Introduction to Networking for NonStop S-Series Servers

Glossary
Introduction to Networking for HP NonStop S-Series Servers—520670-005
Glossary-8
file
subsystem is provided for NonStop K-series servers, and the ServerNet/FX adapter
subsystem is provided for NonStop S-Series servers. See also Expand-over-FOX line-
handler process and FOX ring.
file. A logical construct subject to operations such as reading and writing. The term file is
most commonly used to refer to data stored on a disk, but on the NonStop server,
processes, devices, and various other entities are also defined as files.
file attribute. Information about a file such as filename, storage account, and date and time
of file creation. File attributes are present from one file access to another, although the
actual values of a file attribute can change. See also activity attribute.
file system. A set of system procedures that run as part of a user’s process and send
messages to other processes, such as an input/output process (IOP).
flag. A bit pattern that signifies the beginning or end of a block of data in a bit-synchronous
protocol.
FOX ring. A FOX-connected network. A FOX ring consists of two separate bidirectional
fiber-optic rings and can connect as many as 14 servers in a limited geographical area.
See also Fiber Optic eXtension (FOX).
frame. A block of data in a bit-synchronous protocol.
front-end. A piece of hardware or software that handles communications functions on
behalf of another piece of hardware or software. For example, communications
functions can be performed in a front-end processor, as opposed to a host system; this
delegation of function is common in IBM Systems Network Architecture (SNA)
networks. One common application of HP communications products is a front-end
process that resides logically between application software (such as a Pathway
application) and an HP product controlling one or more communications lines; the
front-end process satisfies the protocol requirements of a specialized device or
supports a communications interface that the application software does not directly
support.
full-duplex transmission. A method of operating a communications circuit so that each
end can simultaneously transmit and receive. Required for two-way simultaneous
(TWS) protocol operation.
functional unit. In Open Systems Interconnection (OSI) terms, a collection of service
primitives needed to provide one of the major operational styles of working. Functional
units determine which set of File Transfer, Access, and Management (FTAM) services
are available for an association, depending on which service class is negotiated.
G4SA. See Gigabit Ethernet 4-port ServerNet adapter (G4SA).
GAP. GAP provides ATP6100 support for AWAN 3883/4/5 and 3886 terminal servers. GAP
is required for non-standard asynchronous devices and protocols that do not work with