Dictionary of Computer Acronyms, Computer Terms, Computer Jargon and Certification Terms
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Confused by all of the alphabet soup in Microsoft computer training and other vendor certification training?
We will continue to add to our list of computer acronyms and provide useful information relating to each term. Please click on the tab alphabet letters above to find the word you are looking for.
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
A+
Basic computer hands-on certification. Usually the first certification for career changers. Required by many break-fix, geek, and deskside support jobs. This is one of the REQUIRED certifications specified in the DoD 8570 computer security mandate. This certification actually consists of two individual certification tests, CompTIA A+ Essentials (2006 A + Computer Training Objectives) CompTIA Exam 220-601 and a choice of ONE of 3 possible specialization exams: A + Network and Deskside IT Technician Computer Training ( A + 2006) CompTIA Exam 220-602; OR 220-603 Comptia Remote Support and Help Desk Technician, OR 220-604 Comptia Depot and Bench Technician. Prior to November 2006, these were: A+ 2003 Linear Core Exam: 220-301 and A+ 2003 Linear OS Exam: 220-302.
ACES PFOC
ACES Professional Fiber Optic Installer. A certification granted by ACES for trained fiber optic installers
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
ADSL
Asymmetrical digital subscriber line. (See "DSL") 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. As an example typical ADSL provides about 6.1 Mb download, but only 640Kb upload speeds.
Aero
Microsoft Vista's ultimate and home premium video interfaces. More efficient and faster than Basic interface - If the computer is equipped with an Aero-capable video card.
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
AIS
Automated Information System
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.
ASD(NII)/DoD CIO
Assistant Secretary of Defense for Networks and Information Integration/DoD Chief Information Officer
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.
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 Microsoft-Kerberos.
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. Most .txt files use almost all ASCII, with some extensions.
B
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.
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.
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.
C
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.
CBT
Computer Based Training
CE
Computing Environment
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+) and dozens of others.
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.
CCNA
Cisco Certified Network Administrator. The first level of certifications on the Cisco certification path. Computer training is in 2 different courses, ICND1 and ICND2. With a CCNA certification, this allows the person to configure most low-level routers and some managed switches, upgrade the Cisco IOS, save and restore router configurations.
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.
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.
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.
CDSL
Consumer DSL. (See "DSL.") An abandoned, much slower (1Mb down, much less up), splitterless DSL.
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.
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.
CISSP
Certified Information Systems Security Professional. One of several security certifications specified by DoD mandate 8570.01-m. It is maintained by (ISC)2 or ISC2. CISSP is a premier security certification, requiring 3 years of computer security experience as a pre-requisite, and which has to be maintained year-by-year, or the holder must re-sit the exam every 3 years to stay certified. Employers, for the most part, have not yet discovered CISSP, so it does not offer premium job pay (MCSA, MCSE, and CCNA all command more pay in the job market). When combined with a CEH (Certified Ethical Hacker) or other security credentials, however, it becomes one of the highest paid skills in the job market today.
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.
Classless IP address
Also known as "CIDR." See CIDR.
Cloud Computing
The common buzzword for "Software as a Service." See SaaS.
CMIS
Corporate Management Information System
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 CTT+
CompTIA Certified Technical Trainer. A vendor-neutral certification that the certified trainer has demonstrated skills to teach not only CompTIA, but also other technical curricula. MOST of the other vendors (Microsoft, Cisco, etc) will accept the CTT+ as sufficient evidence of the ability to train, and they will issue specific vendor certifications, such as MCT (Microsoft Certified Trainer), if the trainer candidate also has the level of certifications to teach the vendor's classroom and/or computer-based courses.
Computer Forensics
Convergence
COOP
Continuity of Operations Plan
Council ASD(NII) / DoD CIO and USD P&R
Information Assurance Training, Certification, and Workforce Management Oversight Advisory Council
COTR
Contracting Officer’s Technical Representative
CPLS
Microsoft Certified Partner for Learning Solutions
CTEC
Microsoft Certified Technical Education Center
D
DAA
Designated Approving Authority
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
Domain Controller
DCPDS
Defense Civilian Personnel Data System
Decimal Numbers
Decimal Point
DEERS
Defense Eligibility Enrollment Reporting System
Delegated Authentication
DFS
Distributed File Sevices
DHCP
Dynamic Host Configuration Protocol
DIMHRS
Defense Integrated Military Human Resources System
DirectX
Software within Windows Vista that is used to manage multimedia output.
DirectX 10 Compliant
A Graphics Processing Unit (GPU) that meets the DirectX 10 specification for gaming and 3D graphics
DISA
Defense Information Systems Agency
DMDC
Defense Manpower Data Center
DNS
Domain Name Services (or Domain Name Server). In all network infrastructures, some form of name-management services have typically been offered. Some are broadcast-based, others use some form of database. In the original ARPA internet model, with a few universities and DoD nodes participating, it was sufficient to maintain a central "hosts" file at one of the universities - users would download fresh copies of "the hosts file" when it became out of date. As the internet grew, the hosts file grew in size and complexity and became inoperable. With the size of the current internet, no one database could be relied upon to provide name services. DNS implements a distributed, hierarchical network of thousands of computers - each has a small part of the answer and a capability of asking the next-higher node in the network.
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
Digital Subscriber Line. A generic term, which is further subdivided into several sub-classes that is generally used to provide high speed, digital network connections over copper telephone wire. It also has the capability to provide simultaneous voice communications, over the same wire. The sub-classes of DSL are generally referred to as xDSL. These could include ADSL, SDSL, HDSL CDSL, IDSL, RADSL, UDSL, VDSL, x2/DSL and even "DSL lite." DSL's use is typically limited by the distance from the end-of-the-wire to the CO (Central office) or POP (Point of presence), typically being limited to about 18,000 feet. Previous to ISDN and DSL, telephone companies ran the "last mile" of wire as far as they could extend it - and analog voice frequencies allowed some pretty long runs. Today, that is a problem for many homeowners who ask for DSL, and are told they are too far away. Earlier versions of DSL, with duplexed voice/digital signals on the same line required little splitters (filters) any where you wanted to connect a telephone - more recently the need for splitters has been overcome by "splitterless DSL," "DSL Lite," "G-Lite," or "Universal DSL."
E-G
E
e-JMAPS
e-Joint Manpower and Personnel System
EBCDIC (eb-see-dick)
Element-K
Enclave
Collection of computing environments connected by one or more internal networks under the control of a single authority and security policy, including personnel and physical security.
Enclave Environment
A contained computing environment (ex: NOSC Enclave; Afloat Enclave; Forward Command Enclave; Airborne Enclave; Forward Deployment Enclave...)
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
F
Firewall
FISMA
Federal Information Security Management Act
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
G
G.Lite
(Also known as DSL Lite, Splitterless ADSL, and Universal ADSL - See "DSL") An evolving form of DSL that doesn't require splitters - but sacrifices some speed to achieve that. The phone companies are pushing these, because they are much less expensive to the phone company. Typical speeds are 1.5-6 Mb up and 128-384 Kb down.
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
GIG
DoD Global Information Grid
Global Catalog
Global Catalog Server
The server(s) which hold copies of the forest global catalog
GPU
Graphics Processing Unit. The built-in graphics CPU on high-end Video Cards.
GRE
Generic Routing Encapsulation/IP Protocol 47
GUID
H-IN
H
Hardware Pixel Shader
A capability which can be built-into a graphics adapter that improves visual performance
HDSL
High Bit-Rate Digital Subscriber Line (See "DSL"). A symmetric (same speed up as down), much higher speed version of DSL - usually installed in corporate or in the telephone company. Usually sold as T1 or E1 1.5-2 Mb lines. (The difference is, T1 uses a complicated CSU/DSU at both ends, for connectivity, but DSL uses one DSLAM at the TELCO end.)
HexaDecimal Number
Originally a convenient way for programmers to write easy-to-convert binary numbers. Hex has recently been adopted for most binary-based numbering systems. For instance the traditional "dotted-decimal-notation" (ex 124.32.102.7) is very difficult for most people to convert to and from binary. Many operating systems now provide capability (or require) entry of IP addresses in Hex; Network interface card MAC addresses have always been notated in hex; and IPv6 will no longer use any form of dotted decimal. Conversion between hex and binary and back are very simple, since one hex digit is actually made up from the first "nibble" (4-bits) or the the last nibble of a binary byte (8-bits). With a little practice, people can "write" hex in binary with effortlessly - they can also "read" binary into hex performing conversions in their head. In the example above, the first octet (124) is expressed in binary as 01111100. This 8-bits (a byte or an octet) is daunting to be read in binary - and conversion from "dotted-decimal" (124) to binary - or binary to dotted-decimal is not obvious. By splitting the binary into two nibbles 0111 1100, this can be "read" as the hex number 7C in hex and just as easily converted back to the binary.
HPC
High Performance Computing. A new clustering and cluster control model in Windows Server 2008, which can conceivably collect thousands of computing cores in one compute cluster.
HPCS
High Performance Computing System. (See HPC)
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.
I
IA
Information Assurance
IAM
Information Assurance Manager
IAS
IASE
Information Assurance Support Environment (DoD IA Portal)
IAT
Information Assurance Technical
IAVA
Information Assurance Vulnerability Alert
ICND
The two courses (ICND1 and ICND2) which lead to
ICS
IDSL
ISDN DSL (See "DSL"). Really just a marketing term for the old ISDN connections. Speeds 128Kb Symmetric (Same speed up as down)
IKE
INFOCON
Information Operations Condition
INFOSEC "Security"
The parenthetical title in DCPDS for civilian personnel performing security (IA) functions
Instructor-led training
Internet Caching
Internet Key Exchange
Intrusion detection
IO-L
I
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
IS
Information System
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.
ISO / IEC
International Organization for Standardization / International Electro-technical Commission
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.
J
Java
JavaScript (or Java Script)
K
Kerberos
KDC
L
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
M
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.
MAC Address
See MAC above.
MCDST
Microsoft Certified Desktop Support Technician
MCITP
Microsoft Certified IT Professional
MCP
Microsoft Certified Professional
MCSA
Microsoft Certified System Administrator
MCSE
Microsoft Certified System Engineer
MCT
Microsoft Certified Trainer
Microsoft Internet Security and Acceleration
Microsoft Official Curricula
MLP
MOC
Montgomery GI Bill
If you are eligible, the Montgomery GI Bill pays for most of your certification tuition and computer training materials, including tests and retesting, if necessary.. You will need to consult your Veterans Administration Counselor to determine your eligibility - and the method of payment.
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
N-O
N
N+
Network+. one of the vendor-neutral certifications by CompTIA. Concentrates on the basics of networks, from history to media, and some small amount of subnetting skills. Network+ has recently been required by the DoD 8570 mandate, for every IT person who does work on a DoD network (even civilian contractors).
NAT
Network Address Translation. Used to translate between many "private" IP addresses, which cannot cross the internet and one (or more) public IP addresses. In the OSI stack, the Session layer assigns a RANDOM port number between 48k and 64k, to identify the data stream that will be returned to the originating application. This port number is maintained and associated with all layers to the destination and back. For instance, a request from a client at 192.168.2.2, for a standard HTML page, will be directed to port 80 on the TARGET web server, with a random return port number (for illustration, pick the random return port number=50000). The packet is directed to the NAT SERVER (e.g. default gateway) because the private 192.168 IP address is not allowed to cross the internet. When the NAT server receives the packet, it creates a table with the return IP and "from" port number for the requesting client. The NAT server then chooses ANOTHER RANDOM PORT NUMBER (choose port number 60492), and adds that "from" port number to the NAT translation table, and to it's own outside IP address (Example: 192.168.2.2:50000:60492) This random port number is then sent from the NAT server's "outside address" as the "from address" (1.2.3.4:60492). When the web server receives the web traffic on port 80, it fills the request and returns the response to 1.2.3.1:60492. When the NAT server receives the response, it does a look up in the NAT translation table for port 60492, remaps the "to" address for the client to 192.168.2.2:50000 and sends it on to the client. The client, in the meantime has no idea that the returning packet(s) have been remapped, and returns the response, via the Session layer, to the application that requested it. NAT servers allow free use of any of the "private" addresses (10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16), while requiring only ONE public IP to service the organization. In addition, the NAT server "hides" the internal IP address information from the internet and the web server. Most high-end firewalls are functionally a NAT server -- and even the simplest NAT server does some firewall duties.
NAT-T
Most NAT servers CANNOT process L2TP/IPSEC tunnels. The only option in these cases is to "open a hole" in the firewall, and hope that the VPN server is hardened enough to survive any attacks from the outside. Some NAT servers (e.g. Microsoft ISA Server 2004/2006), provide NAT-T capabilities. With NAT-T, the server has a copy of the VPN's certificate installed, allowing it to open the VPN packet, inspect it's content, then reseal it - if it is safe.
NE
Network Environment
NETAPP
Network Appliance. A purpose built appliance that performs a specific limited function on a network. NETAPP Inc. is a major vendor in the network attached storage (NAS) arena (#3 in 2008). Also a major player in the Storage Area Network (SAN0 storage market. In the generic definition, it is NOT an ASIC-based device, such as a router, but typically a rules-based, semi-intelligent device, often employing xml-based policies to look deeply into network traffic and apply those rules.
NetBEUI
A legacy TRANSPORT protocol, which was used in early Microsoft and IBM networks. It is strictly a broadcast-based protocol. The sending station broadcasted the target's name, and the target returned it's MAC address, which was used for local addressing. Since it is broadcast-based, it is non-routable. It predated the classic OSI model, and is not used today. It was the default protocol for Windows For Workgroups 3.11, through Windows ME. Windows NT used IPX/SPX (NWLink) as it's default, but loaded NetBEUI as a secondary transport protocol. Windows 2000 had NetBEUI as an optional transport protocol, but Windows 2003 and XP do not offer it (it can still be downloaded, if necessary). NetBEUI is often CONFUSED with NetBIOS, because NetBIOS was the default SERVICE-PROVIDER protocol and was transported on NetBEUI as its TRANSPORT protocol.
NetBIOS
Network
NIBBLE
4-Bits, half a byte. The order of binary jargon is Word (64, 32, or 16 bits), Byte (8 bits), Nibble (4 bits). Some define a crumb (2 bits), but I have never seen it used in practice. A Nibble is also one Hexadecimal character.
NIC
Network Interface Card
NIPRNet
Non-classified Internet Protocol Router Network
NOAA
Non-Volatile Memory
More commonly known as "flash memory" or "ROM." See Volatile Memory
NTLM
O
Octet
Operating system
Otherwise known as OS.
Operational recovery
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 Reference Model
OU
P-R
P
Parity bit
Physical security
PMP
Project Management Professional
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
Q
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.
R
RADSL
Rate-Adaptive DSL (See "DSL"). DSL that is priced by the rate of usage. 640-2.2 Mb down and 272 Kb-1 Mb up. This is a variable-rate, and will provide the lower end-to the higher end speeds, as the customer uses it.
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.
S
S+
Security+. A CompTIA certification in vendor-neutral computer security training. One of the required basic certifications mandated by DoD Instruction 8570.01-M for ALL people having access, either as a military member or as a civilian support person.
SaaS
Software as a Service - also "Cloud Computing." A way of reducing IT up-front expenses by paying for applications by the month. Can be as common as an on-line data backup service, applications that run from the internet, in a web browser, applications that run from the internet - but run on the local machine, or some combination of these. SaaS is growing rapidly in 2008, particularly in Small-to-medium-businesses (SMBs)
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
SDSL
Symmetric DSL (See "DSL"). Also another name for T1 and E1 (1.5 Mb or 2 Mb) lines. (The difference is, T1 uses a complicated CSU/DSU at both ends, for connectivity, but DSL uses one DSLAM at the TELCO end.)
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
SIEM
Security Information and Event Management. Originally tools for regulatory compliance, log management and analysis, trouble-shooting and forensic analysis. This is spreading into software and appliances that are beginning to play a big role in proactive security. Real-time analysis is combined with in-memory correlation, and automated notification and remediation capabilities to provide unprecedented network visibility, security and control.
SIPRNet
Secret Internet Protocol Router Network
Site
SKU
Stock Keeping Unit. Used by many vendors, but notably by Microsoft to differentiate variations in operating systems, etc.
SMB
Server Message Block; or Small-to-Medium-Business.
SMS
Systems Management Server - Microsoft's premier remote, large-batch computer management application. Used to inventory large numbers, determine capabilities of each, and deploy selected software to systems that are capable of receiving the software. Typically, SMS requires a highly skilled operator who is part programmer and part systems manager.
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.
SQL
Structured Query Language
SQL Server
Structured Wiring
Subnet Address
Subnet Mask
Subnetting
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
T-V
T
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
Kerberos Ticket Granting Ticket
Ticket granting service
One of the two services provided by Kerberos. AS is the Authentication Service of Kerberos, which results in the issue of a TGT to the authenticated user
U
UDP
UDP/IP
UDSL
Unidirectional DSL (See "DSL"). A unidirectional version of DSL
User Authentication
USCG
United States Coast Guard
UTM
Unified Threat Management. UTM is the newest model for firewall protection. It provides intrusion guards, content filtering, data leakage blocking, and anti-malware. This is included in a single solution by many vendors (Sonicwall, Microsoft ISA Server, and others) - at varying levels. The integration increases the complexity of a single firewall - but dramatically decreases the complexity of the protection and threat management.
V
VDSL
Very High Data Rate DSL (See "DSL"). Speeds of 51-55 Mb, but limited to 1000 feet of wire (or 300 meters).
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.
VoIP
Voice over IP
Volatile Memory
Typically known as RAM in computer jargon - however RAM is only one of a class of volatile memory types. The "volatile" means that the memory does not retain the data which it contains after power is removed. This is contrasted by non-volatile memory, which does retain its data after the power is removed (or turned off). An example of both Volatile and non-volatile memory is the computer system BIOS. Most of the BIOS is in ROM (non-volatile memory). This retains the BIOS "program" even after the computer has been turned off and disconnected for years. It only changes, when "flashed" by a special program. BIOS, however, requires computer data that is allowed to chage, which cannot be stored in the ROM. These parts are stored in "the CMOS," which, even though it seems to keep its settings after the computer is turned off and disconnected - in actuality it has to have a battery to keep it from losing its settings.
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.
W-Z
W
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.
WBT
Web-Based Training
WDDM
Windows Vista Display Driver Model. Display drivers that are specifically designed to work with Windows Vista.
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 - an almost obsolete method of converting from a computer name and its IP address. Based upon the NetBIOS protocol. Resolves not only the Name, but provides a database to point to a NetBIOS service code. Very similar to DNS (Domain Name Service) in the internet suite of utilities.
Wizards
Workforce Development
Workforce Investment Act
Workgroup
Workstation
Computers come in two basic configurations: (1) computers that are designed to provide services and store data (Servers); and (2) Computers that are designed for hands-on user input and use (Workstations). All vendors have the same basic divisions - in the Microsoft world, for instance, all of the Windows 9x family were "workstations." Then they made a more definitive split with NT Server/NT Workstation, 2000 Server/2000 Pro (Workstation). Windows XP was the "workstation" generation of Windows Server 2003, however XP was released a couple of years before 2003, because of some legal entanglements about Windows Server 2003. In the next generation, Vista (in all of it's models) is the workstation version of Windows Server 2008.
WPA
Windows Product Activation. The aggravation of Activating windows products before you can use - and reactivating them, if you move them or change several components in a previously activated product. Windows Vista allows up to 30 days BEFORE you are required to enter the product key or activate it. This is generally a good idea, just in case you discover that you need to change components and/or reinstall the OS.
X
x2/DSL
A modem (really) to carry 56 Kb on a line that will be upgraded to ADSL, when the modem can be upgraded or flashed to become a real DSL interface.