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3GL
(third-generation language) – is a high-level programming language such as FORTRAN, COBOL, BASIC, Pascal
or C, which compiles to machine language.
4GL (fourth-generation language) – is a high-level language suitable for end-user or programmer data access and capable of reasonably complex data manipulation. It includes two categories of software development tools: application generators for production applications, and information generators for decision-support applications. 4GLs are relatively nonprocedural and easier to use than 3GLs (e.g., COBOL, FORTRAN and C), but are less powerful and more wasteful of computer resources. Generally, three types of 4GL are recognized:
·
A procedural language integrated
with a database management system. Examples include Ideal (Computer
Associates) and Natural (Software AG)
·
An information generator. Examples
include FOCUS (Information Builders), Nomad 2 (Must Software) and Ramis
(Computer Associates)
·
A code generator or nonprocedural
tool. Examples include SQLForms (Oracle) and Telon (Computer Associates). These
tools are also called lower-CASE tools.
3270
– IBM’s interactive communications terminal standard used to communicate
with an IBM mainframe or compatible system.
A
ActiveX
– A set of technologies from Microsoft provides tools for linking desktop
applications to the World Wide Web. Enabled using a variety of programming tools
including Java, Visual Basic, and C++.
Adaptive/Assistive
Technologies (AAT) –
provide access to systems and applications for users with communication,
physical access, or learning disabilities.
American
National Standards Institute (ANSI) – a private, non-profit organization
(501(c)3) that administers and coordinates the
Application
– A set of coded instructions that direct a computer to perform desired
functions. The term is sometimes used in place of “application program,”
“software”, or “program,” which are used to process data for the user.
Applications can be custom-written or purchased.
Application
Architecture – The Application
Architecture is the focal point of an organization’s systems inventory.
It defines how applications are designed, how they cooperate, and where they
reside. Good application architectures will enable a high level of distributed
system integration, reuse of components, rapid deployment of applications and
high responsiveness to changing business requirements.
Application
layer – The software
that “runs” on top of the system services layer.
An
Application Programming Interface (API)
is software, either custom or COTS, that uses a specific implementation to
exchange data with another system. Business rules provide the specific
interaction mechanism. Each reusable component requires a properly documented
API. An API is the specific method prescribed by a computer operating system or
by another application program by which a programmer writing an application
program can make requests of the operating system or another application.
A set of calling conventions that defines how a service is invoked through
software. An interface that enables programs written by users or third parties
to communicate with certain vendor-supplied software. (1) a documented set of
instructions by which a program can invoke the functions of a system, such as a
DBMS or a transaction processing monitor, (2) used to integrate two different
application programs, at least to the extent of allowing them to share data.
Application
Software – A program
that performs a task or process specific to a particular end-user’s needs, or
solves a particular problem.
Architecture
– A structured set of protocols that implements a system’s functions. A
network architecture defines the functions, formats, interfaces, and protocols
required for end users to exchange information.
Architecture
Exception – The process whereby the appropriate governance body reviews
line-of-business or IT project request for an exception to the architecture and
formally arbitrates disputes arising from the Architecture Review process.
Architecture
Management Processes – The collection of processes employed to ensure that
the appropriate activities occur so that an organization’s architecture is
developed and refreshed on a regular basis, and that IT projects and initiatives
comply with the preferred direction set forth in the architecture documentation.
The basic processes that compose Architecture Management are:
Architecture Development and Renewal, Architecture Domain Team
Chartering, Architecture Communications, Architecture Research, Architecture
Review and Architecture Exception.
Architecture
Principle(s) – General
philosophical statements that apply to the design and implementation of systems
and applications within the various IT architectures covered in the IEA
Technical Reference Model. Usually expressed as descriptive statements about the
desirable characteristics of a particular architectural element. For example,
“Effective interfaces and applications appear and behave in ways that are
consistent with users’ expectations”.
Architecture
Review – The formal process of evaluating the extent to which a system
proposed for development and deployed in the organization’s technology
environment conforms to the technology architecture and that the total cost of
ownership for a given proposed system is adequately determined and known to all
stakeholders.
Asynchronous
– In computer programming,
asynchronous (from Greek meaning "not at the same time" and pronounced
"ay-SIN-kro-nus") pertains to processes that proceed independently of
each other until one process needs to "interrupt" the other process
with a request. Using the client-server model, the server handles many
asynchronous requests from its many clients. The client is often able to proceed
with other work or must wait on the service requested from the server.
Authentication
– The process of determining
whether someone or something is, in fact, who or what it is declared to be. In
private and public computer networks (including the Internet), authentication is
commonly done through the use of logon passwords.
Authorization – The process of giving someone permission to do or have access to something. In multi-user computer systems, a system administrator defines for the system which users are allowed access to the system and what privileges of use (such as access to which file directories, hours of access, amount of allocated storage space, and so forth).
B
Bandwidth
– Data/voice/video carrying capacity of a
transmission medium, usually measured in hertz (Hz).
With
Binary Compatibility, there is no need to recompile an application for
different platforms. For example, if an application is going to be deployed on
servers located in State Offices, all servers running that application should be
binary compatible – this must be ensured even if the platforms are from the
same manufacturer. The platforms must run the same version of the operating
system and must not require any recompilation of business applications so that
deployment throughout the various offices means a simple copy of a program from
one office to another. Total binary compatibility will support automated
software distribution across servers, which will reduce support costs and
provide stable computing platforms that can be reliably shared and moved across
the Bureau. Technologies like the Java Virtual Machine and Java servlets fit
this definition of binary compatibility, but may not fit every situation due
to compromised performance.
BIND
– is a cross-platform, open source nameserver that follows the standards
defined in the RFCs related to DNS.
Bus
– (1) A high-speed physical transmission path or channel. Typically an
electrical connection with one or more conductors, wherein all attached devices
receive all transmissions at the same time. (2) Local network topology, such as
that used in Ethernet and the token bus, where all network nodes listen to all
transmissions, selecting certain ones based on address identification. It
involves some type of contention-control mechanism for accessing the bus
transmission medium.
Business
Architecture – This architecture
identifies business systems and their interactions in order to:
· Drive the strategic decisions in the technology architecture.
· Identify business services independent of application-specific invocations of those services.
· Understand how and what data are strategic to the enterprise.
·
Provide the basis for the strategic
applications of information technology.
Business
Driver – A collective term that is used to describe the various
influencing factors that cause (directly or indirectly) changes in an
enterprise’s business processes, including external forces (changes in
competition/market, globalization, economy, customers, regulation, politics, and
technology) and responses to these forces (including business strategies, goals,
objectives, requirements, and strategies).
Business Function – A
logical grouping of functionality used to support execution of Business
Processes.
Business
Information Requirements – The information needs of an enterprise that
result from business drivers, and/or their corresponding business strategies.
Can be identified at a high level by asking:
What information is needed? Where
does the information come from? Who
needs it? When do they need it?
Business
Intelligence Tools –
Employed by end users for decision-making and analytical processes. These tools
allow the users to dynamically query the data and information stored in data
warehouses. They provide query, reporting, graphing, trend analysis,
calculating, and summarizing capabilities. Business intelligence tools provide
the ability to analyze and access data contained in the data warehouse.
Typically, several tools are selected within an organization, based on the
function needed.
Business
Logic – The rules that control how to complete a task or step in a
work process. For example,
application logic that governs processing a payment or address change. These
applications are often transactional in nature – resulting in database/file
updates.
Business
Process – A
collection of business activities (tasks) that transform input(s) into output(s)
of value to the
Business
Rules – Requirements and
specifications for the line-of-business decision-making process. Most business
rules are declarative. Business rules serve to constrain, define, and assert how
business will be transacted. Business rules also define actions to be taken in
a specific circumstance.
Business Strategy – The planned approach to achieving an enterprise’s business drivers.
C
Calendaring
and Scheduling (C & S) – A technology that, by combining with an organization's overall
groupware system(s), provides a methodology for the coordination and
communication of individual and group activities and plans. Time-management
functions that schedule events (such as meetings, lectures, and conferences)
and access (and manage) calendric information about people, facilities, and
equipment.
Calendar
Store – A database
storing C & S information and schedules. The database may reside on a single
server, or may be distributed across multiple servers over the network.
Capability
Maturity Model (CMM)
– The Software Engineering Institute’s (SEI’s) Capability
Maturity Model (and the SCE process based on it) offers an initial basis for
defining software development processes for regulatory purposes.
C
& S Client – The
front-end user interface of the C & S application that runs on the user’s
desktop. It allows users to view and manipulate their calendar and schedule
information, and to coordinate and schedule meetings from their desktop
computer.
C
& S Server – The
hardware and software that provides calendaring and scheduling services to C
& S clients. It manages calendar and schedule information, and the exchange
of C & S information between C & S users. The Calendar store is managed
by the C & S server.
Change
Management – Process of planning,
controlling, and managing enterprise changes.
Classification
– A method for grouping similar or like things.
In the IEA, industry standards and technology products are grouped into
lifecycle classifications that reflect their suitability for use at Interior.
Client
– A system or a program that requests the activity of one or more other
systems or programs, called servers, to accomplish specific tasks. In a
client/server environment, the workstation is usually the client. The client
serves as a user interface, as well as a processor for many time-consuming
tasks, allowing the server to devote itself to central storage and other tasks.
Client/Server
– (1) In TCP/IP, the model of interaction in distributed data processing in
which a program at one site sends a request to a program at another site and
awaits a response. The requesting program is called a client and the answering
program is called a server. (2) In Information Resource Management, a computing
model where functionality is divided between software clients and software
servers. Clients depend on the services provided by servers such as another
application, component, or database to complete the intended function. (3) A
technical architecture that links workstations into networks, enabling increased
productivity by means of sharing information. Individual users, or
“clients,” are “served” over a network by a central machine that acts as
a common repository of information and programs.
Commercial off-the-shelf
(COTS) application – Also known as
COTS software.
Common
Gateway Interface (CGI)
– A data-passing specification used when a Web server must send or receive
data from an application such as a database. A CGI script passes the request
from the Web server to a database, gets the output, and returns it to the Web
client.
Common
Internet File system –
The
common Internet file system uses the
server message block protocol (SMB)
for sharing diskspace from one system among other systems.
Compatibility
– The ability of two devices to communicate with each other understandably, or
the ability of software to run on a particular hardware platform.
The
Common Internet File System (CIFS) uses the server message block protocol (SMB)
for sharing disk space from one system among other systems.
Common
Management Information Protocol (CMIP) – The Open Systems Interconnection (OSI) protocol for the
exchange of network management information.
A
Component – is a piece of software or hardware that is designed to
fulfill a single purpose and to interoperate with other components.
Component
Object Model (COM) – A
framework developed by Microsoft that supports interoperability and reusability
of distributed objects by allowing developers to build systems by assembling
reusable components from different vendors.
Conceptual
Architecture – A principles-based, enterprise-level layer of a technical
architecture to ensure clear decisions to sub-optimize individual components in
order to optimize total effectiveness of the overall enterprise architecture to
enable business strategies.
Content
Management – Tools used for managing the versioning, workflow, and
deployment of web content.
Control
Layer – The layer(s) in an application
that control various aspects of the application functionality.
It is a way to externalize the ordering or flow of functionality
independent of the actual business logic.
This ensures that the business logic can be easily adapted, reordered, or
reorganized in order to meet changing business needs by changing the control not
the actual business logic.
Cookie
– A chunk of information that is passed from one application to another,
with the expectation that the receiver will store the chunk and send it back
later. The most common usage for cookies is to save state in client/server
applications, track user information, and provide a user customizable
experience.
Corporate
Metadata Repository (CMR)
– 1) A repository that contains metadata, which is information about data (for
example, shared data definitions, data aliases, and where OLTP and OLAP data can
be found). A data repository is an important aspect of a successful data
warehouse effort because it contains all the information about the data and
processes used to populate and access a data warehouse. 2) The corporate
metadata repository provides a single enterprisewide source for data
definitions. This tool becomes more important in the XML/EDI world because data
structure, definition and context are important for data integration. The CMR is
the local place to maintain data type definition files.
CORBA
(Common Object Request Broker Architecture) – An Object
Management Group (OMG) interoperability standard for object-oriented
applications communicating within heterogeneous environments.
D
Data
Access Middleware – The
communications layer between data access programs and tools and databases. Data
access middleware is designed to enable communication between a data access
programming tier and a database, as opposed to application communication
middleware, which enables communication between the programming tiers of an
N-tier application system.
Data
Administration – Technologies/strategies for facilitating the
design of maintaining and administering the data in a DBMS.
Database
– A collection of structured data that is application-independent.
Database
Access Tools – Used to
query and retrieve data from existing databases and write reports. These tools
can be provided either through a purchased package or integrated with EIS and
DSS applications by application developers. Some examples of these tools are
Microsoft Access, Microsoft Excel, Lotus
Data Management Architecture – The Data Management Architecture defines the mechanics for managing, securing, and maintaining the integrity of an enterprise’s significant logical entities. These entities must be recorded and accounted for in a business information environment. The architecture provides standards for accessing data, and, if appropriate, business objects.
Database
Management System (DBMS)
– Manages data storage, structure, access, and security. Fields can be indexed
to improve the performance of queries against the data, a system comparable to
that of a dictionary that has tabs for the letters of the alphabet so that it is
easier to look up a word, or to a reference book, which has an index to quickly
find information needed. The following are types of DBMSs.
· Relational Database Management System (RDBMS) – Software designed to manage the collection of data. Data is organized into related tables so that relationships between data can be established. Relational databases can contain normalized data. Normalized data is organized so that unique data is stored only one time, instead of multiple times for each table (e.g., a non-normalized database). A relationship is established between the unique data and its related information.
· Object Database Management System (ODBMS) – Objects provide a rich model for capturing business complexity. Objects can represent complete business entities and the relationships between them. They are easily extensible as business processes change and fit well in a networked application architecture. ODBMSs integrate database functionality with object programming languages. The ODBMS extends an object-oriented programming language with persistent data, concurrency control, data recovery, and associative queries.
·
Multidimensional Database
Management System (MDDBMS)
– Specifically designed for efficient storage and retrieval of large
volumes of data. Data is stored similar to the way it is in a spreadsheet, so it
is easier for end users to understand and manipulate. Multidimensional databases
store data that is closely related and stored, viewed, and analyzed from
multiple perspectives (i.e., dimensions). Multidimensional databases are
sometimes referred to as post-relational databases or a more advanced form of
object-oriented database.
Data
Bus – Software
equivalent of a hardware bus. Applications attach to a data bus with a known
address. Applications can send and receive data on the data bus by using the
addresses of the other applications attached. MQSeries from IBM is an example of
data bus technology. Regardless of the underlying network protocol, data bus
products are packet or message oriented.
Data
Cleansing – Technologies
used to enhance the integrity and validity of the data in a DBMS.
Data
Dictionary – A collection of descriptions of the data objects or
items in a data model for the benefit of programmers and others who might need
to refer to them.
Data
Integrity – Accuracy, validity, and
consistency of data, maintained according to a set of rules for modifying a
database
Data
Mart – A subset of a
data warehouse. Where data warehouses are designed to support many requirements
for multiple business needs, data marts are designed to support specific
requirements for specific Decision Support System (DSS) applications (i.e.,
particular business needs). Although a data mart is a subset of a data
warehouse, it is not necessarily smaller than a data warehouse. Specific DSS
needs may still require large amounts of data. Data marts are typically
considered a solution for distributed users who want exclusive control of the
information required for their business need.
Data
Migration Tool – Copies
selected data from legacy and other OLTP systems. Data transformation reformats
extracted data according to metadata definitions and puts it into a data
warehouse. Extraction and transformation tools are required to integrate data
from multiple sources and to ensure consistency of information derived from data
created in a complex, heterogeneous OLTP environment.
Data
Mining – Used to analyze
the data stored in data warehouses. It can provide valuable insights into the
business. Data mining scans large amounts of data stored in data warehouses to
reveal patterns or correlations.
Data
Model – Specifies the
data formats and the relationships of fields and tables in an application
system. It drives basic database design.
Data
Replication Tools – For
distributed or remote users, there is sometimes a need to distribute data from a
data warehouse to various data warehouses and data marts throughout the
organization. When warehouse data is needed for distributed OLAP processing, it
can be distributed through a replication service. Replication allows data to be
located close to the business users, thus improving performance. This is
particularly useful for eliminating latency problems in distributed systems (e.g., WAN) and for access speed with large
geospatial databases.
Data
Scrubbing Tools –
Validate and cleanse data so that its format is consistent and it is accurate,
complying with metadata definitions. Data
scrubbing is typically performed periodically to ensure that data meets the
metadata standards that have been set. It is also performed when data has been
loaded into a data mart or data warehouse. For data scrubbing to be successful,
data scrubbing tools and defined roles, responsibilities, and procedures are
needed. Data scrubbing is needed at
multiple levels, including the data entry level in OLTP applications and the
data extraction and transformation levels. Data can become “dirty” for many
reasons. For example, consider a data entry application that has an open text
field called “Description.” If no limitations are placed on the entry of
data in that field, end users can type anything in that field, including
misspelled words or multiple text descriptions for the same data element.
Data
Steward – The person or group of people responsible for
implementation of data from a technical perspective including data design,
processing of data into the physical platform and managing the data
availability, integrity and security according to business requirements.
A
Data Store contains data. A data
store will most likely take the form of a relational database management system
(RDBMS). Other data store implementations can be hierarchical, object, and
object-relational databases. Indexed sequential access method (ISAM) files is
another implementation.
A
Data Type Definition (DTD) file is
used by an XML parser to parse XML data. A DTD allows an application using the
DTD to understand an XML data source. A DTD can be defined by a business for its
specific needs. This feature provides the business the capability to rapidly
change as business needs change.
Data
Visualization – is the
method of displaying data resulting from end user queries and data mining from a
data warehouse in a visual format (i.e., graphs, pie charts, and bar and line
charts). Similar to data mining, data visualization can be helpful in realizing
trends or patterns in interrelated data.
A
Data Warehouse stores information
compiled from multiple sources and typically is available to people across the
organization for analytical processing. It can provide more timely answers to
business needs and questions. It is a database for query and analysis, as
opposed to a database for processing transactions. Separating the two functions
improves flexibility and performance.
Decision
Support Systems (DSS) –
A computer program application that analyzes business data and presents it so
that users can make business decisions more easily. It is an “informational
application” (as distinct from an “operational application” that collects
the data in the course of normal business operation). A DSS may present
information graphically and may include an expert system or artificial
intelligence (AI). It may be aimed at business executives or some other group of
knowledge workers.
Development
Tools – The raw
materials by which programmers create custom-built enterprise software.
Directory
Services, Message Handling Systems, and Standards
– An e-mail system uses directory services, Message Handling Services (MHSs),
and standards and protocols to index and manage names,
e-mail messages, distribution lists, and devices (including printers
and other peripherals, and servers) accessible on networks it serves.
Digital
Certificate – The digital equivalent of an ID card used in
conjunction with a public key encryption system. Digital certificates are issued
by trusted third parties known as certification authorities (CAs), such as
VeriSign, Inc., after verifying that a public key belongs to a certain owner.
Distributed
Component Object Model (DCOM) – Microsoft’s distributed version of Component Object Model (COM),
whose version communicates via their version of a remote procedure “call” (RPC).
Distributed
Database – Database whose contents
(tables, views, columns, files, etc.) reside on more than one system in a
network and can be transparently accessed or updated from any system in the
network.
Distributed
Computing Environment (DCE) – An Open Software Foundation (OSF) initiative to create a
vendor-neutral networking and distributed computing environment to support
distributed applications, by integrating the appropriate technology or
combination of technologies into a single environment while addressing
interoperability, standards and security. DCE integrates remote procedure calls,
presentation services, a naming directory, security, threads (sequential flows
of control similar to tasks), time services (to synchronize clocks) and a
distributed file system.
A
Distributed Object is an object that
can be accessed remotely. This means that a distributed object can be used like
a regular object, but from anywhere on the network. An object is typically
considered to encapsulate data and behavior. The location of the distributed
object is not critical to the user of the object. (See Glossary entry for
“Object”.)
Distributed
Control Systems (DCS) – evolved
from centralized process control computers common in the 1960s. The systems were
developed for continuous-flow processes that required loop, analog, and limited
discrete control. A DCS is a real-time, fault-tolerant system for continuous
and complex batch-process applications. Over time, they have evolved from
being proprietary hardware and software systems to being UNIX- and Windows
NT-based systems.
Distributed
Systems Management (DSM) – focuses on the integration of a framework tool such as HP OpenView or
Document
Management System (DMS) –
Allows users to store, search, and manipulate documents electronically and
maintain a library of text and images in a compact space. Most systems also
provide a means for passing documents across a network. A DMS manages the processes of authorship, review, editing, production,
approval, and delivery of (or access to) large sets of documents throughout an
organization.
Documentation
– Data that describes code and data. Documentation can be thought of as
metadata.
Domain – A related set of technologies.
Domain Architecture – A
logical consistent set of principles with rationales and implications, as well
as identified industry standards and products that are classified into lifecycle
categories.
Domain Layer – Also
referred to as "business domain" or "business
functionality". This is the
layer in an application that contains the collection of services that enforce
the business rules, process information, and manage transactions.
This layer must be separated from the presentation and the data to truly
be effective. This ensures your
business rules are not dependent on presentation and data implementations and
are easily transportable (or accessible) to any application on any platform.
The
Domain Name System (or “Service”) (DNS) is an important directory
standard on the Internet and on local TCP/IP networks. It is used to map the
TCP/IP network address of a server (for example, 207.68.156.58) to a
better-known form (i.e., www.microsoft.com). The DNS naming convention is used
for Internet and e-mail addresses that take the form “name@hostname.organization.”
Domain
Team – A domain team is responsible for developing architecture
principles, with associated rationale and implication, identifying applicable
standards and preferred products, and conducting other work assigned by the
Architecture Team, for a given collection of related technologies.
There is a domain team associated with each of the Technical Architecture
Domains
Dynamic
Data Exchange (DDE) – A
limited method of sharing data between two applications or files. When data is
used in both files, with DDE it can be automatically updated in the other. Both
applications must be in use, and DDE does not work over a network. Object
Linking and Embedding (OLE) is a more sophisticated development.
E
Electronic
Data Interchange (EDI) – is
being used to provide an absolute structure to data. For example, bids, order
processing, and invoicing data structure are just a few standards defined by
EDI. EDI is an absolute standard maintained by the American National Standards
Institute (ANSI) Accredited Standards Committee (ASC) X12. There are efforts
underway to integrate EDI into XML.
Electronic
Forms – Workflow software used to create on-screen data entry forms
and provide e-mail routing and tracking of the resulting electronic documents.
Electronic
Mail (or “e-mail”) – is
the groupware type most critical to the business operations of the Bureau. It
enables the fast and efficient exchange of all types of data files across the
enterprise. It is able to function during either synchronous or asynchronous
interactions. These advantages directly benefit the decision-making process and
translate into measurable cost and time savings. The basic characteristics of an
e-mail system include features that create, compose, address, send, and receive
messages.
Emerging
Technologies – New
technologies and products that show sufficient promise for future use and should
be monitored by the IEA.
End-to-end
Services – Offered by
the lower three layers of the Open Systems Interconnection (OSI) Reference
Model.
End-to-end
Storage Management –
A component of an overall systems-management infrastructure that improves
application availability by reducing the number of storage-related outages and
minimizing the length of the outages when they occur.
An
E-mail Client (also referred to as a
Mail User Agent, or MUA) is an application that enables users to compose,
send, receive, and organize e-mail. It's called a client because e-mail systems
are based on a client-server architecture.
An
E-mail Server is an applications
server that provides services such as files distribution, temporary caching of
new messages, and archiving of previously viewed messages. A message
store is an important subcomponent that resides on the e-mail server. It
is a database that enables message-management tasks, such as opening, reading,
and deleting messages; and browsing and searching lists of messages. A directory user agent (DUA) is another important subcomponent that
allows retrieval of information (such as distribution lists and e-mail
addresses) from local and network directory services.
An
E-mail Application Programming Interface (API) allows applications to access
the various components of an e-mail system by connecting a sender’s e-mail
application to a receiver’s application. Using an API, an MUA can manipulate
new and stored e-mail messages, create and delete addresses, access and
manipulate message components, and authenticate users login in to the e-mail
system.
Encryption
– A technique of modifying a bit stream of information to make it
appear to be a random sequence of bits to someone who does not have access to
the encryption scheme.
An
Ethernet
– The standard for local
communications networks developed jointly by Digital Equipment Corp., Xerox, and
Intel. Ethernet baseband coaxial cable transmits data at speeds up to 10
megabits per second. Ethernet is used as the underlying transport vehicle by
several upper-level protocols, including TCP/IP.
Executive
Information Systems (EISs) – extract data from an enterprise system to provide managers a view of
quantitative performance measures on-line. A new generation of systems is meant
to provide this information in near-real time, before it’s too late to do
anything to prevent dysfunctions.
Executive
Reporting System (ERS) –
A system to generate executive summary reports for Congress, executive
management, and oversight groups like the GAO. These reports provide a
high-level summary of IEA information.
Extensible
– Able to integrate new
technology and functionality.
External
Systems – Applications of third party
business partners that support the organization’s business requirements and/or
interact with the organization’s technology portfolios.
Extract/Transform/Load (ETL)
– Technologies used to extract data from source DBMS’s, transform
the data into an appropriate form, and load it into target Data Marts or
Warehouses.
Extranet – Community-of-interest IP networks that provide secure connections between remote users and a main site, or between multiple sites within the same company, including connectivity to business partners, customers, and suppliers.
F
Fax
– Communication of a printed page between remote locations. Fax
machines scan a paper form and transmit a coded image over the telephone system.
Fiber
Optics – A data
transmission medium that uses light conducted through glass or plastic fibers.
Fiber-optic cables have cores capable of conducting modulated light signals by
total internal reflection. Benefits include small diameters, high potential
bandwidth, and lower cost than copper.
File
Transfer Protocol (FTP) – A system for transferring files between
computers over the Internet, Intranet or Extranet.
File-Typing
– (used in the Microsoft
Windows environment) – File types
activate appropriate elements of the Microsoft tool suite, and the tools
themselves extend a common set of base classes that help to maintain a high
degree of behavioral consistency regardless of which tool is in use. Tools based
on object-linking tied to the data's XML description can be synthesized on the
spot.
Firewalls
· Packet filter firewalls historically implemented on routers, filter on user defined content, such as IP addresses. They examine a packet at the network layer of the Open Systems Interface (OSI) model and are application independent, which allows them to deliver good performance and scalability. They are the least secure type of firewall because they cannot understand the context of a given communication, making them easier for hackers to break.
· Application gateway firewalls improve on security by examining all application layers, bringing context information into the decision process. However, they do this by breaking the client/server model. Every client/server communication requires two connections – one from the client to the firewall and one from the firewall to the server. In addition, each proxy requires a different application process, or daemon, making scalability and support for new applications a problem.
· Stateful inspection firewalls overcome the limitations of application gateways and packet filters by providing full application-layer awareness without breaking the client/server model. With stateful inspection, the packet is intercepted at the network layer, but then the firewall extracts state-related information required for the security decision from all application layers and maintains this information in dynamic state tables for evaluating subsequent connection attempts. This solution is dramatically improves on the performance of an application gateway, while offering the same or better security.
G
Gateway
– A computing system or software function that performs a protocol or API
translation, and serves as an intermediary between computing systems or
communications networks.
Geospatial
– Information that identifies the geographical location and characteristics of
natural or man-made features and boundaries of the Earth.
Geoprocessing
– Computer applications which model, interpret and use Earth information.
Granularity
– Degree of parallelism in an
architecture, from job execution level (coarse) to logic device level (fine).
Ability to increase system capacity and performance through incremental
processor expansion.
Graphical
User Interface (GUI)
– facilitates
application use by means of windows, icons, and menus
Groupware
– or collaborative
software, was defined as a new software category by the introduction of Lotus
Notes in 1989. Groupware applications support a wide variety of activities, such
as e-mail, scheduling, and document sharing. Some groupware products are suites
of ready-made applications; others are toolboxes for creating collaborative
applications, with customizable templates included. Groupware enables an
organization to compile, organize, and share its knowledge base, that is, to
perform computer-supported cooperative
work (CSCW). The goal of groupware is to enable collaboration by letting
team members focus on tasks at hand rather than on the process of gathering and
integrating information. Groupware maximizes human interaction while minimizing
technology interference. It increases efficiency by decreasing the time and
effort expended distributing data files and other documents among working groups
and individuals. Groupware provides the infrastructure for groups and
individuals to work cooperatively and share information electronically,
regardless of where they are located.
Governance – A subset of the Architecture Management processes that are focused on ensuring that IT projects either adhere to the preferred direction set forth in the architecture or are explicitly granted an exception to the principles, standards and products dictated by the architecture.
H
Haptic
– Applying tactile
sensation and control to interaction with computer applications.
Hardware
– The physical entities of an enterprise architecture. A computer with one or
more physical network connections.
Hierarchical
– An approach used in numerous technologies, including machine vision, process
control, networking, databases, and planning, whereby the scope of work is
arranged in hierarchies that establish priorities and appropriate routings. A
database architecture in which data elements are arranged in the form of an
inverted tree structure in which no data element has more than one parent.
Hub
& Spoke – A particular architectural pattern where applications and
components exchange information and request services via messages through a
centralized hub or hubs which route and distribute the messages.
Hubs
– Hubs are shared devices that allocate the available bandwidth to all
devices attached.
Hypertext
Markup Language (HTML) – A
world wide web authoring language used for creating and linking Web pages.
Hypertext Tranport Protocol (HTTP) – The communication protocol used to connect to servers on the World Wide Web. Its primary function is to establish a connection with a server and transmit HTML pages to the client browser. Users of the web retrieve documents from servers or "web sites".
I
Information
– Structured data.
Infrastructure
– An underlying base or foundation supporting an organization or system.
Technical infrastructure supports the technical capabilities of business
applications and data repositories, and does not contain business specific logic
or functionality.
Interface
– (1) A shared boundary between two pieces of equipment. (2) The hardware and
software needed to enable one device to communicate with another.
An
Interface Definition Language (IDL)
is a generic term for a language that lets a program or object written in one
language communicate with another program written in a different language. In
distributed-object technology, it's important that new objects are able to be
sent to any platform environment and “know” how to run in that environment.
An IDL within the object-oriented
world is fundamentally the same as in the RPC world; however, here it permits
interfaces to objects to be defined independent of an objects implementation.
After defining an interface in IDL, the interface definition is used as input to
an IDL compiler that produces output that can be compiled and linked with an
object implementation and its clients, thus allowing for client-server
communication across a distributed heterogeneous environment.
Internet
– The “Infobahn” of tens of thousands of public and private networks
worldwide. The Internet’s TCP/IP communications standards mean computers
anywhere in the world — even those running different operating systems and
applications—can communicate with one another. Hypertext Markup Language
(HTML) lets the computers display the accessed information in graphical pages.
Intranet
– Networks within a business using the same technology that is the foundation
of the global Internet. Many industry analysts expect such corporate networks to
provide most of the revenue for computer hardware and software vendors over the
next few years as an increasing number of businesses expand their internal networks
to improve efficiency and build closer ties with customers and suppliers.
Interoperability
– The ability of computers on a network to share application software.
Intrusion
Detection – A process or product for detecting unauthorized entry
or access to a computer or network.
IP
Security Protocol (IPSec)
– A standardized means of implementing security for VPNs. IPSec is a set of Internet
Protocol (IP) extensions that provide security services at the network level
of the OSI stack. IPSec technology is based on modern cryptographic
technologies, making possible very strong data authentication and privacy
guarantees. Furthermore, all of the encryption and authentication algorithms and
security protocols used in IPSec are well studied and have survived years of
scrutiny. Consequently, the Bureau can be confident that the IPSec facility
indeed provides strong security. IPSec can be implemented in routers or
firewalls owned and operated by the IEA. This gives the network management
facility complete control over security aspects of the VPN.
J
Java
– A programming language based on C, developed by Sun Microsystems that
extends and complements the basic capabilities of Hypertext Markup Language
(HTML). Originally developed as a language for consumer-oriented devices such
as TV set top boxes, Java became a viable alternative to other programming languages
with the rapid growth of the Internet as it has the potential to work on an
unlimited number of computing devices and operating systems. Java permits the
creation of applications and application modules (“applets”) that run in the
Java virtual machine (JVM) on the browser, either as software on a PC or on the
Sun picoJava chip, a piece of dedicated hardware. Browsers from both Netscape
and Microsoft have a JVM. Java’s platform independence and security are
designed in, rather than added on, so applications can run on a wide variety of
desktop platforms as long as they can run a Java-enabled browser. Principally a
programming language, but it has been designed by Sun Microsystems to function
as a complete computer operating system. The purpose of the language is twofold
– to create a single standard that will run on a variety of competing computer
systems, and to solve vexing computer security problems introduced by the
widespread reliance on computer networks, which are vulnerable to malicious
programs such as viruses.
Java
Applets – A small piece
of Java code that implements a specific function. Applets may run on a server or
be downloaded and run on the client’s machine.
Java
Database Connectivity (JDBC) – a standard set of Java classes providing vendor-independent access to
relational data.
Java
Remote Method Invocation (RMI) – is Java's
remote procedure call (RPC) mechanism. It functions only within the Java Virtual
Machine (JVM) environment; however, with the Java native method interface (JNI),
a developer can connect to existing and legacy systems. It facilitates
interprocess and intraprocess communication.
Java
Servlets – A form of
server-based Java that operates in conjunction with a Web server and offers an
alternative to using Common Gateway Interface (CGI) and server application
programming interfaces (SAPIs) to communicate with Web server processes. In
addition, servlets are independent of a given type of Web server, as the most
prominent Web servers support servlets.
Java
Transaction Service (JTS) – Controls transaction applications, performs database
updates, provides database connection pooling, and provides reliable
manageability of client connections within the Java environment.
K
Knowledgebase
– Data, including assertions, rules,
objects, constraints, or other items, used by an expert system or
knowledge-based system.
Knowledge-Based
System – Software that
uses artificial intelligence techniques and a base of information about a
specialized activity to control systems or operations.
L
Local
Area Networks (LANs)
– span a limited
geographical area to connect computers and terminals, usually at
moderate-to-high data rates.
Legacy
System – Existing systems using older and
often outdated technology.
Legal
Data – The portion of
the enterprise that contains all of the primary data stores required to be
maintained by law. Legal data is not necessarily stored in electronic format.
Lightweight
Directory Access Protocol (LDAP) – DAP runs over the OSI network protocol stack. That, combined
with its very rich data model and operation set makes it difficult to implement
a full-blown DAP client and have it “fit” on smaller computer systems. LDAP,
however, is, like X.500, both an information model and a protocol for querying
and manipulating it. LDAP's overall data and namespace model is essentially that
of X.500. The major difference is that the LDAP protocol itself is designed to
run directly over the TCP/IP stack, and it lacks some of the more esoteric DAP
protocol functions.
Line
of Business (LOB) – Individual business
unit within a larger organization.
Logical
Model – A model depicting a view of something that is independent of the
way in which it is implemented physically. A
logical view expresses semantics, rules, relationships, and behaviors that are
often used as the basis for physical design.
Local
Area Network (LAN) – A
geographically limited communication network that connects users within a
defined area. A LAN is generally within a building or small group of buildings
and is managed and owned by a single enterprise. The shorter distances within a
building or campus enable faster communications at a lower cost than wide-area
networks (WANs). Although an increasing number of LANs use Internet standards
and protocols, they are normally protected from the public Internet by
firewalls.
Long-Term
Direction – Technologies and products that are planned for the time frame ranging
from 18 months past the publication date of the TRM to five years beyond the TRM
publication date.
M
Message-Oriented
Middleware (MOM) – is
a layer of code which allows for application communication over a distributed
heterogeneous environment. It may employ synchronous or asynchronous
communication, some combination as in beginning a session in synchronous mode
and falling back to asynchronous if need be. The MOM code is required on the
client and the server and ideally should employ message queues which frees both
client and server to go about their business without concern for the message
being received. This flavor of middleware is best suited for event driven
applications involving an occurring event the client application hands off to
the messaging middleware the responsibility of notifying a server that some
action needs to occur.
Message
Transfer Agent (MTA) –
An e-mail delivery application that receives messages from an MUA or another MTA,
stores them while it determines where and how they are to be delivered, and
delivers the messages to individual addressed mailboxes or other MTAs.
Transferring an e-mail message from the composition area to the e-mail server
requires that an MTA communicates via the same protocol (or language) as the
server. The three most commonly used protocols are Post Office Protocol (POP)
and Internet Message Access Protocol (IMAP), which define methods for e-mail
clients to retrieve messages from a server on a TCP/IP network; and the Internet
Simple Mail Transfer Protocol (SMTP), the Internet
e-mail standard used to deliver messages between servers connected to the
Internet.
Messaging
– the standard means for
executing interprocess communication facilitated by middleware technologies.
(See the Middleware Architecture chapter of the TRM.)
Metadata
– information about
data, including the format of the data element, which application system owns
it, where it is located, and how it should be used. Metadata is the global
information about what data exists across the enterprise and the standards
applying to that data. It is very important to the data warehouse effort because
it sets the standards and the rules used for data transformation and cleansing.
Middleware
– connectivity software
that consists of a set of enabling services that allow multiple processes
running on one or more machines to interact across an environment. Middleware is
essential to migrating mainframe applications to client/server applications
and to providing for communication across heterogeneous platforms.
Mirroring
– Writing duplicate data to more than one device (usually two hard
disks), in order to protect against loss of data in the event of device failure.
This technique may be implemented in either hardware (sharing a disk controller
and cables) or in software. It is a common feature of RAID systems.
Module
– A separate and distinct unit of hardware or software.
Monitoring
Tools – Tools used for monitoring a system’s real-time
availability and performing statistical analysis on the results of the
monitoring.
End
users access a multidimensional database through a query language called Multidimensional
Structured Query Language (MDSQL). MDSQL is the multidimensional database
query language, just as SQL is the query language for a relational database.
However, where SQL has an industry standard called ANSI Standard SQL, there are
no current industry standards for MDSQL.
Multimedia
– Integration of text, voice, video,
images, or some combination.
Multiplexer – Electronic equipment that allows two or more signals to pass over one communications channel.
N
Near-Term
Deployment –
Technologies and products that are planned for the time frame ranging from the
TRM publication date to the TRM publication date plus 18 months (full deployment
within 18 months).
Network
Architecture – The Network Architecture provides the communication
infrastructure for the distributed computing environment. It consists of logical
elements (structure, topology, bandwidth, management), physical hardware
components (wiring, LANs, hubs), carrier services (frame relay, leased channels,
ATM), and protocols (access routing, naming).
Network
Connection – A network
connection is a peer to peer, software, bidirectional connection between two
applications. The TCP/IP protocol is the most common network protocol in use
today. Data transmitted via TCP/IP is byte-aligned and is streamed. Applications
receiving data via TCP/IP may receive as little as one byte at a time.
Applications that use streaming network protocols must parse the data stream to
understand it.
The
Network File System (NFS) uses either
TCP/IP or UDP protocols for sharing disk space from one system among other
systems.
Node
– One component of a network where interconnections occur.
N-tier
architectures – Some
systems take the partitioning of applications one step further and split one or
more of the tiers across the network. For example, a distributed database
service enables an enterprises database to run on multiple types of machines and
still present a logical view of a single database to the application logic that
accesses the database. A distributed function service allows the middle tier
that runs the business logic to be partitioned and run on multiple machines. In
such cases, the partition points are not just at the presentation /logic or
logic/data boundary. Partitioning can occur almost anywhere inside the logic or
data section. Physically, the application can run across four, five, or even
more machines (tiers); hence the term N-tier, where “N” equals any number.
O
An
Object is a self-contained bundle of
software with an identity that is unique among the objects in a system. Each
object consists of variables that store data and methods,
or procedures, capable of acting on the object’s variables. The object
encapsulates its variables, and it is only through sending message to the
object’s methods that another object can access the contents of the variables.
Variables can be numbers, character strings, or other data types. In addition to
it’s variables, an object contains methods.
These are the procedures that enable other objects to access variables and
perform operations on them. The main mechanism for bring order to objects is the
class. A class is a template for
objects, which contains the methods we want our object to have plus data-type
definitions for its variables. Objects are instances of classes.
Object
Linking and Embedding (OLE) – A Microsoft protocol that enables creation of compound documents with
embedded links to applications, so that a user does not have to switch from one
application to another to make revisions. The following are features of OLE:
·
Users can create compound
documents using multiple applications
·
Compound documents may
contain text and spreadsheet objects, graphic and chart objects, sound objects,
and video and animated objects
·
Objects that support OLE
automation may be scripted by OLE controllers, such as Visual Basic, and used in
end-user-developed applications.
Object-Oriented
Database – A database
used to store objects that form the basis of object-oriented computing, in which
data, as well as references to the procedures used to perform operations on that
data, are combined.
Object-Oriented
Design (OOD) – A design method in which a system is modeled as a
collection of cooperating objects and individual objects are treated as
instances of a class within a class hierarchy. Four stages can be identified:
identify the classes and objects, identify their semantics, identify their
relationships, and specify class and object interfaces and implementation.
Object-oriented design is one of the stages of object-oriented programming.
Object-Oriented
Programming –
Programming based on objects that communicate by passing messages. An object is
a package of information and descriptions of procedures used to manipulate that
information.
Object-Oriented
Software – Results from
a kind of modular programming. Each object is a software package containing a
collection of related procedures and data that can be reused to shorten
application development time. Objects also make it easier to customize software
systems to mirror actual business processes without negatively impacting the
ability to migrate to later software releases.
Object
Request Broker (ORB) –
Middleware that allows objects to communicate within a distributed environment.
Online
Analytical Processing (OLAP) – 1) Enables a user to
easily and selectively extract and view data from different points-of-view. To
facilitate this kind of analysis, OLAP data can be stored in a multidimensional
database. A multidimensional database considers each data attribute as a
separate dimension. OLAP software can locate the intersection of dimensions and
display them. Attributes such as time periods can be broken down into
subattributes. OLAP can be used for data mining or the discovery of new
relationships between data items. OLAP data is often stored in data warehouses
and data marts (i.e., a specialized subset of a data warehouse). An OLAP
database does not need to be as large as a data warehouse, since not all
transactional data is needed for trend analysis. 2) Online analytical processing
is a process where many system users are retrieving data from a data store for
analysis.
Online
Transactional Processing (OLTP) – 1) A class of program that facilitates and manages
transaction-oriented applications, typically for data entry and retrieval
transactions. Today's online transaction processing increasingly requires
support for transactions that span a network and may include more than one
government organization. For this reason, new OLTP software uses client-server
processing and brokering software that allows transactions to run on different
computer platforms in a network. 2) Online transaction processing is a process
where many system users are creating, updating, and deleting data in a data
store via one or many applications. This process is commonly referred to as
CRUD, for create, update, and delete.
Open
Database Connectivity (ODBC) Drivers – the middleware
used to connect database access tools to relational databases through the use of
a generic API. ODBC drivers are vendor-provided and allow databases to be
connected and used by a generic interface. The ODBC drivers enable access to
data and provide insulation between a program and the specific RDBMS language
used by each database. Database access tools and programs do not have to be
customized for each database, because an ODBC configuration file maintains the
database connections.
Open
Systems – An approach to
computing that stresses the interconnectability of systems based on compliance
to established standards.
OSI
(Open Systems Interconnection) – International
standardization program, facilitated by ISO and CCITT to develop standards for
data networking, which facilitates multivendor equipment interoperability.
Operating
System – A structured
set of system programs that controls the activities of a computer system and
associated peripheral devices, as well as the execution of programs and flow of
data.
Operations
Management – Encompasses
the back office component of systems management, focusing on practices for
delivering available systems with adequate responsiveness. Functions include
software distribution, storage management (including systems backup and
recovery, server performance monitoring and tuning, software license management,
user administration and account management, etc.)
Operational
Data Store – A subject-oriented, integrated,
single source and up-to-date collection of data used to support the tactical
decision-making and day-to-day information needs of the business.
The data primarily comes from a replicated copy of disparate Core
Business Operational legacy data that is updated in a timely manner (i.e. near
real-time up to 24 hour latency). The
data needs to be 100% accurate and should meet the performance requirements
(i.e. typically OLTP and operational reporting processing) set by the business.
OSI Reference Model – Network architectural model developed by ISO and CCITT. The model consists of seven layers, specifying network functions such as addressing, flow/error control, and encapsulation.
P - Q
Partitioning
– Applications can be broken into
three logical parts: presentation, logic, and data. These are areas in which the
program can be separated to facilitate execution of each logical piece on a
different machine. Each segment is known as a partition. For example, the
thin-client Web model requires that interface presentation be handled by the
browser, application logic by the World Wide Web server and other application
servers, and data by a database server. Developers are responsible for
determining where the separation occurs. Early client/server applications used
architectures dictated by the tools employed in their construction. As a result,
most of the early applications used a two-tier client/server architecture. The
tiers of client/server applications refer to the number of executable components
into which the application is partitioned, not to the number of platforms where
the executables are deployed. Sometimes the tiers into which the application is
partitioned is called logical
partitioning, and the number of physical platforms on which it is deployed
is called physical partitioning.
Personal
Digital Assistant (PDA) – A handheld, wireless computer that serves as an organizer, electronic book
or note taker. It typically uses a stylus or pen-shaped device for data entry
and navigation.
Physical
Model – A model used to depict how data is physically implemented.
It should include the physical names, data types, dependencies and
relationships to other data.
Plug-in
– An application used within another application to extend its
functionality.
Portal
– An entry point that collects relevant information to support a theme or
service.
Post-Relational
Database – A new class
of database that combines the speed and scalability of a transactional
multidimensional data model with the power and flexibility of object technology.
Because of their unique capabilities, post-relational databases are ideal for
developing high-performance transaction processing applications.
Presentation
Layer – This is the front-end
client that communicates with the user through an interface.
Good architectural designs ensure that the presentation of an application
is separated from the business logic. This
ensures that an application can have many presentations depending on user needs
(i.e. Web, internal client interface, voice response system, other systems).
Changes in the presentation are easily made without effecting the
underlying business application.
Principles
– Guiding statements of position that communicate fundamental
elements, truths, rules, or qualities that must be exhibited by an enterprise.
Statements of preferred
architectural direction or practice that provide a context for architectural
decision-making. They identify
desired behaviors and eliminate the need for evaluating endless alternatives
through advance agreement on preferred direction.
Program
– (1) A complete, structured sequence of program statements directing a
computer to implement an algorithm. (2) All software programming necessary to
solve a problem.
Programming
Language – An artificial
language that enables people to instruct machines. Computer commands that form
procedures by which software programmers design and implement computer software
programs.
Protocol
– A standard set of procedures that allows data to be transferred among
systems.
Proxy
Servers – Devices that
process and filter all Internet Protocol (IP) packets that are directed to them
and decide which protocols and services can be served out of their caches. Proxy
servers tend to offer the greatest range of protocol and caching support since
they cache Hypertext Transport Protocol (HTTP), Secure Hypertext Transport
Protocol (HTTPS), File Transfer Protocol (FTP) and, in some cases, streaming
content such as RealAudio and PointCast. Each workstation addresses the proxy
server directly by setting specific parameters in each browser on each
workstation.
Public
Key Infrastructure – The process of changing data into a form that
can be read only by the intended receiver. To decipher the message, the receiver
of the encrypted data must have the proper decryption key. In traditional
encryption schemes, the sender and the receiver use the same key to encrypt and
decrypt data. Public-key encryption schemes use two keys: a public key, which
anyone may use, and a corresponding private key, which is possessed only by the
person who created it. With this method, anyone may send a message encrypted
with the owner's public key, but only the owner has the private key necessary to
decrypt it
Push
Technology – Software
that automates the delivery of information to users. In contrast, the World Wide
Web is a “pull” environment that requires a user to seek information. In a
“push” environment, information is sent to a person proactively, through a
Web browser, e-mail, or even voice mail or a pager. In business, push technology
can be used for the conveyance of time-sensitive information, like changes in
commodity pricing or the introduction of promotional programs to a sales force.
Enterprises can employ push technology to communicate externally with their
clients or internally with their employees over a network.
Query
– A request for data that is initiated while a computer program is running.
R
Rapid
Application Development (RAD) – An application development (AD) approach that includes small teams
(typically two to six people, but never more than 10) using joint application
development (JAD) and iterative-prototyping techniques to construct
interactive systems of low to medium complexity within a time frame of 60 to 120
days.
Recommended
Best Practices – Very
specific recommended actions that will aid in the successful implementation of
architectural elements covered in the IT Technical Reference Model. Usually
expressed as simple declarative sentences. For example, “Use font sizes large
enough to be read on standard size monitors”.
Redundant
Array of Independent Disks (RAID) – A method of mirroring or striping data on clusters of low-end
disk drives; data is copied onto multiple drives for faster throughput, error
correction, fault tolerance and improved mean time between failures. With the
exception of RAID 0, all RAID levels provide automated recovery of data in the
event of a disk failure. The RAID levels and their key features are as follows:
· RAID-0 – provides disk striping without parity information; data is written by segment across multiple disks sequentially until the end of the array is reached, and then writing starts at the beginning again. Provides greater logical disk capacity with faster access time on reads (multiple segments read simultaneously). However, RAID-0 provides no data redundancy – if one drive fails, the entire disk array subsystem is unavailable.
· RAID-1 – provides fault tolerance by using disk mirroring (also called shadowing). Each byte of data on a disk is duplicated on another physical drive, providing 100-percent data redundancy. RAID-1 provides immediate access to data when either the primary or secondary drive fails, but it has the highest cost of all RAID types, since duplicate hardware is required.
· RAID-2 – eliminates the 100-percent redundancy overhead of RAID-1 by using a powerful error detection and correction code (Hamming), with bits of the data pattern written across multiple disks.
· RAID-3 – similar to RAID-2, but uses a single check disk per group that contains the bit parity of the data disks; data is interleaved across all disks. Because disk reads are performed across the entire array and all data is transferred to the controller in parallel, RAID-3 is well suited for applications that require high data read/write transfer rates for large sequential files.
· RAID-4 – instead of interleaving blocks of data across all drives, writes the first block on drive 1, the second block on drive 2, and so on. This technique dramatically improves read time, since many reads are single block (single drive), freeing other drives for additional read requests.
· RAID-5 – eliminates the dedicated parity drive by writing parity with the data across all drives in the array. Consequently, the single-write restriction and some performance degradation of RAID-1 through RAID-4 are eliminated. If a drive fails, the controller can rebuild the data from the parity and data on the remaining drives.
· RAID-6 – provides two-disk parity and one spare, so that two simultaneous disk failures per array of disks can be tolerated. With the occurrence of a failure, a spare is brought online and transparent reconstruction begins automatically in the background with negligible impact on performance.
·
RAID-10 – a combination of RAID-0 and RAID-1 that provides the
benefits of striping and fault tolerance (disk mirroring).
Relational
Database Management System (RDBMS) – A database management system (DBMS) that incorporates
the relational-data model, normally including a Structured Query Language
application programming interface. It is a DBMS in which the database is
organized and accessed according to the relationships between data items. In a
relational database, relationships between data items are expressed by means of
tables. Interdependencies among these tables are expressed by data values
rather than by pointers. This allows a high degree of data independence.
Real
Time – Response to
events in a predictable and immediate way. A spreadsheet response in one second
or five seconds is acceptable, but closed-loop control systems need to know
real-time response rates in a more rigorous manner.
Real-Time
System – Computers
designed to receive, process, and respond to data within a time frame set by
outside events, e.g., for air traffic control. A system consists of a
controlling system and a controlled system. A controlling system interacts with
its environment based on information from various sensors and inputs. In many
real-time systems, severe consequences result if the timing and logical
correctness of the system are not satisfied.
Relational
Database – A DBMS in which the
data is perceived by the user as a collection normalized relations of assorted
degrees.
Remote
Access Technology –
a method for providing
traveling or homebound users within the IEA with access to the data networks of
the Bureau. Remote access is usually designed to support communications from
home to mainframes, LANs, e-mail, UNIX systems, and minicomputers.
Remote
Procedure Call (RPC) – A
mechanism that extends the notion of a local (i.e., contained in a single
address space) procedure call to a distributed computing environment, enabling
an application to be distributed among multiple systems in a way that is highly
transparent to the application-level code. Examples of RPCs are Sun
Microsystems’ Open Network Computing, Sybase’s Open Client/Open Serve and
the Open Software Foundation’s Distributed Computing Environment (DCE) RPC.
Replication
– Creating and maintaining a duplicate copy of a database or file
system on a different computer, typically a server. The term usually implies the
intelligent copying of parts of the source database that have changed since the
last replication with the destination. Replication
may be one-way or two-way. Two-way replication is much more complicated because
of the possibility that a replicated object may have been updated differently in
the two locations in which case some method is needed to reconcile the different
versions.
Replication
Services – When
databases are geographically distributed, they are kept up to date from a
central source database through replication. Replication services propagate data
and transactions that occur in a central source database to each participating
remote database.
Reporting
Tool – Technologies used for complex reporting using DBMS data.
Repository
– Passive data dictionary or encyclopedia
that offers a single point of definition for all application components.
Repudiation
– Repudiation is the act of refusing to receive or acknowledging receipt of
a security authorization request. Non-Repudiation
is the security concept that protects "against denial of sending (or
receiving) a data item by the sender (or recipient).
Requirements
for Technical Architecture – The capabilities that the technical
architecture must provide in order to satisfy the business information
requirements.
Router
– Network device used to Interface between two networks.
Routers work at the Network layer of the Open Systems Interconnect (OSI)
reference model.
Rules-Based
System – A functional system in
which knowledge is stored in the form of simple if/then or condition/action
rules.
S
Scalable
– Able to meet demands
for increased performance, processing power, network connectivity, and data
storage.
Search
Engine – A program used for the cataloging and indexing of web
content for the purpose of locating desired information.
Security
Architecture – The Security Architecture defines the components and
functions necessary to ensure that the organization’s systems, applications
and data are secure from internal or external tampering and unauthorized.
It takes into consideration the functions of authentication,
authorization, encryption, access control, message integrity, non-repudiation
and auditing.
Security
Services – These
services include operational methods necessary to enable authenticated user
access to systems and data, virus detection methods to minimize risk to system
integrity, methods to permit remote access for trusted users, methods to enable
on-site access to untrusted users through IEA public rooms, and methods for
off-site access to public information available on IEA systems.
Services
– In an N-tier
service-oriented architecture, applications are partitioned into discrete units
of functionality called services.
Server
– A processor that provides a specific service to the network. In a
client/server architecture, servers perform central storage and other vital
tasks. Servers specialize in high-speed computation and data storage and
manipulation. They can range in size from PCs to mainframes.
Service
Level Agreement (
Session
– A period of continuous interaction
between and user agent and a server.
Shared
Data –
data available for use both within the Bureau and between multiple governmental
organizations. When shared data is used, it is stored and maintained once. It
can then be accessed by each system that needs it. Application systems do not
have to duplicate any efforts to collect, verify, store, and maintain data used
by multiple application systems, whether the application systems run in a single
location or in multiple locations across the Bureau.
Simple
Mail Transfer Protocol (SMTP)
– The standard for sending mail to and from the Internet.
Simple
Network Management Protocol (SNMP) – A Transmission Control Protocol/Internet Protocol
(TCP/IP)-derived protocol governing network management and the monitoring of
network devices.
Software
– Code, data, and documentation maintained in a specific configuration. The
entire set of programs, procedures, and related documentation associated with a
computer.
Source
– A place from which data is taken. Data is taken from a source,
whereas the place it is moved to is called the destination or target.
Spatial
Data Servers – have
emerged in a three-tier database architecture that provides a comprehensive GIS
solution. They provide an open interface between the user and all of the
geographic information in an organization. With this type of spatial data server
architecture, data can be delivered to any client, from any server, anywhere on
the network (within network performance constraints).
Steward
– One who has been assigned the
responsibility to provide day-to-day (operational/tactical) support and manage
the interests of a given data subject area, application area, technology,
process, business unit, organization, or asset, or who as a representative would
be impacted by change to these same interests.
Stove-Piping
– Building systems that do not interoperate or collaborate with each other
(e.g., unable to share data or application modules).
The
Structured Query Language (SQL) is
used to query and retrieve data from relational databases. Allows a client to
access only the data required to satisfy a request for data, cut network
traffic, or improve performance. An accepted standard that most relational
database products implement. The industry standard for SQL is ANSI Standard SQL.
SQL drivers are implemented by each RDBMS vendor to enable database access to
its proprietary database. Vendors may add extensions to the SQL language for
their proprietary databases. SQL provides an implementation for data retrieval
from an RDBMS. The use of SQL requires knowledge of the physical data store.
“Strong”
Passwords – A strong
password will consist of at least eight characters, contain a minimum of one
capitalized letter; one lower case letter, one numeric character, and one
special character (such as!@#$%^&*+=, etc.). Therefore, a password such as
J0hN^4sM1th, although still somewhat easy to remember, will require a brute
force password-guessing program that might take several days to crack the
password. An intruder who fails to guess a password rapidly will probably
abandon the effort to avoid detection.
Switches
– A network device working at the Data Link layer of the OSI model.
A switch has the same function as a bridge.
Synchronous
media, where participants
in computer-supported communication meet at the same time, and Asynchronous
media, where participants connect at different times and leave files and
messages for others to read and comment on. By way of example, telephony is
considered to be synchronous, while e-mail, often used for the same purpose, is
asynchronous.
System
– A system is composed of one or many applications executing against one or
more data stores.
Systems
Management –
Coordination and maintenance of all software on a client/server network,
including performance monitoring, applications distribution, version control,
user administration, job scheduling, data backup, security, and configuration
management.
System
Development Lifecycle (SDLC) – An SDLC provides an established procedure to approach the technical
aspects of a project. It provides
technical definition based on a phased sequential approach to systems
development. The intent of the SDLC
project breakdown is to define a logical, sequential group of activities and
deliverables that lead the team through the project phase by phase.
The
System Services Layer encompasses the
operating system, networking software, system management, file system, database
services, UI (user interface) library, and so on.
T
T1/T1C/T2/T3/T4
– A digital carrier system introduced by the Bell System in the
Technical
Architecture – the
strategy and standards for utilizing technology tools. The Technical
architecture defines the capabilities for loosely coupling components to service
a business process.
Three-Tier
Hardware Architecture –
involves three classes of
machines. The client is usually a PC; the middle tier is usually a workstation
server or a minicomputer; the back end is usually a mainframe. Two-tier
hardware architecture generally involves only the client and either a
middle-tier server or a mainframe.
Thin
Client – Since the major
components of a distributed object application are located on a server (or a network
of servers), the client-side application can be kept small and lightweight (that
is, “thin”). This allows more of
the clients' system resources to remain free while the bulk of the application
processing is performed on the high-end servers.
Three-Tier
Client/Server Model – Current IEA development uses a three-tier client/server
model. The first tier is the Web server layer where the user interface resides.
The second tier is the application server layer where the business rules reside.
The third tier is the database server layer where the data resides. Three-tier
client/server applications offer the following advantages:
Three-tier client/server applications can be easier to modify to
support changes in business rules; with three-tier client/server applications there is less
risk in modifying the code that implements any given business rule; three-tier
client/server applications can be made to support multiple user interfaces
(character, graphical, Web browser, telephones, etc.)
Topology
– The physical layout of a network, including the method of connection between
nodes on the network.
Trade
Studies – Requirements exist for technologies or products that must be chose
based on business requirements and selection criteria.
Transmission
Control Protocol/Internet Protocol (TCP/IP) – The Internet’s communication standard. It allows
different types of computers to share data on a network. Every transmission gets
broken down into standard-sized packets, like little envelopes of data. Each
packet carries an address, but no information about what is inside. A set of
protocols covering (approximately) the network and transport layers of the
seven-layer Open Systems Interconnection (OSI) network model. TCP/IP was
developed during a 15-year period under the auspices of the Department of
Defense. It has achieved de facto standard status, particularly as higher-level
layers over Ethernet. TCP/IP implementations are available on products from more
than 80 vendors, including IBM, Digital Equipment, AT&T, Data General and
Sun Microsystems. The biggest issue for TCP/IP is potential migration to the
International Standards Organization (ISO) protocols for Layers 3 and 4.
Trusted
User – A user that has
full access to all of the resources that the user requires. A trusted user can
be a IEA employee or an employee of another agency such as the Forest Service
that has access requirements (External
Trusted User).
In
a Two-Tier Client/Server Architecture,
application functionality is partitioned into two executable parts, or tiers. On
one model, one tier contains the code that implements a graphical user interface
(GUI) and the code that implements the business rules. This tier executes on
desktop workstations and requests data from the second application tier, which
usually executes on the machine where the application's data is stored. This
model is referred to as two-tier, fat
client because, while the application is partitioned into two tiers of
executable code, most of the application's code is contained in the tier
executing on the desktop workstation, the fat client.
U
Unified
Modeling Language (UML) – A de facto standard notation for modeling objects.
Untrusted
User – Any user not
granted access to IEA’s internal network. Includes the public.
Usability
– A system can be said to be “usable” when specified users, in specified
circumstances, with specified goals, can use it with effectiveness, efficiency
and satisfaction. Improving usability can be accomplished by applying practices
and techniques that help understand and meet the needs of users.
Utility – A program that performs a very specific task, usually related to managing system resources. Operating systems contain a number of utilities for managing disk drives, printers, and other devices. Utilities differ from applications mostly in terms of size, complexity and function. Utilities are sometimes installed as memory-resident programs.
V
VBScript
– A primary form of Microsoft’s Visual Basic (VB). It has been introduced as
Internet-oriented scripting language intended for providing client-side and
server-capable processing within Web pages.
Very
Large Database (VLDB) –
A database which contains 50 million rows or more.
Video
Conferencing – systems
that allow two-way or multi-way calling with live video, essentially a telephone
system with an additional visual component.
Virtual
Private Network (VPN) –
A network that is constructed by using public wires to connect nodes. A VPN is a
way of using a public network transport to form a secure network connection,
either between two enterprise sites (LAN to LAN) or between an individual and a
site (PC to LAN). The purpose of a VPN is to allow an organization such as the
IEA to extend its network trust perimeter over the public network without
sacrificing security. Using the Internet as a backbone, a VPN can securely and
cost-effectively connect IEA telecommuters, mobile workers, and external
customers (such as the USFS or MMS).
Visual
BASIC for Applications (VBA) – A Visual Basic system included with Windows 95 applications and used
for creating basic and customized programs.
Voice
Mail – A messaging tool
that receives and stores voice messages as well as serves as an automated
attendant to route incoming calls and messages.
VoiceXML
(VXML) – A high-level programming language able to handle text-to-speech
applications, output of audio files, and recognition of spoken input.
W
Web
Authoring Tools – A development environment used to create web
content.
Web
Browser – A program used to view, download, upload, and access documents
via Internet protocols. The scope
includes both browsers supported internally for intranet users, and browsers
supported externally for Internet users.
Webcasting
– (1) Delivery of a transmission to two or more “stations” at the same
time, such as over a bus-type local network or by satellite. (2) Protocol
mechanism whereby group and universal addressing is supported.
W3C
– World Wide Web Consortium.
White
Boards – are
a real-time technology that allows two or more people to view and draw on a
shared drawing surface, even from different locations. It can be used for
brainstorming and summarizing ideas, or to work collaboratively on a visual
problem, just as with a standard white board. Most shared white boards are
designed for informal conversation, but they may also serve structured
communications or more sophisticated drawing tasks, such as collaborative
graphic design, publishing, or engineering applications.
Wide
Area Network (WAN) – A
communications network that connects computing devices over geographically
dispersed locations. While a local-area network (LAN) typically services a
single building or location, a WAN covers a much larger area such as a city,
state or country. WANs can use either phone lines or dedicated communication
lines.
Wiring
– Low voltage cabling used to connect network devices at high
frequencies.
Workstation
– A single-user computer, typically with 32-bit messaging and integrated
graphics.
Workflow
Software – Software that automates an enterprise’s business
processes (i.e., the sequence of actions, activities, or tasks used to complete
a business process) and tracks their status (the status of each instance of the
process). Work can be assigned, routed, activated, and managed through
system-controlled rules that mirror business operations and decision processes.
World
Wide Web (WWW) –
Internet system for hypertext linking of multimedia documents, allowing users to
move from one Internet site to another and to inspect the information that is
available without using complicated commands and protocols.
Wrappering
– A process whereby legacy applications can be formed into components by
implementing code (i.e., a “wrapper”) that “wraps” an API around a
legacy service
X– Z
The
X.500 Directory Service provides a
lookup of names and addresses through the Directory
Information Base (DIB). It is a specification for global directory servers
and access. It was designed to work with the old X.400 directory service and
other message handling services. Each object stored in the DIB is grouped within
an hierarchy wherein common name objects are nested within organization-unit
objects (for example, “Finance Department”), which are, in turn, nested
organization objects (for example, “Nuts and Bolts, Incorporated”). X.500 is
an overall model for directory services that encompasses the overall namespace
and the protocol for querying and updating it. The protocol is known as
“Directory Access Protocol” (DAP).
XML
(Extensible Markup Language) – is used to
provide structure to data. For example, a water sample is extracted from a
stream and its temperature is measured as 12 Celsius. The measurement 12 is the
data while many other attributes of the measurement need to be recorded. The
units of measure (Celsius), the location of the measurement, the flow rate of
the stream, the specific type of thermometer used for the measurement, the
identification of the analyst and the clarity of the water sample are possible
attributes to record with the sample temperature. Recording the attributes with
the temperature results in the creation of information from the temperature
datum. XML provides a standard mechanism for structuring and recording data so
that it can be shared and understood by many systems and by people. XML uses
plain text instead of binary encodings. XML is self-describing. XML uses data
type definition (DTD) files to describe the format of the XML. Applications can
understand each other’s XML by exchanging DTDs. XML is maintained by the World
Wide Web Consortium (W3C).
X/Open
Systems Management (XSM) Reference Model – defines the required management interfaces and describes the components and
architecture required to build a comprehensive distributed systems management
environment.