Technical data

Fabric OS Administrator’s Guide Glossary-15
Publication Number: 53-0000518-09
R_RDY Receiver ready. A primitive signal indicating that the port is ready to receive a frame.
R_T_TOV Receiver transmitter timeout value, used by receiver logic to detect loss of synchronization between
transmitters and receivers.
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. See also “JBOD”.
RCS Reliable Commit Service. Refers to Brocade-specific ILS command code.
remote switch An optional product for long-distance fabrics, requiring a Fibre Channel-to-ATM or SONET gateway.
responder The N_Port with which an exchange originator wishes to communicate.
RLS Read Link Status.
route As it applies to a fabric, the communication path between two switches. Might also apply to the specific
path taken by an individual frame, from source to destination. See also “FSPF”.
routing The assignment of frames to specific switch ports, according to frame destination.
RR_TOV Resource recovery timeout value. The minimum time a target device in a loop waits after a LIP before
logging out an SCSI initiator. See also “E_D_TOV”, “R_A_TOV”.
RSCN Registered state change notification. A switch function that allows notification of fabric changes to be
sent from the switch to specified nodes. The fabric controller issues RSCN requests to N_Ports and
NL_Ports, but only if they have registered to be notified of state changes in other N_Ports and
NL_Ports. This registration is performed via the State Change Registration (SCR) Extended Link
Service. An N_Port or NL_Port can issue an RSCN to the fabric controller without having completed
SCR with the fabric controller.
RTWR Reliable transport with response. Might appear as a task in portlogdump command output.
running
disparity
A binary parameter indicating the cumulative disparity (positive or negative) of all previously issued
transmission characters.
RW Read/write. Refers to access rights.
RX Receiving frames.
RX_ID Responder exchange identifier. A 2-byte field in the frame header that can be used by the responder of
the exchange to identify frames as being part of a particular exchange.
S
S_ID Source ID. Refers to the native port address (24 bit address).
SAN Storage area network. A network of systems and storage devices that communicate using Fibre Channel
protocols. See also “fabric”.