Enabling H.323 security Lifesize systems support H.235 security in H.323 calls. Set H.323 Security in Preferences > Security to one of the following values:ValueDescriptionOffEncrypted calls are not supported.AutoBoth encrypted and unencrypted calls are supported. Secure calls are supported only if the far end supports encryption.StrictUnencrypted calls are not supported.Read more about H.323.