2.3. ONT Authentication
G.984.3 defines two authentication mechanisms:
pre-provision of the ONU/ONT to an OLT, using a shared SLID (Subscriber Line IDentifier)
the SLID is unknown and the OLT activates the ONT/ONU on the fly.
There is no verification of the remote OLT, so authentication with a rogue remote OLT is possible, allowing wiretapping. This is another subject.
The SLID can be in different modes:
PERMANENT
VOLATILE
REGISTRATION
The SLID can be saved in two formats: hexadecimal or alphanumeric.
From my research, the SLID for a SFR connection is VOLATILE and is not set to a fixed value: the OLT activates the ONT on the fly.
The SLID for an Orange connection is PERMANENT and is a shared secret between the ONU/ONT and the OLT. The SLID is entered into the ONT by a technician when he comes to your home to install the fiber. The authentication is based on this value. Changing the SLID to an incorrect value will interrupt the connection of the ONT to the remote OLT, which means NO INTERNET.
The SLIDs that were linked to my Orange FTTH accounts were (obfuscated, with 0 for numbers and X for letters):
0W1JXXXX <- it looked like a random string (alphanumeric)
0562100000 <- it looked like a French phone number
da quello che dice slid è sempre un tipo di autenticazione
qui il link dove ho trovato info
https://pierrekim.github.io/blog/2016-11-01-gpon-ftth-networks-insecurity.html
