B) A unit of measurement. One petabyte equals 1,000,000,000,000,000 bytes or 1,000 gigabytes. A byte equals 8 bits. photonics All of the elements of optical communications. This includes fiber, lasers, and optical switches and all elements involved in transmitting light over fiber. ping (Packet Internetwork Groper) A software protocol used to test communications between devices. To "ping" means to send a packet to another device or host to see if the device sends back a response. The ping also tests round-trip delay, the time it takes to send a message to another device. plug-in A small program that adds capabilities to a parent, usually larger, program. Plug-ins are used in browsers and in software defined networks and MANO (Management and Organization). www.TechnicalPDF.com PoE (Power over Ethernet) A standard that defines how power can be carried from wiring closets on floors to the computers and other LAN- connected devices using the same cabling that transmits packetized voice and data. Thus, every device does not need its own power or backup power. PON (Passive Optical Network) Technologies deployed to extend fiber to homes, businesses, and neighborhoods. PONs use non-electrical devices located in the access network that enable carriers to dynamically allocate capacity on a single pair of fibers to multiple homes, buildings in a campus, apartments, and small and medium-sized businesses. POP (Point of Presence) A long-distance company's equipment that is connected to the local telephone company's central office. The POP is the point at which telephone and data calls are handed off between local telephone companies, long-distance telephone companies, and the Internet. POTS (Plain Old Telephone Service) Telephone lines connected to most residential and small- business users. POTS lines are analog from the end user to the nearest local telephone company equipment. People using POTS for data communications with modems are limited in the speed at which they can transmit data. presence The ability of users to know