3.1.5.2 Connection Sequence

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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:

  1. Listen: The terminal server enters the Listen state:

    1. The terminal server binds to a UDP socket, and is ready to accept incoming connections.

  2. Connect/SYN:

    1. The terminal client establishes a UDP socket connection with the terminal server.

    2. The terminal client constructs and sends a SYN datagram, as specified in section 3.1.5.1.1.

  3. SYN/SYN+ACK:

    1. The terminal server receives the SYN datagram.

    2. The terminal server constructs and sends a SYN+ACK datagram, as specified in section 3.1.5.1.3.

  4. SYN+ACK/ACK(+DATA):

    1. 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>

    2. The terminal client generates an ACK for the SYN+ACK datagram.

    3. The terminal client can append Source Packets to the ACK datagram.

  5. ACK:

    1. 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>

    2. The server enters the Established state.