IBM Nways 2216, Руководство по обслуживанию и ремонту

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data circuit-terminating equipment (DCE). In a data
station, the equipment that provides the signal
conversion and coding between the data terminal
equipment (DTE) and the line. (I)
Notes:
1. The DCE may be separate equipment or an integral
part of the DTE or of the intermediate equipment.
2. A DCE may perform other functions that are usually
performed at the network end of the line.
data link control (DLC). A set of rules used by nodes
on a data link (such as an SDLC link or a token ring) to
accomplish an orderly exchange of information.
data link switching (DLSw). A method of transporting
network protocols that use IEEE 802.2 logical link
control (LLC) type 2. SNA and NetBIOS are examples
of protocols that use LLC type 2. See also
encapsulation and spoofing.
data terminal equipment (DTE). That part of a data
station that serves as a data source, data sink, or
both. (I) (A)
data terminal ready (DTR). A signal to the modem
used with the EIA 232 protocol.
dc. Direct current.
DCD. DC distribution (module).
DCE. Data circuit-terminating equipment.
DCE. Data circuit-terminating equipment.
DC48. DC power input type -48V.
dependent LU requester (DLUR). An APPN end
node or an APPN network node that owns dependent
LUs, but requests that a dependent LU server provide
the SSCP services for those dependent LUs.
device. A mechanical, electrical, or electronic
contrivance with a specific purpose.
device address. The unit address transmitted on the
channel path to select a 2216 device. It is also referred
to as subchannel number in S/370 I/O architecture.
This value is defined in the host IOCP by the UNITADD
statement on the CNTLUNIT macro instruction for the
real device.
digital. (1) Pertaining to data that consist of digits. (T)
(2) Pertaining to data in the form of digits. (A)
(3) Contrast with analog.
DLCI. Data link connection identifier.
DLS. Data link switching.
DLUR. Dependent LU requester.
DTE. Data terminal equipment. (A)
DTE. Data terminal equipment.
DTMF. Dual-tone modulation frequency.
DTR. Data terminal ready.
E
E&M. Earth & mark.
EIA. Electronic Industries Association.
EIA unit. A unit of measure, established by the
Electronic Industries Association, equal to 44.45
millimeters (1.75 inches).
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.
Electronic Industries Association (EIA). An
organization of electronics manufacturers that advances
the technological growth of the industry, represents the
views of its members, and develops industry standards.
EMIF. ESCON Multiple Image Facility.
encapsulation. In communications, a technique used
by layered protocols by which a layer adds control
information to the protocol data unit (PDU) from the
layer it supports. In this respect, the layer encapsulates
the data from the supported layer. In the Internet suite
of protocols, for example, a packet would contain
control information from the physical layer, followed by
control information from the network layer, followed by
the application protocol data. See also
data link
switching (DLSw).
ESCD. ESCON Director.
ESCON. Enterprise Systems Connection.
ESF. Extended status flags.
Ethernet. A 10-Mbps 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).
Glossary
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