While in a TLS/SRTP secured call an icon like a padlock with an "S" in it appears on the display. The manual doesn't talk about it. I assume it indicates an encrypted connection. Please provide some details.
Nice to contact you.
As what your said, padlock icon indicates an encrypted connection.
But it is just a display, so we haven't the details.
Do you want to know TLS/SRTP secured and which model do you use?