1.3.2 SSTP Connections

This protocol provides a full-duplex application-level connection (1) between two computer devices that have established a network-layer connection via TCP or another comparable reliable network transport. Clients initiate SSTP connections to other clients and to servers; servers initiate SSTP connections to other servers but not to clients.

To establish an SSTP connection, an initiating device sends an SSTP Connect command to a specified recipient. If delivery is successful, the recipient responds by sending a ConnectResponse command that contains a ResponseId field with a value of Ok. This two-way handshake results in an established SSTP connection. All subsequent application-level communication between these devices is multiplexed over this connection. Either device can close the connection at any time by sending a ConnectClose command.