ATT DEFINITY Communications System Generic 3 Instructions Manual

							Glossary
Issue  3   March 1996GL-3 
Administered Connection (AC)
Administered Connection is a feature that allows the switch to automatically establish and main-
tain end-to-end connections between access endpoints (trunks) and/or data endpoints (data 
modules).
administration terminal
A terminal used to administer and  maintain a system. See also terminal.
Administration Without Hardware (AWOH)
Provides the ability to administer ports without the need for the associated terminals or other hard-
ware to be physically present.
abandoned call
An in comin g c all, where the c aller hangs up before being answered.
agent (or ACD agent)
An answering position who receives calls that are direc ted  to a sp lit. A memb er of an ACD hunt 
g roup (ACD sp lit).
agents in multiple splits
An agent may be logged into more than one split (three maximum). If, while logged into more than 
one split, the agent (1) answers an ACD c all, (2) is in ACW mode for any split, or (3) makes or 
re ceives a direct extension call, the switch will not distribute ad d itional ACD calls to that agent.
agent report
Provides historical traffic information for internally measured agents.
American National Standard Code for Information Interchange 
See ASCII.
analog
The rep resentation of information by means of continuously variab le physical q uantities such as 
amplitude, frequency, and phase.
analog data
Data that is transmitted  over a digital facility in analog (pulse code modulation) form. The data 
must p ass through a modem either at both ends or at a modem pool at the distant end.
analog telephone
A telephone that receives acoustic voice signals and sends analog electrical signals along the 
tele phone line. Analog telephones are usually served by a single wire pair (tip and ring). The 
model-2500 telephone set is a ty pic al example of an analog telephone.
analog-to-digital converter (ADC)
A device that converts an analog signal to digital form. See also digital-to-analog converter.
angel
A microprocessor located on each port card in a pro cessor port network (PPN). The angel uses 
the control-channel message set (CCMS) to manage communications between the port card and 
the archangel on the controlling switch processing element (SPE). The angel also monitors the 
status of other micro processors on a port card and maintains error counters and thresholds. See 
also archangel.
answerback code
An assigned numb er used to respond to a page from a code-calling or loudspeaker-paging sys-
tem, or to retrieve a parked call. 
						

							Glossary
GL-4Issue  3   March 1996 
appearance
A software process that is associated with an extension and whose purpose is to supervise a call. 
Also called ‘‘call appearance,’’ ‘‘line appearance,’’ and ‘‘occurrence.’’
applications processor
A minicomputer used with several user-controlled applications such as traffic analysis and elec -
tronic documentation.
architecture
The organizational structure of a system, including hardware and/or software.
ASCII (American National Standard Code for Information Interchange)
The standard code, using a coded character set consisting of 7-bit coded characters (eig ht bits, 
including p arity c heck), used for information interchange among data processing systems, d ata 
communications systems, and associated equipment. The ASCII set consists of control charac-
ters and graphic characters.
asynchronous data transmission
A method of transmitting data in which each character is pre ceded by a start bit and followed by 
a stop bit, thus permitting data characters to b e transmitted at irregular intervals. This type trans-
mission is advantageous when transmission is not regular (characters typed at a keyboard). Also 
called ‘‘asynchronous transmission.’’ See also synchronous data transmission.
association
An association is a communication channel between the adjunct and switch for messaging pur-
poses. An active association is one which applies to an existing call on the switch or to an exten-
sion on the call.
asynchronous data unit (ADU)
A d ata communications equipment (DCE) type devic e that allows dire ct connection between 
RS232C equipment and a digital switch.
attendant
A person at a console on a customer’s premises who provides personalized service for incoming 
callers and voic e-services users b y p erforming switching and sig naling operations. See also 
attendant console.
attendant console
The workstation used by an attendant. The attendant console allows the attendant to originate a 
call, answer an in comin g c all, transfer a call to another extension or trunk, put a call on hold, and 
remove a c all from hold. Attendants usin g the console can also manage and monitor some sys-
tem operations. Also called ‘‘console.’’ See also attendant.
Audio Information Exchange (AUDIX)
A fully integrated voice-mail system that can be used with a variety of communications systems to 
provide call-history data, such as subscriber identification and reason for redirection.
auto-in trunk groups
Those trunk groups where the CO processes all of the digits for the in comin g call. Whenever the 
switc h d etermines that the CO has seized a trunk from an Auto-In trunk group, it automatically 
(without pro cessing any digits) connec ts the trunk to the destination. The destination will typically 
be an ACD split where(emif there are no agents available(emthe call will go into a queue in which 
the c allers wait to be answered in the order in which they arrived.
auto-in work mode
One of four agent work modes. The work mode where an agent indicates, to the system, that the 
agent is ready to process another call as soon as the current call is completed. Specifically, if an  
						

							Glossary
Issue  3   March 1996GL-5 
agent disconnects from an ACD call while in Auto-in Work Mode, then that agent immediately 
becomes available to receive another ACD c all. 
See Manual-In Work Mode for a contrast.
Automatic Alternate Routing
Automatic Call Distribution (ACD) split
Calls of a similar type are distributed among agents.
Automatic Route Selection
The software program that controls call routing over an ETN is called Automatic Alternate Routing 
(AAR). AAR not only determines the route for a call, but, through the Facilities Restriction Level 
(FRL) function, defines up to eight levels of calling privileges for users of the ETN. Another func -
tion of AAR, Subnet Trunking, can c onvert an on-network numb er to a public network or interna-
tional number. This function is useful when all on-network routes are busy or are not provided.
automatic trunk
A trunk that does not require the sending or receiving of addressing information because the des-
tination is predetermined. A request for service on the trunk, c alled a ‘‘seizure,’’ is sufficient to 
route the call. The normal destination of an automatic trunk is the communications-system atten-
dant group. Also calle d ‘‘automatic in coming trunk’’ and ‘‘automatic tie trunk.’’
automatic restoration
A service that restores disrup te d connections between access endpoints (nonsignaling trunks) 
and data endpoints (devices that connect the switch to d ata terminal and/or communications 
equipment). This restoration is done within seconds of a service disruption so that critical d ata 
applications can remain operational.
auxiliary equipment
Equipment used for optional system features, such as Loudspeaker Pag ing  and  Music-on-Hold.
auxiliary trunk
A trunk used to connect auxiliary equipment, such as radio-paging equipment, to a communica-
tions system.
aux-work mode
In this mode, agents are unavailable to receive ACD c alls. A gents should enter aux-work mode 
when involved in non-ACD activities such as taking a break, g oin g to lunch, or placing an outgo-
ing call.
When agents log in, they are automatically placed in the Aux-Work mode. They can then use the 
Auto-In or Manual-In feature to make themselves available to answer the first call.
Also, the last available agent in a split cannot enter the aux-work mode if any ACD calls are 
remaining in the q ueue. If the last available agent attempts to enter aux-work mode, the following 
occurs: (1) Calls in the queue are routed to the agent until the queue is empty (2) If the last avail-
able agent has an aux-work b utton, the light next to the b utton flashes until all calls in the q ueue 
are answered. When the last call is answered, the lig ht next to the button goes on steadily, and 
the a gent then enters aux-work mode.
B
bandwidth
The difference, expressed in Hertz, b etween the defined hig hest and lowest frequencies in a fre-
quency range. 
						

							Glossary
GL-6Issue  3   March 1996 
barrier code
A security code used with the Remote Access feature to prevent unauthorized  a ccess to the sys-
tem.
baud
In telecommunications applications, a unit of transmission speed equal to the number of signal 
events per second. See also bit rate an d bits per second.
BCC
The Bearer Capability Class (BCC) identifies the type of a call, for example, voice and different 
types of data. Determination of BCC is based on the call originator’s characteristics for non-ISDN 
endpoints and on the Bearer Capability and Low-Layer Compatibility Information Elements of an 
ISDN endpoint.
Current BCCs are:
n0: Voice-grade data and voice
n1: DMI Mode 1, 56 kbps data transmission
n2: DMI Mode 2, synchronous/asynchronous data transmission up to 19.2 kbps
n3: DMI Mode 3, 64 kbps circuit/packet data transmission
n4: DMI Mode 0, 64 kbps synchronous data
n5: Temporary Signaling Connection
n6: Wideband Call, 128 to 1984 kbps synchronous data
bit (binary digit)
One unit of information in binary notation having two p ossible states or values, 0 or 1.
bits per second (bps)
The number of binary units of information that are transmitted or re ceived per second. See also 
baud and bit rate.
bit rate
The speed at which bits are transmitted, usually expressed in bits per second. Also called ‘‘data 
rate.’’ See also baud and bits per second.
bridge (bridging)
The appearance of a voice terminal’s extension at one or more other voice terminals.
BRI
The ISDN Basic Rate Interfa ce specification.
bridged appearance
A call appearance on a voice terminal that matc hes a call appearance on another voice terminal 
for the duration of a call.
buffer
(1) In hardware, a circuit or component that isolates one electrical circuit from another. Typically, 
a buffer hold s d ata from one circ uit or process until another circuit or process is ready to accept 
the d ata. (2) In software, an area of memory used for temporary storage.
bus
A multiconductor electrical path used to transfer information over a common connection from any 
of several sourc es to any of several destinations. 
						

							Glossary
Issue  3   March 1996GL-7 
business communications terminal (BCT)
An integrated digital data terminal used for business applications. A BCT can function via a d igital 
terminal data module (DTDM) or a processor d ata module (PDM) as a spec ial-purpose terminal 
for services provided by an applications processor (AP) or, as a terminal for data entry and 
retrieval.
BX.25
An AT&T version of the CCITT X.25 protocol for data communications. BX.25 adds a fourth level to 
the standard X.25 interface. This uppermost level c ombines levels 4, 5, and 6 of the International 
Standards Organization (ISO) refere n ce m o del.
bypass tie trunks
A one-way, outgoing tie trunk from a tandem switch to a main switch in an electronic tandem net-
work (ETN). Bypass tie trunks, provided in limited q uantities, are used as a ‘‘last-choice’’ route 
when all trunks to another tandem switch are busy. Bypass tie trunks are used only if all a pp lica-
ble intertandem trunks are b usy.
byte
A sequence of (usually eig ht) bits pro cessed together.
C
cabinet
Housing for racks, shelves, or carriers that hold electronic equipment.
cable
The physical connection b etween two pieces of e quipment (em for example, cable from a data 
terminal to a modem (em or between a piece of equipment and a termination field (em for exam-
ple, circuit pack I/O cables.
cable connector
A cable c onnector is either a ja ck (female) or plug (male) on the end of a cable. A cable connec-
tor connects wires on a c a ble to specific leads on tele phone or d ata equipment.
call appearance, attendant console
Six b uttons, labeled ‘‘a’’ through ‘‘f,’’ and used to originate, receive, and hold calls. Each button 
has two lights to show the status of the call appearance.
call appearance, voice terminal
A button labeled with an extension number and used to place outgoing calls, receive incoming 
calls, or hold calls. Two lights next to the button show the status of the call appearance or the sta-
tus of the c all.
call control capabilities
call control capabilities are all the capabilities (
Third  Party Sele ctive Hold, Third Party Reconnect, 
Third  Party Merge
) that can  be used in either of the Third Party Call Control ASE (cluster) subsets: 
Call Control and Domain Control.
call detail recording
A switch feature that utilizes software and  hardware to record call data (same as CDRU).
call detail recording utility (CDRU)
Applications software that collects, stores, optionally filters, and outputs call detail records for 
direct or polled output to p eripheral d evices. 
						

							Glossary
GL-8Issue  3   March 1996 
call management system (CMS)
An application, running on an adjunct processor, that collects information from an Automatic Call 
Distribution (ACD) unit. CMS enables customers to monitor and manage telemarketing centers by 
generating reports on the status of agents, splits, trunks, trunk groups, vectors, and vector direc-
tory numbers (VDNs), and  enables customers to partially administer the ACD feature for a com-
munications system.
call reference value (CRV)
An identifier present in ISDN messages that serves to associate a related sequence of messages. 
In ASAI, the CRVs distinguish between associations.
call vector
A set of up to 15 vector commands to be performed for an incoming or internal call.
callback call
A  call that is automatically returned to a voic e terminal user who activated the Automatic Callback 
or Ringback Queuing feature.
call-waiting ringback tone
A low-pitched tone identical to ringback tone except that the tone decreases in the last 0.2~sec-
ond (in the United States). A call-waitin g ringback tone notifies the attendant that the Attendant 
Call Waiting feature has been activate d and that the called user is aware of the waiting  call. Tones 
in international countries may sound different.
call work code
A number, up to 16 digits, entered by Automatic Call Distribution (ACD) agents to record the 
occurrence of c ustomer-defined events (such as account codes, social security numbers, or 
phone numbers) on ACD calls.
carrier
An enclosed shelf containing  vertical slots that hold circuit p acks.
carried load
The amount of traffic actually served by traffic-sensitive facilities during a given interval.
CCS or hundred call seconds
A unit of traffic measure that is used to  determine usage. In order to determine usage for a facility, 
it is scanned every 100 seconds. If the facility is found busy, then it is assumed to have b een busy 
for the entire s can interval. There are 3600 seconds per hour. The Roman numeral for 100 is the 
capital letter ‘‘C.’’ The abbreviation for call seconds is CS. Therefore, 100 call seconds is abbrevi-
ated as CCS. If a facility is b usy for an entire hour, then it is said to have b een busy for 36 CCS. 
See also Erlang.
capability
A capability is a either a request or in dic ation of an operation. For example, a 
Third Party Make 
Call
 is a request for setting-up a call and an Event Report is an indication that an event has 
occurred.
capability groups
Capability groups are sets of capabilities, provisioned through switch a dministration, that can be 
re quested by an application. Each capability group may contain capabilities from several c a pa-
bility groups. Capability groups are also referred to, in other documentation, as administration 
groups or Application Service Elements (ASEs). Capability groups denote association types. For 
example, 
Call Control is a type of association whic h allows certain func tions (the ones in the capa-
bility group) to be performed over this type of association. 
						

							Glossary
Issue  3   March 1996GL-9 
cause value
A Cause Value is returned in responses to re quests or in event reports when a denial occurs or an 
unexpected condition is encountered. ASAI cause values fall into two ‘‘coding standards’’: Cod-
ing Standard 0 inc ludes any cause values that are part of AT&T and CCITT ISDN specifications, 
and, Codin g standard 3 in clu des any other ASAI cause values. This document uses a notation for 
cause value where the coding standard for the cause is given first, then a slash, then the c ause 
value. For example, CS0/100 is codin g standard 0, c ause value 100.
CCITT
CCITT (Comitte Consultatif International Telephonique et Telegraphique) is now calle d 
Interna-
tional Telecommunications Union
 (ITU). See this name for information.
center stage switch (CSS)
The central interface between the processor port network (PPN) and expansion port networks 
(EPNs) in a CSS-connected system.
central office (CO)
The location housing telephone switc hing e quipment that provides local telephone service and 
access to toll facilities for long-distance calling.
central office (CO) codes
The first three digits of a 7-digit public network telephone number in the USA. CO codes are num-
bered from 200 through 999.
central office (CO) trunk
A telecommunications channel that provides a ccess from the system to the p ub lic network 
through the local CO.
channel
The term channel is nonspecific and must be taken in context. Channel can refer to a cir-
cuit-switched call or a communications path for transmitting voice and/or data.
In wideband, a channel refers to all of the time slots necessary to support a c all. For example, an 
H0-channel uses six 64 kbps time slots. This d efinition of channel is the same whether the time 
slots necessary to support the call are contig uous or noncontiguous.
Channel can also refer to a DS0 on a T1 or E1 facility not specifically associated with a logical cir-
cuit-switched call. In this c ontext, a channel is analogous to a single trunk.
channel negotiation
Channel negotiation is the process by which the channel offered  in the Channel Identification 
Information Element (CIIE) in t he SETUP message is ‘‘negotiated’’ to be another channel accept-
able to the switch receiving the SETUP message and ultimately to the switc h that sent the SETUP. 
Negotiation will only b e attempted if the CIIE is encoded as 
Preferred. Channel negotiation will not 
be attempted for wideband calls.
circuit
(1) An arrangement of electrical elements through which electric current flows, providing one or 
more spec ific functions. (2) A c hannel or transmission p ath between two or more points.
circuit pack
A card on which electrical circuits are printed, and integrated circuit (IC) chips and electric al 
components are installed. A circuit pack is installed in a switch carrier.
Class of Restriction (COR)
A feature that allows up to 64 classes of c all-origination and  call-termination restrictions for voice 
terminals, voic e terminal groups, data modules, and trunk groups. See also Class of Service 
(COS). 
						

							Glossary
GL-10Issue  3   Marc h 1996 
Class of Service (COS)
A feature that uses a number (0 through 15) to specify if voice terminal users c an ac tivate the 
Automatic Callb ack, Call Forwarding(emAll Calls, Data Privacy, or Priority Calling features.
common control switching arrangement (CCSA)
A private telecommunications network using dedicated trunks and a shared switching center for 
interconnectin g company locations.
communications system
The software-controlled processor complex that interprets dialing pulses, tones, and/or keyboard 
characters and makes the proper interconnections both within the system and external to the sys-
tem. The communications system itself consists of a digital computer, software, stora ge d evice, 
and carriers with special hardware to perform the a ctual connections. A communications system 
provides voice and/or data communications services, including access to p ub lic and private net-
works, for telephones and data terminals on a customer’s premises. See also switch.
confirmation tone
A tone confirming that a feature activation, deactivation, or cancellation has been a ccepted.
connectivity
The connection of disparate devic es within a single system.
console
See attendant console.
contiguous
Contig uous, which is a wideband term, refers to adja cent DS0s within one T1 or E1 facility or adja-
cent TDM or fiber time slots. Note that the first and last TDM b us, DS0, or fiber time slots are not 
considered contiguous (no wra paround). For an E1 facility with a %D-channel, DS0s 15 and 17 
are c onsidered contig uous.
control cabinet
See control carrier.
control carrier
A carrier in a multicarrier cabinet  that  contains the switc h pro cessing element (SPE) circuit packs 
and, unlike a G3r control c arrier, port circuit packs. Also called ‘‘control cabinet’’ in a single-car-
rier c ab inet. See also switch processing element.
controlled station
A station that is b ein g monitore d and  c ontrolled  via a domain-control assoc iation.
coverage answer group
A group of up to eight voice terminals that ring simultaneously when a call is re directed to it by 
Call Coverage. Any one of the group can answer the call.
coverage call
A call that is automatically redirecte d from the called party’s extension number to an alternate 
answering position when c ertain c overage criteria are met.
coverage path
The order in whic h c alls are redirecte d to alternate answering  p ositions.
coverage point
An extension or attendant group, vector directory numb er (VDN), or Automatic Call Distribution 
(ACD) s plit desig nated  as an alternate answering position in a coverage path.
covering user
A p erson at a coverage point who answers a redire cted call. 
						

							Glossary
Issue  3   March 1996GL-11 
critical reliability system
A system that has the following duplicated items: control carriers, tone-clo ck  circuit p a cks, expan-
sion interface (EI) circ uit packs, and cabling between port networks (PNs) and  c enter stage 
switc h (CSS)  in a CSS-c o nnected system. See also duplicated common control, duplicate pro-
cessor-only system, and  duplication.
D
data channel
A communications p ath between two points used to transmit digital signals.
data communications equipment (DCE)
The equipment (em usually a modem, data module, or packet assembler/disassembler (em on 
the network side of a communications link that provides the func tions to make the binary serial 
data from the source or transmitter compatible with the communications channel.
data link
The configuration of p hysical facilities enabling end terminals to communicate directly with each 
other.
data module
An interconnection devic e b etween a basic rate interface (BRI) or digital c ommunications proto-
col (DCP) interface of the switch and data terminal equipment (DTE) or d ata communications 
equipment (DCE).
data path
The end-to-end c onnection used for a data-c ommunications link. A data p ath is the combination 
of all the elements of an interprocessor communication in a distributed communications system 
(DCS).
data port
A point of access to a computer that uses trunks or lines for transmitting or re ceiving d ata.
data rate
See bit rate.
data service unit (DSU)
A device designed to transmit digital data on transmission facilities.
data terminal
An in put/output (I/O) device that has either switc hed or dire ct access to a host computer or to an 
applications processor (AP).
data terminal equipment (DTE)
Equipment consisting of the endpoints in a connection over a d ata circuit. For example, in a con-
nection between a d ata terminal and a host, the terminal, the host, and their associated modems 
or data modules make up the DTE. DTE usually consists of the following functional units: control 
log ic, buffer store, and one or more input or output d evices or computers. DTE c an c ontain error 
control, synchronization, and telephone-identification capabilities.
D-channel backup
D-c hannel backup is used with Non-Facility Associated Signaling (NFAS). With D-channel 
backup, a primary D-c hannel provides signalin g for an NFAS D-c h annel group (two or more PRIs 
facilities). A second (redundant) %D-channel, lo cated on a separate PRI facility of the NFAS 
D-c hannel group is designated as backup for the D-channel. The failure of the primary D-channel  
						

							Glossary
GL-12Issue  3   Marc h 1996 
causes an automatic transfer of call-control signaling to the backup D-channel. When this hap-
pens, the b ackup becomes the primary D-channel, and when the previous primary is returned to 
service it becomes the backup D-channel.
DCS
See Distributed Communications System on page GL-13.
delay-dial trunk
A trunk that allows dialing directly into a communications system (em that is, the digits are 
re ceived as they are dialed.
denying a request
Denying a Request is the same as sending a negative acknowledgement (NAK), and is done by 
sending an Facility Information Element (FIE) with a 
return error component (a cause value is also 
provided). It should not be confused with the ‘‘denial’’ event report which applies to calls.
designated voice terminal
The specific voice terminal to which calls, originally dire cte d to a c ertain extension number, are 
re directed. Commonly used to mean the ‘‘forwarded-to’’ terminal when Call Forwarding  All Calls is 
active.
dial-repeating tie trunk
A tie trunk that transmits calle d-party addressing information between two c ommunic ations sys-
tems.
digit conversion
A process used to convert specific dialed numbers into other dialed numbers.
digital communications protocol (DCP)
An AT&T proprietary protocol used to transmit both digitized voice and digitized data over the 
same communications link. A DCP link is made up of two 64~kbps information (I-) channels and 
one 8-kbps signaling (S-) channel.
digital data endpoints
In G3iV2, digital data endpoints include devices such as the 510D terminal or the 515-type busi-
ness c ommunic ations terminal (BCT).
digital multiplexed interface (DMI)
An interfa ce that provid es connectivity b etween a communications system and a host computer 
or between two communications systems using digital signal level-1 (DS1) 24th-channel signal-
ing. DMI provides 23 64~kbps data channels and 1 common signaling channel over a 
twisted-pair connection. DMI is offered through two capabilities: bit-oriented signaling (DMI-BOS) 
and message-oriented signaling (DMI-MOS).
digital signal level 0 (DS0)
A sin gle 64 kbps voice channel. A DS0 is a single 64 kbps c hannel in a T1 or E1 facility and con-
sists of eight bits in a T1 or E1 frame every 125 micro-seconds.
digital terminal data module (DTDM)
An integrated or adjunct data module that shares with a digital telephone the same p hysical p ort 
for connection to a c ommunications system. The function of a DTDM is similar to that of a proces-
sor d ata module (PDM) and  modular processor data module (MPDM) in that it converts RS232C 
signals to DCP signals.
digital-to-analog converter
A d evice that converts data in digital form to the corresponding analo g signals. See also ana-
log-to-digital converter.