Polycom RMX 1500 Administrator's Manual page 135

To enable encryption at the participant level:
>> In the Participant Properties – Advanced dialog box, in the Encryption
list, select one of the following options: Auto, On, or Off.
— Auto - The participant inherits the conference/Entry Queue
encryption setting. The participant connects as encrypted only if
the conference is defined as encrypted.
— Yes - The participant joins the conference/Entry Queue is
encrypted.
— No - The participant joins the conference/Entry Queue is
non-encrypted.
Chapter 2-Additional Conferencing Information
2-73