CUCM force encryption for all phone calls

[TTrebing]

Is there any way to enforce encryption on calls so that a call is not completed if it cannot be encrypted? 

For example, security mode on the cluster is "mixed".  Phone A is setup to support encryption, while phone B is not.  When phone A calls phone B, the call is not encrypted, but is successful.  Is there a way to make the call to phone B fail since phone B is not capable of encryption.  I believe based on my research that the answer is "no", but I need official confirmation from Cisco. 

Thanks!

[Jaime Valencia]

AFAIK you got this right, it's not possible to configure a cluster to prevent non-secure calls, there already some things that are non-secure, like MOH, if that was possible, you'd lose some features because of that.