RA (Rectifier Alarm)
- The discrete lead designation used to report the failure of the start battery
rectifier serving the engine/alternator unit. Can be taken directly from late
model rectifiers or indirectly from an engine alarm cabinet. The alarm is sent
from an engine alarm cabinet as a loop closure. The alarm is also included as
part of the engine/alternator minor alarm (F & A).
Rack (Relay Rack) -
A structure on which equipment is mounted.
Availability Information Group) - Contains information that is
used to attach values of topology state parameters to nodes, links and
RAM (Random Access Memory)
- A chip or collection of chips where data can be entered, read and erased. RAM
is the fastest memory device, but is volatile and will lose its contents when
the power is turned off.
RBOC (Regional Bell
Operating Company) - There are seven RBOCs, each of which own two or
more BOCs (Bell Operating Companies).
RCC (Routing Control
Channel) - VPI=0, VCI=18 is reserved as the VC used to exchange
routing information between logical nodes. An RCC (Routing Control Channel)
that is established between two Logical Group Nodes serves as the logical link
information needed by LGNs to establish the RCC SVC between other nodes in the
peer group and is derived from the existence of uplinks.< /P>
RD (Routing Domain)
- A group of topologically contiguous systems which are running one instance of
RDF (Rate Decrease Factor)
- For ABR, controls the rate at which cell transmission decreases.
Reachable Address Prefix
- A prefix on a 20-octet ATM address indicating that all addresses beginning
with this prefix are reachable.
Real Time - A voice
telephone conversation is conducted in real time; i.e. there is no perceived
delay in the transmission of the voice message or in the response to it. In
data processing or data communications, real time means the data is processed
the moment it enters a computer, as opposed to batch processing, where the
information enters the system and is stored to be processed at a later time.
Real Time Capacity -
The capacity of the central computer processor of a stored program control
telephone system to process the instructions coming in.
Real-Time Clock - a
clock that maintains the time of day, in contrast to a clock that is used to
time the electrical pulses on a circuit.
Conversion of alternating current into current flowing in only one direction
Electrical apparatus or equipment that changes AC power to DC power.
- Operation of more than one rectifier on a parallel load-sharing basis.
Rectify - To
convert alternating current into direct current.
Red Alarm - In T1,
a red alarm is generated for a locally detected failure such as when a
condition like OOF exists for 2.5 seconds, causing a CGA, (Carrier Group
Redundancy - In a
data transmission, the fragments of characters and bits that can be eliminated
with no loss of information.
Redundancy of Chargers
- The process of both quantifying and sizing of the chargers required to enable
continuous system operation upon the failure of a single charger. (May not
recharge batteries in allotted time, but will support the load.) (N+1
Redundant - (1)
More than is actually needed for intelligibility; and (2) items of equipment
which are provided in duplicate or triplicate so that a required grade of
service may be reliably achieved.
Registration - The
address registration function is the mechanism by which Clients provide address
information to the LAN Emulation Server.
Registration Number (FCC
Part 68) - Approval number given to telephone equipment to certify
that a particular device passes the tests defined in Part 68 of the FCC Rules.
These tests certify that the phone won't cause any harm to the public network.
- FCC program which governs the direct connection of terminal equipment,
whether customer-provided or telephone company-provided, to the
telecommunications network without the need for a protective connecting
arrangement (PCA). An applicant for equipment registration is required to show
the equipment meets technical standards developed by the FCC.
Regulated - (1)
Controlled for uniformity; and (2) adhering to the rules of a government
agency. Regulation: (1) Voltage regulation; (2) the regulation of levels over a
transmission system; and (3) the control of sag of an open wire route.
Regulatory Groups -
Local, state or federal entities that issue orders, findings, etc. which are
binding upon providers and users of telecommunications and services.
Relay - An
electro-mechanical device used to switch circuits. Consists of a coil which,
when connected to a complete circuit, will create a magnetic field which will
attract an armature to open or close contacts.
Relaying - a
function of a layer by means of which a layer entity receives data from a
corresponding entity and transmits it to another corresponding entity.
Relay Rack Framework
- Uniframe, ESS frame, unequal lange duct framework, and bulb type framework
(floor supported) with equipment mounted on the side. Sheet metal enclosures
are usually available for single bay applications where it is necessary to
cover current carrying parts.
Reliability - A
measure of how dependably a system performs.
Remote Access -
Communication with a data processing facility through a data link.
Remote Alarm -
Alarm indicating a fault condition at a distant central office.
Remotely Located Equipment
- Any equipment associated with the telephone service, including terminals,
etc., that is located remotely from the switch itself.
Remote Sensing - A
means by which the power supply uses external "sensing" leads to monitor a
stabilized output voltage and/or current at some point external to the power
supply (usually at the batteries).
Repertory Dialing -
Sometimes known as "memory dialing" or "speed-calling." A feature that allows
you to recall from nine to 99 (or more) phone numbers from a phone's memory
with the touch of just one, two or three buttons.
Reset - An action
by which the power supply is brought back into operation after a malfunction
has been corrected.
Resistance - Any
electrical conductor will resist the flow of electrical current. As it resists
the flow of current, the current becomes weaker. Resistance generates heat and
occasionally light, and is measured in Ohms.
- Resistor inserted in grounding circuit to limit current.
Resistor - A device
whose function is to put resistance into an electrical circuit.
Resistor Color Code
- Colored markings on a resistor which indicate the value and tolerance.
Response Time - The
time which elapses between the generation of an inquiry and the receipt of a
reply. It includes transmission time, processing time, time for searching
records and files to obtain relevant data, and transmission time back to the
inquirer. In a data system, it is the elapsed time between the end of
transmission of an inquiry message and the beginning of the receipt of a
response message, measured at the inquiry originating station.
Restricted Transit Node
- A node that is to be used for transit by a call only in restricted
circumstances. It is free from such restriction when it is used to originate or
terminate a call.
RF (Radio Frequency)
- Electromagnetic waves operating between 10 KHz and 3 MHz propagated without
guide (wire or cable) in free space.
RFA (Rectifier Failure
Alarm) - A discrete lead designated denoting the failure of a
rectifier. Normally connected as a grounded make lead.
RFCs (Requests For Comment)
- IETF documents suggesting protocols and policies of the Internet, inviting
comments as to the quality and validity of those policies. These comments are
collected and analyzed by the IETF in order to finalize Internet standards.
RFC1483 - Multiprotocol
Encapsulation over ATM Adaptation Layer 5.
Multiprotocol Interconnect over Frame Relay.
RFC1577 - Classical
IP and ARP over ATM.
RFC1755 - ATM
Signaling Support for IP over ATM.
RFI (Request For
Information) - General notification of an intended purchase of
equipment or equipment and lines sent to potential suppliers to determine
interest and solicit general escriptive product materials, but not prices or a
RFI (Radio Frequency
Interference) - the unintentional transmission of radio signals.
Computer equipment and wiring can both generate and receive RFI.
RFP (Request For Proposal)
- A detailed document prepared by a buyer defining his requirements for service
and equipment sent to one or several vendors. A vendor's response to an RFP
will typically be binding on the vendor, i.e. he will be obliged to deliver
what he says in his RFP at the prices and following the conditions therein.
RFQ (Request For Quotation)
- A document prepared by a buyer defining his needs for service and equipment
in fairly broad terms and sent to one or several vendors.
RG (Ring Ground) -
Use for the grounded output from a self-contained alarm system for power minor
and ABSF audible paired with ±105V 20 cycle ringing.
Ribbon Cable -
Multi-wire cable that is flat instead of round in which conductors are laid
side by side.
RIF (Rate Increase Factor)
- For ABR, controls the rate at which cell transmission increases.
Ring - (1) As in
Tip and Ring, one of the two wires needed to set up a telephone connection. (2)
A reference to the ringing of the telephone set. (3) Design of a Local Area
Network (LAN) in which the wiring loops from one workstation to another,
forming a circle.
Ringback Tone - The
sound you hear when you're calling someone else's phone. The tone you hear is
generated by a device at your central office, and may bear no relationship to
the sound the phone at the other end is (or is not) emitting.
Ring Bus (DC Plants)
- A closed loop bus system of fused bus and battery feeder sections powered by
paralleled rectifiers; an overall highly reliable DC power plant. The loss of a
single section of the ring bus will not result in loss of power to the loads
(service is not affected). Continuity of power is maintained until repair or
replacement can be made.
Alternating Current (AC) sent out from the central office along the local loop
to the subscriber, typically 70 to 90 volts at 16 to 66 Hz (20 Hz is most
Ringing Generator -
A device, either rotary or solid state, that generates voltage for ringing a
telephone. Typically this voltage is 70 to 90 volts at 20 Hz.
Ringing Interval -
In the U.S., ringing current is usually applied to a called line for one
second, followed by three or four seconds of silence before another one second
of ringing. In other countries, different periodicities are sometimes used.
Ringing Monitor - A
device which continually monitors the ringing supply at a central office and
gives an alarm if this fails or if the period of interruption becomes
Ringing Plant -
Electrical apparatus or equipment that provides ringing power for subscribers'
telephones, various tones (such as dial tone and busy tone), and interruption
cadences as required by the type of office in which it is used.
Ringing Signal -
Any AC or DC signal transmitted over a line or trunk for the purpose of
activating a bell or other audible signaling device.
Ringing Tone - A
low tone which is one second ON and three seconds OFF. It indicates that
ringing current is being sent by the central office to the person receiving the
Ring Trans. (Ring Transfer)
- A discrete lead designation signifying that the ring plant has transferred to
the standby unit.
RIP (Routing Information
Protocol) - a distance vector-based protocol that provides a measure
of distance, or hops, from a transmitting workstation to a receiving
Ripple (Output) - A
measurement of the RMS value of A Ccomponents superimposed on a DC source.
Ripple Voltage -
The alternating component of the unidirectional voltage from a rectifier or
generator used as a source of DC power.
RISC (Reduced Instruction
Set Computer) - a generic name for CPUs that use a simpler instruction
set than more traditional designs.
RM (Resource Management)
- The management of critical network resources, such as bandwidth and buffers,
at the node level. A value of 6 is reserved in the PTI (Payload Type
Identifier) to indicate a RM cell.
RMON [version 1.1] (Remote
Network Monitoring) is an extension of MIB-II that gives certain
devices the ability to serve as micro-monitors for their segments of a network.
RMON provides a means of distributing network monitoring functions down through
the network to certain strategically placed smart devices (RMON probes).
RMON agents reside on
network equipment much the same as typical SNMP agents, providing information
to the collection points. Data from the collection points is stored until
software interrogates the probe and displays the information for the network
manager. The information is network and traffic-oriented in contrast to
traditional SNMP information which is more device-oriented.
Information is gathered in
groups such as statistics, history, alarms, hosts, and traffic matrix. RMON is
typically used to get a ground-level view of traffic trends so appropriate
scaling and growth plans can be made.
Roam - Using your
cellular phone in a city besides the one in which you live.
- In T1, refers to the use of the least significant bit of every word of frames
6 and 12 (D4), or 6, 12, 18, and 24 (ESF) for signaling purposes.
ROM (Read Only Memory)
- A memory device which is programmed at the factory and whose contents
thereafter cannot be altered by a power breakdown or by being written to.
Router - a device
that forwards traffic between networks or subnetworks based on network layer
Route Server - A
physical device that runs one or more network layer routing protocols, and
which uses a route query protocol in order to provide network layer routing
forwarding descriptions to clients.
- The process of applying a mathematical algorithm to a topology database to
compute routes. There are many types of routing computations that may be used.
The Djikstra algorithm is one particular example of a possible routing
Routing Protocol -
A general term indicating a protocol run between routers and/or route servers
in order to exchange information used to allow computation of routes. The
result of the routing computation will be one or more forwarding
RPQ (Request for Price
Quotation) - Solicitation for pricing of a specific component,
software product, service, or system.
RR (Relative Rate) -
A feedback mechanism whose end result is to slow the transmission of cells down
by some percentage (i.e., 50%) based on a congested condition.
RR (Round Robin) Queuing
- Developed to allow Fair Queuing to be used with a large number of flows with
a wide variation in bandwidth. It is very similar to Fair Queuing, as each flow
is allocated its own dedicated queue and all queues are processed in some
RS-232-C (also RS-232)
- A set of standards specifying various electrical and mechanical
characteristics for interfaces between computers, terminals and modems. It
consists of a 25-pin plug (male or female), each lead of which has a specific
function such as timing, control, or the sending of data.
RSA (Rural Service Area)
- The FCC designated 428 rural markets across the country and is still in the
process of licensing cellular operators for them. See also MSA.
RTS (Request To Send)
- an RS-232 modem interface signal (sent from the DTE to the modem on pin 4)
which indicates that the DTE has data to transmit.
rtVBR (real time Variable
Bit Rate) - One of the service types for transmitting traffic that
depends on timing information and control and which is characterized by the
average and peak cell rates. It is suitable for carrying traffic such as
packetized (compressed) video and audio.