3.1.5 Message Processing Events and Sequencing Rules
Figure 13: State diagram for the terminal server and terminal client states
The states are described as follows:
Closed state: Both the terminal server sender and the terminal client receiver can be in the Closed state. The endpoint in a Closed state MUST NOT respond to any networking events, and MUST NOT generate or process any datagrams. The endpoint enters the Closed state when the Retransmit timer or the Keepalive timer is fired, as specified in section 220.127.116.11.
SYN_SENT: Only the terminal client receiver can enter this state, after sending a SYN packet and thus initiating the connection.
SYN_RECEIVED: Only the terminal server sender can enter this state, after receiving a SYN packet from the terminal client receiver.
Established: This state indicates that a connection has been established, and datagrams are exchanged between the two endpoints.
Duplicate messages are ignored and discarded by either endpoint. The exchanged messages are specified in the following sections.