Technical data

Glossary-6
FICON
®
A protocol used on IBM mainframes. Brocade SilkWorm switch FICON support enables a SilkWorm
fabric to transmit FICON format data between FICON-capable servers and storage.
FID Fabric ID. Unique identifier of a fabric in a meta-SAN.
FIFO First in, first out. Refers to a data buffer that follows the first in, first out rule.
fill word An IDLE or ARB ordered set that is transmitted during breaks between data frames to keep the Fibre
Channel link active.
firmware The basic operating system provided with the hardware.
FL_Port Fabric loop port. A port that is able to transmit under fabric protocol and also has arbitrated-loop
capabilities. Can be used to connect an NL_Port to a switch. See also Fx_Port.
flash Programmable nonvolatile RAM (NVRAM) memory that maintains its contents without power.
FLOGI Fabric login. The process by which an N_Port determines whether a fabric is present and, if so,
exchanges service parameters with it. See also PLOGI.
frame The Fibre Channel structure used to transmit data between ports. Consists of a start-of-frame delimiter,
header, optional headers, data payload, cyclic redundancy check (CRC), and end-of-frame delimiter.
There are two types of frames: link control frames (transmission acknowledgements and so forth) and
data frames.
frame relay A protocol that uses logical channels, as used in X.25. Provides very little error-checking ability.
Discards frames that arrive with errors. Allows a certain level of bandwidth between two locations
(known as a "committed information rate": CIR) to be guaranteed by service provider. If CIR is
exceeded for short periods (known as "bursts"), the network accommodates the extra data, if spare
capacity is available. Frame relay is therefore known as "bandwidth on demand."
FRU Field-replaceable unit. A component that can be replaced onsite.
FSPF Fabric shortest path first. The Brocade routing protocol for Fibre Channel switches.
FSS Fabric OS state synchronization. The FSS service is related to high availability (HA). The primary
function of FSS is to deliver state update messages from active components to their peer standby
components. FSS determines if fabric elements are synchronized (and thus FSS "compliant").
FTP File Transfer Protocol.
full fabric The Brocade software license that allows multiple E_Ports on a switch, making it possible to create
multiple ISL links.
full duplex A mode of communication that allows the same port to simultaneously transmit and receive frames. See
also half duplex.
Fx_Port A fabric port that can operate as either an F_Port or FL_Port. See also FL_Port.