A state is a distinct phase in a connection between two applications.

• A. TRUE
• B. FALSE
• C. Not sure
• D. Both

Answer: (A)

In TCP and similar connection-oriented protocols, a connection is modeled as a finite-state machine. A state represents a distinct phase in the lifecycle of that connection between two applications, such as opening, established data transfer, or closing. Each state defines what can happen next and which transitions are allowed. For example, during the handshake the client may be in a state waiting for a response after sending SYN (SYN-SENT), while the server may be in LISTEN or SYN-RECEIVED. Once the handshake completes, the connection enters the ESTABLISHED state where data can flow. When finishing, the connection moves through states like FIN-WAIT-1 and CLOSE-WAIT before fully closing. This framing—state as a phase with specific rules and transitions—makes the statement true.