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Confused by all of the alphabet soup in Microsoft computer training and other
vendor certification training? MCSE, MCSA, MCP, A+, Network+,
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Watch for this page to
grow.. as we add more and more helpful information.
This is a WORK-IN-PROGRESS. If you wish to contribute a definition
for a listed acronym, a new acronym, correct or expand on an existing
definition, or add your own listing, email the webmaster at
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3-4-5 Rule or 5-4-3 Rule - A rule which was invoked in the days of the repeater, and is still
appropriate in hubs or switched networks. The original repeaters were designed to extend the range of a network
wire beyond the maximum length of the wire's design distance. This was usually used to set up a network, cross al hall
or between buildings, set up another network, etc. The 3-4-5 rule says you can have at most 4 repeaters, connecting
at most 5 network segments, but only 3 of those segments can be populated with computers.
In practice, in today's networks, the topology and media of the network
can impact this rule, but it should be generally adhered to. The
3-4-5 rule applies to 10 Mb networks, but at 100Mb, guidelines dictate
no more than 2 connected hubs.
A
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A+ - Basic computer hands-on certification.
Usually the first certification for career changers. Required by
many break-fix, geek, and deskside support jobs. This
certification actually consists of two individual certification
tests, A+ Core and A+ Operating Systems (A+ OS). CompTIA A+
certification validates the knowledge and skills of entry-level computer
service technicians. It is an international, vendor-neutral
certification recognized by major hardware and software vendors,
distributors and resellers. Tests include CompTIA A+ 2003 Linear
Core Exam: 220-301 AND CompTIA A+ 2003 Linear OS Exam: 220-302 - OR -
CompTIA A+ 2003 E2C Core Exam: JK0-301 AND CompTIA A+ 2003 E2C OS Exam:
JK0-302. (Click
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Active Directory - Microsoft's implementation of the X.500 directory
service. It is common to the Novell Directory Service and any
number of other modern X.500 directory service implementations.
Microsoft's Active Directory takes directory service far beyond what
X.500 envisioned. First, Active Directory is directly integrated
with Microsoft DNS, using GUIDs, rather than IP addresses to locate the
systems providing various AD services. It's unique container
structure provides extremely powerful, flexible, and even easily
implemented management of security, software deployment, and all of the
other varied attributes that must be managed in a modern server-based
computer architecture. AD also contains all of the user accounts,
and computer accounts, as well as security and distribution groups for
managing these accounts. Microsoft implements a unique combination
of loosely consistent, fully-writable databases on every DC. With
automatic replication and synchronization every 5 minutes. Some of
the functions of AD must be unique (not writable, except at a single
DC). The Flexible Single Master Operations Roles are also managed
by AD.
AC - Alternating Current. The typical household power source, as opposed to DC, which is
commonly known as "battery power." A current (or voltage) which alternates around a base, typically ground potential
ACPI - Advanced configuration and power interface. The more modern version of computer power
management firmware. The older technology is APM or Advance Power Management. ACPI operates within advanced operating systems
such as Windows XP, APM functions at the BIOS level.
Act - A network device abbreviation which means "activity". This is usually indicated by a
blinking LED or icon on the screen. If you have "Link" and "Act" you can assume you probably have a good network connection.
AD - See Active Directory.
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ADSL - Asymmetrical digital subscriber line. One of the several family members of the DSL
ISP connection technologies. ADSL usually has a faster download speed than it's upload speed. SDSL would be the symmetric
counterpart of ADSL. SDSL is designed to have the same speed in both upline and downline directions. Subscription costs for SDSL
is appropriately more expensive than ADSL
AGP - Accelerated graphics port. One of several specialized graphics-only ports in most modern
PCs. It is usually closest to the CPU, is identified by a brown or other color, and is set back from the bracked-side of the
frame by about an inch further than PCI slots
AMD - Advanced Micro Devices. One of several PC CPU
fabricators and vendors. AMD is Intel's major
competitor, especially in the 64-bit CPU market.
AMR - Audio modem riser. A specialized port, usually much shorter than any other port in the
PC bus, which provides a voice/modem port. This riser port was very short-lived, since most new mother boards now contain
on-the-motherboard voice/fax/modems.
APIPA - Automatic private internet protocol addressing. The entire 169.254.0.0/16 ip address
subnet. Before Windows 2000, most computers defaulted to NetBEUI, which required no setup skills. In Windows 2000, NetBEUI
was no longer installed by default, and some mechanism was needed to allow unsophisticated home and small office users to
have the equivalent to NetBEUI network connectivity. New computers are shipped with DHCP IP address assignment as the default.
In home or small office installations, where DHCP is not enabled - or a static IP address assigned, all windows computers since
Windows 2000 take on an arbitrary APIPA IP address, so that they can communicate withing the internal network. In an environment
where DHCP is enabled, the dreaded 169.254.(anything) IP address indicates that the computer cannot contact a DCHP server.
APM - Advanced Power Management - see ACPI for details.
ARP - Address resolution protocol. One of several protocols which exists in the Network
layer of the 7-layer OSI Reference Model. ARP is responsible for determining whether the target IP address is on the same
subnet (by comparing the IP addresses and subnet masks). ARP resolves the next hop MAC address by broadcasting to either the
target IP Address - or the IP address of the default gateway (default-next-router), depending upon ARP's finding about the target
IP address being on the same subnet - or another subnet. ARP keeps a cache to reduce broadcasts of frequently addressed target
IP addresses. After resolving the target next hop MAC address, ARP is
responsible for supplying IP with the MAC address of the next
hop target. ALL COMMUNICATIONS on all networking systems is actually between MAC - or physical - addresses. IP addresses simply
serve as a logical address for routing. (Click
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ASR - Automated system recovery. One of several backup mechanisms on Windows XP. ASR
is intended to be taken infrequently, whenever there are changes in the system. ASR backups, along with the ASR backup
diskette, and an XP CD are designed to provide for "bare-metal" restore of the operating system. Restoration of the data
and other user files must be restored from another source. ASR backup must have sufficient space to contain the .bkf file
for ALL of the files on the System and Boot partitions (including user files), but ASR will not attempt to restore those
user files. (Note, since this is simply a NTBACKUP .bkf file, NTBACKUP can be used to restore any incidental data files
which were backed up by the ASR backup. ASR WILL NOT recognize a USB backup disk for a backup source.)
AT - Advanced technology. The next generation of PCs after the XT computer, and the first
16-bit CPU. (Not really advanced technology these days.)
ATA - Advanced technology attachment. The original name for what we now call an IDE device.
The ATA moniker has been dropped, but is being re-introduced with the use of SATA and PATA to differentiate the two separating
classes of ATA devices.
ATAPI - Advanced technology attachment packet interface.
ATAPI is the real name of the CD-ROM (EIDE CD-ROM) and tape (ATAPI tape
or EIDE tape) interface. This interface was originally developed by a
group of CD-ROM companies with lots of help from Western Digial and Oak
Technology. ATAPI introduced a new command execution protocol for
use on the ATA interface so that these new CD-ROM and tape drives could,
in theory, be on the same ATA cable with an ATA hard disk drive.
Basically, the ATAPI Packet command, command code A0H, is used to send
what looks like a SCSI CDB across the ATA interface. The actual data
transfer (from/to the device media) is done using the ATA PIO or DMA
protocols.
ATM - Asynchronous transfer mode. ATM
is a cell-switching and multiplexing technology that combines the
benefits of circuit switching (guaranteed capacity and constant
transmission delay) with those of packet switching (flexibility and
efficiency for intermittent traffic). It provides scalable bandwidth
from a few megabits per second (Mbps) to many gigabits per second (Gbps).
Because of its asynchronous nature, ATM is more efficient than
synchronous technologies, such as
time-division
multiplexing (TDM). ATM transfers information in fixed-size
units called cells.
Each cell consists of 53 octets, or bytes. The first 5 bytes contain
cell-header information, and the remaining 48 contain the payload (user
information). Small, fixed-length cells are well suited to transferring
voice and video traffic because such traffic is intolerant of delays
that result from having to wait for a large data packet to download.
ATX - Advanced technology extended. PC
motherboards come in several different form factors, which define their
physical dimensions and basic design. Intel introduced the ATX
motherboard specification in 1995 to provide a smaller, more capable
replacement for the bulky and inefficient AT (Advanced Technology) form
factor in use since the mid-1980s. There was much more to ATX than
diminished motherboard dimensions. The specification also introduced a
new, more reliable, power supply standard and reorganized the overall
layout of the motherboard components so they were in much more sensible
places. The CPU, for example, was moved so it would be out of the way of
any expansion slots and closer to the main system-cooling fan. Hard
drive interfaces were positioned closer to the drive bays, meaning PC
manufacturers would no longer have to route large amounts of cable
throughout the inside of the system. Certain ports and connectors were
fused directly into the motherboard, further reducing clutter. ATX is
the standard form factor used in today's desktop PCs.
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Authentication - Often confused with permissions and/or login.
Authentication IS an integral part of the computer login process, but it
speaks only to the mechanisms of verifying that the user or computer
which is presenting credentials is, in fact the user or computer that
they represent themselves to be. (Once authenticated, the system
may still determine that the authenticated user or computer is NOT
GRANTED PERMISSION to the resource sought.) In Microsoft Windows,
prior to Windows 2000, all authentication was done by a process known as
NTLM. With the introduction of Windows 2000, Windows adopted the
well-known (originally designed at MIT for >a UNIX-based project, called
Project Athena) Kerberos Authentication. Microsoft made some
revisions to Kerberos, to make it more compatible with Active Directory
(AD). Associated with these methods are several Authentication
Protocols, including CHAP, MSCHAP, MSCHAP v2, for pre-Kerberos.
There is a very good discussion of Kerberos mutual authentication
technology at
http://www.microsoft.com/technet/prodtechnol/windows2000serv/deploy/confeat/kerberos.mspx.
ASCII - American Standard
Code for Information Interchange (Pronounced ask-ee -
with the ee taking on the sound of "see"). ASCII and EBCDIC (eb-see-dick)
were once competing coding standards for defining characters.
ASCII was designed for Teletype and still contains a number of obsolete
teletype control and "escape characters." It later
evolved into one of the two character sets which were used to encode
magnetic tape. The basic
ASCII character set consisted of 7 binary bits (7-bit ASCII), which could define any
number between 0 and 127. Of these, the first 32 (and in some ways
the last) are designed for teletype control. The remaining are
typically known as the "printable characters." Which includes the
Upper case alphabet, the lower case alphabet, the number set between 0
and 9, and special printable characters including punctuation marks, the
"space character," less than (<), greater than (>) and others. The
basic ASCII alphabet, being 7-characters also lent itself to early modem
transmission, because early modems always reserved the 8th binary bit as
a "parity bit." The parity bit was needed because of the
poor telephone connections that early modems had to cope with.
Basic ASCII does not define any graphics characters -- and many
downloadable programs required all 8-bits to define their code sets.
As a result several flavors of "Extended ASCII" evolved. By
defining the 8th bit (8-bit ASCII), these extended character sets were
able to define the basic ASCII set, with an additional 128 characters.
These included foreign language characters, happy faces, and various
graphics characters. ASCII is generally extinct, but is still
useful where absolute compatibility is required. Most .txt files
use almost all ASCII, with some extensions.
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Back office - A generic name for all of the
Microsoft "Server" licenses, except for the actual server OS.
This would include "Servers" like SQL Server; Exchange Server; and any
other separately-licensed product for Microsoft servers. This term
has been superseded by the Microsoft "Core" License. Standard
usage is about the method of purchasing and licensing Client Access
Licenses (CALs). A Back office license costs more than a single
license, but it permits one user to access an unlimited number of back
office servers. Single licensing would require a separate license
for each server that a user needed to access.
BCD - Binary Coded Decimal. One of
two typical methods of storing numeric data on a computer. Since
"decimal" uses digits 0-9 in each decimal place, an entire half-byte is
used to store each decimal digit. This is the easiest method for
some applications, but it is extremely inefficient. A more compact
way of storing numeric data, which also lends itself to computer-based
computation, is just known as "binary" or "binary numbers."
Binary - in it's most basic form a "base-2"
numbering system. Typically represented as 0 or 1; yes or no; off
or on. Binary numbering system is identical in its for to any
other base, the most popular being our "ten-fingers" base 10. In
base 10, we write numbers from right-to-left, naming each column the
"ones" column, the "tens" column, the 100s column, etc. Many
people have problems relating this simple method, as soon as the word
"binary" is uttered. Yet, it follows the exact same system,
numbering from right-to-left in columns known as the "ones" column; the
"twos" column; the "fours" column, the 8s column, etc. The
similarity, which is missed by most, is the "ones" column represents the
b^0 (base-raised-to-the-0th-power) This is defined as 1 (s).
The next column is b^1 (base-raised-to-the-1-power). In the case
of base 10, this results in the "10s" and in binary, it results in the
"2s"; The next column to the left is b^2. In base 10, 10^2
(10-squared) is 100 (s) or in binary it results in 2^2 (2-squared),
resulting in the 4s column and so on...
Binary - One of several numbering systems
used in computer parlance. Computers are binary devices, being
either adders or subtractors. Binary is often used for packing
data into storage space because the value of a number of bits can be
very high, and still be stored in a small number of bits.
Binary-coded-decimal, (just numbers, as we know them) are very
inefficient for storing numeric data. Binary is the standard for
IP addressing and subnetting, even though we typically express the
results in either "dotted-decimal notation" or in Hexadecimal notation.
Binary-coded decimal - a method of packing
decimal numbers into binary bytes. Since the decimal numbering
system includes 10 values per digit (0 through 9), each 8-bit byte can
contain at most one decimal digit. This is very inefficient.
For instance the maximum number which can be stored in 4 digits (32
bits) of BCD is 9999. Those same 32 bits, if the numeric storage
is in pure binary, could store a maximum value of 4,294,967,295.
BIOS - Basic input/output system. The
firmware which drives a PC computer. Often confused with "CMOS,"
which actually forms a part of the BIOS, containing user- or
system-variable data which is used by the BIOS during POST and boot-up.
Bits - Binary Digits. More often
referred to in IP subnetting as a method of defining the number of
subnets and/or number of hosts which can be defined in a CIDR subnet.
As an example, a formerly classful Class C address, such as 193.4.5.6
would be expressed as having a net mask of 255.255.255.0. In
classless CIDR notation, the three groups of 255 each represent 8 bits,
with a value of 1 for each bit. Hence, the Cider notation would be
expressed as 24 bits. This would typically be written in classless
CIDR notation as 192.4.5.6/24 (again, the 24 bits of the mask). In
pure binary, one bit can take on the values 0 or 1. This
represents two values that can be expressed with 1 bit (The source of
the term "binary"). Given two bits, these can be expressed as 00,
01, 10 or 11, hence 4 values can be expressed with 2 bits. In
scolarly work, this is said to be 2 to the n power. In People-talk
it is much simpler to "count-by-twos" until it becomes a very large
number. 1-bit=2, 2-bits=4, by extension, 3-bits would be equal to
4x2 or 8. In simplest terms, counting from right-to-left, just as
we do in decimal or "base-10" we count from the right to left. the
fist bit is the "ones" bit, the second bit is the "twos" bit, the third
bit is the "fours" bit, etc, doubling each time. Counting the
values, however, we count from right to left, 2, 4, 8, 16,32....and so
on. (Click
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BITS - A Microsoft protocol used with their
SUS or WSUS patch download utility. This protocol minimizes impact
of downloading by using only spare network availability, pausing when
the network or the host system is busy. In addition BITS is
designed so that an interruption of the download does not abort the
download. It simply waits until the connectivity is restored, and
continues the download, where it was interrupted.
BNC - "Bayonet-Neill-Concelman" or "British
Navel Connector." The coaxial cable connectors which are used in
thinnet (10Base2) networks. There are three types of BNC
connectors; "the connector," which is crimped or screwed onto the end of
each piece of coaxial cable; the "T-connector," which is used to
make the junction at each computer; and a "barrel connector." which is
used to splice two runs of coax cable. Please note that the
T-connector must connect directly to the computer or device - no coax
cable is allowed between the T connector and the device. Another
device, which employs a BNC connection, but is not generally
counted as a BNC connector is the 50 ohm terminator at each of the ends
of the thinnet bus.
BRI - Basic rate interface. one of
two tariff plans for ISDN communications. BRI is also known as 2B
+ D (2 bearer-channels and a data channel), where each bearer channel is
64Kbits/sec and each data channel is 8Kb, for a combined bandwidth of 64
+ 64 + 16 = 144Kb. BRI is typically used at the end user, in place
of a MODEM and is the standard of the industry for a backup WAN
connection, since ISDN can be dialed and makes an almost-instant
connection. The counterpart of BRI is PRI, (23B = D) which is
typically used at the ISPs, in place of banks of MODEMS. PRI is
roughly equivalent to T1 in overall speed.
Broadcast - A Networking term which can be
applied to either IP addresses or MAC addresses. By definition,
the "broadcast IP address" is the address, relative to the subnet, which
sets all of the "host bits" to 1s. Conventional wisdom usually
considers this to be the address w.x.y.255 - but that pre-assumes a /24
subnet. If, for instance, the subnet is a /30, each of the "all
1s" host addresses are broadcast addresses for that particular subnet.
Since the /30 mask defines only 4 hosts (0 - to - 3) on each subnet, the
zero subnet has a broadcast address of w.x.y.3, the 1 subnet has a
broadcast address of w.x.y.7, and so on. MAC addresses use a
similar scheme. Most NIC cards are pre-programmed to ignore any
network communications that is not specifically addressed to it's unique
MAC address. It is necessary, however, to occasionally require
every NIC to respond, regardless of it's MAC address. In order to
achieve this a MAC address broadcast of 48 1s is used. Since
MAC addresses are typically expressed in hexadecimal, the MAC broadcast
address is commonly expressed as the ff ff ff ff ff ff MAC address.
BROUTER - A shortened version of "Bridge-Router." This was
an early technology, which took advantage of the (relative) speed of a bridge, but also
provided the capabilities of a router. The brouter was characterized by the term,
"bridge when possible, route when necessary." Brouters were also popular in local
routing scenarios, because they could be utilized to move non-routable protocols (NetBEUI) across
a routed link.
BTX - Balanced technology extended.
Intel has collaborated with the Desktop
Computing industry to create an evolutionary step in the desktop
computer form factor. Balanced Technology Extended (BTX) integrates
cost-effective engineering and design strategies for power dissipation,
structural integrity, acoustic performance, and motherboard design into
a scalable form factor. The BTX specification was introduced at Intel
Developer Forum in Fall, 2003. The industry standard, ATX, was
introduced in 1995, and as technology has evolved, new challenges have
arisen that are increasingly difficult for ATX to handle. The Balanced
Technology Extended (BTX) form factor specification was developed as an
evolutionary follow-on to the ATX. (Click
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Byte - Technically, a string of eight
consecutive bits. Bytes are used to define several objects or
attributes in computer lingo. The most common usage is the
definition of an 8-bit character or letter or number. For
instance, the number zero in ASCII is defined in decimal as 48, the same
digit in Hexadecimal is referred to as 0x030 (or simply 030).
There is a very nice ASCII conversion table on the web at
http://www.lookuptables.com/
A second use of the term Byte is as a secondary reference to an IP
address "Octet." Both Terms refer to 8-bits.
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Cable Modem - Not, in the strictest sense, a "modem." This is the interface
box provided by (Television) cable-based internet service providers (ISPs).
CAL - Client Access License. The cost of clients accessing specially licensed servers. There
are typically two methods of licensing access to a server or a separately-priced service. These were previously known as "Per-
server or per-seat. These terms have now been replaced with "per-device" or "per-user." One per-device license permits an unlimited
number of users to access the server from a single workstation, kiosk or other device. One per-user license permits a single user
to access a server, without restrictions on the number of computers that the user owns or accesses the server from.
By default, a workstation license (such as XP Pro) includes 10 CALs with
each computer license. Servers, on the other hand, have zero (0)
CALs out-of-the-box. Retail sales of servers often bundle 5, 10,
or even 20 CALs in the box for servers, but, in the long run they must be purchased
separately. It is usually far more convenient and economical to
purchase server CALs via a Volume purchase agreement (minimum order for
a volume purchase agreement is 5 CALs).
CAMSLANT - Coast Guard Communication Area
Master Station Atlantic. A USCG-operated Master radio station, located
in Chesapeake VA. CAMSLANT is also a participant in the US
Homeland Security Network, and, in conjunction with NOAA, broadcasts
routine and emergency weather data.
Centrex - Traditionally a local telephone
device, used for internally routing telephone calls from numerous
telephone lines. In the new "digital convergence" age, the centrex
is becoming a network device, which separates the VoIP telephone calls
from the data components on the network.
Certification - Any one of the dozens of
vendor-specific or "vendor-neutral" certificates which are issued to
signify an achievement of a level of competency in that particular
skill. A typical certification issuer is Microsoft, which issues
hundreds of highly-focused and/or general certifications. In the
computer field some other vendor-specific certifications would include
Cisco certifications, HP certifications, Dell certifications, IBM
certifications and numerous others. Some typical "vendor-neutral"
certifications are issued by CompTIA; including CompTIA Security + ( S+
), CompTIA A+, CompTIA Network + ( N+ ), CompTIA Server+, CompTIA LINUX
+ and dozens of others. (Click
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CCD - Charged coupled device. CCDs
(Charge Coupled Devices) a solid-state chip containing a series of tiny,
light-sensitive photosites and was originally developed by Honeywell .
The heart of all electronic and digital cameras. CCD's can be thought of
as film for electronic cameras, but they are also found in video cameras
and desktop scanners. CCDs consist of thousands or even millions of
cells, each of which is light-sensitive and capable of producing varying
amounts of charge in response to the amount of light they receive.
A digital camera uses the lens which focuses the image onto a Charge
Coupled Device (CCD), which then converts the image into electrical
pulses. These pulses are then saved into memory. Just as the film
in a conventional camera records an image when light hits it, the CCD
records the image electronically The photosites convert light into
electrons. The electrons pass through an analog-to-digital converter,
which produces a file of encoded digital information in which bits
represent the color and tonal values of a subject. CCD's are usually
arranged as either a line of cells or a rectangle.
CD - Compact Disk. The CD disk is a
120 mm diameter disk of polycarbonate. The center contains a hole 15 mm
in diameter. The innermost part of the disk does not hold data. The
active data area starts at the 46 mm diameter location and ends at the
117 mm diameter location. The 46-50 mm range is the lead in area and the
116-117 range is the lead out area. Disks are written from the center to
the outside. A CD disk contains a long string of pits written
helically on the disk. The edges of the pits correspond to
binary "1"s. Each pit is approximately 0.5 microns wide and 0.83
microns to 3.56 microns long. (Remember that the wavelength of green
light is approximately 0.5 micron) Each track is separated from the next
track by 1.6 microns. The area between the pits is termed "lands."
CD-ROM - Compact Disc Read-Only Memory.
A CD-ROM is a CD that can be read by a computer with an optical drive.
The "ROM" part of the term means the data on the disc is "read-only," or
cannot altered or erased. Because of this feature and their large
capacity, CD-ROMs are a great media format for retail software. The
first CD-ROMs could hold about 600 MB of data, but now they can hold up
to 700 MB. CD-ROMs share the same technology as audio CDs, but they are
formatted differently, allowing them to store many types of data.
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CD-RW - Compact disc-rewritable. Replacing
the CD-ROM in desktop computers is the CD-RW, standing for Compact Disc
Rewritable. The CD-RW lets you create backup files or make music
compilations by "writing" the files on the disc. This process is also
called CD Burning. Modern machines also have an enhanced CD or DVD
burner, called CD+R or CD+RW. The media for CD- will work in a CD+
device, but backward compatibility is not standard.
CDFS - Compact disc file system. The
Compact Disk File System (CDFS) is based on the ISO 9660 Standard (but
extends it to allow long and double-byte filenames). To applications,
the CDFS file system appears similar to a FAT file system. Windows
95/98, Windows NT, Windows 2000-XP, and subsequent versions support
CDFS.
Child Domain - This term applies equally to
non-active directory DNS names, as well as implying a specific trust
structure in Microsoft active directory design. In DNS terms,
organizations or individuals "register" a "second-level-domain-name"
such as mycompany.com. (In actuality, these are merely leased for
a specified number of years.) Use of the mycompany.com name is
then controlled by explicit rules, and no two entities can ever use
mycompany.com at the same time. The "owner" of mycompany.com can,
however, self-register an unlimited number of "subdomains."
Another term for subdomain, especially in Microsoft active directory,,
CCNA - Cisco Certified Network
Administrator. The CCNA certification (Cisco Certified Network
Associate) indicates a foundation in and apprentice knowledge of
networking. CCNA certified professionals can install, configure, and
operate LAN, WAN, and dial access services for small networks (100 nodes
or fewer), including but not limited to use of these protocols: IP, IGRP,
Serial, Frame Relay, IP RIP, VLANs, RIP, Ethernet, Access Lists.
CCNA certifications are
valid for three years.
To recertify, either
pass the current CCNA
exam, or pass the ICND
exam, or pass any professional level or
Cisco Specialist exam
(excluding Sales
Specialist exams), or
pass a current CCIE
written exam. CCNA
is not really a career certification, but it, when it is added to a
Microsoft Professional certification, such as MCSE, MCSA, or MCP, and
other vendor's professional certifications makes the candidate a prime
candidate for a prospective Employer. (Click
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CCNP - Cisco Certified Network
Professional. The next level of Cisco certification above CCNA.
CCNP certification validates a network professional's ability to
install, configure and troubleshoot converged local and wide area
networks with 100 to 500 or more nodes. Network Professionals who
achieve the CCNP have demonstrated the knowledge and skills required to
manage the routers and switches that form the network core, as well as
edge applications that integrate voice, wireless, and security into the
network.
CIDR - Classless Internet Domain Routing. Pronounced like "apple CIDER."
As the name implies, it ignores the old Class A, Class B, Class C, etc
rules and boundaries (along with the limitations and wastefulness of
classful IP addressing). Subnet masks are defined by the number of
subnet mask bits which the issuing ISP has reserved for subnet bits.
For instance, a classful Class C address would be designated as /24 in
CIDR, a Class B as /16 and a Class A as /8. This where the
similarity ends, because CIDR can define a subnet mask of /23, /24, /25
or any number of bits, for the most economical use of IP address space.
Cisco - not the only one, but one of the major
vendors in the computer
Network routing, switching, firewalls and intrusion detection systems.
Class A IP address - Technically, any IP address which begins with the first
bit equal to 0 (zero). This rule defines all possible IP addresses
from 0 to 127. The "zero subnet address" and the "zero host
address" were reserved, leaving the first IP address as IP address 1.
The highest possible IP address which meets this definition is the
"loopback address" (typically defined as 127.0.0.1, but with a mask of
255.0.0.0, this includes ALL IP addresses which begin with 127.
The net result is the set from IP address 1 to IP address
126.255.255.254. "Classful" IP addresses are no longer issued.
Class B IP address -Technically, any IP
address which begins with the first bit equal to 10 (one zero).
This rule defines all possible IP addresses from 128 to 191. The
"zero subnet address" and the "zero host address" were reserved, leaving
the first IP address as IP address 128.0.0.1. The highest possible
IP address which meets this definition is 191.255.255.254.
"Classful" IP addresses are no longer issued.
Class C IP address - Technically, any IP
address which begins with the first bit equal to 110 (one one zero).
This rule defines all possible IP addresses from 192 to 223. The
"zero subnet address" and the "zero host address" were reserved, leaving
the first IP address as IP address 192.0.0.1. The highest possible
IP address which meets this definition is 223.255.255.254.
Of these, the Classless IP address 192.168.0.0/16 is reserved for
"private IP addresses" "Classful" IP addresses are no longer issued.
Classful IP address - An older method of
assigning address blocks and routing with IP. These were the
"Class A," "Class B," and "Class C" addresses.
Classful IP addressing was extremely wasteful of IP numbers and has been
almost abandoned as a method of obtaining and assigning IP addresses.
This method of address assignment "assumes" a default mask, and the mask
is not transmitted with the IP address. This method did not lend
itself to subdivision. A single "Class A" IP address entitled the
holder to 16 million IP addresses (even if they only use a few thousand
or so); a single "Class B" IP address entitled the holder to 64K IP
addresses, and a "Class C" address assigned the recipient 256 IP
addresses. In contrast, Classless (CIDR) IP addresses are assigned
by the exact number of host (or network) bits that the recipient needs,
without regard for the beginning number of the IP address.
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Classless IP address - Also known as
"CIDR." See CIDR.
CompTIA - Computing Technology Industry
Association. CompTIA serves the IT industry as the world's largest
developer of vendor-neutral IT certification exams. Experts and industry
leaders from the public and private sectors, including training,
academia and government work with CompTIA to develop broad-based,
foundational exams that validate an individual's IT skill set. This
group of experts provides the resources and subject matter expertise
necessary to build vendor-neutral industry-defined computer training and
certification exams.
CompTIA A+ - an international,
vendor-neutral certification recognized by major hardware and software
vendors, distributors and resellers. CompTIA A+ confirms a technician's
ability to perform tasks such as installation, configuration,
diagnosing, preventive maintenance and basic networking. The exams also
cover domains such as security, safety and environmental issues and
communication and professionalism. There are, until at least
12/31/2006 two different versions of A+ certifications available.
One, the 2003 objectives will be phased out sometime around 12/31/2007.
It was comprised of two certification tests, The Core (or hardware) test
and the Operating Systems (OS) Test. These were the only two
options. Beginning with the 2006 objectives, the A+ computer
training certification takes on three separate tracks. All of them
begin with the "Essentials" exam, then the candidate must select from
three similar, but targeted tracks. Track 1, IT Technician (exam
220-602) is intended for the deskside technician, enterprise technician,
field technician, and PC support specialists. Track 2, Remote
Support Technician (220-603) is intended for the remote support, help
desk, and call center technicians. Track 3, Depot Technician
(220-604) is intended for OEM PC builders, and bench repair technicians.
CompTIA N+ - A common abbreviation for
CompTIA's Network + computer training and certification program.
Also, sometimes abbreviated as N + (note the space) - this is difficult
to find on a Google Search, since the + has a special meaning to the
search engine.
CompTIA Network+ - A quite difficult
curriculum for a vendor-neutral network foundation. It covers the
gambit from ancient hardware to computer network architectures to
implementing and troubleshooting TCP/IP networks. MOST computer
administrators do not adequately understand TCP/IP at the foundation
level. This certification is aimed at computer techinicians with
9-months of equivalent experience. See CompTIA N+ above.
More information about this program can be found at
CompTIA A+ Network+ N+
Security+ S+ Computer Training and Networking Certification Training
CompTIA S+ - Another of CompTIA's
unfortunate choices for a certification name. See CompTIA
Security+ below.
CompTIA Security+ - A fairly difficult
vendor-neutral training program created to cover computer security from
learning the acronyms, to writing the company's Security Policy
document, to implementing security, and post-attack recovery. More
information about this program can be found at
CompTIA A+ Network+ N+
Security+ S+ Computer Training and Networking Certification Training
CompTIA CTT+ -
CompTIA Certified Technical Trainer+ -
Computer Forensics -
Convergence -
CPLS -
CTEC -
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DAP -
Directory Access Protocol. A derivative of the X.500 Directory
Access Protocol (DAP) standard, postulated by the ISO many years ago.
DAP and X.500 remained unused for many years because of the complexity
of the DAP access protocol. X.500 is an international standard for
developing and accessing computer directory systems. With the
development of LDAP for accessing the X.500
directories, LDAP and X.500 has become the standard for ALL directory systems,
from Microsoft's Active Directory to Novell's Directory service and many
others.
Data recovery -
DC -
Decimal Numbers -
Decimal Point -
Delegated Authentication -
DFS -
DHCP - Dynamic Host Configuration Protocol
DNS -
Domain -
Domain Controller -
Domain Tree -
Domain Trust -
Dotted Decimal Notation - One of several ways to type an IP address, for example,
192.168.1.1 is a Dotted decimal notation for the IP address 1100000010101000000000100000001
DSL -
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EBCDIC (eb-see-dick) -
Element-K
Enterprise IT Architecture-one of the many
architectures which can be designed to deploy IT functions.
Enterprise IT typically infers multiple domains, distributed across
multiple sites, and often includes child domains multiple domain trees
and domain forests.
Escape Characters -
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Firewall -
Frame Relay - One of the many WAN protocols used primarily for corporate
data communications. Frame Relay is a switched protocol, similar to the Public Switched Telephone
(POTS - Plain old telephone system), it is actually an upgrade to the X.25 switched protocol, without
the overhead of error checking at every node.
FSMO Role - See Flexible Single Master Operations
FTP - File Transfer Protocol
Flexible Single Master Operations -
Forensics -
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Gateway - This term has two, conflicting definitions in computer networking.
Most, by common usage, think of the gateway as the "default gateway," which is either statically programmed
into the network card parameters - or received through DHCP. This usage would have been more aptly named "Default
Next Router," because that is what it is. It is the IP address to which any packet which is not on the local
network or subnet is sent, to be routed to the proper destination. This is usually the address of the "cable
modem" or "DSL modem," but, in an enterprise network it would be another of the "hub" devices, known as
a Router.
GI Bill -
Global Catalog -
Global Catalog Server - The server(s) which hold copies of the forest
global catalog
GRE - Generic Routing Encapsulation/IP Protocol 47
GUID -
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HexaDecimal Number -
Host Address - Can be used to refer to a complete IP address (e.g. 192.168.1.1) or, in IP
subnetting, it refers to the host-bits portion of the IP address, relative to the subnet address bits. For instance, in the
above example, if the subnet mask were 255.255.255.0, then the host address would be, as expected, 1. If, on the other hand, the
subnet mask were defined as 255.255.254.0, the the host address would actually
encompass one bit in the 3rd octet, giving a host
address of 100000001, or 257.
HRCC-Hampton Roads Chamber of Commerce.
A regional organization of Chambers of Commerce which encompasses All of
Tidewater, Southside, and Peninsula of Virginia. Headquartered in
Chesapeake Virginia, and representing Norfolk, Virginia Beach, Suffolk,
Portsmouth, Hampton, and Newport News.
Hub - In the typical usage, this refers to any one of the multi-port network
boxes in a computer network. Technically, it is a multi-port box which does NOT keep a MAC address table
(see Switch), and can only amplify, re-time, and re-shape any packets it receives. It sends every packet
back out on every port. This means that, on a moderately-used network, the CSMA/CD protocol will be having
network collisions on the network, reducing the available bandwidth to about 40-60% of the rated bandwidth
(Megabits), before the network throughput begins to decrease because of packet collisions. Hubs are said
to "operate at the physical layer." See Repeater.
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IAS -
ICND -
ICS -
IKE -
Instructor-led training -
Internet Caching -
Internet Key Exchange -
Intrusion detection -
IP Address -
IP Address Range -
IP Broadcast - See Broadcast
IP Multicasting - See Multicast
IP Subnetting - Often incorrectly referred
to as TCP/IP subnetting. A simple procedure which is often confusing to
beginning IT students and perceived to be difficult. The major
difficulty is in keeping the terminology straight. There are two
components which contribute to how a system interprets an "IP address."
The first component is, in fact, the actual IP address, which is
composed of 32 consecutive binary bits. For ease of "people
reading," these bits are almost always converted to either decimal
numbers or hexadecimal numbers. We typically place dots or
"decimal points" between each "octet" or "Byte."
While this facilitates human reading, remembering, and typing IP
addresses, it actually becomes confusing to the student while leaning IP
subnetting, because all subnetting must be done at the bit-level, and
then converted to human-readable decimal or hexadecimal - this often
occurs in such a way that the "dotted decimal notation" is in
no way related to the divisions of the subnet address and the host
address in the binary notation. Gone are the days of "Class C" or
"Class B" or "Class A" IP addresses. This extremely wasteful
method of allocating IP addresses was about to dry-up the pool of
available IP addresses
IPSEC -
ISA -
ISO -International Standards Organization. An international
body of committees, who's charter is to provide guidance for
standardization in computer interfacing. Their three best-known
standards are the 7-layer OSI TCP/IP Reference Model, the X.400 email
standard, and the X.500 directory services model. X.500 defined a
directory access language, DAP, which was never embraced by the industry
until it was simplified to LDAP. X.500 is now the defacto standard
for all vendors' directory services.
IT -Information Technology. A generic
term which applies to all computer-related activities in a typical
company. Generally encompasses computer programming, computer
systems administration, computer and data networking. In some
organizations, where convergence is practiced, this also includes
telephone centrex and all telephony services.
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Java -
JavaScript (or Java Script) -
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Kerberos -
Kerberos V5 -
Kerberos Version 5 -
KDC -
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LAN - Local Area Network. There are many definitions of LAN. Typically it is
"local" but that is not a criterion. It is usually also a fast, well-connected network or multiple networks
or subnets. The best definition of a LAN includes all of the above, but is
positively characterized by the
fact that, after the initial cost of installation, bandwidth COSTS NOTHING.
L2TP - Layer 2 Tunneling protocol (usually
associated with L2TP/IPSEC)
LDAP - LightWeight Directory Access Protocol. A derivative
of the X.500 Directory Access Protocol (DAP) standard, postulated by the
ISO many years ago. DAP and X.500 remained unused for many years
because of the complexity of the DAP access protocol. X.500 is an
international standard for developing and accessing computer directory
systems. With the development of LDAP for accessing the X.500
directories, this has become the standard for ALL directory systems,
from Microsoft's Active Directory to Novell's Directory service and many
others.
LM -
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MAC - Media Access Control (Address). The physical address of the network
interface in any networked device. Although we think of communications between IP addresses, these must
ultimately be resolved to a (physical) MAC address, to enable communications
between devices. ALL network communications
is MAC-address-to-MAC-address only.
MCDST -
MCP -
MCSA -
MCSE -
MCT -
Microsoft Certified Desktop Support Technician -
Microsoft Certified Partner -
Microsoft Certified Partner for Learning Solutions -
Microsoft Certified Professional -
Microsoft Certified Solutions Partner -
Microsoft Certified Systems Administrator -
Microsoft Certified Systems Engineer -
Microsoft Certified Trainer -
Microsoft Internet Security and Acceleration -
Microsoft Official Curricula -
Microsoft Official Learning Products -
MLP -
MOC -
Montgomery GI Bill -
MOUS -
MOUS Master
MOS -
MOS Master -
MPPE - Microsoft Point-to-point encryption
protocol.
MS-Generally accepted abbreviation for "Microsoft." Typically
used in conjunction with Microsoft training course designations (e.g. MS 2274)
Multicast -
Mutual Authentication -
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N+ -
NAT -
NAT-T -
NetBEUI -
NetBIOS -
Network -
NETWORK+ -
NEXSTEP -
NIC -
NOAA -
NTLM -
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Octet -
Operating system -
Operational recovery -
OPPInc -
Opportunity Inc. -
OS - Operating system. Examples: Microsoft Server 2003; Microsoft Server 2000, Microsoft
Windows XP, Cisco IOS, Linux Server, Linux Workstation, and, of course, the old horse, DOS.
OSI -
OSI Layer 1 -
OSI Layer 2 -
OSI Layer 3 -
OSI Layer 4 -
OSI Layer 5 -
OSI Layer 6 -
OSI Layer 7 -
OSI Reference Model -
OU -
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Parity bit -
Physical security -
PMP -
Portal - portal - it means something different to everyone: an intranet,
the Internet or shared drives. In the IT world, the term has
come to be synonymous with what's past the doorway or login, no matter
what that might be
PPTP - Point-to-Point Tunneling Protocol (TCP port 1723)
Project Management -
Project Management Professional -
Proxy Authentication -
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QOS - Quality of Service. A feature
of some TCP/IP applications to request and reserve (RSVP) a specified
amount of bandwidth. Not well implemented in IPv4, but expected to
be more prevalent in IPv6, after it becomes mainstream.
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RARP - Reverse Address Resolution Protocol. The protocol which allows a user
to broadcast a MAC address on the local network, resulting in the network interface (NIC) returning it's
IP Address - See ARP.
RAS -
Resource Kit -
Repeater - An older technology of the "hub." It usually had one "innie-port" and one
"outie-port." It's function was to extend the reach of network wires, by amplifying, re-shaping, and re-timing
the packets between segments of the same network. See 3-4-5 Rule.
Router -
Routing -
Routing Protocol -
RRAS -
RSVP - Reserved bandwidth request from
certain QOS-capable programs, also requires hardware compatibility from
end-to-end for the RSVP to be honored.
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S+ -
SBS -Small Business Server. A special
edition of Microsoft Server operating system, which provides almost all
of the entire Microsoft Server line of functionality, including "Back
Office" services, such as Microsoft Exchange 2003 email server,
Microsoft Internet Security and Acceleration (ISA) server for Firewall,
Internet Caching, and rules-based outgoing and incoming traffic.
The SBS premium edition Provides the ISA Server and a copy of SQL server
2006.
Schema -
Security -The process of protecting a
valuable from harm and/or disclosure to unauthorized parties.
Security is usually subdivided into physical security, user
authentication, intrusion detection, data and operational recovery and
Computer Forensics
SECURITY+ -
Seminar-an educational meeting, typically several hours to
several days in duration. Seminars usually have focused training
objectives.
Site -
SMS -
Small Business - Generally accepted as any
business with 50 or fewer employees (or computers). There is no
minimum number, but typically 4-5 is considered to be a functioning
small business.
Small Business Server -a specially tailored
version of Microsoft Servers, designed to be owned and operated by small
businesses (4-50 people or computers). It makes extensive use of
"Wizards" to allow the small business owner/manager/technical "go-to"
person to complete most systems administration functions, without
extensive knowlege of what is happening in the background. There
have been several generations of Small Business Servers (SBS), beginning
with Windows NT SBS, followed by SBS 2000, followed by SBS 2003.
SBS 2003 R2 will become the latest version in the Summer of 2006.
SNTP - Simple Network Transfer Protocol
SOA - Service-oriented architecture, or SOA, refers to services that
communicate with each other, such as monitoring a computer network or
e-commerce processes.
Social Engineering -
SQL -
SQL Server -
Structured Wiring -
Subnet Address - See IP Subnetting.
Subnet Mask - See IP Subnetting.
Subnetting - See IP Subnetting
Survivors and Dependents Educational Program -
Switch - As in "network switch." An outgrowth of the original network bridge.
Bridging and switching both alleviate CSMA/CD collisions, allowing a network to operate at or near it's
maximum design speed. This is accomplished by the switch in that it builds an internal table with all of
the MAC addresses on the network, and the port to which that MAC address is attached. When a packet arrives
at the switch (or bridge) destined for that memorized MAC address, it is routed out the proper port - AND NO OTHER
PORTS "HEAR" the packet. Most of the multi-port "hubs" which are in use today are, in actuality, switches.
Systems Administration -
Systems integration -
Switch -
Switching -
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TCP - Transmission Control Protocol
TCP/IP - TCP/IP is a misnomer. Common usage always places these
distantly different protocols together, as if they
were "joined-at-the-hip." See TCP for it's definition, and IP for it's definition. There can, in addition to
TCP/IP also be UDP/IP, ICMP/IP and dozens of other combinations.
TCP/IP Subnetting - See IP Subnetting. TCP does not actually participate in subnetting,
This term is often used - but incorrectly.
TFTP - Trivial File Transfer Protocol
TGT -
Ticket granting service -
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UDP -
UDP/IP -
User Authentication -
USCG -United States Coast Guard. A
semi-military organization which is attached to the Treasury Department,
except in Wartime, when they are attached to the U.S. Navy. Also
performs drug interdiction, harbor safety, and numerous other functions.
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VA Chapter 30 -
VA Chapter 31 -
VA Chapter 35 -
Virtualization -Virtualization is the creation of a virtual, instead of an actual,
version of a storage device, an operating system, a server or network
services.
VLSM - Variable Length Subnet Masking.
Used in conjunction with CIDR subnetting. In CIDR, without VLSM,
all subnet segments can be any number of bits long, but all segments
must be the same length. With VLSM, subnet segments can be defined
which use different CIDR masks for each subnet segment, resulting in
very economical use of available IP addresses. VLSM is a hardware
capability and it must also be supported by the routing protocol being
used.
Vocational Rehabilitation -
VoIP -
VPN - Virtual Private Network. A
secure connection, which can be made over any unsecured internet
connection (or dial-up). VPNs typically use a strong method of
tunneling the secure TCP/IP packets inside of other, innocuous-looking
packets. The VPN can be created with or without encryption, but
unencrypted VPNs are typically only used for troubleshooting
connectivity issues. VPNs can be created with SSL certificates,
PPTP tunneling, with MPPE encryption, L2TP tunneling with IPSEC
encryption, or even point-to-point, using IPSEC in tunneling mode.
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WAN - Wide Area Network. Can be any transmission medium, from the venerable internet
to a simple telephone modem dial-up line (and everything in between). As the name implies, it is typically
a "wide area" data communications medium, but could also be as short as across the street. Classical
definitions
also usually include "slow" in the definition, but recent technologies have removed this barrier. WAN
bandwidth can be purchased by the gigabit. A characterizing attribute of the WAN is that BANDWIDTH COSTS, either by the
month or by the number of packets, or the number of miles or some other
tariff basis.
Web 2.0 - Web 2.0, made famous by tech publisher O'Reilly Media Inc., describes
second-generation Internet-based services focused on communication and
collaboration, such as MySpace.com or Wikipedia.
WINS - Windows Internet Naming Service
Wizards -
Workforce Development -
Workforce Investment Act -
Workgroup -
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X.400 -
X.500 -
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