HP Cisco MDS 9124e Fabric Switch for BladeSystem c-Class - Manual (Page 62)

Glossary 62
R_A_TOV Resource allocation time-out value. The maximum time a frame can be delayed in the
fabric and still be delivered.
RAID Redundant Array of Independent Disks. A collection of disk drives that appear as a
single volume to the server and are fault tolerant through mirroring or parity checking.
request rate The rate at which requests arrive at a servicing entity.
route With respect to a fabric, the communication path between two switches. May also
apply to the specific path taken by an individual frame from source to destination.
routing The assignment of frames to specific switch ports according to frame destination.
RR_TOV Resource recovery time-out value. The minimum time a target device in a loop waits
after a LIP before logging out a SCSI initiator.
RSCN Registered state change notification. A switch function that allows notification of fabric
changes to be sent from the switch to the specified nodes.
SAN Storage area network. A network of systems and storage devices that communicate
using FC protocols.
SDRAM Synchronous dynamic random access memory. The main memory for a switch. See also
switch .
sequence A group of related frames transmitted in the same direction between two N_ports.
service rate The rate at which an entity can service requests.
single mode The fiber optic cabling standard that corresponds to distances up to 10 km between
devices.
SNMP Simple Network Management Protocol. An Internet management protocol that uses
either IP for network-level functions and UDP for transport functions, or TCP/IP for both.
SNMP can be made available over other protocols (such as UDP/IP) because it does
not rely on the underlying communication protocols. See also MIB , trap (SNMP) .
SNS Simple Name Server. A switch service that stores names, addresses, and attributes for
up to 15 minutes, and provides them as required to other devices in the fabric. May
also be referred to as a directory service.
switch Hardware that routes frames according to FC protocol and is controlled by software.
switch port A port on a switch. Switch ports can be E_Ports, F_Ports, or FL_Ports.
SWL Short wavelength. A type of fiber optic cabling that is based on 850 mm lasers and
supports link speeds up to 2 Gb/s. May also refer to the type of transceiver.
tenancy The time span that begins when a port wins arbitration in a loop and ends when the
same port returns to the monitoring state. Also called loop tenancy.
throughput The rate of data flow achieved within a cable, link, or system. Usually measured in bits
per second (b/s).