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Wireless Networking Handbook
(Publisher: Macmillan Computer Publishing)
Author(s): Jim Geier
ISBN: 156205631x
Publication Date: 09/01/96
APPENDIX E Glossary
Symbols
- 10Base-2
- IEEE standard (known as thin ethernet) for 10 Mbps baseband ethernet over coaxial cable at a maximum distance of 185 meters.
- 10Base-5
- IEEE standard (known as thick ethernet) for 10 Mbps baseband ethernet over coaxial cable at a maximum distance of 500 meters.
- 10Base-F
- IEEE standard for 10 Mbps baseband ethernet over optical fiber.
- 10Broad-36
- IEEE standard for 10 Mbps broadband ethernet over broadband cable at a maximum distance of 3600 meters.
- 100Base-T
- IEEE standard for a 100 Mbps LAN.
- 802.11
- IEEE standard for wireless LANs that specifies Medium Access Control (MAC) and Physical Layer (PHY) specifications for 1 Mbps wireless connectivity between fixed, portable, and moving stations within a local area.
A
- Acceptance Testing
- Type of testing that determines whether the network is acceptable to the actual users. The users of the network should participate in developing acceptance criteria and running the tests.
- Access Point
- An interface between the wireless network and a wired network such as ethernet. Access points combined with a wired backbone support the creation of radio cells that facilitate roaming.
- Adaptive Routing
- A form of network routing whereby the path data packets traverse from a source to a destination node depending on the current state of the network. Normally with adaptive routing, routing information stored at each node changes according to some algorithm that calculates the best paths through the network.
- ADCCP (Advanced Data Communications Control Procedures)
- ANSI standard bit-oriented communications protocol.
- Agents
- Software modules that reside in network elements. Agents collect and store management information such as the number of error packets received by a network element.
- Algorithm
- A finite process for the solution to a problem.
- ALOHANET
- Computer sites allowed at seven campuses spread over four islands to communicate with the central computer on Oahu without using existing unreliable and expensive telephone lines.
- Alpha Test
- Product testing done by the vendor.
- Analog Cellular
- A telephone system that uses radio cells to provide connectivity among cellular phones. The analog cellular telephone system uses FM (Frequency Modulation) radio waves to transmit voice grade signals. To accommodate mobility, this cellular system will switch your radio connection from one cell to another as you move between areas. Every cell within the network has a transmission tower that links mobile callers to a Mobile Telephone Switching Office (MTSO).
- Analog Signal
- An electrical signal with an amplitude that varies continuously as time progresses.
- Analyst
- A person capable of gathering information and defining the needs of the users and the organization.
- ANSI (American National Standards Institute)
- The primary standards-forming body in the United States.
- ANSI FDDI (Fiber Distributed Data Interface)
- An ANSI standard for token passing networks. FDDI uses optical fiber and operates at 100 Mbps.
- ANSI X.12
- An ANSI standard for EDI.
- APD (Avalanche Photodiode)
- A high performance device used in an optical communication system that converts light into electrical signals. Normally, the APD is used in conjunction with an injection laser diode light source.
- Appliance
- Runs applications and is a visual interface between the user and the network. There are several classes of user appliancesthe desktop workstation, laptop, palmtop, pen-based computer, Personal Digital Assistant (PDA), and pager.
- Application Layer
- Establishes communications with other users and provides services such as file transfer and electronic mail to the end users of the network.
- Application Process
- An entity, either human or software, that uses the services offered by the Application Layer of the OSI Reference Model.
- Application Requirements
- Specify what specific applications users require.
- Application Software
- Accomplishes the tasks users require, such as word processing, database access, and electronic mail. Therefore, application software directly satisfies network requirements, particularly user requirements.
- ARDIS
- A company that leases access to its wireless WAN that is based on packet radio technology.
- ARP (Address Resolution Protocol)
- A TCP/IP protocol that binds logical (IP) addresses to physical addresses.
- ARPANET (Advanced Research Project Agency Network)
- A Department of Defense network that provided the groundwork for development of the Internet.
- ARQ (Automatic Repeat-Request)
- A method of error correction where the receiving node detects errors and uses a feedback path to the sender for requesting the retransmission of incorrect frames.
- Asynchronous Transmission
- Type of synchronization where there is no defined time relationship between transmission of frames.
- AT Bus
- A PC bus that supports 16 bit-data.
- ATM (Asynchronous Transfer Mode)
- A cell-based connection-oriented data service offering high speed (up to Gbps range) data transfer. ATM integrates circuit and packet switching to handle both constant and burst information.
- AUI (Attachment Unit Interface)
- A 15-pin interface between an ethernet network interface card and transceiver.
B
- Bandwidth
- Specifies the amount of the frequency spectrum that is usable for data transfer. In other words, it identifies the maximum rate a signal can fluctuate without encountering significant attenuation (loss of power).
- Baseband Signal
- A signal that has not undergone any shift in frequency. Normally with LANs, a baseband signal is purely digital.
- Baud Rate
- The unit of signaling speed derived from the duration of the shortest code element of the digital signal. Baud rate is the speed the digital signal pulses travel.
- Beta Testing
- Product testing done by potential users.
- Bit Rate
- The transmission rate of binary digits. Bit rate is equal to the total number of bits transmitted in relation to the time it takes to send them.
- Bridge
- A network component that provides internetworking functionality at the data link or medium access layer of a networks architecture. Bridges can provide segmentation of data frames.
- Bus Topology
- A type of topology where all nodes share a common transmission medium.
C
- Cabling Diagram
- Part of a design specification, illustrating the location of network hardware and the layout of cabling throughout the facility.
- CAD (Computer Aided Design) Software
- Applications that use vector graphics to create complex drawings.
- Carrier Current LAN
- A LAN that uses power lines within the facility as a medium for the transport of data.
- Category 1 Twisted-Pair Wire
- Old-style phone wire, which is not suitable for most data transmission. This includes most telephone wire installed before 1983, in addition to most current residential telephone wiring.
- Category 2 Twisted-Pair Wire
- Certified for data rates up to 4 Mbps, which facilitates IEEE 802.5 Token-Ring networks (4 Mbps version).
- Category 3 Twisted-Pair Wire
- Certified for data rates up to 10 Mbps, which facilitates IEEE 802.3 10Base-T (ethernet) networks.
- Category 4 Twisted-Pair Wire
- Certified for data rates up to 16 Mbps, which facilitates IEEE 802.5 Token-Ring networks (16 Mbps version).
- Category 5 Twisted-Pair Wire
- Certified for data rates up to 100 Mbps, which facilitates ANSI FDDI Token-Ring networks.
- CCITT (International Telegraph and Telephone Consultative Committee)
- An international standards organization that is part of the ITU and dedicated to establishing effective and compatible telecommunications among members of the United Nations. CCITT develops the widely used V-series and X-series standards and protocols.
- CDDI (Copper Data Distributed Interface)
- A version of FDDI specifying the use of unshielded twisted-pair wiring (Category 5).
- CDLC (Cellular Data Link Control)
- Public domain data communications protocol used in cellular telephone systems.
- CDPD (Cellular Digital Packet Data)
- Overlays the conventional analog cellular telephone system, using a channel-hopping technique to transmit data in short bursts during idle times in cellular channels. CDPD operates full duplex in the 800 and 900 Mhz frequency bands, offering data rates up to 19.2 Kbps.
- CDRH (Center for Devices and Radiological Health)
- The part of the U.S. Food and Drug Administration that evaluates and certifies laser products for public use.
- Centronics
- A de facto standard 36-pin parallel 200 Kbps asynchronous interface for connecting printers and other devices to a computer.
- CGA (Color/Graphics Adapter)
- An IBM video display standard providing low-resolution text and graphics.
- CGM (Computer Graphics Metafile)
- A standard format for interchanging graphics images.
- Channel Link
- Consists of the user patch cords, horizontal cross connect, and horizontal wiring. A channel link can span a total of 100 meters.
- CLNP (Connectionless Network Protocol)
- An OSI protocol for providing the OSI Connectionless Network Service (datagram service). CLNP is similar to IP.
- CMIP (Common Management Information Protocol)
- An ISO network monitoring and control standard.
- CMIS (Common Management Information Services)
- An OSI standard defining functions for network monitoring and control.
- CMOL (CMIP over LLC)
- A version of CMIP that runs on IEEE 802 LANs.
- CMOT (CMIP over TCP)
- A version of CMIP that runs on TCP/IP networks.
- Coaxial Cable
- Type of medium having a solid metallic core with a shielding as a return path for current flow. The shielding within the coaxial cable reduces the amount of electrical noise interference within the core wire; therefore, coaxial cable can extend to much greater lengths than twisted-pair wiring.
- Constraints
- Requirements that are impossible or infeasible to change. Constraints limit the project teams options in completing the project. Common constraints are amount of funding, technical requirements, availability of resources, type and location of project staff, and schedules.
- Communications Cabinet Drawings
- Illustrate the placement of network components that require mounting within communications cabinets.
- Concept of Operations
- Defines system-level functionality, operational environment, and implementation priorities of an information system. Project team members use the concept of operations as a basis for planning the development and determining the requirements of the information system.
- Connectivity
- A path for communications signals to flow through. Connectivity exists between a pair of nodes if the destination node can correctly receive data from the source node at a specified minimum data rate.
- Customer Focal Point
- Represents the interests of the people who will be using the network. The customer focal point aims the project team in the right direction when gathering information determining requirements.
D
- Datagram Service
- A connectionless form of packet switching whereby the source does not need to establish a connection with the destination before sending data packets.
- DB-9
- A standard 9-pin connector commonly used with RS-232 serial interfaces on portable computers. The DB-9 connector will not support all RS-232 functions.
- DB-15
- A standard 15-pin connector commonly used with RS-232 serial interfaces, ethernet transceivers, and computer monitors.
- DB-25
- A standard 25-pin connector commonly used with RS-232 serial interfaces. The DB-25 connector will support all RS-232 functions.
- DES (Data Encryption Standard)
- A cryptographic algorithm that protects unclassified computer data. DES is a National Institute of Standards and Technology (NIST) standard and is available for both public and government use.
- Design
- Process that determines how the network will meet requirements. Design involves the selection of technologies, standards, and products that provide a solution to the stated requirements.
- Design Phase
- Consists of selecting a set of technologies, standards, and products that satisfy requirements.
- Design Specifications
- Describe the technologies, standards, components, and configurations of hardware and software comprising the network.
- Desktop Conferencing
- An application enabling users to have televideo conferences directly from PCs located in their offices. Users who participate in a desktop conference can hear and see a video image of each participant. Desktop conferences also enable participants to jointly edit documents and facilitate electronic white boards.
- Desktop Publishing Software
- Applications that provide the ability to effectively merge text and graphics and maintain precise control of the layout of each page of the document.
- Detailed Design
- The final phase of network design that selects components and finalizes network configurations and documentation.
- Diffused Laser Light
- Type of laser transmission where the light is reflected off a wall or ceiling.
- Direct Sequence Spread Spectrum
- Combines a data signal at the sending station with a higher data rate bit sequence, which many refer to as a chip sequence (also known as processing gain). A high processing gain increases the signals resistance to interference. The minimum processing gain that the FCC allows is 10, and most products operate under 20.
- Directional Antenna
- Type of antenna that sends radio waves primarily in one direction.
- Distributed Routing
- A form of routing where each node (router) in the network periodically identifies neighboring nodes, updates its routing table, and, with this information, then sends its routing table to all of its neighbors. Because each node follows the same process, complete network topology information propagates through the network and eventually reaches each node.
- Document Management
- An application enabling users to effectively manage and access information contained within different file types. Most document management software enables users to manipulate both data and images, as well as easily manage files through indexing, search, and query functions.
- DQDB (Distributed Queue Dual Bus)
- A technology that provides full duplex 155 Mbps operation between nodes of a metropolitan area network. The IEEE 802.6 standard is based on DQDB.
- DSU/CSU (Data Service Unit/Channel Service Unit)
- A network component that reshapes data signals into a form that can be effectively transmitted over a digital transmission medium, typically a leased 56 Kbps or T1 line.
- Dynamic Host Configuration Protocol (DHCP)
- Issues IP addresses automatically within a specified range to devices such as PCs when they are first powered on. The device retains the use of the IP address for a specific license period that the system administrator can define. DHCP is available as part of the Microsoft Windows NT Server network operating system.
E
- EGA (Enhanced Graphics Adapter)
- An IBM video display standard providing medium-resolution text and graphics.
- EIA (Electronics Industry Association)
- A domestic standards-forming organization that represents a vast number of United States electronics firms.
- EISA (Extended ISA)
- A PC bus standard that extends the 16-bit ISA bus to 32 bits and runs at 8 MHz.
- Electronic Data Interchange (EDI)
- A service that provides standardized inter-company computer communications for business transactions. ANSI standard X.12 defines the data format for business transactions for EDI.
- Environmental requirements
- Report conditions, such as weather, pollution, presence and intensity of electromagnetic waves, building construction, and floor space that could affect the operation of the system.
- Ethernet
- A 10 Mbps LAN medium-access method that uses CSMA to allow the sharing of a bus-type network. IEEE 802.3 is a standard that specifies ethernet.
F
- FDDI (Fiber Distributed Data Interface)
- An ANSI standard for token-passing networks. FDDI uses optical fiber and operates at 100 Mbps.
- FEC (Forward Error Correction)
- A method of error control where the receiving node automatically corrects as many channel errors as it can without referring to the sending node.
- File Transfer
- Capability to send files from one computer to another. File transfer mechanisms enable you to move a file from a disk directory on one computer to that of another. The File Transfer Protocol (FTP), a de facto standard, is a popular protocol for transferring files. Issues involved with file transfer include file size and type. The larger the file, the more bandwidth it takes to deliver, possibly making it infeasible to send very large files. Some networks will only support the transfer of text-only files, but other networks are capable of sending binary files as well.
- Firewall
- A device that interfaces the network to the outside world and shields the network from unauthorized users. The firewall does this by blocking certain types of traffic. For example, some firewalls permit only electronic mail traffic to enter the network from elsewhere. This helps protect the network against attacks made to other network resources, such as sensitive files, databases, and applications.
- Fractional T-1
- A 64 Kbps increment of a T1 frame.
- Frame Relay
- A packet-switching interface that operates at data rates of 56 Kbps to 2 Mbps. Actually, frame relay is similar to X.25, minus the transmission error control overhead. Thus, frame relay assumes that a higher layer, end-to-end protocol will check for transmission errors. Carriers offer frame relay as permanent connection-oriented (virtual circuit) service.
- Frequency-Hopping Spread Spectrum
- Takes the data signal and modulates it with a carrier signal that hops from frequency to frequency as a function of time over a wide band of frequencies. For example, a frequency-hopping radio will hop the carrier frequency over the 2.4 GHz frequency band between 2.4 GHz and 2.483 GHz. A hopping code determines the frequencies it will transmit and in which order. To properly receive the signal, the receiver must be set to the same hopping code and listen to the incoming signal at the right time at the correct frequency.
- FTAM (File Transfer, Access, and Management)
- An OSI remote file service protocol.
- FTP (File Transfer Protocol)
- A TCP/IP protocol for file transfer.
- Fully-Connected Topology
- A topology where every node is directly connected to every other node in the network.
- Functional Requirements
- Describe what the users and organization expect the system to do. Therefore, functional requirements closely align to the tasks and actions users perform.
G
- Gateway
- A network component that provides interconnectivity at higher network layers. For example, electronic mail gateways can interconnect dissimilar electronic mail systems.
- Global Positioning System (GPS)
- a worldwide, satellite-based radio navigation system providing three-dimensional position, velocity and time information to users having GPS receivers anywhere on or near the surface of the Earth.
H
- Hardware
- Physical elements containing the electronics necessary to move, store, and display information on the network. The hardware provides connectivity between the users and information stored in memory devices. Hardware, such as monitors and printers, provides a means to view the information. Other examples of network hardware elements include network interface cards, server and client platforms, cabling, bridges, and routers.
- Hardware Configuration Plan
- Identifies how the team should configure hardware the network utilizes.
- Hardware Platform
- A computer that provides necessary processors and file storage. The processors execute the program code, enabling the software to run. The file storage facilitates the storage of software programs and data files. With a network, applications and network operating systems normally reside on some type of hardware platform.
- HDLC (High-level Data Link Control)
- An ISO bit-oriented protocol for link synchronization and error control.
- Help Desk
- A central point of contact for users needing assistance when using the network and its resources.
- Hierarchical Topology
- A topology where nodes in the same geographical area are joined together, then tied to the remaining network as groups. The idea of a hierarchical topology is to install more links within high density areas and fewer links between these populations.
- HSSI (High-Speed Serial Interface)
- A standard for up to 52 Mbps serial connections, often used to connect T3 lines.
- HTML (HyperText Markup Language)
- A standard used on the Internet World Wide Web for defining hypertext links between documents.
I
- IEEE (Institute of Electrical and Electronic Engineers)
- A United States-based standards organization participating in the development of standards for data transmission systems. IEEE has made significant progress in the establishment of standards for LANs, namely the IEEE 802 series of standards.
- IEEE 802.1
- IEEE standard for network management.
- IEEE 802.1D
- IEEE standard for inter-LAN bridges.
- IEEE 802.2
- IEEE standard for Logical Link Control (LLC).
- IEEE 802.3
- IEEE standard for CSMA/CD (ethernet) LAN access.
- IEEE 802.4
- IEEE standard for token-bus LAN multiple access.
- IEEE 802.5
- IEEE standard for token-ring LAN multiple access.
- IEEE 802.6
- IEEE standard for DQDB metropolitan area network multiple access.
- IEEE 802.7
- IEEE standard for broadband LANs.
- IEEE 802.9
- IEEE standard for integrated digital and video networking.
- IEEE 802.10
- IEEE standard for network security.
- IEEE 802.11
- IEEE standard for wireless LANs.
- IEEE 488
- IEEE standard for computer-to-electronic instrument communication.
- IEEE 802.12
- IEEE standard for a demand priority LAN access (also called Fast Ethernet).
- IEEE 1284
- IEEE standard for an enhanced parallel port compatible with the Centronics parallel port.
- Information Flow Requirements
- Specify the paths of information flow between people and system, types and formats of information sent, frequency of information transmission, and maximum allowable error rates.
- Infoware
- Applications that provide online encyclopedias, magazines, and other references.
- Infrared Light
- Light waves having wavelengths ranging from about 0.75 to 1,000 microns, which is longer (lower in frequency) than the spectral colors but much shorter (higher in frequency) than radio waves. Therefore, under most lighting conditions, infrared light is invisible to the naked eye.
- Infrared Light LAN
- A LAN that uses infrared light as its medium.
- Installation Plan
- Describes the tools and procedures necessary for an installation team to install and test network hardware and software components.
- Instructor Guide
- Explains how to teach a particular course. This is especially useful if the instructors are people who were not involved in the course development.
- Integration Testing
- Type of testing that verifies the interfaces between network components as the components are installed. The installation crew should integrate components into the network one-by-one and perform integration testing when necessary to ensure proper gradual integration of components.
- Internetwork
- A collection of interconnected networks. Often it is necessary to connect networks together, and an internetwork provides the connection between different networks. One organization having a network may want to share information with another organization having a different network. The internetwork provides functionality needed to share information between these two networks.
- Internetworking
- A mechanism defining the communications process necessary to connect two dissimilar autonomous networks.
- Inward Interference
- Interference coming from other devices, such as microwave ovens and other wireless network devices, that will result in delay to the user by either blocking transmissions from stations on the LAN, or by causing bit errors to occur in data being sent.
- ISA (Industry Standard Architecture)
- A widely used PC expansion bus that accepts plug-in boards, such as ethernet cards, video display boards, and disk controllers. ISA was originally called the AT bus because it was first used in the IBM AT, extending the original bus from eight to 16 bits. Most ISA PCs provides a mix of 8-bit and 16-bit expansion slots. Contrast with EISA and Micro Channel.
- ISDN (Integrated Services Digital Network)
- A collection of CCITT standards specifying WAN digital transmission service. The overall goal of ISDN is to provide a single physical network outlet and transport mechanism for the transmission of all types of information, including data, video, and voice.
- IS-IS (Intermediate System to Intermediate System) Protocol
- An OSI protocol for intermediate systems exchange routing information.
- ISM (Industrial, Scientific, and Medicine)
- Radio frequency bands that the Federal Communications Commission (FCC) authorized for wireless LANs. The ISM bands are located at 902 MHz, 2.400 GHz, and 5.7 GHz.
- ISO (International Standards Organization)
- A non-treaty standards organization active in the development of international standards such as the Open System Interconnection (OSI) network architecture.
- ISO 7498
- ISO standard for the Open System Interconnection (OSI) basic reference model.
- ISO 9001
- ISO standards for quality design, development, production, installation, and service procedures.
- Isochronous Transmission
- Type of synchronization where information frames are sent at specific times.
- ITU (International Telecommunications Union)
- An agency of the United States providing coordination for the development of international standards.
J
- Joint Application Design (JAD)
- A parallel process simultaneously defining requirements in the eyes of the customer, users, sales people, marketing staff, project managers, analysts, and engineers. You can use the members of this team to define requirements.
- JPEG (Joint Photographic Experts Group)
- An ISO standard for lossy compression.
L
- Lantastic
- A peer-to-peer network operating system by Artisoft, Inc.
- LAP (Link Access Procedure)
- An ITU error correction protocol derived from the HDLC standard.
- LAP-B (LAP-Balanced)
- LAP protocol used in X.25 networks.
- LAP-D (LAP-D channel)
- LAP protocol used in the data channel of ISDN networks.
- LAP-X (LAP-Half-dupleX)
- LAP protocol used for ship-to-shore transmission.
- LASER
- Is a common term for Light Amplification by Stimulated Emission of Radiation, a device containing a substance where the majority of its atoms or molecules are put into an excited energy state. As a result, the laser emits coherent light of a precise wavelength in a narrow beam. Most laser MANs use lasers that produce infrared light.
- Learning Objectives
- A training development element specifying what students are expected to do after receiving instruction.
- LED (Light Emitting Diode)
- Used in conjunction with optical fiber, it emits incoherent light when current is passed through it. Advantages to LEDs include low cost and long lifetime, and they are capable of operating in the Mbps range.
- Local Area Network (LAN)
- A computer network confined to a local area, such as a building. The specific uses of a LAN include inter-office communications and peripheral sharing. Usually, a LAN is owned by a single funding organization. That is, a single department, division or organization will normally independently purchase and install the LAN hardware and software.
- Local Bridge
- A bridge that connects two LANs within close proximity.
M
- Mail Gateway
- A type of gateway that interconnects dissimilar electronic mail systems.
- Maintenance
- An operational support function that performs preventative maintenance on the network and troubleshoots and repairs the network if it becomes inoperable.
- Management Information Base (MIB)
- A collection of managed objects residing in a virtual information store.
- MAP (Manufacturing Automation Protocol)
- A protocol used extensively by General Motors for automated factory floor equipment.
- MAU (Multi-station Access Unit)
- A multiport wiring hub for token-ring networks.
- MCA (Micro Channel Architecture)
- An internal 32-bit bus originally introduced by IBM.
- Medium
- A physical link that provides a basic building block to support the transmission of information signals. Most media are composed of either metal, glass, plastic, or air.
- Medium Access
- A data link function that controls the use of a common network medium.
- Meteor Burst Communications
- A communications system that directs a radio wave, modulated with a data signal, at the ionosphere. The radio signal reflects off the ionized gas left by the burning of meteors entering the atmosphere and is directed back to Earth in the form of a large footprint, enabling long distance operation.
- MHS (Message Handling Service)
- A Novell messaging system that supports multiple operating systems and messaging protocols.
- MIB (Management Information Base)
- A collection of objects that can be accessed via a network management protocol.
- Microsoft Windows NT Server
- A server-oriented network operating system offering excellent support of applications, as well as file and print services.
- MIPS (Million Instructions Per Second)
- Identifies the number of instructions a computer processes over time. High-speed personal computers, such as pentiums, are usually capable of operating at 100 MIPS or greater. A 386 PC usually runs between 3 to 5 MIPS. However, MIPS rates are not uniform because some vendors use the best case value of the platform and others use average rates.
- MIDI (Musical Instrument Digital Interface)
- A standard protocol for the interchange of musical information between musical instruments and computers.
- Mobility
- Ability to continually move from one location to another.
- Mobility Requirements
- Describe the movement of the users when performing their tasks. Mobility requirements should distinguish whether the degree of movement is continuous or periodic.
- Modulation
- The process of translating the baseband digital signal to a suitable analog form.
- Motif
- A standard GUI for Unix. Motif is endorsed by the Open Software Foundation.
- MPEG (Moving Pictures Experts Group)
- An ISO standard for lossless compression of full-motion video.
- Multimedia
- The integration of graphics, text, and sound into a single application.
- Multimedia Software
- Applications that add graphics, sound, and video for use in education and specialized applications.
- Multiplexer
- A network component that combines multiple signals into one composite signal in a form suitable for transmission over a long-haul connection, such as leased 56 Kbps or T1 circuits.
N
- Narrowband System
- A wireless system that uses dedicated frequencies assigned by the FCC licenses. The advantage of narrowband systems is that if interference occurs, the FCC will intervene and issue an order for the interfering source to cease operations. This is especially important when operating wireless MANs in areas having a great deal of other operating radio-based systems.
- NetBEUI
- A protocol that governs data exchange and network access. NetBEUI is Microsofts version of NetBIOS.
- NetBIOS (Network Basic Input Output System)
- A standard interface between networks and PCs.
- NetWare
- A server-based network operating system by Novell, Inc.
- NetWare Loadable Module (NLM)
- An application co-existing with the core NetWare network operating system.
- Network Documentation
- A description of the network that identifies and describes all hardware, software, protocols, people, and operating environments. Complete documentation identifies a baseline that describes the current makeup of the system. Documentation is very important because it allows people to effectively use and maintain the system.
- Network Interface Card (NIC)
- An external modem that facilitates the modulator and communications protocols.
- Network Layer
- Provides the routing of packets from source to destination.
- Network Management
- Consists of a variety of elements that protect the network from disruption and provide proactive control of the configuration of the network.
- Network Management Station (NMS)
- Executes management applications that monitor and control network elements.
- Network Monitoring
- A form of operational support enabling network management to view the inner-workings of the network. Most network monitoring equipment is non-obtrusive and can determine the networks utilization and locate faults.
- Network Operating System (NOS)
- A network component that provides a platform for network applications to operate. A NOS normally offers communications, printing, and file services for applications residing on the network.
- Network Re-engineering
- A structured process that can help an organization proactively control the evolution of its network. Network re-engineering consists of continually identifying factors influencing network changes, analyzing network modification feasibility, and performing network modifications as necessary.
- Network Requirements
- Define detailed functional and system requirements, operational environment, and constraints of the network.
- Network Security
- A form of operational support that attempts to protect the network from compromise and destruction, as well as make sure the network will be available when needed. Network security includes elements such as access control, data encryption, and data backup.
- NFS (Network File System)
- A distributed file system enabling a set of dissimilar computers to access each others files in a transparent manner.
- Node
- Any network-addressable device on the network, such as a router or network interface card.
- NSAP (Network Service Access Point)
- A point in the network where OSI network services are available to a transport entity.
O
- ODI (Open Data-Link Interface)
- Novells specification for network interface card device drivers, allowing simultaneous operation of multiple protocol stacks.
- Office Software
- Applications that typical office personnel use, such as word processing, databases, spreadsheets, graphics, and electronic mail.
- Omnidirectional Antenna
- Type of antenna that sends radio waves in all directions.
- Operating Environment
- The physical location where the network will operate.
- Operational Support Plan
- Describes how the organization will support the operational network in terms of system administration, network monitoring and control, accounting and chargeback, maintenance, security, configuration management, training, and system re-engineering.
- Operational Support Preparation Phase
- The planning necessary to effectively support the system after it is installed. Preparations include training development and delivery, and plans for support elements such as maintenance, system administration, and security.
- Operational Support Requirements
- Define any elements needed to effectively integrate the system into the existing operational support infrastructure. For example, you should require the inclusion of Simple Network Management Protocol (SNMP) if current network monitoring stations require SNMP.
- Operator Profiles
- Identify and describe attributes of each person who will be operating the system.
- Optical Fiber
- A type of medium that uses changes in light intensity to carry information through glass or plastic fibers.
- OSI (Open System Interconnection)
- An ISO standard specifying an open system capable of enabling the communications between diverse systems. OSI has seven layers of distinction. These layers provide the functions necessary to allow standardized communications between two application processes.
- OSPF (Open Shortest Path First)
- Routing protocol for TCP/IP routers.
P
- Packet Radio
- Uses packet switching to move data from one location to another across radio links.
- PCM (Pulse Code Modulation)
- A common method for converting analog voice signals into a digital bit stream.
- PCMCIA (Personal Computer Memory Card International Association)
- A standard set of physical interfaces for portable computers. PCMCIA specifies three interface sizesType I (3.3 millimeters), Type II (5.0 millimeters), and Type III (10.5 millimeters).
- Peer-to-Peer Network
- A network where there are communications between a group of equal devices. A peer-to-peer LAN does not depend upon a dedicated server, but allows any node to be installed as a non-dedicated server and share its files and peripherals across the network. Peer-to-peer LANs are normally less expensive because they do not require a dedicated computer to store applications and data. They do not perform well, however, for larger networks.
- Performance Modeling
- The use of simulation software to predict network behavior, allowing you to perform capacity planning. Simulation allows you to model the network and impose varying levels of utilization to observe the effects.
- Performance Monitoring
- Addresses performance of a network during normal operations. Performance monitoring includes real-time monitoring, where metrics are collected and compared against thresholds that can set off alarms; recent-past monitoring, where metrics are collected and analyzed for trends that may lead to performance problems; and historical data analysis, where metrics are collected and stored for later analysis.
- Performance Requirements
- Identify expected values for reliability, availability, and delay.
- Peripherals
- Items such as printers, fax machines, and modems.
- Personal Communications Services (PCS)
- A spectrum allocation located at 1.9 GHz, a new wireless communications technology offering wireless access to the World Wide Web, wireless e-mail, wireless voice mail, and cellular telephone service.
- Physical Layer
- Provides the transmission of bits through a communication channel by defining electrical, mechanical, and procedural specifications.
- Polymorphic Virus
- A virus that, to avoid identification, changes its binary pattern each time it infects a new file.
- Portability
- Defines network connectivity that can be easily established, used, then dismantled.
- POSIX (Portable Operating System Interface for Unix)
- An IEEE 1003.1 standard defining the interface between application programs and the Unix operating system.
- POTS (Plain Old Telephone System)
- The common analog telephone system developed many years ago for voice communications.
- PPP (Point-to-Point Protocol)
- A protocol that provides router-to-router and host-to-network connections over both synchronous and asynchronous circuits. PPP is the successor to SLIP.
- Presentation Layer
- Negotiates data transfer syntax for the application layer and performs translations between different data types, if necessary.
- Project Charter
- Formally recognizes the existence of the project, identifies the business need that the project is addressing, and gives a general description of the resulting product.
- Project Management
- Overseers needed to make sure actions are planned and executed in a structured manner.
- Protocols
- Rules that the system must follow to operate correctly. Most network protocols are based on technology and describe rules for communications among system hardware and software elements. These rules govern format, timing, sequencing, and error control. Without protocols, system elements would not be able to make sense of communications from other elements. Most systems have sets of protocols often referred to as protocol stacks. Many protocols have been established as standards, approved by various national or international organizations. Examples of protocols include ethernet, token-ring, and X.400.
- Prototyping
- A method of determining or verifying requirements and design specifications. The prototype normally consists of network hardware and software that support a proposed solution. The approach to prototyping is typically a trial-and-error experimental process.
R
- RAM Mobile Data
- A company that leases access to its wireless WAN that is based on packet radio technology.
- Red Book
- A document of the United States National Security Agency (NSA) defining criteria for secure networks.
- Relay Node
- Implements a routing protocol that maintains the optimum routes for the routing tables, forwarding packets closer to the destination.
- Remote Bridge
- A bridge that connects networks separated by longer distances. Organizations use leased 56 Kbps circuits, T1 digital circuits, and radio waves to provide long distance connections between remote bridges.
- Repeater
- A network component that provides internetworking functionality at the physical layer of a networks architecture. A repeater regenerates digital signals.
- Requirements
- Identify what the network is supposed to do, not how its supposed to do it. Requirements are crucial in all development projectsthey provide the basis for design, implementation, and support of the system or product.
- Requirements Analysis
- A process of defining what the network is supposed to do, providing a basis for the network design.
- Requirements Phase
- Defines the needs of the users and the organization of the eventual network or system, providing the basis for a solution.
- Resource Requirements
- Identify people and equipment the project will need to accomplish the projects goals.
- Resource Sharing
- A network service allowing users of the network to share the use of network resources, such as printers, disk drives, applications, modems, and fax machines.
- Ring Topology
- A topology where a set of nodes are joined in a closed loop.
- Router
- A network component that provides internetworking at the network layer of a networks architecture by allowing individual networks to become part of a WAN.
- Routing Information Protocol (RIP)
- A common type of routing protocol. RIP bases its routing path on the distance (number of hops) to the destination. RIP maintains optimum routing paths by sending out routing update messages if the network topology changes. For example, if a router finds that a particular link is faulty, it will update its routing table, then send a copy of the modified table to each of its neighbors.
- RS
- Recommended Standard.
- RS-232
- An EIA standard for up to 20 Kbps, 50 foot, serial transmission between computers and peripheral devices.
- RS-422
- An EIA standard specifying electrical characteristics for balanced circuits. RS-422 is used in conjunction with RS-449.
- RS-423
- An EIA standard specifying electrical characteristics for unbalanced circuits. RS-423 is used in conjunction with RS-449.
- RS-449
- An EIA standard specifying a 37-pin connector for high-speed transmission.
- RS-485
- An EIA standard for multipoint communications lines.
S
- SAP (Service Access Point)
- A point at which the services of an OSI layer are made available to the next higher layer.
- Schematic
- A drawing that is normally part of a design specification and illustrates the electrical connections between network hardware components. The schematic serves two main purposes: the installation team uses the schematic to properly install the network, and maintenance technicians use the schematic to facilitate effective troubleshooting.
- SCI (Scalable Coherent Interface)
- An IEEE standard for a high-speed (up to 1 Gbps) bus.
- Scientific Applications
- Applications that provide the analysis of real-world events by simulating them with mathematics.
- Security Requirements
- Identify what information and systems require protection from particular threats. The degree of security requirements depends on the severity of the consequences the organization would face if it lost information or part of the system were destroyed.
- Server-Oriented Network
- A network architecture where the network software is split into two pieces, one each for the client and the server. The server component provides services for the client software; the client part interacts with the user. The client and server components run on different computers, and the server is usually more powerful than the client. The main advantages of a server-oriented network is less network traffic. Therefore, networks having a large number of users will normally perform better with server-oriented networks.
- Session Layer
- Establishes, manages, and terminates sessions between applications.
- SIMM (Single In-line Memory Module)
- Standard packaging for PC memory.
- SLIP (Serial Line Internet Protocol)
- An Internet protocol used to run IP over serial lines.
- SMDS (Switched Multimegabit Digital Service)
- A packet switching connectionless data service for WANs.
- SMTP (Simple Mail Transfer Protocol)
- The Internet electronic mail protocol.
- SNA (Systems Network Architecture)
- IBMs proprietary network architecture.
- SNMP (Simple Network Monitoring Protocol)
- A network management protocol that defines the transfer of information between Management Information Bases (MIBs). Most high-end network monitoring stations require the implementation of SNMP on each of the components the organization wishes to monitor.
- Software Configuration Plan
- Identifies how the team should configure software the network uses.
- SONET (Synchronous Optical NETwork)
- A fiber optic transmission system for high-speed digital traffic. SONET is part of the B-ISDN standard.
- Spectrum Analyzer
- An instrument that identifies the amplitude of signals at various frequencies.
- Spread Spectrum
- A modulation technique that spreads a signals power over a wide band of frequencies. The main reasons for this technique is that the signal becomes much less susceptible to electrical noise and interferes less with other radio-based systems.
- SQL (Structured Query Language)
- An international standard for defining and accessing relational databases.
- ST Connector
- An optical fiber connector that uses a bayonet plug and socket.
- Star Topology
- A topology where each node is connected to a common central switch or hub.
- Statement Of Work (SOW)
- Describes what needs to be done to accomplish the network modification.
- Stealth Virus
- A virus that is undetectable.
- Switched Multimegabit Data Service (SMDS)
- A packet switching interface that operates at data rates ranging from 1.5 Mbps to 45 Mbps. SMDS is similar to frame relay, except SMDS provides connectionless (datagram) service.
- Synchronous Transmission
- Type of synchronization where information frames are sent within certain time periods.
- System Administration
- Type of operational support that provides a human interface between the system and its users. A system administrator assigns user addresses and log-in passwords, allocates network resources, and performs some network security functions.
- System Interface Requirements
- Describe the architectures of these systems and know the hardware, software, and protocols necessary for proper interfacing.
- System Testing
- Type of testing that verifies the installation of the entire network. Testers normally complete system testing in a simulated production environment, simulating actual users in order to ensure the network meets all stated requirements.
T
- T1
- A standard specifying a time division multiplexing scheme for point-to-point transmission of digital signals at 1.544 Mbps.
- TCP (Transmission Control Protocol)
- A common standard transport layer protocol.
- TDR (Time-Domain Reflectometer)
- Tests the effectiveness of network cabling.
- Technical Interchange Meeting (TIM)
- Addresses technical issues needing attention by project team members and customer representatives. A TIM is effective if the solution to a technical requirement or problem cannot be adequately solved by a single team member.
- Technical Service Bulletin (TSB) 67
- Describes how to test Category 5 twisted-pair cable. TSB 67 was published by the Link Performance Task Group, a subcommittee of the Telecommunications Industry Associations TR41 Standards Committee.
- Technology Comparison Matrix
- A documentation method that compares similar technologies based on attributes such as functionality, performance, cost, and maturity.
- Telecommuting
- The concept of electronically stretching an office to a persons home.
- Telnet
- A virtual terminal protocol used in the Internet, enabling users to log into a remote host.
- Terminal Node Controllers (TNCs)
- Interface their computers through ham radio equipment. These TNCs act much like a telephone modem, converting the computers digital signal into one that a ham radio can modulate and send over the airwaves using a packet switching technique.
- Test Case
- An executable test with a specific set of input values and a corresponding expected result.
- Token Ring
- A medium access method that provides multiple access to a ring type network through the use of a token. FDDI and IEEE 802.5 are token-ring standards.
- TOP (Technical and Office Protocol)
- A protocol used extensively by General Motors to exchange information between the factory floor and engineering offices.
- Top-Down Design
- First defines high-level specifications directly satisfying network requirements, then defines the remaining elements in an order that satisfies the most specifications already determined.
- Topography
- A description of the networks physical surface spots. Topography specifies the type and location of nodes with respect to one another.
- Topology
- A description of the networks geographical layout of nodes and links.
- TP0
- OSI Transport Protocol Class 0 (Simple Class), useful only with very reliable networks.
- TP4
- OSI Transport Protocol Class 4 (Error Detection and Recovery Class), useful with any type of network. The functionality of TP4 is similar to TCP.
- Transceiver
- A device for transmitting and receiving packets between the computer and the medium.
- Transmission Control Protocol (TCP)
- A commonly used protocol for establishing and maintaining communications between applications on different computers. TCP provides full-duplex, acknowledged, and flow-controlled service to upper-layer protocols and applications.
- Transport Layer
- Provides mechanisms for the establishment, maintenance, and orderly termination of virtual circuits, while shielding the higher layers from the network implementation details.
- Twisted Pair
- Type of medium using metallic type conductors twisted together to provide a path for current flow. The wire in this medium is twisted in pairs to minimize the electromagnetic interference between one pair and another.
U
- Unit Testing
- Type of testing that verifies the accuracy of each network component, such as servers, cables, hubs, and bridges. The goal of unit testing is to make certain the component works properly by running tests that fully exercise the internal workings of the component.
- Unix
- A multiuser and multitasking operating system originally developed by AT&T.
- UPS (Uninterruptible Power Supply)
- A network component that provides a short supply of power to servers and other critical devices if power discontinues.
- User Interface
- Mechanism that enables users to access network services.
- User Manual
- A document providing user-level procedures on how to log in and utilize network services and applications.
- User Profile Requirements
- Identify the attributes of each person who will be using the system, providing human factors that designers can use to select or develop applications.
V
- V.21
- An ITU standard for asynchronous 0-300 bps full-duplex modems.
- V.21 FAX
- An ITU standard for facsimile operations at 300 bps.
- V.22
- An ITU standard for asynchronous and synchronous 600 and 1200 bps full-duplex modems.
- V.22 bis
- An ITU standard for 2,400 bps duplex modems.
- V.23
- An ITU standard for asynchronous and synchronous 0-600 and 0-1200 bps half-duplex modems.
- V.32
- An ITU standard for asynchronous and synchronous 4800 and 9600 bps full-duplex modems.
- V.32terbo
- An AT&T standard for 19,200 bps modems.
- V.33
- An ITU standard for synchronous 12,000 and 14,400 bps full-duplex modems.
- V.34
- An ITU standard for 28,800 bps modems.
- V.35
- An ITU standard for group band modems combining several telephone circuits to achieve high data rates.
- V.42
- An ITU standard for modem error checking.
- Vertical Market Applications
- Applications that provide customized data entry, query, and report functions for various industries, such as insurance and banking.
- VGA (Video Graphics Array)
- An IBM video display standard.
- VINES
- A server-oriented network operating system by Banyan, Inc.
- Virus
- Software that infects a computer and causes it to malfunction and destroy data.
W
- Wide Area Network (WAN)
- A type of network that makes long-haul, inter-office communications possible. WANs provide information transport between LANs and users, often over a wide geographical area.
- Wireless MAN
- Provides communications links between buildings, avoiding the costly installation of cabling or leasing fees and the down time associated with system failures.
- Wireless Network Interface
- Couples the digital signal from the end-user appliance to the wireless medium, which is air.
- Wiremap Test
- Ensures a link has proper connectivity by testing for continuity and other installation mistakes, such as the connection of wires to the wrong connector pin.
- Work Breakdown Structure (WBS)
- Shows how the team will accomplish the project by listing all tasks the team will need to perform and the products they must deliver.
- World Wide Web
- An interconnection of privately owned and operated servers. Each server stores a set of hypertext pages that users, or Web Surfers, can easily search for and view from their workstations through a Web browser via an Internet connection. Also known as the Web.
X
- X.21
- An ITU standard for a circuit switching network.
- X.25
- An ITU standard for an interface between a terminal and a packet switching network. X.25 was the first public packet switching technology, developed by the CCITT and offered as a service during the 1970s and still available today. X.25 offers connection-oriented (virtual circuit) service and operates at 64 Kbps, which is too slow for some high-speed applications.
- X.75
- An ITU standard for packet switching between public networks.
- X.121
- An ITU standard for international address numbering.
- X.400
- An ITU standard for OSI messaging.
- X.500
- An ITU standard for OSI directory services.
- X Windows
- A windowing system that runs under Unix.
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