IBM 8237, Инструкция по установке и эксплуатации

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8237 Hub Installation and Planning Guide
physical medium of transmission, the protocol, and
associated devices and programs; it is both physical
and logical.
data set ready (DSR). Synonym for DCE ready.
data transfer. (1) The result of the transmission of
data signals from any data source to a data receiver.
(2) The movement, or copying, of data from one
location and the storage of the data at another location.
DCE ready. In the EIA 232 standard, a signal that
indicates to the data terminal equipment (DTE) that the
local data circuit-terminating equipment (DCE) is
connected to the communication channel and is ready
to send data. Synonymous with
data set ready (DSR).
default. Pertaining to an attribute, value, or option that
is assumed when none is explicitly specified.
delimiter. (1) A character used to indicate the
beginning or end of a character string. (T) (2) A bit
pattern that defines the beginning or end of a frame or
token on a LAN.
destination. Any point or location, such as a node,
station, or particular terminal, to which information is to
be sent.
device. (1) A mechanical, electrical, or electronic
contrivance with a specific purpose. (2) An input/output
unit such as a terminal, display, or printer. See also
attaching device.
diagnostics. Modules or tests used by computer
users and service personnel to diagnose hardware
problems.
digital. (1) Pertaining to data in the form of digits. (A)
Contrast with analog. (2) Pertaining to data consisting
of numerical values or discrete units.
duplex mode. The method by which data is
transmitted and received on a data link. Data can be
sent and received at the same time, i.e. full-duplex
mode, or sent and received one at a time, i.e. half-
duplex mode.
E
EIA. Electronic Industries Association.
EIA 232. In data communications, a specification of
the Electronic Industries Association (EIA) that defines
the interface between data terminal equipment (DTE)
and data circuit-terminating equipment (DCE), using
serial binary data interchange.
end delimiter. The last byte of a token or frame,
consisting of a special, recognizable bit pattern.
equipment rack. A metal stand for mounting network
components, such as distribution panels and IBM 8237
Stackable Ethernet Hubs. Synonymous with
rack.
Ethernet. A 10- or 100-megabit baseband local area
network that allows multiple stations to access the
transmission medium at will without prior coordination,
avoids contention by using carrier sense and
deference, and resolves contention by using collision
detection and transmission. Ethernet uses carrier
sense multiple access with collision detection
(CSMA/CD).
Ethernet version 2. Also called DIX Ethernet, for
DEC, Intel, and Xerox. Differs from IEEE 802.3
Ethernet in frame format only. Not an approved
international standard but in more widespread use than
IEEE 802.3 Ethernet.
F
feature. A part of an IBM product that may be ordered
separately by the customer.
field. On a data medium or a storage medium, a
specified area used for a particular category of data; for
example, a group of character positions used to enter
or display wage rates on a panel. (T)
field-replaceable unit (FRU). An assembly that is
replaced in its entirety when any one of its components
fails.
file. A named set of records stored or processed as a
unit. (T)
file server. A high-capacity disk storage device or a
computer that each computer on a network can access
to retrieve files that can be shared among the attached
computers.
File Transfer Protocol (FTP). In TCP/IP, an
application protocol used for transferring files to and
from host computers. FTP requires a user ID and
possibly a password to allow access to files on a
remote host system.
flash memory. A data storage device that is
programmable, erasable, and does not require
continuous power to retain its storage. The chief
benefit of flash memory over other programmable and
erasable data storage devices is that it can be
reprogrammed without being removed from the circuit
board.
forward mode. Method by which incoming data
frames are sent to their destination port in a switch.
frame. (1) The unit of transmission in some LANs,
including the IBM Token-Ring Network and the IBM PC
Network. It includes delimiters, control characters,
information, and checking characters. (2) A housing for
machine elements. (3) In synchronous data link control
(SDLC), the vehicle for every command, every
response, and all information that is transmitted using