SA (see server appliance)

SA (Software Assurance)

A software license maintenance offering from Microsoft.

SAA (Systems Application Architecture)

IBM's name for the architecture once intended to unify its disparate computer

architectures.

SAIC (Science Applications International Corp.)

An IT and systems integration company, founded in 1969 and headquartered in San

Diego.

sales and operations planning (see S&OP)

sales configuration system (see SCS)

sales configurator — see SCS (sales configuration system)

sales force automation (see SFA)

SAM (software asset management)

A process for making software acquisition and disposal decisions. It includes

strategies that identify and eliminate unused or infrequently used software,

consolidating software licenses or moving toward new licensing models. See asset

management.

SAML (Security Assertion Markup Language)

An Extensible Markup Language (XML)-based mechanism that enables disparate

entities to exchange identity-related security information. This information is

presented as assertions about authentication, authorization or various attributes of

the identity in question. See XML.

SAN (storage area network)

A storage network that consists of two tiers: The first tier — the storage plumbing

tier — provides connectivity between nodes in a network and transports deviceoriented

commands and status. At least one storage node must be connected to this

network. The second tier — the software tier — uses software to provide valueadded

services that operate over the first tier.

SANS Institute

A research and education organization based in Bethesda , Maryland , that provides

information security training and certification. The acronym stands for "sysadmin,

audit, network, security."

Santa Cruz Operation (see SCO)

SAP

An enterprise resource planning (ERP) vendor based in Walldorf , Germany . The

letters "SAP" stand for "Systeme, Anwendungen, Produkte in der

Datenverarbveitung," German for "Systems, Applications and Products in Data

Processing." See ERP.

SAPI (Speech Application Programming Interface)

A Microsoft programming standard designed to help developers to incorporate

speech recognition and text-to-speech functions into applications.

satellite communications

The use of geostationary orbiting satellites to relay transmissions from one earth

station to another or to multiple earth stations.

SATS (semiconductor assembly and test services)

Services wherein which a supplier performs some or all of the operations associated

with semiconductor packaging, assembly and testing under contract to a customer.

SAX (Simple API for XML)

A public-domain alternative to Document Object Model (DOM) for enabling

programming languages to work with XML documents. SAX is application

programming interface (API) that uses "start events" and "stop events" to parse an

XML document so that an application can interact with it. In essence, it provides the

application with a "keyhole view" of the document without describing its overall

structure. See API, XML and DOM.

SCADA (supervisory control and data acquisition)

A system used in manufacturing for acquiring measurements of process variables

and machine states, and for performing regulatory or machine control across a

process area or work cell.

scalability

The measure of a system's ability to increase or decrease in performance and cost in

response to changes in application and system-processing demands. Examples would

include how well a hardware system performs when the number of users is

increased, how well a database withstands growing numbers of queries, or how well

an operating system performs on different classes of hardware. Enterprises that are

growing rapidly should pay special attention to scalability when evaluating hardware

and software.

Scalable Linear Recording (see SLR)

Scalable Processor Architecture (see SPARC)

Scalable Vector Graphics (see SVG)

scanner

A device that renders a printed image (such as a photograph or business document)

as a stream of bits for electronic image capture or transmission purposes.

scattering

A cause of signal loss in fiber-optic transmission. Scattering is the diffusion of a light

beam caused by microscopic variations in the material density of the transmission

medium.

SCE (supply chain execution)

A subset of supply chain management (SCM). SCE is a framework of executionoriented

applications that enable the efficient procurement and supply of goods,

services and information across enterprise boundaries to meet customer-specific

demand. In its broadest sense, SCE includes manufacturing execution systems,

warehouse management systems and other execution systems within the enterprise,

as well as throughout the supply chain. The logistics-oriented elements of SCE

include transportation management, warehouse management and supply chain

inventory visibility systems. See SCM.

schematic

A diagram that details the electrical elements of a circuit or system.

Science Applications International Corp. (see SAIC)

SCIV (supply chain inventory visibility)

A category of applications that allow enterprises to monitor and manage events

across the supply chain to plan their activities more effectively and pre-empt

problems. SCIV systems enable enterprises not only to track and trace inventory

globally on a line item level, but also submit plans and receive alerts when events

deviate from expectations. This visibility into orders and shipments on a real-time

basis gives enterprises reliable advance knowledge of when goods will arrive.

SCM (semiconductor contract manufacturing)

A service in which a supplier performs some or all semiconductor manufacturing

operations under contract to a customer. In its broadest sense, SCM can encompass

wafer fabrication, packaging, assembly and testing of semiconductor products.

SCM (software configuration management)

Also known as "software change management," SCM is a methodology for software

change request initiation and tracking, change impact analysis, distribution, version

control, security administration, and quality reviews.

SCM (supply chain management)

The process of optimizing the delivery of goods, services and information from

supplier to customer. SCM is a set of business processes that engages a tradingpartner

community in the common goal of satisfying the end customer. Functionally,

SCM encompasses both supply chain planning (SCP) and supply chain execution

(SCE) processes. See SCP and SCE.

SCO ( Santa Cruz Operation)

A company founded in 1979 and best known in the 1990s for its Unix-based

operating-system products. In 2001, SCO sold off its Unix business to Caldera and

changed its name to Tarantella (after the thin-client product it launched in 1997 and

retained after the Caldera deal). Caldera, in turn, changed its own name to SCO

Group to capitalize on the recognized SCO brand name.

SCOR (Supply Chain Operations Reference)

A supply chain management (SCM) reference model from the Supply-Chain Council.

It includes a common supply chain framework, terminology, common metrics and

benchmarks, and best practices. SCOR can be used as a model for evaluating,

positioning and implementing SCM software.

SCORM (Shareable Content Object Reference Model)

A reference model containing specifications for e-learning capabilities supporting

interoperability and accessibility, created in 1999 in an initiative led by the U.S.

Department of Defense working with other government agencies and the private

sector. SCORM was developed in support of the Defense Department's Advanced

Distributed Learning Initiative as a means integrating and the work of these

organizations into a common reference model. The model contains:

• A course structure specification based on Extensible Markup Language (XML)

• Runtime environment specifications, including an application programming

interface and data model

• Specifications for records containing course and content metadata

See e-learning and XML.

SCP (service control point)

The database at the apex of a Signaling System 7 (SS7) network, containing

information on how to process, route and bill calls. See SS7.

SCP (Supply Chain Planner)

A supply-chain-planning tool from i2 Technologies ( Irving , Texas ).

SCP (supply chain planning)

A subset of supply chain management (SCM), SCP is the process of coordinating

assets to optimize the delivery of goods, services and information from supplier to

customer, balancing supply and demand. An SCP suite sits on top of a transactional

system to provide planning, what-if scenario analysis capabilities and real-time

demand commitments. Typical modules include network planning, capacity planning,

demand planning, manufacturing planning and scheduling, distribution and

deployment planning, and transportation planning and scheduling.

SCPC (single channel per carrier)

A transmission system in which a physical channel is allocated solely to one carrier

for the duration of the transmission.

SCR (sustainable cell rate)

In asynchronous transfer mode (ATM), the average cell rate a source is allowed to

maintain. See ATM.

screen pop

A call center system function that populates an agent's screen with just-in-time

customer information.

screen sharing

A feature of data-conferencing and other real-time collaboration technologies that

enables multiple users to view the same document or computer screen

simultaneously. Unlike application sharing, screen sharing allows only one user,

rather than multiple users, to control the screen or document. See application

sharing.

SCS (sales configuration system)

A system used to automate the configuration of ship-to-order, assemble-to-order or

engineer-to-order products, and to configure product-related information, such as

pricing, discounts and customized financing plans. SCSs (also known as "sales

configurators") are designed to reduce complexity and improve productivity for

salespeople by helping them match customer needs to unique products and service

offerings.

SCSA (Signal Computing System Architecture)

A layered hardware/software architecture for building multivendor computertelephony

integration (CTI) systems. Originally defined by Dialogic, SCSA was later

handed off to the Enterprise Computer Telephony Forum (ECTF). See CTI and ECTF.

SCSI (Small Computer System Interface)

A peripheral interface for up to seven devices. SCSI provides a high-speed, parallel

data transfer of up to 40 megabits per second (Mbps) and has the advantage of

connecting multiple peripherals while taking up only one slot in the computer.

SCSI Over IP (see iSCSI)

SCSL (Sun Community Source Licensing)

The Sun Microsystems license model for Java. The agreement leverages a

community-based development model similar to "open-source software" initiatives

that have existed over the years.

SDH (Synchronous Digital Hierarchy)

A standard for digital transmission over optical networks in Europe . SDH is the

European equivalent of the Synchronous Optical Network (SONET), with transmission

speeds and network management suited to the European market. See SONET.

SDK (software development kit)

A set of development utilities for writing software applications, usually associated

with specific software environments (for example, the Java Development Kit).

SDLC (Synchronous Data Link Control)

An IBM-defined protocol used for serial (by bit) information transfer over a data

communications channel. Concerned with the lower two layers of the Open Systems

Interconnection (OSI) model (the physical and data link layers), SDLC was part of

IBM's Systems Network Architecture (SNA) attack on the diverse link controls, access

methods and terminal types that existed in the pre-SNA era. See SNA and OSI.

SDLT (Super Digital Linear Tape)

A Quantum storage product architecture that extends the capacity and transfer rate

of digital linear tape (DLT) drives. See DLT.

SDRAM (synchronous dynamic random-access memory)

A category of dynamic random-access memory (DRAM) in which memory access is

synchronized with the system bus data transfer rate The introduction of SDRAM in

the late 1990s enabled a major improvement in system performance over traditional,

asynchronous varieties of DRAM technology. See DRAM.

SDSL (symmetric digital subscriber line)

A digital subscriber line (DSL) technology that operates over voice-grade lines at 1.5

megabits per second one way, or 768 kilobits per second both ways, over an 8,000-

foot distance. See DSL.

SEA-ME-WE (Southeast Asia-Middle East-Western Europe 2)

A submarine cable network that went into operation in 1994, linking over one dozen

countries from France to Singapore .

SEA-ME-WE 3 (Southeast Asia-Middle East-Western Europe 3)

A fiber-optic submarine cable network that went into service in 1999, linking over 30

countries between Western Europe and Southeast Asia .

search engine

A tool that enables Web pages to be found and retrieved based on the words they

contain. Search engines use a searchable index of Web pages that is automatically

updated by spiders or Web crawlers and housed on a central server connected to the

Internet. Examples include Google, Yahoo and AltaVista.

search index

A machine-searchable matrix of documents used by a search engine.

SECAM (Sequential Couleur a Memoire)

A color television broadcasting system using 625 picture lines and a 50-hertz field

frequency, in which the two color-difference signals are transmitted sequentially

instead of simultaneously. It was developed in France and is also used in the former

Soviet Union . See NTSC and PAL.

second-generation office systems

The class of multiuser, time-sharing, integrated office systems introduced around

1983, including Digital Equipment's ALL-IN-1 and IBM's PROFS. These products were

largely superseded by client/server third-generation products of the 1990s.

secret key

The symmetric key used in secret-key cryptography. It is a secret shared between

communicating parties, but is not truly private. See secret-key cryptography,

private key and public-key cryptography.

secret-key cryptography

In this cryptography method (also known as symmetric-key cryptography), the

single key needed to encrypt and decrypt messages is a shared secret between the

communicating parties. The biggest problem with this method is that the secret key

must be communicated through an external mechanism separate from the

communication channel over which the encrypted text flows. In addition, secret-key

systems do not support digital signatures. These limitations are addressed in publickey

cryptography (see separate entry).

Secure Electronic Transaction (see SET)

Secure Hash Algorithm (see SHA)

Secure Hypertext Transport Protocol (see S-HTTP)

Secure Multipurpose Internet Messaging Extensions (see S/MIME)

Secure Sockets Layer (see SSL)

Security Assertion Markup Language (see SAML)

SEI (Software Engineering Institute)

A recognized source of research, process models and appropriate practices for

application development. Based at Carnegie Mellon University , the SEI uses its

Capability Maturity Model (CMM) as a framework for examining the adequacy of an

enterprise's processes and improving those processes. It also provides hands-on

experience to practitioners through groups such as software process improvement

networks. See CMM.

self-describing

A term denoting messages that contain not only data, but also metadata that

describes the format and the meaning (that is, the syntax and the semantics) of that

data. For example, Extensible Markup Language (XML) is a self-describing message

format that consists of tag/value pairs. See XML.

Self-Monitoring Analysis and Reporting Technology (SMART)

self-test

A feature in which a system tests itself — typically at predetermined times, such as

during system startup or shutdown routines — and issues an alert if any faults are

found. This feature often expedites service by pinpointing faulty equipment, saving

diagnostic time.

selling, general and administrative (see SG&A)

sell side

A general term encompassing services or processes associated with the vendor (as

opposed to buyer) side of business-to-business transactions, such as supply chain

management methods and tools.

SEM (Strategic Enterprise Management)

A suite of SAP analytical applications that support integrated planning, decision

making and performance monitoring. SEM uses multidimensional online analytical

processing (OLAP) functionality to process data held in SAP's Business Information

Warehouse. See OLAP.

semantics

The basic meaning of data items and the relationships among them. Semantic data

descriptions make it easier to develop application programs and to maintain the

consistency of data when it is updated.

semantic net

A type of knowledge representation used in some text mining or search tools.

Semantic nets are graphs in which nodes represent key phrases, and the thicknesses

of the links represent the frequency of their co-occurrence nearby in the same

document.

semiconductor assembly and test services (see SATS)

semiconductor contract manufacturing (see SCM)

Sequenced Packet Exchange (see SPX)

Sequential Couleur a Memoire (see SECAM)

serial

A term describing a sequential flow of bits over a single pathway. See serial

interface and serial transmission.

serial impact dot matrix (see SIDM)

serial interface

An interconnection that transmits information bit by bit rather than a whole character

at a time. It is much slower and cheaper than a parallel interface.

Serial Line Internet Protocol (see SLIP)

Serial Storage Architecture (see SSA)

serial transmission

A method whereby the bits of a character are sent sequentially on a single

transmission channel. See parallel transmission.

server

A system or a program that receives requests from one or more client systems or

programs to perform activities that allow the client to accomplish certain tasks. The

term usually denotes computers that provide specific services to other computers on

a network. Routing servers connect subnetworks of like architecture; gateway

servers connect networks of different architectures by performing protocol

conversions; and terminal, print and file servers provide interfaces between

peripheral devices and systems on the network.

server appliance

A type of computing appliance that creates, manipulates or provides information to

other network-connected computing devices. Unlike storage appliances, server

appliances use an application context for the creation, manipulation or provision of

information. Examples include Sun Microsystems' Cobalt Qube, Oracle's 8i Appliance

and Dell Computer's PowerApp.web. Potential server appliance functions include

database, e-mail, file storage and directory services. See computing appliance and

storage appliance.

Server Message Block (see SMB)

server virtualization

The pooling of server resources in a way that masks the physical nature and

boundaries of those resources from users or administrators.

service bureau

A company that processes various types of data for a client for a fee. For example, a

telephone service bureau typically provides call detail reporting (CDR) and callcosting

reports. See CDR.

service control point (see SCP)

service desk

A help desk that is equipped with the resources for resolving service requests and

problem calls. A service desk gives the customer service representative the ability to

efficiently diagnose, troubleshoot and correct technical-support problems (rather

than merely relaying a message or handing off the call to another party).

service-level agreement (see SLA )

service-level management (see SLM)

service-level objective (see SLO)

service-oriented architecture (see SOA)

service-oriented development of applications (see SODA)

service pack

A minor software product revision that contains feature updates or bug fixes, but not

enough new code to warrant a new version number.

service parts planning (see SPP)

service process optimization (see SPO)

serving area

1. The region surrounding a broadcasting station where signal strength is at or

above a stated minimum.

2. The geographic area handled by a telephone exchange, generally equivalent to a

local access and transport area (LATA). See LATA.

servlet

A server-side Java process that operates in conjunction with a Web server and offers

an alternative to using Common Gateway Interface (CGI) and server application

programming interfaces to communicate with Web server processes. Servlets are

independent of a given type of Web server, as the most prominent Web servers

support servlets. See Java.

session

1. The period during which an end user engages in dialogue with an interactive

computer system.

2. The period during which a communications link is established between two

communicating systems on a network.

session layer

Layer 5 of the Open Systems Interconnection (OSI) reference model for network

architectures. See OSI.

Session Initiation Protocol (see SIP)

SET (Secure Electronic Transaction)

A standard in conceived 1995 by Visa and MasterCard to ensure that all Internetbased

payment transaction details are encrypted, the parties authenticated,

acknowledgments fully recorded and the customer payment details made available

only to the bank. Due to its complexity and security flaws, SET failed to gain

widespread acceptance. Meanwhile, Visa and MasterCard have pushed ahead with

their own, separate standards: Verified by Visa and MasterCard Secure Payment

Application.

SFA (sales force automation)

The use of technology to automate the sales process. Technologies used in SFA

include laptop computers, personal digital assistants, contact databases and

interactive selling systems.

SFC (shop floor control)

A system of computers and controllers used to schedule, dispatch and track the

progress of work orders through manufacturing based on defined routings.

SG&A (selling, general and administrative)

A category of expenses reported in corporate financial statements.

SGML (Standard Generalized Markup Language)

An International Organization for Standardization (ISO) standard adopted in 1986 for

the markup of electronic documents, identifying the basic structural elements of a

text document. SGML addresses the structure of a document, not its format or

presentation. See ISO.

SHA (Secure Hash Algorithm)

An authentication algorithm developed by the U.S. National Institute of Standards

and Technology and National Security Agency, designed for use with digital

signatures.

Shareable Content Object Reference Model (see SCORM)

shared service center (see SSC)

shared services

The centralization and consolidation of multiple service departments or functions into

a single organization — often called a shared service center (SSC). Shared services

reduce personnel costs and build expertise. Consolidating to one central location or

process lowers cost and increases efficiency. See SSC.

Shared Virtual Array (see SVA)

shell

A user interface environment that is usually character-based (as opposed to a

graphical user interface), and is provided as a feature of some operating systems

(for example, Linux).

shielded twisted pair (see STP)

shim

A software modification inserted into an operating system or application, to intercept

the normal data flow and provide additional functionality. Often used by third party

vendors to provide enhanced networking features or intrusion detection functions.

Short Message Service (see SMS)

shrink-wrapped

1. A term used to refer to packaged software applications (from the shrink-wrapped

packaging typical of such products).

2. A term used to describe a software license agreement that is deemed accepted

when the user breaks a shrink-wrapped seal or opens an enclosed sealed

envelope in the package containing the software media, such as a floppy disk or

CD. A variant of this term, "click-wrapped," is used to refer to software license

agreements that are accepted electronically. See click-wrapped.

shop floor control (see SFC)

S-HTTP (Secure Hypertext Transport Protocol)

Also known as HTTPS, this is an extension of Hypertext Transport Protocol (HTTP)

that provides security services for transaction confidentiality, authenticity and

integrity between HTTP servers and clients. For the purposes of Internet browsers,

S-HTTP is a competitive alternative to the more widely used Secure Sockets Layer

(SSL) standard. Developed by Enterprise Integration Technologies (which was

acquired by Verifone in 1995), S-HTTP was designed for use in browser applications,

so it cannot be used to secure non-browser-based Internet applications.

SI (see system integration and system integrator)

SIC (Standard Industrial Classification)

A system of numeric codes defined by the U.S. government for the purposes of

identifying numerous business categories in a range of industry sectors, such as

agriculture, mining, manufacturing, wholesale and retail trade, and business

services.

sideband

A frequency band on either the upper or lower side of the carrier frequency within

which fall the frequencies produced by the process of modulation.

SIDM (serial impact dot matrix)

A type of printer, suitable for making carbon copies, but now largely obsolete.

signal

A physical, time-dependent energy value used for the purpose of conveying

information through a transmission medium, such as copper, fiber or air.

Signal Computing System Architecture (see SCSA)

signal filtering (see filtering)

signaling

The process by which a caller or equipment on the transmitting end of a

communication channel informs a particular party or equipment at the receiving end

that a message is to be communicated.

Signaling System 7 (see SS7)

signal-to-noise ratio (see SNR)

signature verification

A biometric technique that uses characteristics of a person's signature (including

pressure, pen lifts, and speed and direction of pen strokes) to authenticate identity.

It is less accurate than some other biometric approaches (such as fingerprint

recognition) but is popular in document authentication applications that have

traditionally used written signatures. Some growth may be fueled by the adoption of

pen-based devices (such as the Palm Pilot) that can double as a signature input

tablet.

sign-off (see log-off)

sign-on (see log-on)

SIIA (Software & Information Industry Association)

A software industry trade association based in Washington , D.C.

silicon on insulator (see SOI)

SIM (subscriber identity module)

A small, programmable smart card containing a cellular service subscriber's identity

key. The SIM contains codes to identify a subscriber to a digital mobile service and

the details of the special services the subscriber has elected to use. The SIM may be

fixed within the phone, or removable (enabling users to swap phones without

changing their subscriptions). The SIM is the key to security on Global System for

Mobile Communications (GSM) networks. In addition to GSM SIMs, two other types

have been developed: the removable user identity module (R-UIM), which can be

used in code division multiple access (CDMA) networks along with GSM ones, and the

universal SIM (USIM), designed for use in third-generation (3G) networks. See GSM,

smart card, R-UIM, CDMA, USIM and 3G.

SIMD (single instruction, multiple data)

A design for parallel computers characterized by instructions that can directly trigger

a large number (in parallel) of data operations on different data. Vector processors

fall into this category.

SIMM (single in-line memory module)

A small printed circuit board that plugs into a socket on a personal computer and

increases the available random-access memory (RAM). See RAM.

Simple API for XML (see SAX)

Simple Mail Transfer Protocol (see SMTP)

Simple Network Management Protocol (see SNMP)

Simple Object Access Protocol (see SOAP)

simplex

A form of data transmission in which signals travel in one direction only. See half

duplex and full duplex.

simulation

The use of a mathematical or computer representation of a physical system for the

purpose of studying the effects of various condition scenarios, or forecasting

outcomes. For example, historical information may be used to simulate future

alternatives for supply chain operations design.

single channel per carrier (see SCPC)

single in-line memory module (see SIMM)

single instruction, multiple data (see SIMD)

single-mode fiber

An optical fiber with a small core diameter, allowing the propagation of a single light

path.

single sign-on (see SSO)

SIO (strategic information office)

A business-unit-neutral information office whose role is to communicate the

importance of enterprise information management to all business units, generate

support for these initiatives, negotiate organizational and technological issues across

the enterprise, and enforce standards implementation and compliance at all levels of

the enterprise. Members of the SIO should have in-depth knowledge of, and

experience in, both business and technology, with at least one representative from

senior management.

SIP (Session Initiation Protocol)

A protocol used to initiate interactive communication sessions of various types —

including voice, video, chat, interactive games and virtual reality — between Internet

users. A proposed standard of the Internet Engineering Task Force (IETF), the

protocol is administered under the IETF's SIP Working Group.

SIPP (Stable Image Platform Program)

A program launched by Intel in June 2003. SIPP aims to give PC manufacturers and

enterprises greater platform stability and advanced notice of future PC desktop and

notebook changes.

SIS (student information system)

A system used in academic environments to enroll and register students, and to

track student information such as prior transcripts, courses taken, grades received

and progress toward a degree.

SITA (Societe Internationale de Telecommunications Aeronautiques)

A European provider of telecommunications and IT services to the airline industry,

headquartered in Geneva .

Six Sigma

A quality philosophy designed to dramatically improve the way enterprises address

customer and user requirements, while efficiently monitoring labor expenditures and

controlling costs. It was first developed at Motorola, with a focus on manufacturing

quality. The name derives from the goal of reducing out-of-specification product or

service delivery to the Six Sigma (i.e., less than one-in-a-million) level. While

ostensibly a quality program, Six Sigma is process-centric, rather than productcentric

— all business practices are examined and steps are taken to reduce or

eliminate variation.

SKU (stock-keeping unit)

A unique identification number that defines an item at the identifiable inventory

level; for example, in retail applications, the SKU may designate style, size and

color. A more detailed level would be at the serial number or unique identifier level.

SLA (service-level agreement)

An agreement that sets the expectations between a service provider and its

customer. It describes the products or services to be delivered, the single point of

contact for end-user problems and the metrics by which the effectiveness of the

process is monitored and approved.

slave

A computer or device that is entirely controlled by another computer or device (the

"master").

SLC (subscriber line charge)

An access charge paid by all telecommunications customers, established by the

Federal Communications Commission to help local-exchange carriers pay for their

installed network infrastructure and new development after the split-up of AT&T in

1984.

SLI (system-level integration)

A type of integrated circuit (also called a "system on a chip," or "SOC") that is

dedicated to a specific application, and that contains a computing engine, memory

and logic on a single chip.

SLIP (Serial Line Internet Protocol)

A protocol used for communication over an Internet Protocol (IP) network using a

serial line (such as telephone line, for dial-up remote access). SLIP is defined in

request for comment 1055 from the Internet Engineering Task Force. An enhanced

version of SLIP is provided by the Point-to-Point Protocol (PPP). See PPP.

SLM (service-level management)

The ongoing process of using service-level agreements (SLAs) to maintain high

quality in the provision of services — and to ensure that service-level objectives

(SLOs) and performance meet the changing needs of the recipient's business —

through continuous improvement of service activities, functions and processes. See

SLA and SLO.

SLM (software license management)

A mechanism for systematically ensuring compliance with vendors' software license

restrictions (for example, maximum users or maximum nodes).

SLO (service-level objective)

A goal defined in a service-level agreements (SLAs). SLOs are the objectives that

must be achieved — for each service activity, function and process — to provide the

best opportunity for service recipient success. See SLA .

SLR (Scalable Linear Recording)

A quarter-inch tape format developed by storage vendor Tanberg Data.

small and midsize businesses (see SMBs)

Small Computer System Interface (see SCSI)

small office/home office (see SOHO )

Small Value Payments Co. (see SVPCo)

SMART (Self-Monitoring Analysis and Reporting Technology)

A storage technology standard. Disk drives incorporating SMART technology can

monitor operating conditions and predict near-term degradation or fault conditions.

smart card

A plastic card that contains a memory chip and, optionally, a microprocesser. Smart

cards with microprocessors can add, delete and manipulate information on the card.

Those that contain only a memory chips, such as phone cards, can only add

information. By maintaining all necessary functions and information on the card,

smart cards do not require access to remote databases.

smartphone

A large-screen, voice-centric handheld device designed to offer complete phone

functions while simultaneously functioning as a personal digital assistant (PDA). See

enhanced phone and PDA.

SMB (Server Message Block)

A protocol designed to enable PCs to share files and printers over a network. It was

developed by IBM, Microsoft and Intel in the 1980s.

SMBs (small and midsize businesses)

Businesses which, due to their size, have different IT requirements — and often face

different IT challenges — than large enterprises, and whose IT resources (usually

budget and staff) are often highly constrained. For the purposes of its research,

Gartner defines SMBs using the following approximate size categories:

• Small business: In the United States, less than $50 million in annual revenue and

up to 100 employees; in Europe , less than $10 million in annual revenue and up

to 75 employees

• Midsize business: In the United States, between $50 million and $300 million in

annual revenue and between 100 and 1,000 employees; in Europe , between $10

million and $150 million in annual revenue and between 75 and 300 employees

SMDS (Switched Multimegabit Data Service)

A high-volume, high-speed, switched digital communications service supporting

speeds ranging from 1.544 megabits per second (Mbps) to 45 Mbps (with 155 Mbps

possible in the future). It is based on the Institute of Electrical and Electronics

Engineers' 802.6 standard for metropolitan-area networks (MANs). See MAN.

SME (small-to-midsize enterprise)

Another name for an SMB — see SMBs (small and midsize businesses).

SMI (supplier-managed inventory) — see VMI (vendor-managed inventory)

SMIL (Synchronized Multimedia Integration Language)

One of the first four Extensible Markup Language (XML) specifications, approved by

the Worldwide Web Consortium (W3C) in 1998, along with XML, Document Object

Model and Mathematical Markup Language. The primary goal of SMIL is to decrease

the bandwidth required to transmit television-like multimedia content through the

Web. If adopted, SMIL will greatly enhance the ability of commercial content

providers to bring television-like consumer content to the Web. See XML and W3C.

S/MIME (Secure Multipurpose Internet Messaging Extensions)

An e-mail security standard promoted by RSA Security. The S/MIME method for

protecting and digitally signing e-mail encapsulates a message within a Multipurpose

Internet Messaging Extensions (MIME) envelope and uses RSA's Public Key

Cryptography Standard No. 7 (PKCS #7) to encrypt it. S/MIME specifies that X.509

certificates validate the correspondent's public keys and electronic signatures. See

RSA, MIME, PKCS and X.509.

SMP (symmetric multiprocessing)

A multiprocessor architecture in which all processors are identical, share memory

and execute both user and operating-system code.

SMR (specialized mobile radio)

A wireless communications technology that competes with analog cellular services.

In an SMR system, the base station equipment supplier is the licensee of the

transmitters. Users have access to the multiple channels of the network rather than

the limited number of channels of a private mobile radio network. Many users share

all of the available channels on a "first come, first served" basis.

SMS (Short Message Service)

A bidirectional paging function that is built into Global System for

Telecommunications (GSM) systems. Each message can be up to 160 characters

long. The network stores messages for several days (typically a maximum of 72

hours) and attempts to deliver the messages whenever the portable phone is

switched on. Confirmation of receipt is available as an option in some networks.

SMS (system-managed storage)

A architectural concept for the attachment, management and reconfiguration of

secondary storage. Among the basic design goals of SMS is the separation of logicaldevice

management from physical-device management.

SMS (Systems Management Server)

A system management software product from Microsoft. It is used for distributing

software, monitoring and analyzing network usage, and performing a variety of other

network administration functions.

SMT (surface mount technology)

An integrated-circuit mounting system that uses flat pads instead of pins, eliminating

the need to drill boards and making automated mounting easier.

SMTP (Simple Mail Transfer Protocol)

A messaging protocol governing e-mail transmission in Transmission Control

Protocol/Internet Protocol (TCP/IP) networks. It is a server-to-server protocol that

supports only text and cannot handle attachments. See TCP/IP.

SNA (Systems Network Architecture)

An IBM-developed network architecture, with layers similar to those of the Open

Systems Interconnection (OSI) network reference model (see OSI). The layers

isolate applications from system network services, enabling users to write

applications independent of the lower networking layers.

SNAP (System Network Assurance Program)

A security industry certification program established by the SANS Institute. It

consists of a standard series of briefings, courses and tasks used to demonstrate a

more-detailed technical body of knowledge.

SNIA (Storage Networking Industry Association)

A storage network trade association headquartered in San Francisco .

sniffer

A network management tool that monitors data packets on a network to help

administrators ensure message integrity and service quality.

SNMP (Simple Network Management Protocol)

A Transmission Control Protocol/Internet Protocol (TCP/IP) protocol governing

network management and the monitoring of network devices. Strictly speaking,

SNMP is the Management Information Base (MIB) described in the SNMP standard;

extensions to this MIB proposed by the Electronic Messaging Association permit the

monitoring and reporting of all conforming messaging components through standard

SNMP management tools for network components.

SNOMED (Systematized Nomenclature of Medicine)

A nomenclature created by the College of American Pathologists (CAP) for use in

pathology. SNOMED has gradually been extended to cover other domains of

medicine. The SNOMED controlled medical vocabulary (CMV) contains over 150,000

terms and includes coverage for numerous medical specialties. The most recent

versions released by CAP's SNOMED division are SNOMED Clinical Terms (SNOMED

CT) and SNOMED Reference Terminology (SNOMED RT). See CMV, SNOMED CT and

SNOMED RT.

SNOMED CT (Systematized Nomenclature of Medicine Clinical Terms)

A version of the Systemized Nomenclature of Medicine (SNOMED) controlled medical

vocabulary (CMV) released in January 2002 by the College of American Pathologists '

SNOMED division. It combines the content and structure of the SNOMED Reference

Terminology (SNOMED RT) CMV with version 3 of the Clinical Terms CMV from U.K.

National Health Service. See SNOMED and SNOMED RT.

SNOMED RT (Systematized Nomenclature of Medicine Reference

Terminology)

A version of the Systemized Nomenclature of Medicine (SNOMED) controlled medical

vocabulary released in January 2002 by the College of American Pathologists '

SNOMED division. SNOMED RT was designed to help aggregate and integrate medical

information within electronic medical records. See SNOMED.

SNR (signal-to-noise ratio)

The power of a signal relative to channel noise (that is, interference).

SOA (service-oriented architecture)

An application topology in which the business logic of the application is organized in

modules (services) with clear identity, purpose and programmatic-access interfaces.

Services behave as "black boxes": Their internal design is independent of the nature

and purpose of the requestor. In SOA, data and business logic are encapsulated in

modular business components with documented interfaces. This clarifies design and

facilitates incremental development and future extensions. An SOA application can

also be integrated with heterogeneous, external legacy and purchased applications

more easily than a monolithic, non-SOA application can.

SOAP (Simple Object Access Protocol)

A protocol introduced by a group of vendors led by Microsoft. Designed to be simple,

it creates transparent mapping of the Distributed Component Object Model (DCOM)

interface definition language and Extensible Markup Language (XML) definitions. It

provides the key transport technology for Web services, the next-generation

paradigm for delivering applications as a set of Internet-enabled services. See

DCOM, XML and Web services.

SOC (system on a chip) — see SLI

Societe Internationale de Telecommunications Aeronautiques (see SITA)

Society for Worldwide Interbank Financial Telecommunication (see SWIFT)

socket

A concept used as part of the interprocess communications model defined in the Unix

and Linux operating systems. A socket specifies the end points of a two-way channel

that enables processes to exchange information.

SOCKS

An Internet Engineering Task Force standard for IP-based security and policy

management (the name is short for "socket server"). SOCKS enables administrator

to set user-access policies based on specific protocols, such as Hypertext Transport

Protocol.

SOD (statement of direction)

A vendor's announcement of future plans.

SODA (service-oriented development of applications)

The use of software services to create applications. Software services are

components that allow a developer to create programmatic interfaces that can

access underlying platform models, such as .NET or Java 2 Enterprise Edition (J2EE),

without having to be specific to any single model. See .NET and J2EE.

softswitch

A type of network-switching technology. Softswitches are software-based products

used to control communications networks.

software

Programs that control computer hardware. The two primary categories are system

software (which governs the workings of the computer itself, such as the operating

system and utilities) and application software (which performs specific tasks for the

user, such as word processing, spreadsheets and accounts payable).

software asset management (see SAM)

Software Assurance (see SA)

software configuration management (see SCM)

software development kit (see SDK)

Software Engineering Institute (see SEI)

Software & Information Industry Association (see SIIA)

software license management (see SLM)

software maintenance

Updating software, adding new functions, fixing bugs and solving problems.

Technology vendors often sell a maintenance contract with their software. This

contract is usually calculated as an annual fee based on some percentage of the total

software cost. It generally provides for overall support and maintenance of a

software product, including applications. Support may include telephone assistance

time as well.

software process improvement (see SPI)

Software Process Improvement Network (see SPIN)

software token

A software component that restricts the use of a specific ID/password combination to

the machines on which the token is installed. Software tokens can be installed over

the Internet on additional machines for a single session, or semipermanently, by

providing the token server with the answers to a randomly ordered set of questions

defined by the user at the time he or she initially enrolled in the authentication

system. Such questions might include, "What is your mother's maiden name?" or

"What was your roommate's nickname in your first year of college?"

SOHO (small office/home office)

A market segment for office equipment or computing peripherals (such as printers or

copiers). Products targeted to the SOHO market tend to be lower in price and

functionality than those designed to support large, corporate office environments.

SOI (silicon on insulator)

A type of integrated circuit substrate material that features an insulating oxide layer

on top of the silicon wafer, and another silicon layer on top of the oxide. Advantages

over previous generations of substrate materials include lower power consumption

and faster performance.

solid-state

A general descriptive term for electronic components (such as semiconductors) that

control current without the use of moving parts.

solid-state disk (see SSD)

SONET (Synchronous Optical Network)

A International Telecommunications Union standard for high-speed communications

over fiber-optic networks. It offers synchronous transmission at speeds up to

multigigabit rates — defined at various "Optical Carrier" (OC) levels (see OC-N) —

and includes features to enable multivendor interoperability, improved

troubleshooting and network survivability. As standard that operates at Layer 1 of

the Open Systems Interconnection (OSI) network model, it is a foundation for

Broadband Integrated Services Digital Network (B-ISDN) services. See OSI and BISDN.

S&OP (sales and operations planning)

A formal planning process used to determine the sales and operations strategy that

best meets all aspects of the enterprise's objectives. The SOP process mediates

sales, marketing, finance, operations and logistics objectives to formulate a single,

achievable plan for the near-term — usually under one year.

SOP 98-1 (Statement of Position 98-1)

A U.S. standard used to account for the cost of developing and maintaining software

in-house. Under SOP-98-1, approved by the American Institute of Certified Public

Accountants 1998, legacy software should be accounted for as an internal

maintenance expense — but if a company significantly enhances a system's

functionality, that work may be capitalized.

source routing

A technique used in local-area networks (LANs) in which the source of the frame

specifies the route that the frame has to follow; the source furnishes a routing

information field that designates the entire route to the destination.

sourcing

The procurement of resources — whether from internal or external sources — to

accomplish business objectives. Sourcing purely from external sources is known as

"outsourcing" (see outsourcing).

sourcing strategy

The set of scenarios, plans, directives and decisions that define and integrate the

internal and external resources required to fulfill an enterprise's business objectives.

SOW (statement of work)

A document that provides comprehensive descriptions of required services — along

with realistic information concerning the current environment — to ensure that

vendors deliver what the enterprise needs at the price that has been negotiated. The

essential elements of a statement of work include:

• Description of service

• Service environment

• Service levels and credits

• Roles and responsibilities

• Project resource usage

• Pricing information

SP (see service pack)

space segment

The segment of a satellite communications system that includes the satellites

themselves, and the tracking, monitoring and control functions associated with them.

It excludes any ground equipment.

spam

Electronic messages (such as electronic mail, newsgroup or bulletin board messages)

flooded to many users indiscriminately. The term is most commonly used in

reference to unsolicited commercial e-mail.

spanning tree

A technique used for bridging local-area networks without loops, as defined in the

Institute of Electrical and Electronics Engineers' 802.1d standard. The spanning-tree

algorithm ensures that only one path connects any pair of stations, selecting one

bridge as the root bridge from which all paths are considered to radiate.

SPARC (Scalable Processor Architecture)

A reduced instruction set computer (RISC) architecture developed by Sun

Microsystems and used in the Sun workstation family. SPARC chips are available

from several semiconductor manufacturers, as Sun positions SPARC as a de facto

standard.

spare-parts planning — see SPP (service parts planning)

SPC (statistical process control)

Maintaining or improving process capability by employing statistical techniques to

analyze process outputs and provide feedback for process control loops. See

process control.

speakerphone

A telephone device that has a speaker/microphone unit, allowing hands-free

conversation.

speaker verification

A biometrics-based alternative to typed passwords or personal identification

numbers. A computer verifies the identity of an individual by matching his or her

spoken voice to an electronically captured voice sample (analogous to a unique

fingerprint).

SPEC (System Performance Evaluation Cooperative)

A vendor consortium that selects and standardizes benchmark programs submitted

by members or others, for the purpose of rating and comparing the performance of

processors.

SPECfp (SPEC floating point)

A benchmark established by the System Performance Evaluation Cooperative (SPEC).

It measures processor speed at handling floating-point operations. See SPEC.

specialized mobile radio (see SMR)

SPECint (SPEC integer)

A System Performance Evaluation Cooperative (SPEC) benchmark to measure the

integer performance of a processor. See SPEC.

spectrum

A continuous range of frequencies, usually wide in extent, within which waves have

some specific common characteristics.

Speech Application Programming Interface (see SAPI)

speech circuit

A circuit designed for the transmission of speech, either analog or encoded, but

which can also be used for data transmission or telegraphy.

speech recognition

A computer's ability to convert spoken input into text, or to interpret spoken

commands (also known as or "automatic speech recognition" or "voice recognition").

Special software is used to digitize vocal sounds and compares them to a library of

sound patterns. When matches are found, the computer can recognize those words

as though they had been typed on a keyboard. Applications for speech recognition

include dictation software and interactive voice response (IVR) systems. The

technology generally falls into three categories along a continuum:

• Command systems were the earliest and simplest form; the computer learns a

small number of voice commands like "open file" or "print document," freeing the

user from having to use a keyboard or mouse to perform those tasks.

• Discrete speech recognition, the second stage in this evolution, can be used for

dictation and other natural speaking conditions, but pauses are required between

words.

• Continuous speech recognition software is emerging today. These systems

understand natural speech without pauses, and their vocabularies and accuracy

will continue to expand and improve.

speed dialing

A telephone feature that enables phone numbers to be stored in advance, so that

they can be dialed automatically by entering a short (one- to three-digit) code, or by

pushing a special button on the handset.

SPI (software process improvement)

The practice of continuously improving an enterprise's software development

processes, typically through the use of a formal methodology, such as the Software

Engineering Institute's Capability Maturity Model (CMM). See CMM.

spider

A piece of software (also called a Web crawler) designed to follow hyperlinks to their

completion, and return information on Internet addresses passed.

SPIN (Software Process Improvement Network)

A best-practices group run by the Software Engineering Institute (SEI) that provides

hands-on experience to IT professionals. See SEI.

splitter

A simple device that takes one input and sends it to several identical ports without

amplification. Splitters are commonly used residentially for sharing telephone lines

between handsets and modems, or for using two televisions on one antenna or cable

point.

SPO (service process optimization)

Software designed to track and allocate the major resources of service companies or

departments — people, intellectual capital and time. Most SPO applications address

of six core areas of functionality:

1. Project initiation (opportunity management)

2. Engagement structuring

3. Engagement execution (project management)

4. Resource management

5. Knowledge management

6. A business-to-business exchange for procuring resources and collaborating with

clients and colleagues

Professional services administration (PSA) is a related term, but one that applies only

to external service providers (ESPs). SPO applies to internal service departments as

well as ESPs. See PSA.

spoofing

1. A process whereby a router responds to keep alive messages from a host rather

than passing them on the remote client, thus saving call charges. Used mainly in

Integrated Services Digital Network (ISDN).

2. Of an e-mail message or network packet, falsely claiming to be from an address

different from that from which it actually originated.

spooling

Temporary storage of batch data until it is ready to be handled (for example, by a

processor or printer).

spot beam

A satellite signal that is concentrated on a small geographic area.

SPP (service parts planning)

A specific aspect of supply chain planning (SCP) dealing with parts used to repair or

maintain products (also known as "spare-parts planning"). See SCP.

spread spectrum

A technology used in radio transmission, enabling multiple signals to be broadcast

simultaneously over a single frequency band. Forms include direct-sequence spread

spectrum (DSSS) and frequency-hopping spread spectrum (FHSS), both of which are

commonly used in wireless local-area networks (WLANs). See DSSS, FHSS and

WLAN.

SPSS (Statistical Package for the Social Sciences)

A statistical analysis software package invented in 1968, which became the founding

product of Chicago-based analytical-software firm SPSS, Inc.

SPX (Sequenced Packet Exchange)

A Novell NetWare session-based communications protocol used to govern the

transport of messages across a network. It is designed to provide reliable end-to-end

data transport, including error detection between two end-user devices.

SQL (Structured Query Language)

A relational data language that provides a consistent, English-keyword-oriented set

of facilities for data querying, definition, manipulation and control. It is a

programmed interface to relational database management systems (RDBMSs). IBM

introduced SQL as the main external interface to its experimental RDBMS, System R,

which it developed in the 1970s. SQL statements include:

• Data manipulation language (DML) statements: "select," "insert," "update" and

"delete"

• Data definition language (DDL) statements, including the "create" and "drop"

statements for tables and indexes

• Data control language (DCL) statements that control access and update

privileges: "grant" and "revoke."

SQL statements are called "dynamic" when they are not completely specified until

the program is executed, and "static" when they are completely specified when the

program is compiled. SQL is precise, because it is based on predicate logic, but is

difficult for average users to deal with, and its most fruitful position is as a protocol

for software-to-software connectivity, rather than for human-to-software access.

SRAM (static random-access memory)

A category of random-access memory (RAM) that is volatile (that is, does not retain

information when the power is turned off), and that has a minimum of four

transistors per memory cell. See RAM.

SRDF (Symmetrix Remote Data Facility)

An EMC storage feature that provides controller-to-controller remote-copy capability.

SRM (supplier relationship management)

A systematic approach to supplier evaluation, selection and ongoing relationship

management, with the goal of cutting the costs of goods and services and boosting

profits. SRM spans functional areas and enterprise boundaries, providing important

decision support processes and functions to purchasing departments and key

decision makers within the supply chain. It uses an extended-enterprise approach to

squeeze waste out of the supply chain and to re-engineer the processes that link

buyers and suppliers together.

SS7 (Signaling System 7)

The equivalent of a "central nervous system" for the public switched telephone

network (PSTN). It is used to control the PSTN and facilitate intelligent network (IN)

capabilities (see IN). SS7 enables:

• Calls to be directed and routed within and among networks.

• Advanced services (such as toll-free dialing, caller ID and local number

portability) to be enabled and delivered to end users.

• Operation, administration and management information to be collected for use in

back-office operation support systems.

SSA (Serial Storage Architecture)

An IBM architecture for disk subsystems. For most purposes, it is a single-source,

proprietary interface, especially useful for users who have standardized on RS/6000

systems with applications that require very high data rates that are not particularly

cache-friendly.

SSA (System Software Associates)

An enterprise resource planning (ERP) software vendor, headquartered in Chicago .

Once formally known as System Software Associates, the company's full name

became SSA Global Technologies following a corporate restructuring in 2000.

SSC (shared service center)

A process-driven, technology-leveraged service delivery facility set up within an

enterprise to provide expert staff, tools and procedures to foster continuous

improvement. As a result of globalization and the rise of decentralized, "virtual"

enterprises, SSCs have emerged as an efficient and cost-effective service delivery

model for a variety of business processes. The idea behind SSCs is to centralize

routine service and administrative activities — such as human resources and

procurement — that would otherwise be replicated in multiple locations.

SSD (solid-state disk)

A storage device with no moving parts. It typically includes one or more circuit

boards loaded with memory chips, and a controller that presents a standard disk

drive interface to the computer system.

SSL (Secure Sockets Layer)

An Internet security standard developed by Netscape Communications. SSL offers

session-level security — that is, after a secure session has been initiated, all

information transmitted over the Internet during that session is encrypted. SSL also

offers features such as server and client authentication as well as message integrity.

SSO (single sign-on)

A term used to describe technology that enables a user to access multiple computer

platforms (usually a set of hosts on the same network) or application systems after

being authenticated just one time.

SSP (storage service provider)

A company that provides computer storage capacity and management services. In

addition to the storage itself, SSPs typically offer periodic backup and archiving, and

some offer to consolidate data from multiple enterprise locations so that all locations

can share the data effectively.

Stable Image Platform Program (see SIPP)

stack

1. An area in memory for the temporary storage of information. Information stored

here is retrieved not by address, but rather in chronological or "last-in, first-out"

order.

2. A hierarchy of protocols — see protocol stack.

staging area

1. An architectural database construct used to move data from one style of

database to another (for example, from an operational data store to a data

warehouse or data mart). No user updating or analysis is performed on data in

the staging area; rather, its contents are accessed only through programmatic

means (for example, by data transformation or cleansing utilities).

2. A repository used by a Web content management system to store newly

developed content before it is deployed into production.

stalking horse

A conceptual model under which statements are posited, or ideas are advanced, for

the purposes of testing out new concepts and stimulating dialogue about them.

standard

A specification or practice that is widely accepted by users and adopted by multiple

vendors. Standards are critical to the compatibility of hardware, software and

communications technologies. They provide specifications to vendors that enable

them to create products that will work together. De jure standards are developed by

internationally or nationally recognized standards bodies. De facto standards are

created by vendors under a proprietary process, but are widely adopted by other

vendors and thereby achieve "standard" status.

Standard for the Exchange of Product Model Data (see STEP)

Standard Generalized Markup Language (see SGML)

Standard Industrial Classification (see SIC)

star network (see star topology)

star topology

A network topology in which each station is connected to a central station by a pointto-

point link, and communicates with all other stations through the central one.

start-stop

A type of data transmission in which each group of code elements corresponding to a

transmitted character is preceded by a start signal (which serves to prepare the

receiving mechanism for the reception and registration of character) and is followed

by a stop signal (which serves to bring the receiving mechanism to rest in

preparation for the reception of the next character).

stateful

A term describing technology that maintains, or refers to, information regarding the

"state" of a network session (such as source and destination address of packets

delivered as part of that session, and the protocol used). Some firewalls or other

intrusion detection technologies are said to use "stateful" packet inspection if they

maintain awareness of the state of a network session, and reject or accept certain

network packets based on that information.

stateless

A term describing a system or technology that operates without regard to

information concerning "state" of a communication session (such as source and

destination address of all packets delivered as part of that session, and the protocol

used). A stateless system or protocol does not maintain such state information from

one transaction or request to the next.

statement of direction (see SOD)

Statement of Position 98-1 (see SOP 98-1)

statement of work (see SOW)

static random-access memory (see SRAM)

station

One of the input or output points of a communications network. Examples include a

telephone in a voice network, or the point where a computer interfaces to a data

network (also called a node).

station message detail recording (SMDR) — see CDR (call detail recording)

statistical multiplexing

A time division multiplexing (TDM) technique in which time slots are dynamically

allocated on the basis of need — that is, slots are allocated to equipment that has

data to be transmitted. See TDM.

Statistical Package for the Social Sciences (see SPSS)

statistical process control (see SPC)

STEP (Standard for the Exchange of Product Model Data)

An international standards effort for defining the exchange of complete,

unambiguous product model data. The goal of STEP is not only neutral file exchange,

but also to serve as the basis for implementing, sharing and archiving entire product

databases.

stickiness

A term used to describe a Web site's ability to attract and hold visitors — or, more

generally, the features of any product or service that help attract and retain

customers.

STM (synchronous transfer mode)

A technique for multiplexing several circuits over transmission links and switches. In

STM, time is divided into slots or buckets, and circuits are given time units whether

or not they have any data to transmit. See ATM (asynchronous transfer mode).

STM (Synchronous Transport Module)

A system of fiber-optic transmission rates defined in the Synchronous Digital

Hierarchy (SDH) scheme (see SDH). STM levels are the European equivalent of

Synchronous Optical Network (SONET) Optical Carrier Level N (OC-N) hierarchy in

North America (see SONET and OC-N). Like those of OC-N, levels in the STM

hierarchy are ordered by the bit rate of their aggregated signals, with the number

after "STS-" representing the multiple of the 155 megabit per second (Mbps) STM-1

foundation rate (compared to 51.84 Mbps OC-1 foundation rate of SONET). Above

that, each level quadruples, as follows:

• STM-4: 622 Mbps

• STM-16: 2.5 gigabits per second (Gbps)

• STM-64: 10 Gbps

• STM-256: 40 Gbps

STM-1

A Synchronous Digital Hierarchy (SDH) specification for fiber-optic transmission at

155 megabits per second. STM-1 is the European equivalent of OC-3 in the North

American Synchronous Optical Network (SONET) system. See STM (Synchronous

Transport Module), SDH, SONET and OC-N.

STM-16

A Synchronous Digital Hierarchy (SDH) specification for fiber-optic transmission at

2.5 gigabits per second. STM-16 is the European equivalent of OC-48 in the North

American Synchronous Optical Network (SONET) system. See STM (Synchronous

Transport Module), SDH, SONET and OC-N.

STM-256

In the Synchronous Digital Hierarchy (SDH), transmission at approximately 40

gigabits per second. STM-256 is the European equivalent of OC-768 in the North

American Synchronous Optical Network (SONET) system. See STM (Synchronous

Transport Module), SDH, SONET and OC-N.

STM-4

A Synchronous Digital Hierarchy (SDH) specification for fiber-optic transmission at

622 megabits per second. STM-4 is the European equivalent of OC-12 in the North

American Synchronous Optical Network (SONET) system. See STM (Synchronous

Transport Module), SDH, SONET and OC-N.

STM-64

A Synchronous Digital Hierarchy (SDH) specification for fiber-optic transmission at an

approximate rate of 10 gigabits per second. STM-64 is the European equivalent of

OC-192 in the North American Synchronous Optical Network (SONET) system. See

SONET and OC-N.

STN (super-twisted nematic)

A type of liquid crystal display (LCD) technology. See LCD.

stock-keeping unit (see SKU)

stop word

A word ignored by a search engine. Different document bases and search engines

might employ different stop words, although most stop-word lists include common

conjunctions, articles and prepositions (such as "and," "or," "the," "a," and "of" in

English-language documents). See search engine.

storage appliance

A type of computing appliance that provides data to, or manages data for, other

network-connected computing devices. Unlike server appliances, storage appliances

provide or manage data without an application context. This category of computing

devices includes network-attached storage (NAS) and storage-area network (SAN)

devices. See computing appliance, server appliance, NAS and SAN.

storage area network (see SAN)

Storage Networking Industry Association (see SNIA)

storage service provider (see SSP)

store and forward

A type of transmission wherein data is stored in an intermediate location before

being transmitted over a network.

stored procedure

A limited form of remote procedure call (RPC) that enables procedural code to be

stored in a database management system (DBMS). The DBMS provides a facility for

storing procedural code associated with the database, and enforces its use during

any database operation. See RPC and DBMS.

STP (shielded twisted pair)

A pair of twisted transmission wires with a metallic shield to minimize interference.

STP (straight-through processing)

A system configuration in which a transaction (such as a payment, a trade or a

change to a residential phone service) is entered only once. Thereafter, it proceeds

in an automated fashion through the rest of its life cycle, which may include dozens

of steps in different application systems in various locations. The goal is to avoid rekeying

information, thereby reducing input errors and shortening the time to

completion.

straight-through processing (see STP)

Strategic Enterprise Management (see SEM)

strategic information office (see SIO)

strategic sourcing

The dynamic delivery of internal and external business- or IT-oriented resources and

services to meet business objectives. Strategic sourcing enables businesses to

manage innovation and to deliver process and services effectively and efficiently,

both to the internal organization and to business partners, clients and other external

constituencies.

stream cipher

An old concept for encoding data, originally implemented with simple

electromechanical or electrical circuits. A modern-day example of a stream cipher is

Rivest Cipher 4 (RC4). Stream ciphers work on a serial bit stream — rather than a

block of data, like a block cipher — and are thus naturally suited for electronic

transmission of data. See RC4 and block cipher.

streaming

One-way (either point-to-point or broadcast to multiple receivers) transmission of

video and audio content over the Internet or advanced wideband wireless networks.

structured analysis and design

A traditional, process-oriented approach to software system analysis and design

(also known as "structured analysis/structured design," or "SA/SD"). Structured

analysis and design uses a process-based methodology to ensure that designers

focus on requirements definition, business process analysis and data modeling before

proceeding to the design and construction phases of development.

structured analysis/structured design (SA/SD) — see structured analysis

and design

Structured Query Language (see SQL)

STS (Synchronous Transport Signal)

A hierarchy of transmission levels for electrical signaling in Synchronous Optical

Network (SONET) networks. STS levels are the "electrical equivalent" of SONET

optical carrier (OC) levels — that is, they are defined for electrical signals converted

to or from the optical ones (see SONET and OC-N). As such, the data rate for each

STS level is identical to its corresponding OC level, as follows:

• STS-1: 51.8 megabits per second (Mbps)

• STS-3: 155 Mbps

• STS-12: 622 Mbps

• STS-48: 2.5 gigabits per second (Gbps)

• STS-192: 10 Gbps

• STS-768: 40 Gbps

student information system (see SIS)

subnet

A portion of a network that shares the same network address as another portion

(although it may be physically independent of that portion), and that is distinguished

by a subnet number.

subportal

A commercial or enterprise portal that provides highly targeted aggregate content

and interactive capabilities, and focuses on a more narrowly defined segment than a

regular, general-interest portal. Subportals are hybrid environments in that they can

be deployed as intranet or Internet solutions, or a combination of both. See portal.

subscriber identity module (see SIM)

subscriber line charge (see SLC)

suite

A group of programs designed to work together, and which often use the same

underlying architecture.

Sun Community Source Licensing (see SCSL)

Sun ONE — see ONE (Open Net Environment)

SunOS

A older version of the Unix operating system from Sun Microsystems. SunOS was the

precursor to Solaris.

supercomputer

A high-performance computing (HPC) system designed for applications or

commercial functions that require extensive and rapid computational capabilities.

Supercomputer technologies include vector computing, superscalar symmetricmultiprocessing

and massively parallel processing (MPP). Applications that lend

themselves to the supercomputer platform include atmospheric simulation, nuclear

physics, and high-level decision support and online analysis. See HPC and MPP.

Super Digital Linear Tape (see SDLT)

Super Video Graphics Array (see SVGA)

supervisory control and data acquisition (see SCADA)

supplier-managed inventory (SMI) — see VMI (vendor-managed inventory)

supplier relationship management (see SRM)

supply chain execution (see SCE)

supply chain inventory visibility (see SCIV)

supply chain management (see SCM)

Supply Chain Operations Reference (see SCOR)

Supply Chain Planner (see SCP)

supply chain planning (see SCP)

Supranet

A Gartner term describing the emerging, ubiquitous network infrastructure that links

the "e-world" (the world of electronic devices, such as computers, phones and

televisions) and the "p-world" (the physical world of paper, houses, people, vehicles

and other objects) within natural human interactions. The Supranet is enabled by

four key phenomena:

• Embedded computers in many everyday objects

• Next-generation wireless networking, providing global indoor and outdoor

connectivity to the Internet

• Interfacing technologies that enable bidirectional communication between pworld

and e-world components (such as bar code scanning, speech recognition

and electronic identification)

• The design of applications that satisfy user needs in a natural way with

combinations of media and devices

surface mount technology (see SMT)

sustainable cell rate (see SCR)

SVA (Shared Virtual Array)

A direct-access storage device (DASD) product introduced by Storage Technology

(StorageTek) in 1999. SVA is based on the same technology as the RAMAC Virtual

Array, an IBM-branded storage system for which StorageTek served as the original

equipment manufacturer.

SVC (switched virtual circuit)