1.4 Relationship to Other Protocols
The following network stack diagram shows the relationship of SSTP to other protocols.
Figure 1: SSTP protocol stack
The Secure Socket Tunneling Protocol (SSTP) allows encapsulation of PPP traffic over HTTPS. As a result, SSTP uses both PPP and HTTPS for operation. For more information about HTTPS, see [RFC1945], [RFC2616], and [RFC2818]. For more information about PPP, see [RFC1661].