Yealink SIP-T48G Administrator's Manual page 512

Administrator's Guide for SIP-T2_Series_T4_Series IP Phones
If it is set to 1 (Enabled), the IP phone will authenticate the server certificate based
on the trusted certificates list. Only when the authentication succeeds, the IP phone
will trust the server.
If it is set to 0 (Disabled), the IP phone will trust the server no matter whether the
certificate sent by the server is valid or not.
Note: If you change this parameter, the IP phone will reboot to make the change
take effect.
Web User Interface:
Security->Trusted Certificates->Only Accept Trusted Certificates
Phone User Interface:
None
security.ca_cert
Description:
Configures the type of certificates in the Trusted Certificates list for the IP phone to
authenticate for TLS connection.
0-Default certificates
1-Custom certificates
2-All certificates
Note: If you change this parameter, the IP phone will reboot to make the change
take effect.
Web User Interface:
Security->Trusted Certificates->CA Certificates
Phone User Interface:
None
security.cn_validation
Description:
Enables or disables the IP phone to mandatorily validate the CommonName or
SubjectAltName of the certificate sent by the server.
0-Disabled
1-Enabled
Note: If you change this parameter, the IP phone will reboot to make the change
take effect.
Web User Interface:
498
Parameters Permitted Values
0, 1 or 2
0 or 1
Default
2
0