Acronym List

Acronym List

A-links	Access links
AAL	ATM adaptation layer
ABOM	A-bis Operations and Maintenance
AC	authentication center
ACD	automatic call distribution
ACG	Automatic Code Gap
ACM	address complete message (message)
AE	application entity
AERM	alignment error rate monitor
AIN	Advanced Intelligent Networks
AK	data acknowledgment
AMI	alternate mark inversion
ANI	automatic number identification
ANM	answer message (message)
ANSI	American National Standards Institute
ASE	application service element
ASN-1	Abstract Syntax Notation One
ASP	Application Service Part
ATM	asynchronous transfer mode
B-links	bridge links
BIB	backward indicator bit
BISDN	broadband ISDN
BISUP	broadband ISUP
BITS	building integrated timing system
BLA	blocking acknowledgment (message)
BLO	blocking (message)

BOP	bit-oriented protocol
BRI	basic rate ISDN
BSC	base station controller
BSDB	business service database
BSN	backward sequence number
BSS	base station subsystem
BSSMAP	Base Station Subsystem Mobile Application Part
BTA	basic trading area
BTS	base transceiver station
BTSM	Base Transceiver Station Management
C-links	cross-links
CAE	Communications Applications Environment
CBA	changeback acknowledgment (message)
CBD	changeback declaration (message)
CC	connection confirmed (message)
CCE	consistency check end (message)
CCEA	consistency check end acknowledgment (message)
CCR	continuity check request (message)
CCRA	consistency check request acknowledgment (message)
CCS	common channel signaling
CD	carrier detect
CESID	Callers Emergency Service Identification
CFN	confusion (message)
CGB	circuit group blocking (message)
CGBA	circuit group blocking acknowledgment (message)
CGU	circuit group unblocking (message)
CGUA	circuit group unblocking acknowledgment (message)
CIC	circuit identification code
CLLI	Common Language Location Identifier
CMC	call modification completed (message)
CMR	call modification request (message)
CMRJ	call modification reject (message)
CMSDB	call management services database (message)
CON	connect (message)
COO	changeover order (message)
COT	continuity test (message)
CPG	call progress (message)
CPU	central processor unit
CQM	circuit query message (message)
CQR	circuit query response (message)

CR	connection request (message)
CRA	circuit reservation acknowledgment (message), also consistency check request (message)
CRC	cyclic redundancy check
CREF	connection refusal (message)
CRG	charge information (message)
CRM	circuit reservation message (message)
CRST	cluster-route-set-test (message)
CSA	Canadian Standards Association
CTIA	Cellular Telecommunication Industry Association
CTS	clear to send
CVM	circuit validation test (message)
DCE	data communications equipment
DN	directory number
DPC	destination point code
DPNSS	Digital Private Network Signaling System
DRS	delayed release (message)
DSR	data set ready
DSU	data service unit
DTAP	Direct Transfer Application Part
DTE	data terminal equipment
DTMF	dual-tone multifrequency
DTR	data terminal ready
DT1	data form 1
DT2	data form 2
DUP	Data User Part
EA	expedited data acknowledgment (message)
EAS	exchange access signaling
ED	expedited data (message)
EIA	Electronic Industries Association
EIR	equipment identification register
ERR	error (message)
FA	Framework Advisory
FAA	facility accepted (message)
FAR	facility request (message)
FCC	Federal Communications Commission
FDDI	Fiber Distributed Data Interface
FIB	forward indicator bit
FISU	fill-in signal unit
FOT	forward transfer (message)

FR	Family of Requirement
FRJ	facility rejected (message)
FSN	forward sequence number
GMT	Greenwich Mean Time
GPS	Global Positioning System
GRA	circuit group reset acknowledgment (message)
GRS	circuit group reset (message)
GSM	Groupe Special Mobile
GUI	graphical user interface
HLR	home location register
IAA	IAM acknowledgment (message)
IAM	initial address message (message)
IAR	IAM reject (message)
IN	Intelligent Network
INA	information network architecture
INF	information (message)
INR	information request (message)
IP	intelligent peripheral
ISDN	integrated services digital network
ISDNUP	Integrated Services Digital Network User Part
ISNI	Intermediate Signaling Network Identification
ISO	International Standards Organization or International Organization for Standardization
ISUP	ISDN User Part
IS-41	Interim Standard-41
IT	inactivity test (message)
ITU	International Telecommunications Union
ITU-D	ITU Telecommunication Development Sector
ITU-RS	ITU Radiocommunication Sector
ITU-TS	International Telecommunications Union Telecommunications Standardization Sector
LAN	local area network
LAPD	Link Access Procedure on the D Channel
LATA	Local Access Transport Area
LI	length indicator
LIDB	Line Information Database
LLI	logical link identifier
LPA	loopback acknowledgment (message)
LSB	least significant bit
LSSU	link status signal unit

MAP	Mobile Application Part
MF	multifrequency
MIN	mobile identification number
MLPP	Multi-Level Precedence and Preemption
MSC	mobile switching center
MSU	message signal unit
MTA	major trading area
MTP	Message Transfer Part
NISDN	narrowband ISDN
NNI	network-to-network interface
NOF	Network Operations Forum
NRC	Network Reliability Council
NRM	network resource management
NRZ	nonreturn to zero
OAMP	Operations, Administration, Maintenance, and Provisioning
OLM	overload message (message)
OMAP	Operations, Maintenance, and Administration Part
OMC	Operations and Maintenance Center
OOS	out of service
OPC	origination point code
OPDU	Operations Protocol Data Unit
OS	operations system
OSI	Open Systems Interconnections
OSS	Operations Support System
PAM	pass-along message
PBX	private branch exchange
PCR	preventive cyclic retransmission
PCS	Personal Communications Services
PIN	personal identification number
POP	point-of-presence
POTS	Plain Old Telephone Service
PRI	primary rate ISDN
PRS	primary reference source
PSC	PCS switching center
PSTN	Public Switched Telephone Network
PVC	permanent virtual circuit
QoS	Quality of Service
RAO	regional accounting office
RBOC	Regional Bell Operating Company

RD	receive data
REL	release (message)
RES	resume (message)
RJ	registered jack
RLC	release complete (message)
RLSD	released (message)
RSA	regional service area
RSC	reset confirmation (message) also reset circuit (message)
RSR	reset request (message)
RTS	request to send, ready to send
SAM	subsequent address message
SAP	service access point
SAT	supervisory audio tone
SBR	subsystem-backup-routing (message)
SCCP	Signaling Connection Control Part
SCE	service creation environment
SCLC	SCCP connectionless control
SCMG	SCCP management
SCOC	SCCP connection-oriented control
SCP	service control point
SCRC	SCCP routing control
SDLC	signaling-data-link-connection
SDU	service data unit
SF	status field, single frequency
SGM	segmentation message
SIF	service information field
SIO	service indicator octet
SLC	signaling link code
SLS	signaling link selection
SLTA	signaling-link-test-acknowledgment
SLTM	signaling-link-test-message
SMDR	station detailed message recording
SMS	service management system
SNR	subsystem-normal-routing
SOG	subsystem-out-of-service-grant
SONET	Synchronous Optical NETwork
SOR	subsystem-out-of-service-request
SR	Special Reports
SRCT	signaling-route-set-congestion-test
SRST	signaling-route-set-test

SRT	subsystem-routing-status test
SSA	subsystem-allowed
SSP	service switching point also subsystem-prohibited
SST	subsystem-status-test
SS7	Signaling System #7
ST	Science and Technology (publication)
STP	signal transfer point
SUERM	signal unit error rate monitor
SUS	suspend message
SIB	status indicator-busy
SIE	status indicator-emergency
SIN	status indicator-normal
SIO	status indicator-out of alignment
SIOS	status indicator-out of service
SIPO	status indicator-processor outage
TA	Technical Advisory
TCA	transfer-cluster-allowed
TCAP	Transaction Capabilities Application Part
TCP	transfer-cluster-prohibited
TCR	transfer-cluster-restricted
TD	transmitted data
TFA	transfer-allowed
TFC	transfer-controlled
TFP	transfer-prohibited
TFR	transfer-restricted
TIA	Telecommunication Industry Association
TR	Technical Reference
TRA	traffic-restart-allowed
TRW	traffic-restart-waiting
TUP	Telephone User Part
T1A6	T1 Advisory Group
UCIC	unequipped circuit identification code
UBA	unblocking acknowledgment (message)
UDT	Unitdata
UDTS	Unitdata Service
UL	Underwriters Laboratories
UNI	user-to-network interface
UPA	user part available
UPT	user part test
USIS	user-to-user indicators

USR	user-to-user information (message)
VPCI	virtual path connection identifiers
VLR	visitor location register
WATS	Wide Area Telephone Service
XUDT	Extended Unitdata
XUDTS	Extended Unitdata Service