A GPON system supports the following ONU authentication modes: The OLT authenticates an ONU by checking the SN of the ONU. The first four characters represent the manufacturer. These parameters include serial numbers, PLOAM passwords, vendor identification, and equipment metadata that must be correctly set for successful GPON registration. If authentication and authorization are performed by the device itself, it is called local. The new version of OLT firmware will set the MGMT/GE/SFP+ interface to DHCP mode by default. GE and SFP+ ports are usually used for uplink. After the OLT is adopted by the Omada Controller, the Automatic Authentication.