18.8.4.3. CA Certificate Upload 
CA Certificate for the GW certificate verification is possible to
upload to the phone via DLS server only.
This option is located in menu: Deployment service > IP Devices
> IP Phone Configuration > Signaling & Payload encryption >
SPE CA Certificate
Figure 412. DLS Phone CA Certificate Setting
For new CA certificate import or currently used CA certificate rewriting
use Import Certificate button. On following screen press Browse
button and select appropriate CA certificate file to import. Check Import
certificate to DLS and activate on device check box and press OK.
Figure 413. DLS Phone Import CA Certificate Dialog
