R

R for Raid

abbreviation / acronyms term definition
R_A_TOV resource allocation timeout value In fibre-channel technology, a value used to time out operations that depend on the maximum possible time that a frame can be delayed in a fabric and still be delivered.
R&D research and development A descriptive term for the function, organization or budget allocation devoted to researching and developing new products or technologies.
RAB

Raid Advisory Board

Reverse-Link Activity Bit

Industry organization of manufacturers and users of disk systems and related products whose mission is to educate users regarding all aspects of storage technology, and in particular, RAID technology.

determining the data rate of a reverse link communication of a mobile communication system.

RAC Real Application Cluster RAC is a component of the Oracle 9i database product that allows a database to be installed across multiple servers.
RACF Resource Access Control Facility Provides improved security for an installation's data. RACF protects your vital system resources and controls what users can do on the operating system
RACH Random Access Channel the channel used by mobiles in GSM and W-CDMA systems to gain access to the system when first attaching to it.
racon radar beacon A transmitter-receiver associated with a fixed navigational mark which, when triggered by a radar, automatically returns a distinctive signal which can appear on the display of the triggering radar, providing range, bearing and identification information.
RAD

radiation absorbed dose

Rapid Application Development

the basic unit of measure for expressing absorbed radiant energy per unit mass of material.

A way of developing a system by completing a working part, implementing it, and adding more working parts every few months, instead of waiting to finish the entire project before putting the system into use.

RADA random access discrete address A communications technique in which radio users share one wide frequency band instead of each user's being assigned a narrow band.
RADCAB Relevancy Appropriateness Detail Currency Authority Bias It was created by Karen Christensson, a library media specialist, for helping students research topics on the Web.
RADIUS Remote Authentication Dial-In User Service A security protocol used to transport passwords between the access device and the authentication server.
RADSL Reverse ADSL A term for a DSL stream that is asymmetrical in the upstream direction; that is, a reverse ADSL link has a small downstream and large upstream communications path.
RADVD router advertisement daemon run by Linux or BSD systems acting as IPv6 routers. It sends Router Advertisement messages, specified by RFC 2461, to a local ethernet LAN periodically and when requested by a node sending a Router Solicitation message.
RAI remote alarm indication A signal transmitted in the outgoing direction when a terminal determines that it has lost the incoming signal. RAI is commonly called the yellow alarm signal.
RAID Redundant Array of Independent Disks
RAID is a method of storing data on multiple hard disks. When disks are arranged in a RAID configuration, the computer sees them all as one large disk. However, they operate much more efficiently than a single hard drive.
RAM Random Access Memory RAM is the storage medium used within the computer to store programs and data while the computer is switched on and running. Once the power to the computer is switched off, any programs or data not saved to the Hard Disk Drive will be lost permanently.
RAMDAC Random Access Memory Digital to Analog Converter Chip on a video board that generates the analog video signals
RAN Radio Access Network the ground-based infrastructure required for delivery of third-generation (3G) wireless communications services, including high-speed mobile access to the Internet.
RARE Reseaux Associés pour la Recherche
Européenne
The European Association of Research Networks. Now called TERENA
RAPI Rsvp Application Programming
Interface
An RSVP-specific API that enables applications to interface explicitly with an RSVP process
RARP Reverse Address Resolution Protocol The protocol which allows a user to broadcast a MAC address on the local network, resulting in the network interface (NIC) returning it's IP Address
RAS

Registration, Admission, Status

remote-access server (services)

Row Address Select

Row Address Strobe

Remote Announcing System

a management protocol between terminals and Gatekeepers in the H.323 network.

A server that facilitates network connections to an enterprise local-area or wide-area network from users remotely accessing the network over cable or telephone lines using a modem. The server uses various protocols to authenticate and connect remote users.

A control pin on a DRAM used to latch and activate a row address. The row selected on a DRAM is determined by the data present at the address pins when RAS becomes active.

a signal sent by the processor to a DRAM circuit to tell it that an associated address is a row address.

a switch feature that allows an outside caller, with proper access, to make announcements over the local public or office announcing system.

RAT Remote Administration Tool refers to products such as PC Anywhere and Carbon Copy but is more often used to refer to trojan RATs such as Back Orifice and NetBus.
RBA Run Book Automation automate IT operations processes across different IT management disciplines. RBA products have an orchestration interface to design, administer and monitor processes; a workflow to support the processes; and integration to many IT operations tools needed to support the processes.
RBAC role-based access control RBAC is a strategy for implementing security policy management, specifically in the area of authorization. The idea behind RBAC is to define roles as sets of privileges to different systems that represent common access rights for users.
RBL Real-time Black-hole List or Real-time Block List RBLs hold information about blocked sites, typically used to list site that generate spam.
RBOC Regional Bell Operating Company The local telephone company in each of the seven U.S. regions.
RC Release Candidate A version (of software) that is released before the final release. A release candidate may contain outstanding issues (or bugs) or incomplete functionality. Also know as a "technical preview" or "beta release".
RC2/4/5 Rivest Cipher 2/4/5

a family of proprietary ciphers developed by Ronald Rivest of RSA Security.

RC2 is a secret-key block cipher — that is, it encrypts data one fixed-size block at a time — for bulk encryption.

RC4 is stream cipher —it encrypts data as a sequence of bits, one bit at a time.

RC5 is a block cipher; it is more secure than RC4, but slower.

RCA Radio Corporation of America (cables) The standard, single-ended analog cables used to connect audio and video devices to each other. Typically a red input is for the left channel of sound, white is for the right, and yellow is for compsite video.
RCC radio common carrier A telecommunications common carrier that provides radio communications services but is not engaged in the business of providing landline local exchange telephone service.
RCM Revision and Configuration Management HP service - RCM collects configuration, revision, and patch data from your supported systems
rcp Remote copy A UNIX utility that copies files over an Ethernet.
RCP Rich Client Platform Minimal set of plug-ins needed to build a rich client application.
RCS Revision Control System Manages multiple revisions of files by automating the storage, retrieval, logging, identification, and merging of revisions. It's particularly useful for text that is revised frequently, such as programs, documentation, graphics, papers, and form letters
RCU Rapid Cloning Utility included with the NetApp FlexClone license. RCU is an integrated cloning and provisioning utility for virtual machines that instantly replicates data volumes and data sets as transparent virtual copies
RDAC Redundant Disk Array Controller Provides application-transparent protection for array controller and data path failures using a special-purpose daemon process and kernel-resident I/O driver
RDBA Remote Database Access a standard permitting the exchange of information between different DBMS systems.
RDBMS relational database management system RDBMS is a program that lets you create, update, and administer a relational database.
RDDL Resource Directory Description
Language
XML-based language for describing a resource directory. A resource directory provides a text description of some class of resources and of other resources related to that class. It also contains a directory of links to these related resources
RDF

radio direction-finding

Resource Description Framework

Radiodetermination using the reception of radio waves for the purpose of determining the direction of a station or object.

a specification that defines how metadata, or descriptive information, should be formatted. The RDF model uses a subject-predicate-object format, which is a standardized way of describing something.

RDI remote defect indication A signal transmitted at the first opportunity in the outgoing direction when a terminal detects specific defects in the incoming signal.
RDL Report Definition Language XML-based industry standard used to define reports
RDM Remote Deployment Manager An IBM tool (formerly called LANClient Control Manager, or "LCCM") that allows systems administrators to remotely configure and deploy operating systems and applications on IBM systems.
rDNS Reverse DNS a method of resolving an IP address into a domain name, just as the DNS resolves domain names into associated IP addresses.
RDP

Remote Desktop Protocol

Router Discovery Protocol

a protocol designed for secure communications in networks using Microsoft Terminal Services. RDP is available for most versions of the Windows operating system as well as Mac OS X, Linux and FreeBSD.

A standard protocol, to inform hosts of the presence of routers to which they can send packets. You can also use RDP instead of host wiretapping routing protocols (for example, RIP).

RDR Rate of Defect Recurrence How many times a defect is reintroduced over the life of an application
RDT remote digital terminal

An intelligent network element that interfaces between customer access lines and digital facilities.

The digital loop carrier (DLC) multiplexer that is at the end of the DLC that is closest to the network interface (NI).

RED

Random Early Detection

Reputation Enabled Defense

A congestion-avoidance algorithm developed in the early 1990s built on the base-level TCP behavior of automatically slowing transmissions when packet loss is detected

WatchGuard RED uses a cloud-based WatchGuard reputation server that assigns a reputation score between 1 and 100 to every URL.

REG Range Extender with Gain

A unit that provides range extension in a loop for both transmission and signaling.

ReGS Reporting Grid Services A set of core Open Grid Services Architecture (OGSA) services for logging, tracing, and monitoring applications in OGSA-based grid environments.
REJ Reject. In communications a command or response that requests data be retransmitted.
Rel Recorder element The minimum distance between two recorded points (spots) in an imagesetter.
REL Rights Expression Language A language for specifying rights to content, fees or other consideration required to secure those rights, types of users qualified to obtain those rights
RELAX REgular LAnguage description for Xml Uses XML syntax to express the structure relationships that are present in a DTD, and adds the XML Datatype Schema mechanisms, as well
REN Ringer Equivalency Number 1 REN = the energy to ring one Plain Old Telephone POL or Single Line Telephone (SLT). The REN number can be found on the FCC label on the device.
RePDV Reputation Digital Vaccine HP TippingPoint service that protects enterprises from the latest security risks by providing greater visibility into malicious activity on corporate networks.
Res resolution A term used to define image resolution instead of ppi. Res 12 indicates 12 pixels per millimeter.
RES Robots Exclusion Standard Standard that allows web site administrators to indicate to visiting robots which parts of their site should not be visited by the robot
REST REpresentational State Transfer A loosely defined specification for HTTP-based services where all of the information required to process a request is present in the initial request and where each request receives only a single response, and where the response is in a machine-readable form.
RETAIN Remote Technical Assistance and Information Network Database used by IBM Support Centers to record all known problems with IBM licensed programs.
REVS Rapid Exchange of Virus Samples list. A mailing list for antivirus companies, allowing their virus analysis staff to securely send samples of 'emergency' viruses to other antivirus developers and for the lab staff to discuss emerging 'virus emergencies'.
REXX Restructured EXtended eXecutor

connet A general-purpose, high-level, programming language, particularly suitable for EXEC procedures or programs for personal computing.

connet The i5/OS implementation of the Systems Application Architecture Procedures Language.

RF Radio frequency Describes the portion of the spectrum used to transmit radio signals. Often used adjectivally.
RFB Remote Framebuffer a protocol for remote access used by the remote control application VNC (Virtual Network Computing)
RFC

radio-frequency choke

Request For Comments

an inductor (coil) designed to keep high-frequency signals from flowing into power supply lines and other interconnections.

The name of the result and the process for creating a standard on the Internet. New standards are proposed and published on the Internet, as a Request For Comments.

RFCOMM Radio Frequency Communication a Bluetooth protocol which is a simple set of transport protocols, providing emulated RS232 serial ports.
RFI remote failure indication A signal transmitted in the outgoing direction when a terminal determines that specific defects have persisted long enough to declare a received signal failure.
RFID radio frequency identification An analog-to-digital conversion technology that uses radio frequency (RF) waves to transfer data between a movable item and a reader for identification, tracking or location purposes. It does not require physical contact or a line of sight between the reader or scanner and the tagged item.
RFMD RF Micro Devices global leader in the design and manufacture of high-performance semiconductor components.
RFS / RFU Ready For Service / Use Ready For Service / Use
RFP Request For Proposal A request for bids that indicates the specifications for a software project or other system needs.
RFT

Request For Technology

revisable-form text

A request from the Open Software Foundation for proposals for new standards.

A data stream defined by document content architecture that is used to exchange unresolved documents (which cannot be directly printed or displayed) between systems.

RGB Red/Green/Blue An RGB signal has four separate elements; red/green/blue and sync. This results in a cleaner
image than with composite signals due to the lower level of distortion and interference.
RGMP Router-port Group Management Protocol IP multicast constraining mechanism for router-only network segments. RGMP must be enabled on the routers and on the Layer 2 switches
RTGS Radioisotope Thermoelectric Generators a simple electrical generator which obtains its power from radioactive decay.
RHCE Red Hat Certified Engineer Mid to advanced level certification for IT professionals who are able to install and configure Red Hat Linux, understand limitations of hardware and configure basic networking and file systems
RHCS Red Hat Cluster Suite Red Hat's software to create a high availability and load balancing cluster
RHEL Red Hat Enterprise Linux RED HAT OS
RHR radio horizon range The distance at which a direct radio wave can reach a receiving antenna of given height from a transmitting antenna of given height.
RHSBL Right-Hand Side Blacklist A type of DNSBL that uses domain names instead of IP addresses.
RIA Rich Internet Application Evolution of the web development and deployment model
RIM

Reference Information Model

Research In Motion

A comprehensive, object-oriented information model for clinical healthcare. RIM serves as a semantic point of reference for all HL7 standards development efforts.

vendor of wireless communication products based in Waterloo, Ontario. Its products include the popular BlackBerry handheld device www.rim.com.

RIMM Rambus In-Line Memory Module RIMM is a synchronous dynamic RAM module that is used on newer motherboards. RIMM's are manufactured by Rambus Corporation.
RIP

raster image processor

Routing Information Protocol

a device that handles computer output as a grid of dots. Dot-matrix, inkjet, and laser printers are all raster image processors.

An internal router protocol used for informing network computers of changes in configuration.

RIPE Réseaux IP Européens the Internet registry organization for Europe. http://www.ripe.net/
RIR regional Internet registry an organization that manages the allocation and registration of Internet number resources within a particular region
RISC Reduced Instruction Set Computer A processor supporting simple instructions (typically only one memory access per instruction) and often reduced instruction set size, sacrificing complexity for greater speed.
RJ11 Registered Jack 11 The physical specification for the four-wire jack commonly used in U.S. telephone systems.
RJ45 Registered Jack 45 A type of eight-wire connector commonly used in local-area networks.
RJE Remote Job Entry Transmission of a batch job to a remote computer which processes the job.
RLC Radio Link Control a link-layer protocol that is responsible for error recovery and flow control in 3G (UMTS) cellular systems.
RLE run-length encoding

A technique for compressing data that avoids repeatedly having to code data elements of the same value

A type of compression that is based on strings of repeated, adjacent characters or symbols, which are called "runs."

RLP Radio Link Protocol a link layer protocol used for 2G (GSM and cdmaOne) and CDMA-2000 (3G) network-based error corrections to ensure robust data transmission.
RLL Run Length Limited an encoding scheme used to store data on certain PC hard disks.
rlogin remote login the UNIX command that allows you to use your computer as a terminal on another computer.
RMA

rate monotonic analysis

Return Materials Authorization

The process of analyzing a real-time system to assign individual thread priorities according to the rate monotonic algorithm.

This is a number issued to return equipment for service, validation, upgrades, or exchange.

RMC

Raptor Management Console

Resource Monitoring and Control

Symantec term

IBM term. Scalable, reliable backbone subsystem of RSCT. It runs on a single machine or on each node (operating system image) of a cluster and provides a common abstraction for the resources of the individual system or the cluster of nodes

RME

Rack Mount Equipment

resource model engine

RME is equipment which is designed to mount in a standard steel framework consisting of parallel pairs of steel channel verticals spaced 19" and drilled for mounting screws.

An analysis engine that is used to identify, notify, and cure performance and availability problems.

RMI Remote Method Invocation technique for calling a method in a Java class located on a machine (such as a web server) differsent from the machine (such as the browser client) on which the current application is running.
RMON Remote Monitoring A network monitoring protocol defined in RFC 2074
RMS

Record Management System

Right Management Service

Root Mean Square

an API for device-dependent use of audio and video.

A feature in Vista to encrypt confidential documentation with policies.

a fancy way of describing the average voltage level of an audio signal.

RMU Rack Mount Unit A single RMU is 1.75 inches of vertical space in a rack housing. It is typically in the form of a number such as this; 4U, meaning 4 units or RMUs.
RNA

Ribonucleic acids

Ring No Answer

a class of nucleic acids that act as a carrier for genetic information as well as catalyzing important biochemical reactions. RNAs contain sugar ribose and the organic base uracil.

What you get when the modem you just called doesn't answer

RNC Radio Network Controller the governing element in the UMTS radio access network (UTRAN) responsible for control of the Node Base Stations (BS), that is to say, the base stations which are connected to the controller.
R-NE remote-network element A type of network element (NE) that contains a DUA (directory user agent), an optional local cache, and possibly other application processes such as the registration agent.
RNI Raw Native Interface Native interface proposed by Microsoft
RNR receive not ready In communications, a data link command or response that indicates a temporary condition of being unable to accept incoming frames.
ROA recognized operating agency Any operating agency, as defined in the ITU Convention (Geneva, 1992), which operates a public correspondence or broadcasting service
ROADM reconfigurable optical add-drop multiplexer a device that is utilized on many different fiber optic networks. Essentially, this type of multiplexer has the ability to control the direction and focus of both infrared and visible light emissions within a range of different wavelengths.
ROD record oriented data The type of document definition used to describe proprietary document formats.
RODM Resource Object Data Manager In IBM Tivoli NetView for z/OS, a component that provides an in-memory cache for maintaining real-time data in an address space that is accessible by multiple applications.
RoHS Restriction of Hazardous Substances The RoHS directive has been adopted by the European Union. RoHS restricts the use of six hazardous substances: lead (Pb), mercury, cadmium, hexavalent chromium, polybrominated biphenyls (PBB) and polybrominated diphenyl ethers (PBDE) in all electrical and electronic products, and their component parts
ROI Return on Investment Return on Investment
ROKSO Register of Known Spam Operations a list of over 500 professional spammers that is maintained by the Spamhaus Project, an organization dedicated to identifying and exposing spam operators. Any spammer known to have been terminated by three consecutive ISPs is added to the list.
ROLR receive objective loudness rating The ratio in dB of the voltage entering a loop and telephone to the sound pressure produced by the telephone's receiver.
ROM

read-only memory

Report Object Model

Data stored in computer memory that can be accessed and read by the user, but not modified. ROM is often permanent, and stores system control software.

Object model at the base of the Business Intelligence and Reporting Tools (BIRT)

ROOM Real-Time Object-Oriented Modeling An Object-Oriented Object-Oriented analysis and design approach
ROP Raster Operation A set of low-level graphics operations in Windows, i.e., operations that deal with raster graphics.
RoR Ruby on Rails A web application stack based upon the Ruby programming language, a webserver (like Apache or lighttpd), and a database server (like MySQL).
ROR remote outdoor router a device that connects a remote location in a WLAN to either another remote location with an ROR for a point-to-point connection or to the system's COR for point-to-multipoint connections.
ROS run of site in Online Advertising ROS is a type of online ad buying campaign where the banner, image, or media ad can appear on any page within the targeted Web site.
ROSE Remote Operations Service Element OSI RPC mechanism used by various OSI network application protocols.
rot13 rotate 13 a type of ENCRYPTION commonly used on the Internet to conceal answers to puzzles and the like. To encode a message, the first 13 letters of the alphabet are swapped with the last 13.
RP-SMA Reverse Polarity SubMiniature version A a type of antenna connector used on brands of routers including Buffalo and Asus.
RP-TNC Reverse Polarity Threaded Neill-Concelman a type of antenna connector used on Linksys access points.
RPA Recursive Pyramid Algorithm a reformulation of the classical pyramid algorithm (PA) for computing the discrete wavelet transform (DWT).
RPC Remote Procedure Call
Most computer programs run procedures, or sets of instructions, using the computer's CPU. In other words, the instructions are processed locally on the same computer that the software is running from.
RPF Reverse Path Forwarding Enables routers to correctly forward multicast traffic down the distribution tree. It makes use of the existing unicast routing table to determine the upstream and downstream neighbors
RPG

Report Program Generator

role-playing game

A programming language that was developed by IBM in the 1960s to simplify programming for business applications.

role-playing game

RPI Rockwell Protocol Interface A feature in some modems that allows data compression and error correction to be performed by software instead of hardware. HTTP://WWW.ROCKWELL.COM.
RPL

Remote Program Load

Requested Privilege Level

Recognized Prior Learning

Bootable network device protocol, developed and used mostly by IBM

a level of privilege within the architecture of a computer system where the most privileged layer is usually zero.

an industry acknowledgement of a person's skills and knowledge obtained through learning programs outside of a formal education system.

RPM

Rapid Predictive Modeler

Red Hat Package Manager

Revolutions Per Minute

Route Processor Module

BI product that automatically step through a behind-the-scenes workfow of data preparation, variable selection, and transformation

A packaging system based on files with the .rpm extension that contain dependency information, pre- and post-install scripts, and the actual user runtimes (files/executables) that are part of the package.

The speed at which a disk drive rotates is measured in revolutions per minute.

Cisco term

RPN Reverse Polish Notation A way of expressing a sequence of calculations without using parentheses to show which operation must be performed first. Reverse Polish notation goes in the opposite direction from Polish notation.
RPO recovery point objective A term used in DR and BCP. The RPO defines what constitutes an acceptable loss of data — specifically, the required timeliness of the data that can be recovered using backups, journals or transaction logs.
RPP

receiving party pays

The convention under which the party receiving a communication pays all or some of the end-to-end cost of the communication.

RPR Resilient packet ring The IEEE 802.17 technological specification to deliver packet-based services over SONET rings. RPR is an OSI-Rm (OSI Reference Model) Layer 2 technology with framing very similar to that of Ethernet.
RPT radio personal terminal A light-weight, pocket-size portable radio terminal (or "personal terminal") providing the capability for the user to be either stationary or in motion while accessing and using telecommunication services.
RQN Real-Quick Newsletter FreeBSD newsletter
RR

Register to Register

repeatable read

The class of CPU instructions (and assembler codes that go with them) relating to only registers, not main memory

An isolation level that prevents any row that is read from being changed by other applications until the transaction is completed.

RR / RRS round-robin scheduling

a scheduling algorithm that iterates through all available choices before beginning again with the first choice.

Round robin DNS is usually used for balancing the load of geographically distributed Web servers.

RR_TOV resource recovery timeout value In fibre channel networks, the minimum time a target device in a loop waits after a loop initialization primitive (LIP) before logging out a SCSI initiator.
RRI Reverse Rate Indicator a parameter in a 3G wireless network provided by the reverse link, which aids the Access Point in determining the rate at which the reverse link is sending data.
RRPP Rapid Ring Protection Protocol link layer protocol
RS

Recommended Standard

Reed-Solomon

Remote Scripting

RuneScape

for example, RS-232C. More recent designations use EIA, for example, EIA-232C.

codes are block-based error correcting codes with a wide range of applications in digital
communications and storage.

Allows code in a client page to call functions in an ASP page running on the server

a fantasy MMORPG www.runescape.com/

RS-MMC Reduced Size Multi-Media Card Found mostly in camera phones.
RSA

Remote Supervisor Adapter

register save area

Rivest, Shamir and Adleman

rural service area

PCI adapter which simplifies remote system management by providing around-the-clock remote access to the server. The RSA monitors the server and sends out alerts to designated recipients via LAN, pager, email or SNMP if a failure is detected

The area of main storage in which the contents of registers are saved.

An asymmetric encryption technique, named after its inventors Rivest, Shamir and Adleman. Based on the assumption that the factoring of the product of two large prime numbers is very difficult. www.rsa.com

cellular service areas used by the FCC to license cellular telephone service.

RSBAC Rule Set Based Access Control targets actions based on rules for entities operating on objects.
RSCT Reliable Scalable Cluster Technology Set of software components, used for AIX and Linux, to provide clusters with improved system availability, scalability, and ease of use
rsh Remote Shell Protocol a protocol that allows a user to execute commands on a remote system without having to log in to the system. For example, rsh can be used to remotely examine the status of a number of access servers without connecting to each communication server, executing the command, and then disconnecting from the communication server.
RSIP Realm Specific Internet Protocol Like NAT, RSIP translates between public and private IP addresses. But instead of requiring a boundary router to translate, RSIP uses a simple protocol between a user's desktop PC and a boundary router to perform preparatory signaling
RSL received signal level The signal level at a receiver input terminal.
RSM

Relational Storage Manager

Remote Storage Management

Route Switch Module

IBM database term

Microsoft OS term

Basically a router on a card in the switch for routing between Virtual Local Area Networks

RSN Real Soon Now at an indefinite time in the future, probably much later than promised.
RSPAN Remote Switched Port Analyzer extends SPAN by enabling remote monitoring of multiple switches across your network.
RSS

RDF Site Summary / Really Simple Syndication

Receive Side Scaling

Relay Spam Stopper

RSS is method of providing website content such as news stories or software updates in a standard XML format. RSS content can be accessed with an RSS-enabled Web browser or other programs designed for retrieving RSS feeds.

increases performance on multi-processor systems by efficiently balancing network loads across CPU
cores

Queryable DNS-based database of spam-relaying mail servers. See http://work-rss.mail-abuse.org/rss/

RSSI Relative Signal Strength Indicator a measurement of radia signals at the point in which they are received and measured.
RSU

Recommended Service Upgrade

remote switching unit

IBM-recommended PTFs (Program Temporary Fix) supplied as part of monthly z/OS service support

The subtending remote switching device that depends in part on its host switch for call control but is capable of providing intra-unit switching.

RSVP Resource Reservation Protocol A transport-layer protocol used to improve network quality of service (QOS) by reserving the resources (such as bandwidth and buffer space) that applications require. Developed by the Internet Engineering Task Force (IETF), RSVP relies on end devices to request their priority so that resources can be reserved for flows to facilitate the requested QOS.
RTC Rich Thin Client All about technologies for thin client with rich functionality and widget set, as opposed to Html clients
RTD Real-Time Decisions Oracle's intelligent process automation (IPA) for operational decisions
RTE

real-time enterprise

round-trip engineering

An enterprise that achieves competitive advantage by using up-to-date information to progressively remove delays in the management and execution of its critical business processes.

The mechanism used to synchronize code and model information. This term includes the code generation and reverse engineering features.

RTF Rich Text Format A file format that encodes documents so their messages include boldface, italics and other limited text stylings across platforms and applications. Differences exist between implementations by Lotus and Microsoft.
RTG

Radioisotope Thermoelectric Generators

Receive/transmit Transition Gap

a simple electrical generator which obtains its power from radioactive decay

a concept in the mobile wireless network, is a gap between the last sample of the uplink burst and the first sample of the subsequent downlink burst at the antenna port of the BS in a time division duplex (TDD) transceiver.

RTK Real Time Kinematic highly-accurate, highly-repeatable positioning. With RTK, a base station receiver is placed on a stable (ideally immobile) mount, allowing multiple GPS rover receivers to utilize this type of correction within a limited range of the base station.
RTM Read The Manual Read The Manual
RTMP routing table maintenance protocol a communication protocol used by AppleTalk to ensure that all routers on the network have consistent routing information
RTO recovery time objective recovery time objective
RTP Real-Time Transport Protocol An end-to-end network-transport protocol suitable for applications transmitting real-time data (such as audio, video, or simulation data) over multicast or unicast network services.
rtPS Real-Time Polling Service one of the five QOS service types defined in the IEEE 802.16 WiMAX.
RTS request to send A control packet used by a station to indicate that it has data to send. After sending an RTS, the station must receive a clear to send (CTS) from the destination station before transmitting data packets.
RTSC Read the Source Code a software developer asks a question about undocumented code.
RTSE Reliable Transfer Service Element A lightweight ISO/OSI application service used above X.25 networks to handshake application PDUs across the session service and TP0
RTSP Real Time Streaming Protocol RTSP is an official Internet standard (RFC 2326) for delivering and receiving streams of data such as audio and video. The standard allows for both real-time ("live") streams of data and streams from stored data.
RTT

Radio Transmission Technology

Real-Time Technology

round-trip time

the “voice” protocol for CDMA-enabled cellular devices, usually abbreviated as “1X”.

Refers to a technology that allows a user to receive data during the actual time that a physical process occurs, known as real time. Real time is measured in milliseconds or microseconds

Time required for a network communication to travel from the source to the destination and back. RTT includes the time required for the destination to process the message from the source and to generate a reply.

RTTY radio teletypewriter A teletypewriter employed in a communication system using radio circuits.
RTU

Remote Terminal Unit

Right To Use

a device located at a remote site to collect data and transmit the data back to a central station (or master). An RTU also collects information from the master device and implements processes that are directed by the master.

The Sun software licensing, usually included in the price of the software

R-UIM removable user identity module A smart card that is designed to be used in mobile phones based on CDMA. It allows roaming across CDMA and GSM networks.
RUOW remote unit of work

A unit of work that allows for the remote preparation and execution of SQL statements.

The form of SQL distributed processing in which the application is on a system different from the relational database

A unit of work that lets a user or an application program read or update data at one location per unit of work.

RUP Rational Unified Process RUP is a software development process from Rational, a division of IBM. It divides the development process into four distinct phases
RUS Recipient Update Service Microsoft Exchange Mail Server Service that generates and updates email addresses seen in the Global Address List (GAL)
RVLC Reversible Variable Length Code MPEG-4 Audio Error Resilience (ER) technique that reduces error propagation within scale factor data
RVI Reverse Interrupt A communications control character that is transmitted by a receiving terminal requesting a cancellation of the current transmission, so that it may send a message of its own that is of higher priority.
RW Read Write Device capability to read and write its media
RWI radio and wire integration The combining of wire circuits with radio facilities.
RWM Read-Write Memory Memory with RW capability
RWP Remote Write Protocol An Internet protocol for exchanging short messages between terminals.
RWU remote wake-up a generic term for the action of turning on a computer over a network from a remote location.
RX / RXD Receive / Receiving Data A modem status signal indicated by a light on the modem, which means the local modem is receiving data.
rack A framework or structure that holds computer servers or networking equipment, usually by means of shelves or mounting plates. The height of computer equipment is expressed in U, which equal the distance between shelf increments in a standard rack
Radeon Radeon is a brand of GPU and RAM produced by AMD
Ransomware a form of malware in which rogue software code effectively holds a user's computer hostage until a "ransom" fee is paid. Ransomware often infiltrates a PC as a computer worm or Trojan horse that takes advantage of open security vulnerabilities.

RealAudio

RealPlayer

a communication protocol developed by Real Networks (www.realaudio.com) that allows audio signals to be broadcast over the Internet.

a widely used program for playing RealAudio files, distributed by Real Networks

red book
Another name for the CD-DA audio CD format introduced by Sony and Philips, the Red Book standards defines the number of tracks on the disc that contain digital audio data and the error correction routines that save sound from minor data loss.
Remote Desktop a feature of some versions of Microsoft Windows that allows one computer to serve as the screen, keyboard, and mouse of another; thus, any computer can be operated remotely.
Retina display screen technology introduced by Apple in the iPhone 4. It features a 960 x 640 resolution, an 800:1 contrast ratio and four times the number of pixels than earlier iPhone models.
rich clients

Two-tier fat clients. There are two types of rich clients:

Stand-alone rich clients are the more flexible of the two rich client types in that they can support both disconnected and connected operations, allowing a single client architecture to execute in both online and offline modes.

Browser-based rich clients don´t work well in a disconnected mode, but they do enjoy the luxury of having a predefined operating environment installed on just about every PC they might need to run on.

Rip
To transfer data to a hard disk from something else.
Router A special-purpose computer that handles the connection between 2 or more Packet-Switched networks. Routers spend all their time looking at the source and destination addresses of the packets passing through them and deciding which route to send them on.
routing table In internet working, the process of moving a packet of data from source to destination.
Ruby a scripting language for object-oriented programming similar in intent to PERL and PYTHON. Ruby was developed by Yukihiro Matsumoto in 1995. See www.ruby-lang.org