18.8.4.1. Protocol Setting 
For device protocol setting is possible to use also Deployment service
server. This option is located in the menu: Deployment service >
IP Devices > IP Phone Configuration > Signaling & Payload encryption
> HFA Setting > HFA Transport Protocol
Figure 409. DLS Phone Protocol Setting
For SPE choose from HFA Transport Protocol and HFA Backup
Transport Protocol select box with item TLS protocol.
In order to validate GW certificate on the phone side fill HFA
server validation and HFA backup server validation check boxes.