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C
cable modem
A device that enables a broadband
connection to the Internet by using cable television infrastructure.
Access speeds vary greatly, with a maximum throughput of 10 megabits per
second (Mbps).
cache
For DNS and WINS, a local
information store of resource records for recently resolved names of
remote hosts. Typically, the cache is built dynamically as the computer
queries and resolves names. It also helps optimize the time required to
resolve queried names.
cache file
A file used by the Domain Name
System (DNS) server to preload its names cache when service is started.
Also known as the root hints file because DNS uses resource records stored
in this file to help locate root servers that provide referral to
authoritative servers for remote names. For Windows DNS servers, the cache
file is named Cache.dns and is located in the %SystemRoot%\System32\Dns
folder.
caching
The process of temporarily storing
recently used data values in a special pool in memory for quicker
subsequent access. For DNS, typically the ability of the DNS server to
store information learned about the DNS namespace during the resolution of
DNS queries. (For example, the DNS server can cache DNS records received
from other DNS servers.) Caching is also available through the DNS Client
service as a way for DNS clients to keep a cache of information learned
during recent queries.
caching resolver
A client-side DNS name resolution
service that performs caching of recently learned DNS domain name
information. The caching resolver service provides system-wide access to
DNS-aware programs for resource records obtained from DNS servers during
processing of name queries. Cached data is used for a limited period of
time and aged according to the active Time-to-Live (TTL) value. You can
set the TTL individually for each resource record (RR). Otherwise, it
defaults to the minimum TTL set in the SOA RR for the zone.
callback number
The number that a remote access
server uses to call back a user. This number can be preset by the
administrator or specified by the user at the time of each call, depending
on how the administrator configures the user's callback options. The
callback number should be the number of the phone line to which the user's
modem is connected.
callback security
A form of network security in which
a remote access server calls a user back at a preset number after the user
has made an initial connection and has been authenticated.
called subscriber ID (CSID)
string
A string that specifies the called
subscriber ID transmitted by the receiving fax machine when receiving an
inbound fax. This string is usually a combination of the fax or telephone
number and the name of the business. It is often the same as the
transmitter subscriber ID.
canonical (CNAME) resource
record
A resource record used to map an
alternate alias name to a primary canonical DNS domain name used in the
zone.
canonical name
An object's distinguished name
presented with the root first and without the LDAP attribute tags (such
as: CN=, DC=). The segments of the name are delimited with forward slashes
(/). For example,
CN=MyDocuments,OU=MyOU,DC=Microsoft,DC=Com
is presented as
microsoft.com/MyOU/MyDocuments
in canonical form.
cartridge font
A font contained in a plug-in
cartridge and used to add fonts to laser, ink-jet, or high-end dot-matrix
printers. Cartridge fonts are distinguished both from internal fonts,
which are contained in ROM in the printer and are always available, and
from downloadable (soft) fonts, which reside on disk and which can be sent
to the printer as needed.
cascading hubs
A network configuration in which
hubs are connected to other hubs.
catalog
For Indexing Service, a collection
of all index information and stored properties for a particular group of
file system directories. By default, Indexing Service indexes the System
and Web catalogs on your hard drive.
CD-R
Recordable compact disc. Data can be
copied to the CD on more than one occasion; however, data cannot be erased
from the CD.
CD-RW
Rewritable compact disc. Data can be
copied to the CD on more than one occasion and can be erased.
certificate
A digital document that is commonly
used for authentication and secure exchange of information on open
networks, such as the Internet, extranets, and intranets. A certificate
securely binds a public key to the entity that holds the corresponding
private key. Certificates are digitally signed by the issuing
certification authority and can be issued for a user, a computer, or a
service. The most widely accepted format for certificates is defined by
the ITU-T X.509 version 3 international standard.
certificate revocation list
(CRL)
A document maintained and published
by a certification authority that lists certificates that have been
revoked.
certificate store
Typically, a permanent storage where
certificates, certificate revocation lists, and certificate trust lists
are stored.
certificate template
A Windows construct that profiles
certificates (that is, it prespecifies the format and content) based on
their intended usage. When requesting a certificate from a Windows
enterprise certification authority (CA), certificate requestors are,
depending on their access rights, able to select from a variety of
certificate types that are based on certificate templates, such as
User and Code Signing.
certificate trust list
(CTL)
A signed list of root certification
authority certificates that an administrator considers reputable for
designated purposes, such as client authentication or secure
e-mail.
certification authority
(CA)
An entity responsible for
establishing and vouching for the authenticity of public keys belonging to
users (end entities) or other certification authorities. Activities of a
certification authority can include binding public keys to distinguished
names through signed certificates, managing certificate serial numbers,
and certificate revocation.
certification
hierarchy
A model of trust for certificates in
which certification paths are created by means of the establishment of
parent-child relationships between certification authorities.
certification path
An unbroken chain of trust,
consisting of certificates from trusted certificate authorities, from a
specific certificate to the root certification authority in a
certification hierarchy.
Challenge Handshake Authentication
Protocol (CHAP)
A challenge-response authentication
protocol for PPP connections documented in RFC 1994 that uses the
industry-standard Message Digest 5 (MD5) one-way encryption scheme to hash
the response to a challenge issued by the remote access server.
channel
A path or link through which
noncontrol information passes between two devices. A single Basic Rate
Interface (BRI) connection, for example, has one physical connection but
two channels for exchanging information between devices. This is often
called a bearer channel, implying a channel that carries information.
On the Internet, a Web site designed
to deliver content from the Internet to your computer, similar to
subscribing to a favorite Web site.
CHAP (Challenge Handshake
Authentication Protocol)
An authentication protocol used by
Microsoft remote access and Network Connections. Using CHAP, a remote
access client can send its authentication credentials to a remote access
server in a secure form. Microsoft has created a Windows-specific variant
of CHAP called MS-CHAP.
character mode
A display mode in which the monitor
can display letters, numbers, and other text characters, but no graphical
images or character formatting (italics, superscript, and so
on).
checkpoints
child object
An object that resides in another
object. A child object implies relation. For example, a file is a child
object that resides in a folder, which is the parent object.
Class A IP address
A unicast IP address that ranges
from 1.0.0.1 through 126.255.255.254. The first octet indicates the
network, and the last three octets indicate the host on the
network.
Class B IP address
A unicast IP address that ranges
from 128.0.0.1 through 191.255.255.254. The first two octets indicate the
network, and the last two octets indicate the host on the
network.
Class C IP address
A unicast IP address that ranges
from 192.0.0.1 to 223.255.255.254. The first three octets indicate the
network, and the last octet indicates the host on the network. Network
Load Balancing provides optional session support for Class C IP addresses
(in addition to support for single IP addresses) to accommodate clients
that make use of multiple proxy servers at the client site.
classical IP over ATM
(CLIP)
A proposed Internet standard,
described in RFC 2225, that allows IP communication directly on the ATM
layer, bypassing an additional protocol (such as Ethernet or Token Ring)
in the protocol stack.
clear
To turn off an option by removing
the X or check mark from a check box. You clear a check box by clicking
it, or by selecting it and then pressing the SPACEBAR.
client
Any computer or program connecting
to, or requesting the services of, another computer or program. Client can
also refer to the software that enables the computer or program to
establish the connection.
For a local area network (LAN) or
the Internet, a computer that uses shared network resources provided by
another computer (called a server).
client application
A Windows-based application that can
display and store linked or embedded objects. For distributed
applications, the application that imitates a request to a server
application.
client request
A service request from a client
computer to a server computer or, for Network Load Balancing, a cluster of
computers. Network Load Balancing forwards each client request to a
specific host within the cluster according to the system administrator's
load-balancing policy.
ClipBook Server
A system service that supports
ClipBook Viewer, which allows pages to be seen by remote
ClipBooks.
cluster
In data storage, the smallest amount
of disk space that can be allocated to hold a file. All file systems used
by Windows organize hard disks based on clusters, which consist of one or
more contiguous sectors. The smaller the cluster size, the more
efficiently a disk stores information. If no cluster size is specified
during formatting, Windows picks defaults based on the size of the volume.
These defaults are selected to reduce the amount of space that is lost and
the amount of fragmentation on the volume. A cluster is also called an
allocation unit.
In computer networking, a group of
independent computers that work together to provide a common set of
services and present a single-system image to clients. The use of a
cluster enhances the availability of the services and the scalability and
manageability of the operating system that provides the
services.
cluster adapter
The adapter that, when using
multiple network adapters in each host of a Network Load Balancing
cluster, handles the network traffic for cluster operations (the traffic
for all hosts in the cluster). This adapter is programmed with the host's
cluster IP address.
Cluster Administrator
An application that is used to
configure a cluster and its nodes, groups, and resources. Cluster
Administrator can run on any member of the trusted domain regardless of
whether the computer is a cluster node.
Cluster Administrator
extension
A software component that implements
the Cluster Administrator extension application programming interface
(API) for allowing Cluster Administrator to configure a new resource
type.
Cluster API
A collection of functions that are
implemented by the cluster software and used by a cluster-aware client or
server application, a cluster management application, or a Resource DLL.
The Cluster API is used to manage the cluster, cluster objects, and the
cluster database.
cluster disk
A disk on a shared bus connected to
the cluster nodes, which all the cluster nodes can access (though not at
the same time).
Cluster service
The essential software component
that controls all aspects of server cluster operation and manages the
cluster database. Each node in a server cluster runs one instance of the
Cluster service.
cluster-aware
application
An application that can run on a
cluster node and that can be managed as a cluster resource. Cluster-aware
applications use the Cluster API to receive status and notification
information from the server cluster.
cluster-unaware
application
An application that can run on a
cluster node and be managed as a cluster resource but that does not
support the Cluster API.
Cluster.exe
An alternative to using Cluster
Administrator to administer clusters from the command prompt. You can also
call Cluster.exe from command scripts to automate many cluster
administration tasks.
Cmd Show Override,
with
When checked, opens the DDE server
application as specified by the integer in value. Possible values
are 1 (normal), 2 (minimized), 3 (maximized), and 10 (application
default).
When cleared, the DDE server
application opens.
CMYK color space
Multidimensional color space
consisting of the cyan, magenta, yellow, and black intensities that make
up a given color. Commercial color printing devices generally use this
system of four-color process inks.
code page
A means of providing support for
character sets and keyboard layouts for different countries or regions. A
code page is a table that relates the binary character codes used by a
program to keys on the keyboard or to characters on the
display.
codec
Hardware that can convert audio or
video signals between analog and digital forms (coder/decoder); hardware
or software that can compress and uncompress audio or video data
(compression/decompression); or the combination of coder/decoder and
compression/decompression. Generally, a codec compresses uncompressed
digital data so that the data uses less memory.
color depth
The number of colors per pixel your
monitor and graphics adapter support.
color gamut
The particular range of colors that
a device is able to produce. A device such as a scanner, monitor, or
printer can produce a unique range of colors, which is determined by the
characteristics of the device itself.
color management
Process of producing accurate,
consistent color among a variety of input and output devices. A color
management system (CMS) maps colors between devices such as scanners,
monitors, and printers; transforms colors from one color space to another
(for example, RGB to CMYK); and provides accurate on-screen or print
previews.
color profile
A profile that contains the data
needed for translating the values of a color gamut. This data includes
information about color, hue, saturation, and brightness.
color space
A set of three values that defines
how a color can be represented on computer devices such as monitors,
scanners, and printers. For example, in the LAB color space, the terms
luminance or whiteness (L), redness-greenness (A), and yellowness-blueness
(B) are used; in the HVC system, the terms are hue (H), value (V), and
chroma (C). Color space refers to the three-dimensional space that is
defined by the respective values, such as L, A, and B.
command prompt window
A window displayed on the desktop
used to interface with the MS-DOS operating system. MS-DOS commands are
typed at an entry point identified by a blinking cursor.
common groups
Groups that appear in the program
list on the Start menu for all users who log on to the computer.
Only administrators can create or change common groups.
communication port
A port on a computer that allows
asynchronous communication of one byte at a time. A communication port is
also called a serial port.
communication
settings
Operating parameters, such as bits
per second (bps) and modem type, that apply to serial ports on a
computer.
community name
A name used to group SNMP hosts.
This name is placed in SNMP messages sent between SNMP-managed devices
such as Windows 2000-based server computers and SNMP management
stations. Typically, all hosts belong to Public, which is the standard
name for a common community of all SNMP hosts.
compatibility mode
A feature of a computer or operating
system that allows it to run programs written for a different system.
Programs often run slower in compatibility mode.
Complementary Metal Oxide
Semiconductor (CMOS)
A specific type of semiconductor
technology that requires very little power. The term has been popularized
to mean a small storage area where your system keeps track of certain
hardware parameters, such as the size of your hard disk, the number of
serial ports your computer has, etc. CMOS is also called Setup
RAM.
Compression Control Protocol
(CCP)
A protocol used in the negotiation
process in a PPP connection. Compression Control Protocol is one type of
Network Control Protocol (NCP). NCPs are used to establish and configure
different network protocol parameters for IP, IPX, and NetBEUI.
computer account
An account that is created by a
domain administrator and uniquely identifies the computer on the domain.
The Windows computer account matches the name of the computer joining the
domain.
computer
administrator
A user who manages a computer. The
computer administrator makes system-wide changes to the computer,
including installing programs and accessing all files on the computer, and
can create, change and delete the accounts of other users.
Computer Browser
service
A service that maintains an
up-to-date list of computers and provides the list to applications when
requested. The Computer Browser service provides the computer lists
displayed in the My Network Places, Select Computer, and
Select Domain dialog boxes and (for Windows 2000 Server only)
in the Server Manager window.
Computer Management
A component you can use to view and
control many aspects of the computer configuration. Computer Management
combines several administration utilities into a single console tree,
providing easy access to a local or remote computers administrative
properties and tools.
computer quota
For Message Queuing, the storage
size limit for messages on a computer, based on the total size of the
messages. When a computer quota is reached, Message Queuing can no longer
send messages to that computer until one or more messages are removed from
queues. Message Queuing enforces the computer quota before it enforces the
queue quota on a computer.
connect
To assign a drive letter, port, or
computer name to a shared resource so that you can use it.
connected, authenticating
user
A user's status when a telephone
connection has been established but authentication has not yet taken
place. The user may be trying to prove security clearance, or the system
may be idle. If this condition occurs, followed by the Waiting for Call
phase, then the user was unable to provide a correct user name or
password. If this phase is repeated, followed by the Waiting for Call
phase, an unauthorized attempt to access the network may be under
way.
connected, user
authenticated
A user's status when a telephone
connection has been established and the user has entered a correct user
name and password. If the user has callback permission and has requested
callback, the connection is followed by the calling-back phase. If the
calling-back phase is followed by a waiting-for-call phase, then the
server was unable to reach the user at the specified number. The user may
have supplied an inaccurate callback number (in the case of set-by-caller
callback), or an unauthorized attempt to access the network may be under
way (in the case of preset-to callback).
connector application
For Message Queuing, an application
that enables Message Queuing computers to communicate with computers that
use other messaging systems.
connector queue
For Message Queuing, a queue created
on servers running a connector application. You can use the connector
application to exchange messages with computers that are running other
message-queuing products.
console tree
The left pane in a Microsoft
Management Console (MMC) that displays the items contained in the console.
By default it is the left pane of a console window, but it can be hidden.
The items in the console tree and their hierarchical organization
determine the capabilities of a console.
constant bit rate
(CBR)
An ATM service type that supports
constant bandwidth allocation. This service type is used for voice and
video transmissions that require little or no cell loss and rigorous
timing controls during transmission.
container object
An object that can logically contain
other objects. For example, a folder is a container object.
convergence
The process of stabilizing a system
after changes occur in the network. For routing, if a route becomes
unavailable, routers send update messages throughout the internetwork,
reestablishing information about preferred routes.
For Network Load Balancing, a
process by which hosts exchange messages to determine a new, consistent
state of the cluster and to elect the host with the highest host priority,
known as the default host. During convergence, a new load distribution is
determined for hosts that share the handling of network traffic for
specific TCP or UDP ports.
copy backup
A backup that copies all selected
files but does not mark each file as having been backed up (in other
words, the archive attribute is not cleared). Copying is useful if you
want to back up files between normal and incremental backups because
copying does not affect these other backup operations.
count limit
For Process Control, the maximum
number of active processes in a process group. You can configure this in
the Process Control snap-in.
CPU Time
In Task Manager, the total processor
time, in seconds, used by a process since it started.
CPU Usage
In Task Manager, the percentage of
time that a process used the CPU since the last update. On the Task
Manager Process tab, the column heading is CPU.
crash consistency
A feature of shadow copy backups
that ensures all files are backed up, regardless of their
state.
CRC errors
Errors caused by the failure of a
cyclic redundancy check. A CRC error indicates that one or more characters
in the data packet received were found garbled on arrival.
credentials
A set of information that includes
identification and proof of identification that is used to gain access to
local and network resources. Examples of credentials are user names and
passwords, smart cards, and certificates.
CRL distribution
point
An optional extension in an X.509v3
certificate that identifies how information is obtained. Also, a directory
entry or other distribution source for certificate revocation
lists.
cross-reference
object
Objects in which Active Directory
stores information about directory partitions and external directory
services. An example of an external directory service is another
LDAP-compliant directory.
CryptoAPI
An application programming interface
(API) that is provided as part of Microsoft Windows. CryptoAPI provides a
set of functions that allow applications to encrypt or digitally sign data
in a flexible manner while providing protection for the user's sensitive
private key data. Actual cryptographic operations are performed by
independent modules known as cryptographic service providers
(CSPs).
cryptographic service provider
(CSP)
The code that performs
authentication, encoding, and encryption services that Windows-based
applications access through the CryptoAPI. A CSP is responsible for
creating keys, destroying them, and using them to perform a variety of
cryptographic operations. Each CSP provides a different implementation of
the CryptoAPI. Some provide stronger cryptographic algorithms, while
others contain hardware components, such as smart cards.
cryptography
The processes, art, and science of
keeping messages and data secure. Cryptography is used to enable and
ensure confidentiality, data integrity, authentication (entity and data
origin), and nonrepudiation.
custom file type
Typically, files with extensions
that have been created for special kinds of files. Custom file types are
not tracked by the system registry. |
