Allowing or blocking network packets into or out of a device or the network based on their application (port number). See TCP/IP port and opening a port.
"port filtering." YourDictionary, n.d. Web. 17 August 2018. <http://www.yourdictionary.com/port-filtering>.
port filtering. (n.d.). Retrieved August 17th, 2018, from http://www.yourdictionary.com/port-filtering