- Hosted PBX Users - Your VoIP provider must support TLS and SRTP for this to work.
- Onsite PBX Users - Your PBX also needs to be correctly configured and have the required certificate(s) installed for this to work.
Also, Snom IP telephones do not verify server certificates by default. If you want to turn this feature on, go to the “Certificates” page in the phone setup and click “Activate”. But bear in mind you must either use a certificate from a known CA or import your own certificate into each phone manually. Certificates must be in DER format.