RACE RADIO AUSTRIA RAID
RAIN RAM RARE
RARP RAS RAW
RBHC RBOC RCCN
RCP RDBMS Reassembly
Recursion redirect redirector
RedIRIS redistribution redundancy
regional REGIS regular expression
relative pathname relay reliability
remote bridge remote host remote login (rlogin)
Renater Repeater request/response unit
Restena reverse channel RF
RFC RFC 822 RFD
RFS RG-58 RG-62
RGB RIF ring group
ring latency ring monitor ring topology
RIP RIPE RIPE NCC
RISC RJ-11 RJ-45
RJE RLL rlogin
RMI RMW ROM
root directory ROSE route
Routed routed protocol route extension
route processor router routing
routing domain
routing metric routing protocol routing table
routing update RPC RRCP
RS-232-C RS-422 RS-449
RSRB RTFM RTMP
RTN RTP RTS
RTSE RTT
RTV RU RUB
RACE (Researcher
and Development Program in Advanced Communications in Europe). Project
sponsored by the European Community for the development of broadband networking
capabilities.
RADIO AUSTRIA A PSN
based in Austria
RAID (Redundant Arrays of
Inexpensive Disks).
RAIN
RAIN is France Telecom Transpac's
name for their commercial Internet service.
RAM (Random-Access Memory)
RARE (Reseaux Associes pour
la Recherche Europeenne). European association of research networks. [Source:
RFC1208]
Merged with EARN in 1994 to from
TERENA
RARP (Reverse Address Resolution
Protocol). A protocol, defined in RFC
903, which provides the reverse function of ARP. RARP maps a hardware
(MAC) address to an internet address. It is used primarily by diskless
nodes when they first initialize to find their internet address. See also:
Address Resolution Protocol, BOOTP,
internet address, MAC
address. [Source: RFC1392]
RAS (Row-Address Strobe).
RAW (Raw image format). This
file format can be useful for transferring an image to different platforms
that may not read similar file formats. It simply reads and write the raw
information of the image.
RBHC (Regional Bell
Holding Company). One of seven telephone companies created after the AT&T
divestiture in 1984. The RBHC crosses state lines.
RBOC (Regional Bell Operating
Company). One of seven telephone companies created after the AT&T divestiture
in 1984. The RBOC exists entirely in one state. See also BOCs.
RCCN
(Rede da Comunidade Cientifica Nacional). The portuguese Scientific
national network .
RCP (Remote Copy Program).
RDBMS (Relational Database
Management System). A program that enables you to develop, customize, and
maintain database applications.
RTFM (Read the Fantastic
Manual). This acronym is often used when someone asks a simple or common
question. The word `Fantastic' is usually replaced with one much more vulgar.
[Source: ZEN]
Reassembly The IP
process in which a previously fragmented packet is reassembled before being
passed to the transport layer. See also: fragmentation.
[Source: Top
Index Home-Page
Search
Recursion The
facility of a programming language to be able to call functions from within
themselves. [Source: ZEN ]
redirect A
part of the ICMP and ES-IS
protocols that allows a router to tell a host that use of another router
would be more effective.
redirector Software
that intercepts requests for resources within a computer and analyzes them
for remote access requirements. If a remote access is required to satisfy
the request, the redirector forms a RPC
and sends the RPC to lower-layer protocol software for transmission through
the network to the node that can satisfy the request.
RedIRIS
RedIRIS is the spanish network for research and
development.
redistribution Allowing
routing information discovered through one routing protocol to be distributed
in another routing protocol's update messages.
redundancy In
telephony, the portion of the total information contained in a message
that can be eliminated without loss of essential information or meaning.
In computing, multiple (redundant) system elements that perform the same
function.
Redundancy/ Redundant Card or Power Backup
components used to ensure uninterrupted operation of a system in case of
failure, Also called "failsafe".
regional See:
mid-level network
REGIS (Remote
Graphics Instruction Set).
relative expression In
UNIX a text pattern consisting of a combination of alphanumreic characters
and special characters known as metacharacters.
See UNIX
File System for a more detailed explanation.
relative pathname In
UNIX the name of a directory or file given in relation to your current
working directory.
relay OSI
terminology for a device that connects two or more networks or network
systems. A Layer 2 relay is a bridge
a Layer 3 relay is a router.
reliability Ratio
of expected to received keepalives from a link. If the ratio is high, the
line is reliable. Used as a routing metric.
remote bridge A
bridge that connects ohysically disparate network segments via WAN
links.
remote host Any
host on the network which you are
not presently using.
remote login (rlogin).
Operating on a remote computer, using a protocol over a computer network,
as though locally attached. See also: Telnet.
[Source: RFC1392]
Renater
(Réseau National de télécommunications
pour la Technologie, l'Enseignement et la Recherche). Is the french national
network for education and research.
Repeater A
device which propagates electrical signals from one cable to another. See
also: bridge, gateway,
router. [Source: RFC1392]
In OSI terminology, a repeater is a Physical
Layer intermediate system.
request/response unit See
RU.
Restena
(Réseau Téléinformatique
de l'Education Nationale et de la Recherche). Is Luxembourg's educational
and research network.
reverse channel See
back channel
RF (Radio
Frequency). Generic term referring to frequencies that correspond to radio
transmissions. Cable TV and broadband networks use RF technology.
RFC (Request
For Comments) The document series, begun in
1969, which describes the Internet suite of protocols and related experiments.
Not all (in fact very few) RFCs
describe Internet standards, but all Internet standards are written up
as RFCs. The RFC series of documents is unusual in that the proposed protocols
are forwarded by the Internet research and development community, acting
on their own behalf, as opposed to the formally reviewed and standardized
protocols that are promoted by organizations such as CCITT
and ANSI. See also: For
Your Information, STD. [Source: RFC1392]
RFC
822 The Internet standard format for electronic
mail message headers. Mail experts often refer to "822 messages". The name
comes from "RFC 822", which contains the specification (STD
11, RFC
822). 822 format was previously known as 733
format. See also: Electronic Mail.
[Source: COMER]
RFD (Request
For Discussion) Usually a two- to three-week period in which the particulars
of newsgroup creation are battled out. [Source: ZEN]
RFS (Remote
File System). AT&T
RG-58 Coaxial
cable with 50-ohm impedance. Used by IEEE
802.3 10BaseT.
RG-62 Coaxial
cable with 93-ohm impedance. Used by ARCnet.
RGB (Red-Green-Blue).
RIF Routing
Information Field. A field in the IEEE
802.5 header that is used by a source-route
bridge to determine through which Token
Ring network segments a packet must transit. A RIF is made up of ring
and bridge numbers as well as other
information.
ring group A
collection of Token Ring interfaces on one or more Cisco routers that is
part of one bridged Token Ring
network.
ring latency Ther
time required for a signal to propagate once around a ring in a Token
Ring or IEEE 802.5 network.
ring monitor Centralized
management tool for Token Ring
networks based on IEEE 802.5 specification.
See also active monitor and standby
monitor.
ring topology Topology
in which the network consists of a series of repeaters connected to one
another by ubndirectional transmission links to form a single closed loop.
Each station on the network connects to the network at a repeater.
RIP (Routing
Information Protocol). A distance vector, as opposed to link state, routing
protocol. It is an Internet standard IGP
defined in STD
34, (updated
by .
See also: Interior Gateway Protocol,
Open Shortest Path First..... [Source:
RFC1392]
Also: (Raster-Image Processor).
RIPE
(Réseaux IP Européens). A collaboration
between European networks which use the TCP/IP protocol suite. [Source:
RFC1392]
RIPE
NCC The RIPE Network Coordination Centre supports
all those RIPE activities which cannot be effectively performed by volunteers
from the participating organisations. Besides supporting RIPE activities
in general the NCC provides the following
services to Internet service providers and network operators across Europe.
RISC (Reduced-Instruction-Set
Computer). A microprocessor designed to decode and execute only a small
set of instructions, which optimizes performance and allows the processor
to run much faster than CISC chips.
RJ-11 Standard
4-wire connectors for phone lines.
RJ-45 Standard
8-wire connectors for IEEE 802.3
1Base5 (StarLAN) network. Also
used as phone lines in some cases.
RJE (Remote
Job Entry). IBM-oriented acronym referring to an application that is batch-oriented,
as opposed to interactive. In RJE environments, "jobs" are submitted to
a computing facility and output received later.
RLL (Run Length
Limited). Storing data on and retrieving in from a hard disk by translating
patterns of bits into digital form, significantly raising the density of
data over that achieved by older technologies.
rlogin Terminal
emulation program, similar to Telnet,
offered in most UNIX implementations.
RMI (Remote
Method Invocation). Lets you create Java
objects whose methods can be invoked from another virtual machine, analogous
to remote procedure call (RPC.
RMW (Read,
Modify, Write).
ROM (Read-Only
Memory).
root directory In
UNIX the directory located at the top of the Unix file system. It is represented
by the "/" (forward slash) character.
ROSE (Remote
Operations Service Element). A lightweight RPC
protocol, used in OSI Message
Handling, Directory, and Network
Management application protocols.
Route The
path that network traffic takes from its source to its destination. Also,
a possible path from a given host to another host or destination. [Source:
RFC1392]
Routed (Route
Daemon). A program which runs under 4.2BSD/4.3BSD UNIX systems (and derived
operating systems) to propagate routes among machines on a local area network,
using the RIP protocol. Pronounced "route-dee". See also: Routing
Information Protocol, Gated.
[Source: RFC1392]
routed protocol A
protocol that can be routed by a router. To route a router protocol, a
router must understand the logical internetwork as perceived. Examples
of routed protocols include DECnet,
AppleTalk, and IP.
route extension In
SNA, a path from the destination subarea node through peripheral equipment
to a NAU.
route processor In
Cisco's hardware architecture, a processor board that determines router
and runs configuration, security, accounting, debugging, and network management
processes. Also sometimes called a supervisory processor. The CSC/3
and the CSC/4 are route processors.
Router A
device which forwards traffic between networks. The forwarding decision
is based on network layer information and routing tables, often constructed
by routing protocols. See also: Bridge,
Gateway, Exterior
Gateway Protocol, Interior Gateway Protocol.
[Source: RFC1392]
Routing The
process of selecting the correct interface and next hop for a packet being
forwarded. See also: hop, Router,
Exterior Gateway Protocol, Interior
Gateway Protocol.
Routing Domain A
set of routers exchanging routing information within an administrative
domain. See also: Administrative Domain,
Router. [Source: RFC1392]
routing metric The
method by which a routing algorithm determines that one route is better
than another. This information is stored in routing tables. Metrics include
reliability, delay,
bandwidth, load, MTUs,
communication costs, and hop count.
See also path cost.
routing protocol A
protocol that accomplishes routing through the implementation of a specific
routing algorithm. Examples of routing protocols include IGRP,
RIP, and OSPF.
routing table A
table stored in a router or some other internetworking device that keeps
track of routes (and, in some cases, metrics associated with those routes)
to particular network destinations.
routing update A
message sent from a router to indicate network reachability and associated
cost information. Routing updates are typically sent at regular intervals
and after a change in network topology.
RPC (Remote
Procedure Call). An easy and popular paradigm for implementing the Client-Server
Model of distributed computing. In general, a request is sent to a
remote system to execute a designated procedure, using arguments supplied,
and the result returned to the caller. There are many variations and subtleties
in various implementations, resulting in a variety of different (incompatible)
RPC protocols. [Source: RFC1208]
RRCP (Redundancy/Redundant
Card or Power).Backup components used to ensure uninterrupted operation
of a system in case of failure, Also called "failsafe"
RS-232-C A
very popular interface definition between data terminal equipment and data
communication equipment, on behalf of the Electronic Industries Association
(EIA), for bit rates up to 20 kbps.
RS-422 A
balanced electrical implementation of RS-449 for high-speed data transmission.
RS-423An unbalanced electrical
implementation of RS-449 for RS-232-C compatibility.
RS-449 Popular
physical layer interface. Essentially a faster (up to 2 Mbps) version of
RS-232-C capable of longer cable runs.
RSRB (Remote
Source-Route Bridging). source-route
bridging over WAN links. RSRB
is supported by Cisco routers in its 9.0 software release.
RTMP (Routing
Table Maintenance Protocol). Apple Computer's proprietary routing protocol.
RTMP was derived from RIP.
RTN (Recursive
Transition Network).
RTP (Real-time
Transport Protocol) RTP provides end-to-end network transport functions
suitable for applications transmitting real-time data, such as audio, video
or simulation data, over multicast or unicast network services. RTP does
not address resource reservation and does not guarantee quality-of- service
for real-time services. The data transport is augmented by a control protocol
(RTCP) to allow monitoring of the data delivery in a manner scalable to
large multicast networks, and to provide minimal control and identification
functionality. RTP and RTCP are designed to be independent of the underlying
transport and network layers. The protocol supports the use of RTP-level
translators and mixers. A protocol, defined in RFC
1889
Also: (Routing Table Protocol). Used in Banyan VINES
routing with delay as a routing metric
RTS (Request
To Send). A modem control signal sent from the DTE
to the modem, used to tell the DTE has data to send.
RTSE (Reliable
Transfer Service Element). A lightweight OSI
application service used above X.25
networks to handshake application PDUs
across the Session Service and TP0. Not
needed with TP4, and not recommended
for use in the U.S. except when talking to X.400
ADMDs.
RTT (Round-Trip
Time). The time required for a network communication to travel from the
source to the destination and back. RTT therefore includes time required
for the destination to process the message from the source and generate
a reply. RTT is used by some routing algorithms to aid in calculating optimal
routes.
RTV (Real-Time
Video).
RU (Request/response
Unit). SNA request and response messages
exchanged between NAUs in an SNA network.
RUB (Router
Hub). Product jointly developed by CISCO and SynOptics Communications that
combines the capabilities of a router and a hub.