An OLT performs interactive authentication with an optical module, and determines a time sequence parameter of the optical module. The optical module stores the time sequence parameter in a register of the optical module. When the optical module is inserted into the OLT and is in a working state, the OLT reads the time sequence parameter stored in the optical module. Then, based on the time sequence parameter, the OLT determines and configures time sequence information of an ONU corresponding to the optical module.