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).

62 Glossary

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Cisco Systems 9124E Request rate, Route, Routing, Sequence, Service rate, Single mode, Switch port, Tenancy, Throughput