Generally for every connection into and out of a server, a network port is needed. When you open your browser and go to you are actually opening a connection to port 80 (the phone number) within the LumenVox web server (the exchange). Think of a port number as a telephone number, and a computer/server as a telephone exchange. This is often referred to as the Reserved Port Range, since the use of any port in this range is typically reserved for some predefined purpose, and should not typically be used for a general purpose application to avoid conflicts. Generally, these long established and 'well known' ports are in the numeric range between. There are many other ' well known' ports used for a variety of purposes from FTP to network management, timekeeping and other purposes. There are a finite number of ports that can be assigned on a single machine.Ĭertain port numbers have special meaning, such as the HTTP port number 80, which is used when you browse to a website. Typically this involves a network port on the client and another on the server that the client is communicating with. Any application or service that communicates over a network uses some sort of 'port' object as a reference to a specific network connection endpoint.

Open ephemeral ports