What is TCP Port Monitoring?
The Transmission Control Protocol, or TCP, is one of the most commonly used protocols on the Internet. The port availability monitor checks to see if a device is listening for and accepting connections on a specified TCP port.
In a typical client-server model, an application waits for incoming data, the connection request (Listening on a Port), or sends data (connection request), to the known TCP port, which is finally opened by the application server (client).