IBM DICTIONARY
`OF COMPUTING
`
`Compiled and edited by
`GEORGE MCDANIEL
`
`
`
`McGRAW-HILL, INC.
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`While the Editor and Publisher of this book have made reasonable efforts to
`ensure the accuracy and timeliness of the information contained herein, nei-
`ther the Editor nor the Publisher shalt have any liability with respect to loss or
`damage caused or alleged to be caused by reliance on any information con-
`tained herein.
`
`Copyright © 1994 by International Business Machines Corporation. All rights
`reserved. Printed in the United States of America. Except as permitted under
`the United States Copyright Act of 1976, no part of this publication may be
`reproduced or distributed in any form or by any means, or stored in a data
`base or retrieval system, without the prior written permisssion of the pub-
`lisher.
`1
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`1234567890 DOC/DOC 99876543
`
`ISBN 0-O7-031488-8 (I-IC)
`ISBN 0-07-031489-6 (PBK)
`
`The sponsoring editor for this book was Daniel A. Gonneaa and the
`production supervisor was Thomas G. Kowalczyk.
`
`Printed and bound by R. R. Donneiley & Sons Company.
`
`Tenth Edition (August 1993)
`
`This is a major revision of the IBM Dictionary of Computing SC20—1699—8,
`which is made obsolete by this edition. Changes are made periodically to the
`information provided herein.
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`It is possible that this material may contain reference to, or information about,
`IBM products (machines and programs), programming, or services that are
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`construed to mean that IBM intends to announce such IBM products, pro-
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`NC27709.
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`International Edition
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`Copyright © 1994 by International Business Machines Corporation. Exclusive
`rights by McGraw-Hill, Inc. for manufacture and export. This book cannot be
`re—exported from the country to which it is consigned by McGraw—I-Iill. The
`International Edition is not available in North America.
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`When ordering this title, use ISBN 0-07-113383-6.
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`This book is printed on acid-free paper.
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`

`
`NMVT
`
`NMVT Network management vector transport.
`
`NN Network node.
`
`NNCP Network node control point.
`
`Node
`
`NNT NetView-NetView task.
`
`No In SAA Advanced Common User Access architec-
`
`ture, a push button that is used in messages to provide
`a negative response to a question.
`
`no-buffer queue In ACF/TCAM, the chain of CPBS
`for read operations when no buffers are in the buffer
`pool.
`
`systems with multiple
`condition In
`no-consoles
`console support, a condition in which the system is
`unable to access any fu}l~capability console device.
`
`no-CPB queue In ACF/TCAM, the chain of elements
`to be processed by the CPB initialization routine.
`
`node (1) In a network, a point at which one or more
`functional
`units
`connect
`channels
`or
`data
`circuits. (I)
`(2) In network topology, the point at an
`end of a branch. (T)
`(3) The representation of a
`state or
`an event by means of a point on a
`diagram. (A)
`(4) In a tree structure, a point at
`which subordinate items of data originate.
`(A)
`(5)
`An endpoint of a link or a junction common to two or
`more links in a network. Nodes can be processors,
`communication controllers, cluster controllers, or ter-
`minals. Nodes can vary in routing and other func-
`tional capabilities.
`(6) In VTAM, a point
`in a
`network defined by a symbolic name.
`See major
`node, minor node.
`(7) In the IBM 8100 Information
`System, a junction point in a network represented by
`one or more physical units.
`(8)
`In NETDA/2, a com-
`bination of hardware, software, and microcode that can
`generate message traffic, receive and process message
`traffic, or receive and relay message traffic.
`(9) See
`Figure 100.
`
`node identification A unique string of characters that
`Identifies a node.
`
`the portion of the
`node identifier In ACF/TCAM,
`network address of a resource that
`indicates which
`
`TCAM node provides message queuing for
`resource. See resource identifier.
`
`that
`
`node initialization block (NIB) In VTAM, a control
`block associated with a particular node or session that
`Contains information used by the application program
`to identify the node or session and to indicate how
`Communication requests on a session are to be handled
`by VTAM.
`
`Path
`
`Figure 100. Node
`
`node name In VTAM, the symbolic name assigned to
`a specific major or minor node during network defi-
`nition.
`
`node operator In SNA, a person or program respon-
`sible for controlling the operation of a node via the
`physical unit control point (PUCP). See also domain
`operator, network operator.
`
`node table For ACF/TCAM extended networking, a
`main storage tabie that associates each node identifier
`with internodal destination queues.
`
`node type A designation of a node according to the
`protocols it supports or the role it plays in a network.
`Node type was originally denoted numerically (as I,
`2.0, 2.1, 4, and 5) but is now characterized more Spe-
`cifically by protocol type (APPN network node, LEN
`node,
`subarea node,
`and interchange
`node,
`for
`example) because type 2.1 nodes and type 5 nodes
`support multiple protocol types and roles.
`
`security
`level of
`node verification An additional
`beyond that provided by the network addressing
`scheme. Node verification helps to ensure that a con-
`nection reaches the correct remote station.
`It is avail~
`able on LU—LU 6.2 connections only. See also BIND
`password.
`
`no-input zone Synonym for dead zone.
`
`noise (1) A disturbance that affects a signal and that
`can distort the information carried by the signal. (T)
`(2) Random variations of one or more characteristics
`of any entity such as voltage, current, or data. (A)
`(3) A random signal of known statistical properties of
`amplitude, distribution, and spectral density. (A)
`(4) Loosely, any disturbance tending to interfere with
`nonnal operation of a device or system. (A)
`(5) In
`acoustics, any undesired sound.
`See ambient noise,
`background noise,
`burst
`noise,
`impulsive
`noise.
`(6) See reference noise.