Mar 1, 2004 12:00 PM, By Oliver Masciarotte

Just before the end of the year, I received an e-mail from my editor that read, “We have a feature on network storage systems that we're trying to figger out, [so] what we'd like from you, your mission if you agree to accept it, is a glossary of common storage and network terms. An IT glossary for the uninitiated pro audio folks. Whaddya think? A whole column of pedants in a box.” So began this month's “Bitstream,” a bass-ackward version of my usual offering. [Note that italicized words are terms that will be defined in the glossary, some in upcoming parts.
— Eds.]

Granted, I could never compete with the many excellent IT glossaries out there on the Web, but I've tried to gather the most common TLAs, techie phrases and geek-speak for your edification. For those who need a bit of a mental housecleaning, this month will either sweep away some cobwebs or increase your BBF by several orders of magnitude!

1394: See IEEE 1394.

802.11: See IEEE 802.nx.

AAC (Advanced Audio Codec): an, um, advanced version of the widely used MP3 perceptual sub-band/transform codec with additional tools to reduce the encoded data rate while simultaneously reducing encoding artifacts. It is formally known as MPEG-2 AAC.

AAF (Advanced Authoring Format): an ad hoc standard promoted by a coalition of vendors, chiefly Avid and Microsoft, along with developers and end-users. AAF is a wrapper file format.

Abstraction Layer: virtual programming buffers or software insulators that reside between the inner details of some individual resource and any external entity that may want to use that resource.

AC-3 (Audio Coded [Version] 3): Known to consumers as Dolby Digital, AC-3 is Dolby Laboratories' third generation of perceptual sub-band/transform codec. AC-3 is one of the mandated audio formats for both DVD-Video and ATSC Digital TV.

AIT (Advanced Intelligent Tape): a proprietary, mid-level, 8mm, helical-scan data tape standard from Sony that pioneered the feature of embedded memory in the cartridge.

AP (Access Point): An access point is a specially configured node on a wireless network that bridges the WLAN and a wired LAN.

API (Application Programming Interface): In the world of software, APIs are structured abstraction layers between the gory details of an individual application, operating system or hardware item and the world outside that software or hardware.

Application: executable software that provides useful tool(s) or function(s). In ye olden days, applications were called “programs.”

ASF (Active Streaming Format): a proprietary streaming format developed by Microsoft that provides streaming media services for the Windows Media framework.

ASP (Application Service Provider): a commercial entity that sells Web services.

Asset: To a rich media geek, it's a file that represents a valuable commodity or could be useful at some time in the future. Digital video or audio files are both considered assets.

Asymmetrical: refers to different, unequal or unbalanced data services, such as ADSL's send/receive data rate.

Asynchronous: refers, among other things, to techniques that do not require a common clock between communicating devices. Because IT streams and files are self-clocking, timing signals are derived from framing bits within the data stream.

ATM (Asynchronous Transfer Mode): a high-speed, fixed-packet data transport standard that interoperates with the switched circuit telephony network. Although providing valuable QoS features, ATM is being supplanted by less-expensive, IP-based standards that better interoperate with LANs and MANs.

Availability: as used by IT professionals, the amount of uptime. A product, system or service with three nines or better uptime is referred to as “high availability.”

Baseband: the lowest scale or simplest rate at which messaging occurs in a communications system.

Bit Rate: The data rate plus metadata and framing overhead make up the bit rate. Data rate refers to the “raw” or baseband data rate over time at which some file or stream is being delivered.

BBF (Bitstream Boggle Factor): the tendency for “Bitstream” readers' eyes to roll back into their heads as the dense geek-speak causes the reader to fall into a deep sleep.

Bridge to Bridge: a device, either hardware or software, that “bridges” or connects two networks of the same type or protocol.

Carrier Class: a marketing term used to denote a ruggedly constructed, full-featured product suitable for high-availability uses, as in, “This equipment is carrier class, buddy!”

CLEC (Competitive Local Exchange Carrier): the commercial entities created to compete with the ILECs when the Baby Bells were broken up. Covad and OneEighty Networks are two examples of CLECs.

Codec (Encoder/Decoder): a broad class of signal processing that first transforms a signal from the original storage method into another to improve the distribution in some way. After distribution, the signal, or in our case data, is transformed back into some semblance of the original. DTV, POTS and MP3 are all household examples of codecs.

Coding, Coding Method: This refers to transforming or changing the characteristics of a signal to make it more suitable for some intended application, usually for transmission from one location to another or for storage onto some medium that is different than the original medium. Coding can improve fidelity, optimize carrier bandwidth, increase essence carriage, improve security or provide error detection and correction.

COFDM (Coded Orthogonal Frequency Division Multiplexing): the modulation method chosen for U.S. domestic DAB service, some versions of ADSL and DTV services in Europe and Australia. COFDM is used to encode or impose digital audio data onto an analog carrier signal.

Co-Location: This refers to renting a designated space where a company's servers are situated, along with other companies in the same physical location. All machines share common HVAC and power. For physical security, each company usually has a lockable wire cage for its equipment.

DAB (Digital Audio Broadcast): the TLA for wireless digital radio services, also known as IBOC/DAB. DAB is terrestrial radio in that it's local or location-based, as opposed to national digital satellite “radio.” IBOC, or in-band on-channel, means that DAB shoehorns a digital stream into the existing AM and FM analog services, maintaining backward compatibility. DAB employs lossy codecs to reduce the transmitted data rate.

DAM (Digital Asset Management): a catch-all phrase that describes the process of managing digital “assets,” files whose essence is deemed valuable by an organization. DAM usually refers to audio, motion and still-image files in particular.

Data: Data is fundamentally any information of interest, but these days, the word data implies a binary (base 2 arithmetic), machine-readable representation of information.

Data Center: a physical structure, usually a stand-alone building, that is designed to house a multiplicity of computers. Data centers can be private, serving a single company or, more commonly, a public “utility” serving a variety of companies.

Data Rate: Often conflated with bit rate, data rate refers to the actual throughput or aggregate rate over time at which the essence is being delivered.

DDS (Digital Data Storage): DDS is a proprietary, entry-level performance, 8mm data tape standard originally based on the DAT, or digital audio tape format. DDS is close to the end of the product life cycle and is being supplanted by more modern formats such as VXA.

Directory Services: On a LAN or WAN, directory services provide an abstraction layer, identifying network assets including users, resources and the various policies assigned to each. The result is that resources and users are accessible without possessing the details about a particular resource or node. Directory services also abstract network topologies and protocols.

Distributed: For an IT nerd, distributed means decentralized rather than concentrated in one node, physical location or server.

DLT (Digital Linear Tape): a proprietary, mid-level, linear data tape standard originally developed by Matsushita.

To be continued next month…

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OMas almost bit off more than he could chew when he took on this month's assignment. He couldn't have completed this installment without the influence of Jean Luc Picard, er, Patrick Stewart's “engage”-ing spoken word recording of Charles Dickens' A Christmas Carol.

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