IBM Cloud Object Storage System Slicestor 2212..., Руководство по обслуживанию и ремонту

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available from a host or gateway and the operations
allowed. (3) In OSI, the conceptual repository of
management information within an open system.
MB. Megabyte (1 048 576 bytes).
Mbps. Megabits per second (1 048 576 bits per
second).
metropolitan area network (MAN). A network formed
by the interconnection of two or more networks which
may operate at higher speed than those networks, may
cross administrative boundaries, and may use multiple
access methods. (T) Contrast with
local area network
(LAN) and wide area network (WAN).
MIB. (1) MIB module. (2) Management Information
Base.
modem (modulator/demodulator). (1) A functional
unit that modulates and demodulates signals. One of
the functions of a modem is to enable digital data to be
transmitted over analog transmission facilities. (T) (A)
(2) A device that converts digital data from a computer
to an analog signal that can be transmitted on a
telecommunication line, and converts the analog signal
received to data for the computer.
MPC. Multi-Path Channel.
MPC+. High-Performance Data Transfer (HPDT)
Multi-Path Channel.
ms. Millisecond (1/1000 second).
N
network. (1) A configuration of data processing
devices and software connected for information
interchange. (2) A group of nodes and the links
interconnecting them.
network architecture. The logical structure and
operating principles of a computer network. (T)
Note: The operating principles of a network include
those of services, functions, and protocols.
network management. The process of planning,
organizing, and controlling a communication-oriented
data processing or information system.
NIC. Network Information Center.
NMS. Network management station.
NNI. Network-to-network interface.
non-return-to-zero change-on-ones recording
(NRZ-1). A recording method in which the ones are
represented by a change in the condition of
magnetization, and zeros are represented by the
absence of change. Only the one signals are explicitly
recorded. (Previously called
non-return-to-zero inverted,
NRZI, recording.)
NRZ-1. Non-return-to-zero change-on-ones recording.
NSAP. Network service address point.
NSC. Network Support Center.
NVDM. NetView Distribution Manager/6000.
O
OSI. Open systems interconnection.
P
packet loss ratio. The probability that a packet will
not reach its destination or not reach it within a
specified time.
packet mode operation. Synonym for packet
switching.
packet switching. (1) The process of routing and
transferring data by means of addressed packets so
that a channel is occupied only during transmission of a
packet. On completion of the transmission, the channel
is made available for transfer of other packets. (I)
(2) Synonymous with
packet mode operation. See also
circuit switching.
PBX. Private branch exchange.
PCM. Pulse code modulation.
PDH. Plesiochronous digital hierarchy.
permanent virtual circuit (PVC). In X.25 and frame
relay communications, a virtual circuit that has a logical
channel permanently assigned to it at each data
terminal equipment (DTE).
physical circuit. A circuit established without
multiplexing. See also
data circuit. Contrast with virtual
circuit.
PM. Presentation Manager.
PMF. Parameter Management Frame.
PNP. Private numbering plan.
Point-to-Point Protocol (PPP). A protocol that
provides a method for encapsulating and transmitting
packets over serial point-to-point links.
X-6
2212 Service and Maintenance