Hi there,      A few things on this. 1) Rick thanks for chiming in 2) Rick is right that the option must be set in the GUI. This causes the server to force SRTP when calling TO the phone 3) For calls FROM the phone, you must manually enable SRTP on the phone itself. I think it MAY be in the provisioner tool as well but remains untested to my knowledge. 4) Finally, for all this to work ,you must override the default proxy with: secure-us-east.p.zswitch.net secure-us-west.p.zswitch.net This is a