- The designation given to the highest resolution for HDTV standards. 1080i TV sets offer 1920 X 1080 pixels of resolution, and the little i stands for interlaced, which offers the fastest refresh rate, resulting in the smoothest video technology available. Most videophiles insist on 1080i technology for their TV sets.
- Short for Single Carrier (1x) Radio Transmission Technology. This technology supports peak data speeds up to 144 kbps, and up to a doubling of voice capacity. 1xRTT is a 3G wireless technology based on the CDMA platform. 1xRTT has the capability of providing ISDN-like speeds of up to 144 Kbps. 1xRTT is also referred to as CDMA2000.
- 2600 Hz is the frequency (in cycles per second) that AT&T formerly put as a steady signal (which they called the Supervisory Tone) on any long-distance telephone line that was not currently in use. Prior to widespread use of out-of-band signaling, AT&T used in-band signaling, meaning that signals about telephone connections were transmitted on the same line as the voice conversations. Since no signal at all on a line could indicate a pause in a voice conversation, some other way was needed for the phone company to know when a line was free for use. So AT&T put a steady 2600 Hz signal on all free lines. With this knowledge, certain people developed a way to use a whistle or other device to generate a 2600 Hz tone on a line that was already in use, making it possible to call anywhere in the world on the line without anyone being charged. Cracking the phone system became a hobby for some early hackers, who came to be known as phone phreaks. In the 1960s, a breakfast cereal named Captain Crunch included a free prize: a small whistle that generated a perfect 2600 Hz sine wave. By dialing a number and then blowing the whistle, you could fool the phone company into thinking the line was not being used while; in fact, you were now free to make a call to any destination in the world. A phone phreak – who took on the moniker of Captain Crunch – shared this information with all of his hacker friends. Today, long-distance companies use Signaling System 7, which puts all channel signals on a separate signaling channel, making it more difficult to break into the phone system. However, there is now a club of hackers, crackers, and even a magazine publication called “2600 Hacker’s Quarterly” that appeals to a whole new generation of phreaks.
- 419 SPAM
- 419 SPAM or Advance-Fee Fraud, is a confidence trick in which the target is persuaded to advance sums of money in the hope of realizing a significantly larger gain.
- A wireless networking protocol established by the IEEE. 802.11a describes the wireless networking standard for a WLAN WLAN that operates in the 5 GHz radio band (ISM frequency band). 802.11a-based WLANs can achieve a maximum speed of 54 Mbps, providing nearly five-times faster networking data rate than 80211b, and can handle more traffic than 802.11b-based networks.
- 802.11b is a WLAN communication standard defined by the IEEE. 802.11b is one of the wireless Ethernet standards in the 802.11 series. Compared to alternatives like 802.11a and 802.11g, 802.11b network equipment costs less. Its relatively low cost naturally resulted in many home and small business networks adopting 802.11b. 802.11b LANs support a maximum data rate of 11 Mbps. Although 802.11b performs much better than traditional dial-up networking, the performance of 802.11b is still significantly less than 802.11a and other, newer standards. Also Known As: Wi-Fi
- 802.11g is a proposed IEEE standard, describing a wireless networking method for a WLAN that operates in the 2.4 GHz radio band (ISM — Industrial Scientific Medical frequency band). By using OFDM technology, 802.11g-based WLANs will be able to achieve a maximum speed of 54 Mbps. 802.11g is backward compatible with the 802.11b standard.
- Asymmetric Digital Subscriber Line. It’s called asymmetric because the speed of data going out (upload speed) is slower than the data coming in(download speed). ADSL is sometimes referred to as a broadband connection. ADSL is asymmetric in the sense that it uses most of the channel to transmit downstream to the user and only a small part to receive information from the user.
- Asynchronous Transfer Mode. A high bandwidth, high speed (up to 155 Mbps), controlled-delay fixed-size packet switching and transmission system integrating multiple data types (voice, video, and data). ATM uses fixed-size packets also known as “cells” (ATM is often referred to as “cell relay”).
- Active Directory
- A Microsoft technology based on Lightweight Dicertory Access Protocol (LDAP) that provides a standard view and way to manage all objects on a network. Active Directory was first introduced with Windows 2000, and is a replacement for the Domain Controller Microsoft systems/network management method first introduced with Microsoft NT.
A Microsoft technology based on COM technology, and is designed to facilitate the embedding of interactive objects (such as multimedia) on Web pages. To interact with ActiveX on sites that support it, your browser must support it as well, and have the ActiveX feature enabled.
- BlackBerry is a line of mobile email devices and services from Research In Motion (RIM). BlackBerry is a complete package that includes airtime, software and choice of BlackBerry mobile device. BlackBerry is currently available in the United States, Canada and the United Kingdom. In the United States and Canada, BlackBerry depends on either narrowband PCS 800 MHz DataTAC networks or narrowband PCS 900 MHz Mobitex networks. In the UK, BlackBerry works over GPRS networks.
- A contraction for Web Log. Blogs are specialized websites where Internet users can post their opinions – sometimes anonymously – regarding a wide variety of topics ranging from new technical developments to national politics. Posted opinions usually appear in reverse chronological order; in other words, the most recent opinions are listed first. Most blogs (but not all blogs) are moderated. People that contribute to blogs or run blogs are called bloggers.
- Blue Jack
- Temporarily hijacking another person’s BlackBerry and/or cell phone by sending it an anonymous text message using the Bluetooth wireless networking system.
- A global initiative by Ericsson, IBM, Intel, Nokia and Toshiba to set a standard for cable-free connectivity between mobile phones, mobile PCs, handheld computers and other peripherals. It will use short-range radio links in the 2.4 GHz Instrumentation Scientific and Medical (ISM) “free band”.
- A bot is a program (or robot)that surreptitiously installs itself on a computer so it can be controlled by a hacker. A bot net is a network of such robot, or “zombie,” computers, which can harness their collective power to do considerable damage, launch Distributed Denial of Service (DDoS) attacks, and/or send out huge amounts of SPAM (junk email).
- An army of zombies (compromised PCs) under the remote control of a zombie master. Botnets can consist of anywhere between a few dozen PCs to thousands of PCs. There are currently 10 million zombies connected to the Internet; there are several hundred botnets. Generally speaking, botnets are available for rent to nefarious organizations that commit online crimes, such as running Phishing scams.
- A transmission medium capable of supporting a wide range of frequencies, typically from audio up to video frequencies. It can carry multiple signals by dividing the total capacity of the medium into multiple, independent bandwidth channels, where each channel operates only on a specific range of frequencies. When most people refer to broadband, they are generally referring to a high-speed Internet connection.
- A programming language developed in the late ’60s specifically to create the UNIX operating system. C was written by programmers (Brian W. Kernighan and Dennis M. Ritchie) for programmers, and is a well-structured programming language. C programs can run on any computer system that has a C compiler that can translate the C source code into native executable machine language (in other words, just about any computer).
- An extension of the C programming language that includes support for object-oriented programming techniques.
- Certificate Authority. A trusted third-party company or organization that issues digital certificates. The CA guarantees that the holder of the digital certificate is who he or she says he or she is. The issuing CA always confirms and verifies the information provided to it by a rigorous verification process.
- Code Division Multiple Access. A 2G digital wireless technology (developed by Qualcomm, Inc. and Ericsson) that allows multiple calls to share a radio frequency 1.23 MHz wide in the 800 MHz-to-1.9 GHz band without causing interference. This is accomplished by assigning each call a unique code and varying its signal by that code to allow only the caller and receiver with that code to securely communicate with each other. The original CDMA standard allowed transmission of up to 14.4 Kbps per channel, with up to 8 channels being able to be utilized at once for 115 Kbps speeds.
- Component Object Model (COM)
- A Microsoft specification that describes methods of communication between components. For example, if you were to drag an item over a window, the item and window would have some rules of communication that they would follow. Those rules are described in the Component Object Model.
- A small text file of information that certain Web sites attach to a user’s hard drive while the user is browsing the Web site. A Cookie can contain information such as user ID, user preferences, archive shopping cart information, etc. Cookies can contain personal information, and therefore be a potenial vulnerability that spyware programs could exploit.
- Distributed Denial of Service attack. A network attack launched against a network or server(s) designed to flood the network or server(s) with so many requests that the network or server(s) often crash (stop working). Unlike a DoS, a DDoS is launched from several different points of origin, sometimes separated by several degrees of separation, making it nearly impossible to trace back to the original perpetrator. Botnets are often used to launch DDoS attacks.
- Dynamic Host Configuration Protocol. A method of automatically assigning a TCP/IP address to a network node whenever the network node boots up when connected to the LAN. A DHCP server is used to assign (and keep track of) an TCP/IP address from a pool of TCP/IP addresses to a client that that is configured to acquire an IP Address using DHCP.
Typically when you connect to your ISP over a modem or broadband your computer is assigned a dynamic (non-static) IP Address via DHCP. The big advantage to DHCP is that you don’t need to manually assign a TCP/IP address to a client, as the DHCP server takes care of that. After an amount of time passes (known as the lease time) where the client does not contact the server, the server puts the IP address of the client back into the pool to be assigned to that client or any other client hat requests an IP address. The disadvantage of DHCP for the DHCP client is that the client is not guaranteed to have a particular IP Address at any given time. For that you want a static IP address – which can still be assigned to a client, provided that the DHCP server supports a feature called DHCP reservations.
- Dynamic Hyper Text Markup Language. This was independently defined by Microsoft and Netscape and implemented in version 4 of their browsers to allow for more dynamic and user-interactive Web pages, and better positioning of Web elements. Both the Netscape and Microsoft versions of dynamic HTML include some support for Cascading Style Sheets, which is a standard defined by the World Wide Web Consortium.
- Domain Name Service. The underlying protocol (transparent to users) that translates (resolves) domain names (such as acme.com – which we as human beings prefer to use) into IP addresses (such as 10.49.36.119 – which machines such as computers, handheld network devices, and network routers actually use to communicate data). There are sveral protocols, such as SMTP and HTTP that are dependant on DNS protocols. DNS Services run on computers known as Name Servers.
- Digital Subscriber Line. A relatively inexpensive method of connecting to the Internet via broadband technology. DSL connections come in many speeds, ranging from 56 Kbps to T1 speeds (1.544 Mbps). DSL connection services are usually offered to subscribers via the local phone company, Incumbent Local Exchange Carriers (ILECs), or Competitive Local Exchange Carriers (CLECs).
- Denial of Service attack. A network attack launched against a network or server on a network designed to overwhelm the available network bandwidth or server resources to the point where response times slow down, or services stop responding altogether. DoS attacks used to originate from a single source, making it rather easy to trace the attack back to the original perpetrator.
- A program that is usually installed surreptitiously, and automatically starts downloading additional or updated malicious software – often for the purpose of sending out SPAM, Phishing scams, or turning a PC into a zombie.
- Electronic Mail. Email is a form of messaging designed to transmit/receive text messages and/or attachments over a network (such as the Internet) using SMTP (Simple Mail Transfer Protocol) protocols. Email is a client-server network application; in other words, email requires client workstations (or handheld devices) to transmit (relay) a message through a mail server, which can then deliver the message to other mail servers, or the intended recipient’s mailbox, which can then be downloaded by the recipient using their client workstation (or handheld device). Email was the first killer application used over the Internet.
- A local area network (LAN) protocol developed by Xerox Corporation in a cooperative venture with Digital Equipment Corporation (DEC) and Intel in 1976. It is one of the most widely implemented LAN standards.
- File Transfer Protocol. FTP is one of the earliest protocols offered in the TCP/IP suite of internetworking protocols. Since the dawn of the modern day computing era (a.k.a. The Epoch), data has been organized into files, some of which needed to be shared amongst other computer users. One of the ways files can be shared (uploaded or downloaded to other computers) in the early days was to use the FTP protocol. It is still in use today to transfer information between networked computers.
- Graphical Interchange Format. Invented by CompuServe for efficient transmission of graphics, this format can only support 256 colors, or 8 bits. The newer revision, 89a, allows for multiple images in one file to simulate animation. Unisys owns the patent to a form of compression used in GIF files and occasionally decides to demand licensing fees. Thus, you may want to use the newer and completely free PNG format instead of using GIF files.
- Global Positioning System. A system of satellites around the Earth that broadcast the time via radio signals based on an internal atomic clock. GPS devices can receive the signals from multiple satellites, and by measuring the time it took the signal to arrive they can determine your current position on the Earth.
- Global System for Mobile Communication. Global system for mobile communication (GSM) is a globally accepted standard for digital cellular communication. GSM is the name of a standardization group established in 1982 to create a common European mobile telephone standard that would formulate specifications for a pan-European mobile cellular radio system operating at 900 MHz. It is estimated that many countries outside of Europe will join the GSM partnership. GSM uses narrowband TDMA, which allows eight simultaneous calls on the same radio frequency.
- The computer or network device onto which the first hop needs to go to get out of your network and onto another network or the Internet. The default gateway – as it relates to TCP/IP – is tried when a resource is not found on the local network (provided that this TCP/IP setting is configured correctly).
- Developed at the University of Minnesota (uminn.edu), this is often said to be the first incarnation of the World Wide Web. It is an information source based on textual links, now outdated and superceded by the Web (HTTP protocols).
- High bit-rate Digital Subscriber Line. A form of DSL that provides T1 (1.544 Mbits/second) or better transfer rates and is meant to displace business T1 connections. HDSL requires much less bandwidth than standard T1 encoding to transfer the same amount of data.
- Hyper Text Markup Language. A standard language initially created for typesetting. Although it is a language, it isn’t really a programming language. It is mainly used for creating documents on the World Wide Web. HTML includes provisions for displaying graphics and links to other pages.
- Hyper Text Transfer Protocol. HTTP is the underlying protocol used by the World Wide Web. By its very nature, HTTP encourages web pages to be linked together via Hyper Text links. Users typically use a tool called a browser to display web pages on their screen, and can simply click on Hyper Text links to navigate to other web pages. This activity is sometimes referred to as web surfing. HTTP is dependent on working DNS protocols.
- A system left open and unprotected to entice hackers to break into it. Usually this is done so that system administrators can monitor the methods used to break in, the frequency of attack, or just to throw off attackers from the real goodies.
- ISDN Digital Subscriber Line. A method of providing DSL technology over existing ISDN lines. Even though the transfer rates for IDSL are about the same as ISDN (144kbps v. 128kbps), and IDSL circuits typically only carry data (not voice), the major benefits of switching to IDSL from ISDN are always-on connections, thus eliminating call setup delays; flat rate billing, instead of per minute fees; and transmission of data over the data network, rather than the PSTN. An advantage that IDSL circuits have over other types of DSL circuits is that IDSL circuits can generally reach subscibers that live farther than the maximum 15,000 feet (which is the DSL maximum distance) from the Central Office. IDSL was developed by Ascend Communications, now part of Lucent Technologies.
- Institute for Electrical and Electronics Engineers, a professional organization which sets standards for telecommunications and computers. This body also sets the standards for networking protocols.
- IP Address
- A unique address assigned to network devices (nodes) connected a TCP/IP network. IP addresses are 32-bit addresses (4 bytes) that are divided into four octets separated by a dot (.) – such as 10.49.36.119. Since each octets actually represents a byte internally, each octet can have a [decimal] numeric value between 0 and 254.
- Apple’s iPOD is a small portable music player that plays digital music in MP3 file format. Users can transfer songs to their iPOD with their computer, iTunes, and the iPOD software.
- Integrated Services Digital Network. An international standard for end-to-end digital transmission of voice, data, and signaling. In a videoconference it is a system that provides simultaneous voice, video, and text transmission between individual desktop videoconferencing systems and group (room) videoconferencing systems.
- JPEG (JPG)
- Joint Photographic Experts Group. A popular format for digital graphic images. It was specifically made for storing images with more than 256 colors in a small file size. JPEG files use lossy compression. You can also set the amount of compression you would like for the graphic; however, the higher the compression the less quality the graphic has. On the down side, even at 100% quality (or 0% compression) the graphic is not perfect, already losing some detail (thus the “lossy” compression). JPEG files use the file extension “.jpg.”
- A platform-independent programming language developed and introduced in 1991 by Sun Microsystems. Java is similar in form to C++, but is designed to focus on Internet communications and be cross-platform compatible. Java mainly runs on Web browsers, but it can also run natively on operating systems, in a Java Virtual Machine, or on servers as Java Servlets.
- Key Logger
- Key logging software is a specific form of spyware (or a Trojan) that logs users’ keystrokes as they log into password-protected websites, such as an online banking websites, or online stock trading websites. The captured username and passwords are then covertly transmitted to a central repository on the Internet where perpetrators will commit cyber-crimes such as Identity Theft.
- L1 Cache
- Level 1 Cache. A small piece of very fast memory that resides on the CPU chip itself. It’s located between the CPU registers and the L2 cache. L1 cache has a lower latency than L2 cache, making it more expensive to produce and harder to produce in larger quantities without additional complexity.
- L2 Cache
- Level 2 Cache. A piece of fast memory that sits between the L1 cache of the processor and main memory. It is usually larger than L1 cache, and unless the L1 and L2 caches are unified, the L1 cache checks the L2 cache before going to main memory for data. These days L2 caches are almost always on the same die as the microprocessor chip.
- L3 Cache
- This type of cache is becoming more common as microprocessor manufacturers integrate more processors with L1 and L2 cache. L3 cache is then the extra cache that sits on the motherboard between the processor and main memory, since the processor already contains L1 and L2 cache. Some processors are starting to ship with L3 cache built-in as well to speed up memory operations further. In those cases the L3 cache often sits on a separate area of the die, not built directly into the chip’s core.
- Local Area Network. A small isolated network at one office or physical location. Most office computers are connected to a LAN; LANs could also be interconnected to other LANS, the Internet or a Wide Area Network (WAN).
- Lightweight Directory Access Protocol. An Open Source client/server protocol standard for accessing a directory service, such as Active Directory or Novell’s Directory Services. It is a simplified version of the X.500 protocol.
- A measurement of time indicating how long it takes to get a response from something. This term is used to refer to network response speed, storage devices (hard drives, CD-ROM drives, etc.), and/or retrieving data from memory (or cache).
- Leased Line
- A phone line that can be leased from the telephone company with the assurance that the company using it is the only one on the line, thus giving faster data speeds. These lines are also known as dedicated lines, and are often used to connect different branch locations of companies.
- License (Software license)
- Most corporations need multiple copies of software, but do not need the media in which they come, either because they already have it or because they allow users to download/install the software from a software server on their network. Companies still need to purchase a copy for each user, however, so they need a way to prove they have actually purchased a copy of each. These companies purchase software licenses with no associated media. Such licenses are typically just sheets of paper that cost a lot of money, but allow you to use additional copies of the software legally.
- An Open Source, UNIX-like operating system originally developed by Linus Torvalds. Linux is freeware by default, but may be sold for the cost of packaging, bundling, and technical support. Companies such as Red Hat, SuSe, and Caldera sell Linux packages; however, they also allow you to download them for free. Linux was first developed for Intel x86 computers, but now runs on a wide variety of platforms.
- Longhorn (Vista)
- “Longhorn” was Microsoft’s internal code name for the next version of their Windows operating system. When the long-awaited Longhorn will be released (presumably in early 2006), it will be called Vista. Microsoft Vista will be the replacement software for Microsoft’s XP
- MAC Address
- Media Access Control Address. A unique 48-bit address of a network card or device. The first part of the address (the first 24 bits – or first 3 bytes) is unique to the company that produced the device, and is referred to as the manufacturer’s code; the rest of the address (the last 3 bytes – or 24 bits) is the unique part of the MAC Address.
- Metropolitan Area Network. A collection of several LANs linked by faster backbone connections (such as an ATM network). A MAN is usually smaller than a WAN; an example of a MAN is a college campus with several LANs linked on the same network.
- Master Boot Record. The first sector on a hard disk or other disk media. When a computer boots up it searches for a Master Boot Record wherever the BIOS tells it to (usually the master hard drive on the first IDE channel, but this can also be checked for in CD/DVD drives and floppy drives) and, based on how the Master Boot Record is configured, loads up an operating system. If the Master Boot Record becomes corrupt or is altered by a virus, it can render your computer to be unable to boot.
- MPEG-1 Audio Layer-3. A compression standard for audio. It enables compression of CD-audio by approximately 10 times, depending on the bit and sampling rate. It does not stand for MPEG-3, but rather it is the audio part of the MPEG-1 audio/video compression standard.
- Moving Pictures Expert Group. An ISO group that works to develop standard formats for compressing video. The standards associated with the group include MPEG-1, MPEG-2 (used in DVD movies), and MPEG-4 (used sometimes to further compress DVD movies onto CD-ROM media). There are other MPEG standards as well. MPEG standard are typically not open standards, and require licensing fees. MPEG files in Windows use a “.mpg” file extension.
- Message Transfer Agent. In the X.400 Message Handling System this is a program that stores and forwards messages between different mail servers. The MTA is the software that resides on email servers, and is responsible for relaying your email messages to other mail servers as well as receiving email messages from other email servers. Sendmail, Qmail, and Micsorosft Exchange are examples of MTAs.
- Mean Time Between Failure. A time normally given in hours that predicts the failure rate of a device, based on manufacturer’s laboratory stress tests and in-the-field averages. The larger the number the better.
- Maximum Transmission Unit. The largest size (in bytes) that a data packet can be when sent over a TCP/IP or frame-based network. Ethernet typically uses an MTU of 1,500 bytes, while the standard Internet MTU is 576 bytes. Using a higher MTU is recommended for fast networks, while slower or more congested networks need a smaller MTU, as there is a greater chance that not all of the packet will make it through at once. Using a small MTU on a fast network causes a lot of extra traffic to be generated, as the packet has to be split into smaller pieces, which increases the need for more conversations in order for the data to be transmitted.
- Memory Leak
- A condition where a program or subroutine continues to request more memory from an operating system and doesn’t tell the operating system when it is no longer using the memory. Programs with memory leaks can end up using all of the memory available, or at least enough to cause performance problems. Memory leaks in programs are fixed by including proper memory management techniques in the software source code.
- Network Attached Storage. The use of specialized devices that function simply as hard drives connected to a network. NAS devices typically consist of one or more hard drives in a housing that contains a simple operating system and a network connection. The use of NAS devices allows for cheaper and more easily expandable (scalable) storage without requiring more complex and expensive multi-purpose servers to do the work of delivering data to network users.
- Network Address Translation. A method that network administrators use to extend their IP addressing to support more addresses than they own. The interior network uses one addressing scheme, and the exterior network uses the standard IPv4 Internet addressing. NAT devices can be routers, firewalls, or proxy-servers. To program a NAT device you must supply translation rules for how interior IP addresses are displayed to the outside world. You could, for example, set your firewall to act as if all traffic coming from inside your corporate network was coming from the firewall’s IP address. Typically, IP addresses on the inside of a NAT device are private IP addresses, while only public IP addresses are visible outside of the NAT device. This is a common technique used on firewalls to help secure corprate networks.
- Network Time Protocol. A protocol running over TCP/IP port 123 that is designed to synchronize clocks on servers, workstations, and other network nodes. You can set up a strata of NTP servers and NTP clients. Clients receive time data from the NTP server, and can adjust their clocks as necessary. Ideally the server is connected to some type of atomic clock that keeps regular time.
- Name Server
- A server that runs DNS Name Services. (See DNS). There are two types of name servers: internal name servers (name servers that only resolves internal hostnames and IP addresses) and public name servers (name servers that are officially registered and recognized by the Internet). Internal name servers typically advertise hostnames and/or IP addresses to users inside a specicif DNS zone (typically a company or organization). Registered (public) name servers advertise hostnames and/or IP addresses to the entire Internet.
- The purposeful manipulation of matter at the atomic level to achieve a defined goal. Atomic constructs can be measured in nanometers. Nanotechnology is already being used to send a group of tiny machines into a person’s bloodstream and free up clogged arteries. Sci-fi authors fear that a bunch of tiny nano-war machines could be built that could unintentionally change the entire earth into a gray blob of nano-devices.
- Internet Etiquette. There is an informal code of conduct that most people abide by on the Internet. Usually people that break the code are the victims of flame emails or communications. Netiquette includes not sending email or messages in ALL CAPS or with too many exclamation points!!!!!!!!!!!!!!, or asking repetitive questions in forums that have FAQs posted. Sending SPAM is also a violation of netiquette. You’re not legally obligated to follow proper netiquette, but you may have an easier time communicating with others over the Internet if you do. Of course, we expect all Neptune.Net users and customers to set a good example by following proper netiquette.
- A user that is brand new to the Internet, and most-likely hasn’t been indoctrined in netiquette.
- Open DataBase Connectivity. A standard API for communicating with database servers. There are different ODBC drivers supporting most of the major database servers, such as Oracle and Microsoft SQL Server. If you program to ODBC you get the advantage of (theoretically) being able to easily use your application on different databases without reprogramming. However, ODBC drivers are not always perfect.
- Open Source
- Software that can be freely distributed and must be distributed along with its source code. Thus the source can easily be modified, and programs can be altered to fix bugs or add features. Depending on the Open Source license (see FreeBSD license and GNU Public License), you may be unable to redistribute altered code or charge money for the distribution of the software. Some popular examples of Open Source software are Linux and Mozilla; an example of software that is not Open Source is Micsrosoft Windows.
- PHP Hypertext Preprocessor. The PHP Hypertext Preprocessor is a programming language that allows web developers to create dynamic content that interacts with databases. PHP is basically used for developing web based software applications. And yes, the first P in the acronym does indeed stand for PHP!
- Point-to-Point Tunneling Protocol. PPTP is a protocol (set of communication rules) that allows corporations to extend their own corporate network through private tunnels (encrypted connections) over the public Internet. In essence, a corporation can use a Wide-Area Network as if it were a single large Local Area Network. A company no longer needs to lease its own lines for wide-area communication but can securely use a public network such as the Internet. This kind of interconnection is known as a Virtual Private Network (VPN).
- The act of sending an email to a user falsely claiming to be an established legitimate enterprise in an attempt to scam the user into surrendering private information that will be used for identity theft. The email directs the user to visit a Web site where they are asked to update personal information, such as passwords and credit card, social security, and bank account numbers, that the legitimate organization already has. The website, however, is bogus and set up only to steal the user’s information. Phishing, also referred to as brand spoofing or carding, is a variation on “fishing”, the idea being that bait is thrown out with the hopes that while most will ignore the bait, some will be tempted into biting.
- The information stored for a single grid point in a digital image. A complete digital image – such as a JPEG or a GIF image – is a rectangular array of pixels.
- This references the type of computer keyboard used – which is based on the old typewriter keyboard layout. QWERTY derives its name from the set of keys on the top row of alphabetic characters (read from left-to-right) of a standard typwriter or computer keyboard.
- In general, a query (noun) is a question, often required to be expressed in a formal way. In computers, a query is what a user of a search engine or SQL database enters to initiate a search. To query (verb) means to submit a query (noun). A SQL database query can be either a select query or an action query. A select query is simply a data retrieval query; an action query can ask for additional operations on the data, such as insertion, updating, or deletion. Languages used to interact with databases are called query languages, of which the Structured Query Language (SQL) is the industry standard.
- In general, a queue is a line of people or things waiting to be handled, usually in sequential order starting at the beginning or top of the line or sequence. In computer technology, a queue is a sequence of work objects that are waiting to be processed. For example, CPUs process (or execute) a series of commands that are stacked up in the processor queue. Naturally, multi-processors can process the processor queue much faster than a single-processor. Servers also reply to requests that are stacked up in the queue, usually on a first-come, first-serve basis. Queue management is an integral part of system/network performance tuning.
- Redundant Array of Inexpensive Disks. A method of linking multiple storage devices (hard disk drives) together such that they function as a single logical unit. RAID requires all drives to be of the same size, as compared to JBOD setups. RAID can be used for increased performance, but is also used to increase redundancy. There are 6 basic levels of RAID configurations – RAID 0 through RAID 5; there is also a compound version of RAID, called RAID 10, which combines RAID 1 and RAID 0 levels. Although RAID levels 2, 3, and 4 are also available, they are seldom used.
- RAID 0
- RAID 0 is also known as disk striping, the form of RAID combines two or more hard drives into a single logical drive. All data is simultaneously written in equal-sized blocks to each disk drive member in the RAID 0 stripe, thus increasing disk I/O performance by the number of disk drive members in the RAID 0 stripe. RAID 0 configuration sacrifices redundancy for raw speed. The more drives you use the faster your logical drive will be. The overall available disk storage capacity on the logical drive is the sum of the space on all of the disk drive members used in the RAID 0 stripe. If drives are of disparate sizes, RAID 0 generally only uses a piece of the drive equal to the smallest drive. If one drive dies, you lose all of the information on the entire RAID, so use RAID 0 with care.
- RAID 1
- There are two forms of RAID 1: disk mirroring and disk duplexing. Disk mirroring involves two hard drives that are on the same drive controller. The same data is written to both drives, so disk write operations are slower because you must write data to two drives. Disk read operations are the same speed, as if you only had one drive. Disk duplexing is much like disk mirroring, but each drive is on a separate controller. This speeds up the normally slow write operations while also offering an additional level of redundancy, in case one of your controller cards dies. With RAID 1 you get half the space you paid for because you’re writing twice as much data; however, if one of the disk drive crashes, the mirrored data on the other disk drive is still available.
- RAID 10
- This form of RAID was originally called RAID 1+0, and is now commonly referred to as RAID 10. Basically, this is a bunch of RAID 0 drives mirrored with RAID 1 configuration. Hence you get the speed benefits of RAID 0 with the redundancy benefits of RAID 1. The only problem is that you use a lot of drives to do it. As with RAID 1, you only get half of the space that you’ve paid for. Of course it may be worth it if you can rest easier at night. RAID 10 is generally a bit faster than RAID 5, but twice as expensive.
- RAID 2
- This level of RAID uses striping across disks with some disks storing error checking and correcting (ECC) information. It has no advantage over RAID-3.
- RAID 3
- This type uses striping and dedicates one drive to storing parity information. The embedded error checking (ECC) information is used to detect errors. Data recovery is accomplished by calculating the exclusive OR (XOR) of the information recorded on the other drives. Since an I/O operation addresses all drives at the same time, RAID 3 cannot overlap I/O. For this reason, RAID 3 is best suited for single-user systems with long record applications.
- RAID 4
- This type uses large stripes, which means you can read records from any single drive. This allows you to take advantage of overlapped I/O for read operations. Since all write operations have to update the parity drive, no I/O overlapping is possible; therefore RAID 4 offers no advantage over RAID 5.
- RAID 5
- A RAID 5 configuration utilizes three or more hard drives and stripes the data across them, much like RAID 0. The difference is that parity information is striped across the drives as well, so if member disk drive crashes, the information can be reconstructed from the parity information. For example, with four disk drives, data is read from and written to a stripe that spans all the member drives evenly. When data is written, parity data is also written to a separate parity stripe. The amount of space required by the parity stripe in this example will take up 1/4 of the RAID 5 disk capacity. If your RAID 5 configuration consists of 5 member disks, then the amount of space required by the parity stripe will take up 1/5 of the RAID 5 disk capacity. In the 4 disk example, if one drive fails, you get a mix of parity and data on the remaining 3 disk drives, and the system can reconstruct all of the data from the failed disk drive. While the data is being reconstructed the RAID operates in “degraded mode” and is slower than normal. To reconstruct the data you must remove the failed drive and replace it with another, or use a “hot spare.” During reconstruction the RAID 5 array continues to be slow. Once the RAID is reconstructed performance returns to normal levels. RAID 5 performance is similar to RAID 0 performance, but a bit slower due to the parity information. Performance increases, like RAID 0, when more drives are added. With RAID 5 you get most of the space that you’ve paid for, minus one drive’s worth. A common option with RAID 5 is the hot spare, where a drive sits idle until needed. If you lose a drive, the hot spare takes over and the RAID is rebuilt automatically. Of course you still get the performance penalty during the data reconstruction stage, but it can be configured to happen automatically, which is very convenient in case a disk drive fails in the middle of the night.
- An acronym for Remote Access Trojan. A Trojan (as in Homer’s Trojan Horse) is a piece of software that when installed, will allow people with less-than-honorable intentions remote access to your PC. RATs are usually spread via email attachments and/or infected websites; RATs are the latest techniques used by zombie masters to increase recruitment for their botnet armies.
- A program (usually delivered as an attachment to an email) that if opened, will encrypt the unsuspecting recipients’ personal data in such a way that the data is rendered useless. The perpetrator will then offer to decrypt the data for a specified amount of money. In other words, this is a high-tech form of extortion.
- Small Computer Systems Interface. Pronounced “skuzzy” – this is a standard data pathway used mostly for hard drives and CD-ROM drives (or any other device that can be connected to a SCSI bus, such as scanners or printers). It is the fastest (and the most flexible) method of interfacing with hard drives. It comes in numerous varieties, and is mainly used in servers and high-end workstations. SCSI drives are much more expensive than IDE drives, but SCSI drives can have features, like 15,000 RPM spin speeds and 5-year warranties, that IDE drives currently do not. SCSI disk drives can also handle multiple simultaneous disk I/O operations, resulting in faster seek times and write times.
- Symmetric Digital Subscriber Line. SDSL is a broadband technology for transmitting digital information at a high bandwidth on existing phone lines to homes and businesses. SDSL is the version of DSL where the upload speeds and download speeds are the same.
- Simple Message Transfer Protocol. This is the underlying protocol used by networked mail clients and mail servers; this is the protocol that makes email work. SMTP was introduced as a TCP/IP application circa 1980, and by convention, uses TCP port 25 to send (relay) electronic mail (email) messages. Since SMTP relays (mail servers) makes use of domain names, SMTP is reliant on DNS protocol working properly.
- (n.) Also spelled as spIM, spam over instant messaging (IM). Spim is perpetuated by bots that harvest IM screen names off of the Internet and simulate a human user by sending spam to the screen names via an instant message. The spim typically contains a link to a website that the spimmer is trying to market. Also referred to as instant spam or the less-intrusive sounding “IM marketing”.
(v.) To send someone spam through an instant messaging application.
A spimmer is the individual or organization responsible for sending spim.
- Much like spam and spim, as internet telephony becomes more popular with consumers, spit is sure to follow. SPIT is an acronym that stands for Spam over Internet Telephony or Voice-Over IP (VoIP) that involves making phone calls using the Internet.
- Secure Socket Layer. A protocol that allows for “secure” passage of data. It uses public key encryption, including digital certificates and digital signatures, to pass data between a browser and a server. It is an open standard and is supported by most modern browsers and web servers.
- A socket is network connection that consists of an IP address and a port number. For example, a socket could be port 25 on 10.49.36.119. In hardware context, socket refers to the pin grid array interface that forms the connector receptacle that chips and CPUs can plug into, such as the sockets on a motherboard.
- A technique used by spammers to circumvent messages being caught by spam filters, usually by intentionally misspelling key words like “Viagra” (E.G., viakgra) in order to get around users’ spam filters. Since Neptune’s spam filter systems are based on artificial intelligence, we can easily recognize spamoflage attempts.
- Impersonating or masquerading as a user other than yourself. Some SPAM programs use spoofing techniques to send unsolicited email that looks like you sent it to yourself: your name appears on the “From” line as well as the “To” line. For example, Joe Schmoe might receive a message addressed to “email@example.com” that purports to be from “firstname.lastname@example.org.” In many cases, a message may appear to be sent from your exact email address. Spoofing is also an attempt to gain access to a system by posing as an authorized user. Synonymous with impersonating, masquerading or mimicking.
- Any software that covertly gathers user information through the user’s Internet connection without his or her knowledge, usually for advertising purposes. Spyware applications are typically bundled as a hidden component of freeware or shareware programs that can be downloaded from the Internet; however, it should be noted that the majority of shareware and freeware applications do not come with spyware. Once installed, the spyware monitors user activity on the Internet and transmits that information in the background to someone else. Spyware can also gather information about email addresses and even passwords and credit card numbers.
Spyware is similar to a Trojan horse in that users unwittingly install the product when they install something else. A common way to become a victim of spyware is to download certain peer-to-peer file swapping products that are available today.
Aside from the questions of ethics and privacy, spyware steals from the user by using the computer’s memory resources and also by consuming bandwidth as it sends information back to the spyware’s home base via the user’s Internet connection. Because spyware is using memory and system resources, the applications running in the background can lead to system crashes or general system instability.
Because spyware exists as independent executable programs, they have the ability to monitor keystrokes, scan files on the hard drive, snoop other applications, such as chat programs or word processors, install other spyware programs, read cookies, change the default home page on the Web browser, consistently relaying this information back to the spyware author who will either use it for advertising/marketing purposes or sell the information to another party.
Licensing agreements that accompany software downloads sometimes warn the user that a spyware program will be installed along with the requested software, but the licensing agreements may not always be read completely because the notice of a spyware installation is often couched in obtuse, hard-to-read legal disclaimers.
- Transmission Control Protocol. The part of the TCP/IP suite of protocols that is responsible for forming data connections between nodes that are reliable, as opposed to UDP, or IP, which TCP is based on (which is by default connectionless and potentially unreliable).
- Transmission Control Protocol / Internet Protocol. The TCP/IP suite first saw use on the original Department of Defense Internet in the early 1970s. Its first implementation was amazingly successful, and it is still THE protocol of the Internet. In fact, it has grown even more, and is being used in private networks around the world. TCP/IP is a suite of communications protocols that allows communication between groups of dissimilar computer systems from a variety of vendors. It scales better than NetBEUI because NetBEUI is not routable, and beat out IPX/SPX as it was easier to route than that once-dominant protocol found in the Novell world.
- Trivial File Transfer Protocol. A network transfer protocol that allows you to connect to a device and download code onto it. For example, it can be used to download boot code onto a diskless workstation, or connect and download firmware updates to networking devices.
- Tag Image File Format. A bitmap graphics file format developed by Aldus in 1986 to provide a common format for scanners and FAXes. TIFF is mainly used for that purpose, desktop publishing, and as the data format for scanned faxes. TIFF files are usually designated with a “.tif” file extension.
- User Datagram Protocol. UDP transports data as a connectionless protocol, using packet switching. UDP is part of the TCP/IP suite of protocols. UDP is the part of the TCP/IP suite used by applications to transfer datagrams. It is also the part of TCP/IP responsible for port addresses. UDP got the short end of the stick in some ways in that its name isn’t included in TCP/IP, but would you really want to call it TCP/UDP/IP?
- Virtual Private Network. A collection of two or more LANs, usually separated by wide areas of geography that are securely connected via a public network such as the Internet. The inside of the LANs are usually shielded from the Internet using a private IP addressing scheme, and the outside (or public side) are assigned public IP addresses – which are known as VPN end points. VPN technology can be leveraged to offset the high cost of leased lines by using lower cost Internet connectivity solutions, such as DSL, ISDN and/or Cable modem.
- Wide Area Network. A communications network that uses media such as telephone lines, satellite dishes, or radio waves to span a large geographic area, such as a state, country or a continent (or even several continents). The Internet – a global network – would be the largest WAN.
- Wireless Local Area Network. A local area network that uses high frequency radio signals to transmit and receive data over distances of a few hundred feet, using ethernet protocols such as 802.11a, 802.11b, or 802.11g, etc.
- War Driving
- A computer cracking technique that involves driving through a neighborhood with a wireless-enabled notebook computer and mapping houses and businesses that have unsecured wireless access points.
- To access the data on a wireless network without authorization. (like Wireless Hacking, get it?).
- Wireless Fidelity. A term for certain types of wireless local area networks (WLAN) that use specifications conforming to IEEE 802.11a, IEEE 802.11b, and/or IEEE 802.11g. WiFi has gained acceptance in many environments as an alternative to a wired LANs. Many airports, hotels, and other services offer public access to WiFi networks so people can log onto the Internet and receive emails on the move. These locations are known as hotspots.
- A computer that has been implanted with a daemon that puts it under the control of a malicious hacker without the knowledge of the computer owner. Zombies are used by malicious hackers to launch DoS attacks. The hacker sends commands to the zombie through an open port. On command, the zombie computer sends an enormous amount of packets of useless information to a targeted Web site in order to clog the site’s routers and keep legitimate users from gaining access to the site. The traffic sent to the Web site is confusing and therefore the computer receiving the data spends time and resources trying to understand the influx of data that has been transmitted by the zombies. Compared to programs such as viruses or worms that can eradicate or steal information, zombies are relatively benign as they temporarily cripple Web sites by flooding them with information and do not compromise the site’s data. Such prominent sites as Yahoo!, Amazon and CNN.com were brought down in the summer of 2000 by zombie DoS attacks.
- A family of worms that made their debut in August 2005. Variants include Mytob, Esbot, Bobax and Rbot. These worms are yet another series of malware that exploits Microsoft buffer overflows. Neptune’s mail servers automatically filter out these unwanted worms.