Yealink VC400 Administrator's Manual page 260

Administrator's Guide for Yealink Video Conferencing Systems
Rules of H.235 security in H.323 calls:
Far
Compulsory
Optional
Disabled
When H.235 is enabled on both systems, calls will be encrypted, and the lock icon
on the display device of each system during a call.
To configure H.235 for StarLeaf Cloud platform via web user interface:
Click on Account->Cloud.
1.
Select StarLeaf from the pull-down list of Platform Type.
2.
Select the desired value from the pull-down list of H.235 Encryption.
3.
Click Confirm to accept the change.
4.
To configure H.235 for H.323 via web user interface:
Click on Account->H.323.
1.
244
Near Compulsory
H.235 Call
H.235 Call
Fail to establish a call
Optional Disabled
H.235 Call Fail to establish call
H.235 Call RTP Call
RTP Call RTP Call
appears