IBM SAN16B-2 User Guide - Page 79

node port (N_port). A port on a node that can connect to a Fibre Channel port or to another N_Port in a point-to-point connection. nonparticipating mode. A mode in which a loop port (L_port) in a loop is inactive and cannot arbitrate or send frames, but can retransmit any received transmissions. This mode is entered if there are more than 127 devices in a loop and an arbitrated loop physical address (AL_PA) cannot be acquired. See also participating mode. nonvolatile random access memory (NVRAM). Random access memory (storage) that retains its contents after the electrical power to the machine is shut off. A specific part of NVRAM is set aside for use by the system ROS for the boot device list. N_port. See node port. NTP. See network time protocol NVRAM. See nonvolatile random access memory. Nx_port. A node port that can operate as either a node port (N_port) or node loop port (NL_port). See also node port and node loop port. O operating system (OS). A collection of system programs that control the overall operation of a computer system. ordered set. A transmission word that uses 8b/10b mapping and begins with the K28.5 character. Ordered sets occur outside of frames, and include frame delimiters, primitive signals, and primitive sequences. Ordered sets are used to differentiate Fibre Channel control information from data frames and to manage the transport of frames. See also frame delimiter, primitive signal, and primitive sequence. OS. See operating system. out-of-band. Transmission of management protocol outside of the Fibre Channel network, usually over Ethernet. P packet. A set of information transmitted across a network. See also frame. parallel. The simultaneous transmission of data bits over multiple lines. participating mode. A mode in which a loop port (L_port) in a loop has a valid arbitrated loop physical address (AL_PA) and can arbitrate, send frames, and retransmit received transmissions. See also nonparticipating mode. path selection. The selection of a transmission path through the fabric. Switches use the Fibre Channel shortest path first (FSPF) protocol. PDU. Power distribution unit. Performance Monitoring. A software feature that provides error and performance information to the administrator and user for use in storage management. phantom address. An arbitrated loop physical address (AL_PA) value that is assigned to a device that is not physically in the loop. Also known as phantom AL_PA. phantom device. A device that is not physically in an arbitrated loop, but is logically included through the use of a phantom address. PLDA. See private loop direct attach. PLOGI. See port login. P/N. Part number. point-to-point. A Fibre Channel topology that employs direct links between each pair of communicating entities. See also topology. port cage. The metal casing extending out of the optical port on the switch, and in which the gigabit interface converter (GBIC) or small form-factor pluggable (SFP) can be inserted. port card. A hardware component that provides a platform for field-replaceable, hot swappable ports. port login (PLOGI). The port-to-port login process by which initiators establish sessions with targets. See also fabric login. port module. A collection of ports in a switch. port_name. The unique identifier assigned to a Fibre Channel port. Communicated during login and port discovery. POST. See power-on self-test. PPP. Point-to-Point Protocol. power-on self-test (POST). A series of diagnostics that are automatically run by a device when the power is turned on. primary FCS switch. Primary fabric configuration server switch. The switch that actively manages the configuration and security parameters for all switches in the fabric. See also backup FCS switch and FCS switch. primitive sequence. A part of an ordered set that indicates or initiates port states. See also ordered set. Glossary 57