3.1.5.2 Connection Sequence
The protocol's connection sequence is illustrated in the figure in section 3.1.5. The following list describes the states that the terminal server and terminal client enter:
Listen: The terminal server enters the Listen state:
The terminal server binds to a UDP socket, and is ready to accept incoming connections.
Connect/SYN:
The terminal client establishes a UDP socket connection with the terminal server.
The terminal client constructs and sends a SYN datagram, as specified in section 3.1.5.1.1.
SYN/SYN+ACK:
The terminal server receives the SYN datagram.
The terminal server constructs and sends a SYN+ACK datagram, as specified in section 3.1.5.1.3.
SYN+ACK/ACK(+DATA):
The terminal client receives a SYN+ACK datagram. If the terminal client does not receive a response for a SYN datagram that was retransmitted at least three and no more than five times, the endpoint will enter the Closed state.<5>
The terminal client generates an ACK for the SYN+ACK datagram.
The terminal client can append Source Packets to the ACK datagram.
ACK:
The server receives an ACK for the SYN+ACK datagram sent. If the terminal server does not receive a response for a SYN + ACK datagram that was retransmitted at least three and no more than five times, the endpoint will enter the Closed state.<6>
The server enters the Established state.