Network+

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physical port An opening on a network device that allows a cable of some kind to be connected. Ports allow devices to be connected to each other with cables.


physical ring topology A network topology that is set up in a circular fashion. Data travels around the ring in one direction, and each device on the ring acts as a repeater to keep the signal strong as it travels. Each device incorporates a receiver for the incoming signal and a transmitter to send the data on to the next device in the ring. The network is dependent on the ability of the signal to travel around the ring.


physical star topology Describes a network in which a cable runs from each network entity to a central device called a hub. The hub allows all devices to communicate as if they were directly connected. See also hub.


physical topology The physical layout of a network, such as bus, star, ring, or mesh.


Ping A TCP/IP utility used to test whether another host is reachable. An ICMP request is sent to the host, who responds with a reply if it is reachable. The request times out if the host is not reachable.


Ping of Death A large ICMP packet sent to overflow the remote host’s buffer. This usually causes the remote host to reboot or hang.


plain old telephone service (POTS) Another name for the Public Switched Telephone Network (PSTN). See asymmetrical digital subscriber line, digital subscriber line, Public Switched Telephone Network.


plenum-rated coating Coaxial cable coating that does not produce toxic gas when burned.

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