ATT DEFINITY Communications System Generic 3 Instructions Manual

							Glossary
Issue  3   March 1996GL-13 
digital transmission
A mode of transmission in which the information to be transmitted is first converted to digital form 
and then transmitted as a serial stream of p ulses.
digital trunk
A circuit in that carries digital voice and/or digital data in a telecommunications channel.
dial-repeating trunks
A PBX tie trunk that is c apable of handling PBX station signaling information without attendant 
assistance.
direct agent
A switch feature accessed only via Adjunct Switch Ap p lications Interface (ASAI) which allows a 
call to be placed in a split queue but routed only to a specific agent in that split. This allows a call 
to receive normal ACD call treatment (for example, announcements) and to b e measured as an 
ACD c all while ensuring that a particular agent answers.
Direct Extension Selection (DXS)
A feature on an attendant console that allows an attendant direc t access to voice terminals by 
pressing a group select button and a DXS button.
Direct Inward Dialing (DID)
A feature that allows an incoming call from the p u blic network (not FX or WATS) t o r each a spe-
cific telephone without attendant assistance. DID calls to DID-restricted tele phone lines are 
route d to an attendant or recorded announcement, depending on the option selected.
direct inward dialing (DID) trunk
An incoming trunk used for dialing directly from the public network into a communications system 
without help from the attendant.
disk drive
An electromechanical device that stores data on and retrieves data from one or more disks.
distributed communications system (DCS)
A network configuration linking two or more communic ations systems in such a way that selec ted  
features appear to o perate as if the network were one system.
domain
Available d omains are VDNs, ACD splits, and stations. The VDN domain is only used for 
active-notific ation associations, the station domain is only used  for the domain-control associa-
tions. The ACD-split domain is for active-notification assoc iations and domain-control associa-
tions.
domain-control association
A 
Third Party Domain Control Request capability initiates a uniq ue ‘‘CRV/link number’’ combina-
tion, which is referred  to as a domain-c ontrol association.
domain-controlled split
A sp lit for which 
Third Party Domain Control request has been a c cepted. A domain-c ontrolled 
split provides an event report for logout.
domain-controlled station
A station for which a 
Third_Party_Domain_Control request has been a ccepted. A domain-con-
trolled  station provides event reports for calls that are alerting , connected, or held at the station.
domain-controlled station on a call
A station active on a call which provides event reports over one or two domain-c ontrol associa-
tions. 
						

							Glossary
GL-14Issue  3   Marc h 1996 
duplicated common control
Two pro c essors ensuring c ontinuous operation of a c ommunic ations system. While one processor 
is on-line, the other functions as a b ackup. The backup processor g oes on-line period ically or 
when a pro blem condition occurs.
duplication
The use of redundant c omponents to improve availab ility. When a duplic ated subsystem fails, its 
backup redundant system automatically takes over.
duplication option
A system op tion that duplicates the followin g:
nControl carrier, which contains the switch processing element (SPE)
nExpansion interface (EI) circuit packs in carriers
nFiber-optic cabling between port networks (PNs)
nCenter-stage switch (CSS) in a CSS-connected system
E
E1
A digital transmission standard that c arries traffic at the rate of 2.048 Mbps.
The E1 facility is divided into 32 channels (DS0s) of 64 kbps information numbere d from 0~to 31. 
Channel 0 is reserved for framing and synchronization information. When a D-channel is present, 
it occupies c hannel 16.
ear and mouth (E&M) signaling
Trunk supervisory signaling, used between two communications systems, where by sig nalin g 
information is transferre d through two-state voltage conditions (on the E and M leads) for analog 
applications and through a single bit for digital applications.
electronic tandem network (ETN)
A tandem tie trunk network that has automatic call routing capabilities based on the number 
dialed and the most preferred route available at the time the call is placed. Each switch in the net-
work is assigned a unique private network offic e  code (RNX) , and each voice terminal is assigned 
a unique extension number.
Electronics Industries Association (EIA)
A trade  association of the electronics  industry that establishes electrical and functional standards.
emergency transfer
If a major system failure occurs, the automatic transfer within a communications system of a pre-
defined set of central office (CO) lines to a group  of answering telephones with at least one tele-
phone c apable of making outgoing calls. The system operates in this mode until the failure is 
re paired and the system automatically returns to normal operation. Also called  ‘‘power-failure 
transfer.’’
end-to-end signaling
The transmission of touch-tone signals generated by dialing from a voice terminal user to remote 
computer e quipment. A connection must first be established over an outg oin g trunk from the call-
ing p arty to the computer equipment. Then additional digits can be dialed to transmit information 
to be processed by the computer equipment. 
						

							Glossary
Issue  3   March 1996GL-15 
enhanced private-switched communications service (EPSCS)
An analog private tele communications network based on the No. 5 Crossbar and 1A ESS that pro-
vides advanced voice and data telecommunications services to companies with many locations.
Erlang
A unit of traffic intensity, or load, used to express the amount of traffic it takes to keep one facility 
busy for one hour. One Erlang is e qual to 36 CCS. See also Hundred Call Seconds.
expansion archangel (EAA)
A network-control microprocessor located on an expansion interface (EI) port circuit pack in an 
expansion port network (EPN) . The EA provides an interface between the EPN and its controlling 
switc h processing element (SPE).
expansion-archangel link (EAL)
A link-access function on the D-channel (LAPD) logical link that exists between a switc h process-
ing element (SPE) and an expansion archangel (EA). The EAL c arries control messages from the 
SPE t o the EA and to port circ uit packs in an expansion port network (EPN).
expansion control cabinet
See expansion control carrier.
expansion control carrier
A carrier in a multicarrier cabinet that c ontains extra port circuit p a cks and a maintenance inter-
face. Also called ‘‘expansion control cabinet’’ in a single-carrier c a binet.
expansion interface (EI)
A port circuit pack in a port network (PN) that provides the interfa ce between a PN’s time-division 
multiplex (TDM) bus and packet bus, and a fiber-optic link. The EI c arries circuit-switched data, 
packet-switched data, network c ontrol, timing control, and DS1 c ontrol. In a dd ition, an EI in an 
expansion port network (EPN)  c ommunicates with the master maintenance circuit pack to provide 
the EPN’s environmental and alarm status to the switch pro cessing element (SPE).
expansion port network (EPN)
A port network (PN) that is connected to the TDM bus and p acket bus of a pro cessor port network 
(PPN). Control is achieved b y indirect connection of the EPN t o the PPN via a port-network link 
(PNL). See also port network.
extension-in
Extension-In (ExtIn) is the work state agents go into when they answer (receive) a non-ACD call. If 
the agent is in Manual-In or Auto-In and receives an extension-in  call, it is re cord ed  by CMS as an 
AUX-In call.
extension-out
Extension-Out (ExtOut) is the work state agents go into when they place (originate) a non-ACD 
call. If the agent is in Manual-In or Auto-In and places an extension-out call, it is recorded by CMS 
as an AUX-Out call.
external measurements
Refers to those ACD measurements that are made by the External CMS adjunct.
extension number
A 1- to 5-digit number b y which calls are routed through a communications system or, with a Uni-
form Dial Plan (UDP) or main-satellite dialing plan, through a private network. Extension numbers 
are primarily used for telephones and data terminals b ut can also be used with spec ific features.
external call
A connection between a communications system user and a party on the public network or on 
another communications system in a private network. 
						

							Glossary
GL-16Issue  3   Marc h 1996 
F
facility
A g eneral term used for a telecommunic ations transmission pathway and associate d equipment.
facility associated signaling (FAS)
Signaling in which a D-channel carries the sig naling only for those channels on the same physical 
interface.
feature
A specifically defined function or service provided by the system.
feature button
A labeled button on a telephone or attendant console used to access a specific feature.
fiber optics
A technology using materials that transmit ultrawideband electromagnetic light-frequency ranges 
for high-capacity c arrier systems.
fixed
Fixed is a trunk allocation term. In the fixed  allocation s cheme, the time slots necessary to support 
a wideband call are contig uous, and the first time slot is constrained to certain starting points.
flexible
Flexible is a trunk allocation term. The flexible allo cation scheme allows the time slots of a wide-
band call to occupy noncontiguous positions within a single T1 or E1 facility.
floating
Floatin g is a trunk allocation term. In the floating allocation scheme, the time slots necessary to 
support a wideband c all are contiguous, but the position of the first time slot is not fixed .
foreign exchange (FX)
A central office (CO) other than the one providing local access to the p ublic tele phone network.
foreign exchange trunk
A telecommunications channel that directly c onnects the system to a c entral office (CO) other 
than its lo cal CO.
foreign numbering-plan area code (FNPAC)
An area c ode other than the local area code. The FNPAC must b e dialed to call outsid e the local 
geographical area.
G
Generic 3 Management Applications (G3-MA)
DEFINITY Communications System Generic 3 Management Applic ations, a PC-based tool which 
offers the following capabilities: emulation with DEFINITY switches and voice products, data 
exchange with voic e products, flexible report creation, storage of switch changes to be executed 
later, global changes of switch forms, auditing  of switch translations, automatic updates to CAS 
for Window Call A c counting  software and  b ulk a dministration of stations. 
						

							Glossary
Issue  3   March 1996GL-17 
Generic 3 Management Terminal (G3-MT)
DEFINITY Communications System Generic 3 Management Terminal, a management terminal 
used for system administration and maintenance in the switch room or optionally at some dis-
tance from the switch.
generalized route selection (GRS)
An enhancement to Automatic Alternate Routing/Automatic Route Selec tion (AAR/ARS) that per-
forms routing based on c all attributes, such as Bearer Capability Classes (BCCs), in addition to 
the a ddress and fa cilities restriction level (FRL), thus facilitatin g a Uniform Dial Plan (UDP) that is 
independent of the type of call being placed.
glare
The simultaneous seizure of a two-way trunk by two communications systems, resulting in a 
standoff.
grade of service
The number of call attempts that fail to receive service immediately. Grade of service is also 
expressed as the quantity of all calls that are blocked or delayed.
ground-start trunk
A trunk on which, for outgoing calls, the system transmits a request for services to a distant 
switc hing system by grounding the trunk ring lead. To receive the digits of the called number, that 
system grounds the trunk tip lead. When the system detec ts this ground, the digits are sent.
H
handshaking logic
A format used to initiate a data connection between two data module d evices.
H0
An ISDN information transfer rate for 384 kbps d ata defined by CCITT and ANSI standard s.
H11
An ISDN information transfer rate for 1536 kbps data defined by CCITT and ANSI standards.
H12
An ISDN information transfer rate for 1920 kbps data defined by CCITT and ANSI standards.
Hertz (Hz)
A unit of frequency equal to one cycle per second.
high reliability system
A system having the following: two control carriers, d up licate expansion interface (EI) circ uit 
packs in the PPN (in G3r with CSS), and  d up licate switc h node clock circuit p a cks in the switc h 
node (SN) carriers. See also duplicated common control, duplication, duplication option, and 
critical reliability system.
holding time
The total length of time in minutes and seconds that a facility is used during a call.
home numbering-plan area code
The local area code. The area code does not have to be dialed to call numbers within the local 
geographical area. 
						

							Glossary
GL-18Issue  3   Marc h 1996 
hop
Nondirect communication between two switch communications interfa ces (SCIs) where b y the SCI 
message passes automatically without interme diate processing through one or more intermediate 
SCIs.
host computer
A computer, c onnected to a network, that processes data from d ata-entry d evices.
hunt group
A group of extensions that are assig ned the Station Hunting feature so that a call to a b usy exten-
sion will reroute to an idle extension in the group.
I
immediate-start tie trunk
A trunk on which, after making a c onnection with a distant switching system for an outgoing call, 
the system waits a nominal 65 ms before sending the digits of the called number. This allows time 
for the distant system to prepare to receive digits. On an in coming call, the system has less than 
65 ms to prepare to receive the digits.
information exchange
The e x change of data between users of two different systems, such as the switch and  a host com-
puter, over a local area network (LAN).
information systems network (ISN)
A wide area network (WAN) and local area network (LAN) with an open architec ture combining 
host computers, minicomputers, word processors, storage d evices, PCs, high-speed printers, 
and nonintelligent terminals into a sing le packet-switching system.
inside call
A call placed from one telephone to another within the local communications system.
Integrated Services Digital Network (ISDN)
A p ub lic or private network that provides end-to-end digital communications for all services to 
which users have access by a limited set of standard multipurpose user-network interfaces 
defined by the CCITT. Through internationally accepted standard interfaces, ISDN provides digi-
tal circuit-switched or packet-switched communications within the network and links to other 
ISDNs to p rovide national and international digital communications. See also Integrated Services 
Digital Network Basic Rate Interface and Integrated Services Digital Network Primary Rate 
Interface.
Integrated Services Digital Network Basic Rate Interface (ISDN-BRI)
The interface between a communications system and terminal that includes two 64-k bps B-chan-
nels for transmitting voice or data and one 16-kbps D-channel for transmittin g associated B-chan-
nel call control and out-of-band signaling information 
— an arrangement called ‘‘2B+1D.’’ 
ISDN-BRI also includes 48-kbps for transmitting framing and D-channel contention information, 
for a total interface speed of 192 kbps. ISDN-BRI serves ISDN terminals and digital terminals fit-
ted  with ISDN terminal adapters. See also Integrated Services Digital Network Primary Rate 
Interface.
Integrated Services Digital Network Primary Rate Interface (ISDN-PRI)
The interface between multiple c ommunic ations systems that in North America includes 24 
64-kbps channels, corresponding to the North Americ an  digital signal level-1 (DS1) standard rate 
of 1.544 Mbytes per second. 
						

							Glossary
Issue  3   March 1996GL-19 
The most common arrangement of channels in ISDN-PRI i s  2 3  64-kbps B-channels for transmit-
ting voice and data and one 64-kbps D-channel for transmitting associated B-channel call control 
and out-of-band signaling information 
— an arrangement called ‘‘23B+1D,’’ although with nonfa-
cility-associated signaling (NFAS) ISDN-PRI can include 24 B-channels and no D-channel. See 
also Integrated Services Digital Network and Integrated Services Digital Network Basic Rate 
Interface.
intercept tone
An tone that indicates a dialing error or denial of the service requested.
interface
A common b oundary between two systems or pie ces of equipment.
internal call
A connection between two users within a system.
International Tele-communications Union (ITU)
Formerly known as International Telegraph and Telephone Consultative Committee (CCITT), ITU 
is an international organization that sets universal standard s for data communications, including 
Integrated Services Digital Network (ISDN). ITU memb ers are from telecommunications compa-
nies and organizations around the world. See also BX.25.
International Telegraph and Telephone Consultative Committee
See International Telecommunications Union (ITU).
interflow
Allows c alls to forward to other sp lits on the same PBX or a different PBX usin g the Call Forward  
All Calls switch feature.
intraflow
Allows c alls to be redirected to other splits on the same PBX on a conditional or unconditional 
basis using call c overage ‘‘busy,’’ ‘‘don’t answer,’’ or ‘‘all’’ criteria.
internal measurements
Refers to those BCMS measurements that are ma de by the system. ACD measurements that are 
made external to the system (via External CMS) are referred to as external measurements.
in-use lamp
A red light on a multiappearance voice terminal that is illuminated to show which call appearance 
will be selected when the handset is lifte d or whic h c all appearance is active when a user is 
off-hook.
ISDN Gateway (IG)
A feature allowing integration of the switch and a host-b ased telemarketing application via a link 
to a gateway adjunct. The g ateway adjunct is a 3B-based pro duct that notifies the host-based 
telemarketing application of c all events.
ISDN trunk
A trunk administered for use with Inte grated Services Digital Network primary rate interface 
(ISDN-PRI). Also called ‘‘ISDN fac ility.’’
ISDN-PRI Terminal Adapter
A terminal adapter a cts as interface between endpoint applications and an ISDN PRI facility. 
ISDN-PRI terminal a dapters are currently availa ble from other vendors and are p rimarily desig ned 
for video conferencing applications. Accordingly, currently availa ble terminal adapters adapt the 
two pairs of video codec d ata (V.35) and dialing (RS-366) ports to an ISDN PRI facility. 
						

							Glossary
GL-20Issue  3   Marc h 1996 
L
light-emitting diode (LED)
A semic onductor device that produces lig ht when voltage is a p plied. LEDs provid e a visual indi-
cation of the o perational status of hardware components, the results of maintenance tests, and 
the alarm status of circuit packs, and the activation of telephone features.
lightwave transceiver
Hardware that provides an interface to fiber-optic c able from port circ uit packs and digital signal 
level-1 (DS1) converter circuit packs. Lightwave transceivers convert ele ctrical signals to light 
signals and vice versa.
line
A transmission path between a c ommunications system or c entral office (CO) switching  system 
and a voice terminal or other terminal.
line port
The hardware that provid es the access point to a communications system for each circuit associ-
ated with a telephone and/or data terminal.
link
A transmitter-receiver channel that connects two systems.
link-access procedure on the D-channel (LAPD)
A link-layer protocol on the Inte grated Services Digital Network basic rate interfa ce (ISDN-BRI) 
and primary rate interface (ISDN-PRI)  data-link layer (level 2). LAPD provides d ata transfer 
between two devices, and error and flow control on multiple logical links. LAPD is used for signal-
ing and low-speed packet d ata (X.25 and mode 3) on the signaling (D-) channel and for mode-3 
data communications on a bearer (B-) channel.
local area network (LAN)
A networking arrangement desig ned for a limited geographical area. Generally, a LAN is limited 
in range to a maximum of 6.2 miles and provid es high-speed carrier service with low error rates. 
Common config urations inc lude daisy chain, star (including circuit-switched), ring, and bus.
logical link
The communications path between a processor and  a basic rate interface (BRI) terminal.
loop-start trunk
A trunk on which, after establishing a c onnection with a distant switching system for an outgoing 
call, the system waits for a signal on the loop  formed  by the trunk leads before sending the digits 
of the called number.
M
main-satellite-tributary
A private network configuration that can either stand alone or access an electronic tandem net-
work (ETN). A ‘‘main’’ switch provides interc onnection, via tie trunks, with one or more subtending 
switc hes, called ‘‘satellites’’; all attendant positions for the main/satellite configuration; and  a c cess 
to and from the public network. To a user outside the complex, a main/satellite c onfiguration 
appears as one switch, with one listed  directory number (LDN). A ‘‘tributary’’ switc h is connected 
to the main switch via tie trunks, but which has its own attendant positions and  LDN. 
						

							Glossary
Issue  3   March 1996GL-21 
maintenance
The activities involved in keeping a telecommunications system in proper working c ondition: the 
detection and isolation of software and hardware faults, and automatic and manual recovery from 
these faults.
management terminal
The terminal that is used  b y the system administrator to a dminister the switc h. The terminal may 
also be used to a ccess the BCMS feature.
major alarm
An in dic ation of a failure that has caused critic al degradation of service and requires immediate 
attention. Major alarms are automatically displayed on LEDs on the attendant console and mainte-
nance or alarming circuit p a ck, logged to the alarm log, and reporte d to a remote maintenance 
facility, if applicable.
manual-in work mode
In this mo de, agents automatically enter the ACW mode when they disconnect from an ACD call. 
However, in order to become availab le to re ceive another ACD c all, they must then manually enter 
the Auto-In or Manual-In mode. 
See Auto-In Work Mode for a contrast.
memory
A device into which information can be copied and held, and from which the information can be 
obtained at a later time.
message center
An answering service that supplies agents to and stores messages for later retrieval.
message center agent
A member of a message c enter hunt group who takes and  retrieves messages for voice terminal 
users.
minor alarm
An in dic ation of a failure that could affect customer service. Minor alarms are automatically dis-
played on LEDs on the attendant console and  maintenance or alarming circuit p ack, sent to the 
alarm log, and reported to a remote maintenance facility, if a p plicable.
modem
A device that converts digital d ata signals to analog signals for transmission over telephone cir-
cuits. The analo g signals are converted back to the original digital d ata signals by another 
modem at the other end of the circuit.
modem pooling
A capability that provides shared conversion resources (modems and data mo dules) for 
cost-effective access to analog facilities  by data terminals. When needed, modem pooling inserts 
a conversion resource into the path of a d ata call. Modem pooling serves both outgoing and 
incoming calls.
modular processor data module (MPDM)
A processor data module (PDM) that can be config ured to provide several kinds of interfa ces 
(RS232C, RS449, an d  V.35) t o customer-provid ed  d ata terminal equipment (DTE). See also pro-
cessor data module.
modular trunk data module (MTDM)
A trunk data module (TDM) that can be config ured to provide several kinds of interfa ces 
(RS232C, RS449, an d  V.35) t o customer-provid ed  d ata terminal equipment (DTE).
modulator-demodulator
See modem. 
						

							Glossary
GL-22Issue  3   Marc h 1996 
multiappearance voice terminal
A terminal equipped with several call a ppearance buttons for the same extension number, allow-
ing  the user to handle more than one c all, on that same extension number, at the same time.
multicarrier cabinet
A structure that hold s one to five carriers. See also single-carrier cabinet.
multifrequency-compelled (MFC), release 2 (R2) signalling
A sig nal consisting of two frequency components, such that when a signal is transmitted from a 
switc h, another sig nal acknowledging the transmitted signal is received by the switch. ‘‘R2’’ des-
ignates signaling used in the USA and  c ountries outside the USA.
multiplexer
A d evice used to c ombine a number of individual c hannels into a single common bit stream for 
transmission.
multiplexing
A process whereby a transmission facility is divided into two or more channels, either b y s plitting 
the frequency band into a numb er of narrower bands or  by dividing the transmission channel into 
successive time slots. See also time-division multiplexing.
multirate
Multirate refers to the new N x DS0 service (see N x DS0).
N
N x DS0
N x DS0, equivalently referred to as N ~x 64 ~kbps, is an emerging standard for wideband calls 
separate from H0, H11, and H12 ISDN c hannels. The emerging N x DS0 ISDN multirate circuit 
mode bearer service will provid e circuit-switc hed calls with data rate multiples of 64 kbps up to 
1536 kbps on a T1 facility or up to 1920 kbps on an E1 facility. In the switch, N x DS0 channels will 
range up to 1984 kbps using NFAS E1 interfaces.
narrowband
A circuit-switched call at a data rate up to and including 64 kbps. All nonwideband switch calls 
are c onsidered narrowband.
Non-Facility Associated Signaling (NFAS)
A method that allows multiple T1 and/or E1 facilities to share a single D-channel to form an Inte-
grated Services Digital Network primary rate interface (ISDN PRI) . I f D-Channel Backup is not 
used, one fa cility is configure d with a %D-channel, while the other facilities that share the D-chan-
nel are config ured without D-channels. If D-Channel Backup is used, two facilities are configured 
to have D-channels (one D-channel on each facility), while the other facilities that share the 
D-c hannels are configured without D-c hannels.
On every facility, all DS0s that are not %D-channels are available as %B-c hannels. Therefore, a 
T1 fa cility without a D-channel has 24~B-channels, and an E1 facility without a %D-channel has 
31~B-channels.
network
A series of points, nodes, or stations connecte d b y communications channels.