3.1.1.7.1 Session Initialization

The following sequence diagram demonstrates session initialization.

Figure 12: Sequence for session initialization

The initiator MAY<41> begin session initialization by sending a Ping Request, as specified in Ping Message (section 2.1.2), on the UDP or SPX transport to the acceptor to determine whether it is available and can accept a connection. In that case, the acceptor MAY<42> respond with a Ping Response, as specified in section 2.1.2, indicating that it is available.

Next, the initiator initiates a protocol session by sending an EstablishConnection Packet (section 2.2.3) to the acceptor. The acceptor accepts the connection and responds with an EstablishConnection Packet. The initiator sends a ConnectionParameters Packet (section 2.2.2) to the acceptor to communicate session parameters such as timeouts and window size. The acceptor confirms the session parameters by responding with a ConnectionParameters Packet response packet.