18.1.2. Scenarios - Overview 
Signaling and payload encryption is supported in the following scenarios:
- IP trunking (see Section 3.3.2, “SPE for IP Trunking”)
- SIP subscriber (see Section 3.4.2, “SPE for IP Subscribers”)
- HFA subscribers (see Section 3.4.2, “SPE for IP Subscribers”)
- IPDA (see Section 3.5, “Activation / Deactivation of SPE for Access Points”)
- OpenScape 4000 SoftGate (see Section 3.6, “OpenScape 4000 SoftGate SPE Activation / Deactivation”)
- Analog and TDM terminals (see Section 3.4.1, “SPE for Analog/TDM Endpoints”)
- Analog and TDM trunking connections (see Section 3.3.1, “SPE for Analog / TDM Trunks”)