The Acronyms

Guideedited by

Erin MaloneChris Janson

1st edition

Publisher Acknowledgement:

This is the first edition of this book. Please notify us of any acronyms we may have missed by submitting them via the form at www.ciena.com/acronymsguide. We will be happy to include them in further editions of “The Acronyms Guide”. For additional information on Ciena’s Carrier Ethernet or Optical Communications Certification programs please contact techcerts@ciena.com.

Table of Contents

Numerics ..........................1A .......................................1B .......................................2C .......................................3D .......................................5E .......................................7F........................................9G .....................................10H .....................................11I .......................................12J ......................................14K .....................................14L ......................................14M ....................................15N .....................................17O.....................................18P .....................................20Q.....................................22R .....................................22S......................................23T .....................................26U .....................................28V .....................................29W ....................................29X .....................................30Z......................................30

1

Acronym GuideNumerics 2F Two-Fiber10 GbE 10 Gigabit Ethernet10 GFC 10 Gigabit Fibre Channel (Same as

FC1200)100G 100 Gigabits16-QAM 16 (points) Quadrature Amplitude

Modulation3D Three Dimensional3G 3rd Generation40G 40 Gigabits4C Consortium of Intel, IBM, Matsushita,

and Toshiba4F Four-Fiber5C Consortium of Intel, Sony, Matsushita,

Toshiba, and HitachiA A/D Analog-to-DigitalAAL ATM Adaptation LayerAAL0 ATM Adaptation Layer Type 0AAL1 ATM Adaptation Layer Type 1AAL2 ATM Adaptation Layer 2 TransportAAL3/4 ATM Adaptation Layer Type 3 and 4AAL5 ATM Adaptation Layer 5ABR Available Bit RateABT Advanced BiCMOS TechnologyAC Alternating Current; Administrative

Complex; Atomic ClockAC-3 Audio Coding Revision 3ACAC Actual Call Admission ControlACEG Alternating Current Equipment GroundACK AcknowledgeACL Active Control List; Access Control ListACO Alarm CutoffACQ AcquireACR Allowed Cell RateACS Automatic Channel Shutdown; Alarm

Correlation and SuppressionACSE Association Control Service ElementACSS Automatic Channel Shutdown

Suppression; Automatic Channel Shutdown State

ACT ActiveADC Analog-to-Digital Converter; Add/Drop

Coupler

ADI Asset Distribution InterfaceADM Add/Drop MultiplexerADP Actual Departure Potential; Automatic

Data ProcessingADSL Asymmetric Digital Subscriber LineADT Actual Departure Time; Automatic Data

TransmissionAE Automation Engine; Automation Envi-

ronmentAES Advanced Encryption Standard;

Application Environment SpecificAESA ATM End System Address; ATM End

Station AddressAFI Authority and Format IdentifierAFM APS Mode Mismatch FailureAGC Automatic Gain Control; Access Group

ControllerAGGR AggregateAID Access Identifier; Application IdentifierAIM Auto Image Management; Active

Inventory MapAIN Advanced Intelligent NetworkAINI ATM Inter-Network InterfaceAINS Automatic in Service StateAIR Additive Increase RateAIS Alarm Indication SignalAISDP Alarm Indication Signal Decay PeriodAISIP Alarm Indication Signal Integration

PeriodAIS-L Alarm Indication Signal - LineAIS-P Alarm Indication Signal - PathAIS-S Alarm Indication Signal - SectionAIS-V VT Alarm Indication SignalALS Automatic Laser Shutdown; Application

Layer ServiceAM Amplitude Modulation; Application

ManagerAMF APS Mode Mismatch FailureAMI Access Method Interface; Alternate

Mark InversionAMP Amplifier; AmperesAMS Asset Management System; Agent

Management SystemANSI American National Standards InstituteAO Autonomous OutputAOD Advertising on DemandAPC Angled Physical Contact

2

APD Avalanche PhotoDiodeAPI Application Program InterfaceAPS Automatic Protection SwitchingAPSBF Automatic Protection Switching Byte

FailureAPSCM Automatic Protection Switching

Channel MismatchAPSMM Automatic Protection Switching Mode

MismatchARC Alarm Reporting ControlARP Address Resolution ProtocolARPU Average Revenue per Unit (or User)AS Autonomous SystemASAP Alarm Severity Assignment ProfileASCII American Standard Code for Informa-

tion InterchangeASD Access Security DeviceASE Amplified Spontaneous Emission; Ap-

plication Service ElementASI Asynchronous Serial Interface;

Asynchronous SCSI InterfaceASIC Application-Specific Integrated CircuitASN.1 Abstract Syntax Notation OneASP Applications Service Provider; Average

Selling PriceASYNC AsynchronousAT Advanced TechnologyAT&T American Telephone and Telegraph

CompanyATA Advanced Technology AttachmentATAF ATM Test Access FunctionATAG Autonomous TagATAGSEQ Autonomous Tag SequenceATC Alarm Traffic ControllerATDMA Asynchronous Time Division Multiple

AccessA-TDMA Advanced Time Division Multiple

AccessATM Asynchronous Transfer ModeATM SAM ATM Service Access MultiplexerATMVCL ATM Virtual Channel LinkATMVPL ATM Virtual Path LinkATTN AttenuatorAU/AU-x Administrative UnitAUG Administrative Unit GroupAUI Autonomous Unit Interface

AU-n Administrative Unit nAUX AuxiliaryAVC Attribute Value ChangeAWG American Wire GaugeAWGN Additive White Gaussian Noise

B B/P BackplaneB3ZS Bipolar With 3-Zero SubstitutionB6ZS Bipolar With 6-Zero SubstitutionB8ZS Bipolar With 8-Zero SubstitutionBA Booster AmplifierBB BroadbandBBE Background Block ErrorBBER Background Block Error RatioBBE-RS Background Block Error Regenerator

Section (an SDH regenerator section error)

BC Business Continuity; BroadcastBCD Binary-Coded DecimalBCST BroadcastB-DCS Broadband Digital Cross-connect

SystemBDFB Battery Distribution Fuse Bay; Battery

Distribution Fuse BoardBE Block Error; Best EffortBECN Backward Explicit Congestion Notifica-

tionBELLCORE BELL Communications Research, Inc. BER Bit Error RateBE-RS Block Errors-Regenerative SectionBER-SD-P Path Signal Degrade BERBER-SF-P Path Signal Failure BERBERT Bit Error Rate TestBFP Back Facet Power; Basic Format PacketBGP Border Gateway ProtocolBGP4 Border Gateway Protocol, version 4BICI Broadband Inter-Carrier Interfaces;

B-ISDN Inter-carrier InterfaceBICSI Building Industry Consulting Services

InternationalBIOS Basic Input/Output SystemBIP Bit Interleaved Parity; Breaker Interface

PanelB-ISDN Broadband ISDN

3

BIT Built-In Test; Binary DigitBITS Building Integrated Timing Systembits/sym Bits per SymbolBLSR Bidirectional Line Switched RingBML Business Management LayerBNC Bayonet Neill-Concelman British

National ConnectorBOC Bell Operating CompanyBOD Bandwidth on Demand BOL Beginning of LifeBOM Bill of MaterialsBONDING Bandwidth ON Demand

Interoperability GroupBOOTP Bootstrap ProtocolBP BackplaneBPI Baseline Privacy InterfaceBPI+ Baseline Privacy Interface PlusB-PON Broadband Passive Optical NetworkBPP Backplane Protocolbps bits per secondBPSR Bidirectional Path Switched RingBPT Band Pass-ThroughBPV BiPolar ViolationsB-RAS Broadband Remote Access ServerBRI Basic Rate InterfaceBRM Backward RMBSC Board SC ConnectorBSP Board Support PackageBSS Business Support SystemBT British Telecom; Burst ToleranceBtag Beginning TagBTM Bits Termination Circuit PackBTO Build Transfer OperateBTS Business Telecom ServicesBTU/hr British Thermal Unit per hourBW BandwidthBWDM Band Wavelength Division MultiplexerBYT Total Byte Count

C C Celsius; CriticalC/I Carrier-to-Interface RatioC/N Carrier-to-Noise Ratio C2O Cable to Optic

CA Content Archived; Carrier AccessCAB Conformity Assessment BodyCAC Connection Admission Control; Call

Admission ControlCAD Computer Aided DesignCALA Central America and Latin AmericaCAM Content Addressable MemoryCANARIE Canadian Network for Advancement of

ResearchCAP Competitive Access ProviderCAPEX Capital ExpenditureCAS Channel Associated SignalingCATV Community Antenna Television; Cable

TelevisionCB, C/B Circuit BreakerCBDS Connectionless Broadband Data

ServiceCBN Common Bonding NetworkCBR Constant Bit RateCC Cross Connection; Clear Channel;

Calling CentersCCAF Call Control Agent Function, IN blockCCB Configuration Control BoardCCC Cross Connect ControllerCCC768 Cross Connect Fabric with 768x768

STS-1 capacityCCCG Cross Connection and Control GroupCCC-PC CCC Processor CardCCDF Complementary Cumulative

Distribution FunctionCCI Content Control InformationCCITT Consultative Committee on Interna-

tional Telegraphy and TelephonyCCK Complimentary Code KeyingCCW CounterclockwiseCDE Common Desktop Environment (UNIX)CDMA Code Division Multiple AccessCDP Contracted Deadline PotentialCDR Call Detail Recording; Clock and Data

RecoveryCD-ROM Compact Disc Read Only MemoryCDT Connection Dropping ThresholdCDTS Chromatic Dispersion Test SetCDV Cell Delay VariationCDVT Cell Delay Variation ToleranceCD-WO Compact Disc - Write One

4

CE Consumer ElectronicsCEA Consumer Electronics AssociationCELP Code Excited Linear PredictiveCER Cell Error Ratio; Codeword Error RationCES Circuit Emulation ServiceCEV Controlled Environmental VaultCFDM Command Frequency Division

MultiplexerCFG ConfigurationCFM Cubic Feet per MinuteCFU Cooling Fan UnitCH ChannelCHASEH Environmentally Hardened ChassisCHASYNC Chassis with SyncCI Compact Intelligence; Craft Interface;

Customer Interface; Certified IntegratorCID Circuit Identification; Craft Interface

DeviceCIF Client InterfaceCIFS Common Internet File SystemCIM Client Interface ModuleCINOT Ciena Optical Transport SystemCIT Craft Interface Terminal; Craft

Interface ToolCL Coupling Loss; ClearedCLASS Custom Local Area Signalling ServicesCLEC Competitive Local Exchange CarrierCLEI Common Language Equipment

IdentifierCLEITM Common Language Equipment

IdentifierCLFI Common Language Facility IdentifierCLI Command Line InterfaceCLIP Calling Line Identification PresentationCLIR Calling Line Identification RestrictionCLLI Common Language Location IdentifierCLNP Connectionless Network Layer ProtocolCLNS Connectionless Network ServiceCLP Cell Loss PriorityCLR Cell Loss RatioCLTP Connectionless Transport Protocolcm centimeterCM Control Module; Cable ModemCM-CLI Control Module Command Line

Interface

CME Compressed Multiplication EquipmentCMF Channel Mismatch Failure; Client

Management FrameCMIP Common Management Information

ProtocolCMIS Common Management Information

ServicesCMISE Common Management Information

Service ElementCMR Cell Misinsertion RateCMS Call Management ServerCMTS Cable Modem Termination SystemCMU Clock Multiplier UnitC-n Container C-11=1,544 Mb/s;

C-12=2,048 Mb/s; C-2=6,312 Mb/s; C-3=34,368 Mb/s and 44,736 Mb/s; C-4=139,264 Mb/s

CNIPS Core Network Integrated Planning System

CNIR Carrier-to-Noise/Ingress RatioCNMP Customer Network Management PortalCNR Carrier-to-Noise RatioCO Central OfficeCOAX Coaxial CableCOBRA Copper and Optical Broadband Re-

mote AccessCODEC Coder/DecoderCOE Central Office EquipmentCOFA Change of Frame AlignmentCOLD Central Office Layout DesignCOLL Collision CountCONDTYPE Condition TypeCONS Connection Oriented Network ServiceCOO Chief Operating OfficerCOPS Common Open Policy ServicesCORBA Common Object Request Broker

ArchitectureCOS Class of Service; Common Object

Services; CORBA Object ServicesCoS Class of ServiceCOT Central Office TerminalCOTS Commercial off the ShelfCP Circuit Pack; Control Processor;

Connection Provisioner; Call Processing; Customer Premise

CPCI Compact Peripheral Component Interconnect

5

CPD Common Path DistortionCPE Customer Premises Equipment; Cus-

tomer Provided EquipmentC-Plane Control PlaneCPLD Complex Programmable Logic DeviceCPM Cross-Phase ModulationCPRM Content Protection for Recordable

MediaCPT Channel Pass-ThroughCPTTAG Connection Termination Point TagCPU Central Processing UnitCR Circuit Reliability; Carriage Return;

Critical AlarmCRC Cyclic Redundancy CheckCRG Circuit Restoration GroupCR-LDP Constraint-based Routing Label

Distribution ProtocolCRS Cross ConnectCRT Cathode Ray TubeCRx Line Client Receive LineCS Control Sub-span; Convergence

Sublayer; CoreStreamCSA Canadian Standards AssociationCSC Command Signal and ControlCSD Core Switching DivisionCSES Consecutive Severely Errored SecondsCsh C ShellCSH Common Signal HeaderCSI Convergence Sublayer IndicatorCSM Core Switching ManagerC-SMF Conventional Single Mode FiberCSO Composite Second OrderCSP Customer Service Profile CSR Customer Service RepresentativeCS-RZ Carrier-Suppressed Return-to-ZeroCST Central Standard TimeCSU Channel Service Unit; Customer Service

UnitCSV Comma-Separated ValueCT CriticalCTAM Cable & Telecommunications

Association for MarketingCTB Composite Triple BeatCTC Common Transmit ClockCTD Cell Transfer Delay

CTG Cradle-To-GraveCTN Core Transmission NetworkCTP Connection Termination PointCTS Clear To SendCTx Line Client Transmit LineCUG Closed User GroupCV Code ViolationCV-FE Code violation - Far EndCV-L Code Violation - LineCV-P Code Violation - PathCV-PFE Code Violation - Path Far EndCV-S, CVS Code Violation - Section; Code

Violation -- Seconds CW Clockwise; Continuous Wave

D D&C Drop and ContinueD/A Digital-to-AnalogD/I Drop and InsertDAC Digital to Analog Converter; Digital

Addressable ControllerDACS Digital Access and Cross-Connect

SystemDAD Direct Access DeviceDADM Data Add/Drop MultiplexerDARPA Defense Advanced Research Projects

Agency (US)DAS Direct Attached StorageDATE Duly Authorised Telecommunications

EntitydB decibelDB DatabaseDB-9 Data Bus 9 Pin ConnectorDBA Database AdministratordBc Decibel referenced to the carrierdBm Decibel reference to milliwattsDBMS Database Management SystemDBPSK Differential Binary Phase Shift KeyingDBS Direct Broadcast SatellitedBW Decibels referenced to WattsDC Direct Current; Data ConnectionDCC Data Communications ChannelDCE Data Communications Equipment;

Data Circuit Terminating EquipmentDCF Dispersion-Compensating Fiber

6

DCG Dispersion Compensation GratingDCM Dispersion Compensation ModuleDCME Digital Compressed Multiplication

EquipmentDCMS Digital Circuit Multiplication SystemDCN Data Communication NetworkDCOM Distributed Component Object ModelDCP Digital Communications Protocol;

Device Control ProtocolDCS Digital Cross-connect System; Digital

Connection SystemDCS 1800 Digital Cellular System, GSM variant at

1800 MHzDCU Dial up Data Channel UnitDDI Direct Dialing InwardDDS Digital Data Storage; Digital Data

Service; Digital Data System; Digital Data Stream

DE Discard EligibleDEC Digital Electrical CarrierDECT Digital European Cordless Telephone/

TelecommunicationDEG Degraded SignalDEMUX DemultiplexerDENI Digital Entertainment Networking

InitiativeDENY Transaction DenierDFB Distributed FeedbackDG Disc GroupDGD Differential Group DelayDHCP Dynamic Host Configuration ProtocolDHWG Digital Home Working GroupDID Direct Inward DialerDiffServ Differentiated ServicesDIO Digital Input/OutputDIP Dual In-line Package (switch)DIR DirectionDiv DivisionDLC Digital Loop CarrierDLCI Data Link Connection IdentifierDLL Dynamic Link Library; Data Lind Layer

(driver); Downline LoadDLT Digital Linear Tape DrivesDM Degraded Minute; Dispersion

MitigationDMA Direct Memory Access

DMACS Distributed Monitoring and Control System

DMB Digital Multipoint Bridge; Document Maintenance Bulletin

DMC Dual Modem CardsDMH Degraded Modem HoursDMM Digital Multi-MeterDMOP Detailed Method of ProcedureDMS Dispersion-managed SolutionDMUX [Optical] DemultiplexerDNCS Digital Network Control SystemDNR Do Not RevertDNS Domain Name Server; Domain Name

SystemDOCSIS Data-Over-Cable Service Interface

SpecificationsDOD Department of DefenseDOS Disk Operating SystemDoS Denial of ServiceDP Distribution Point; Data ProcessingDPDT Double-Pole, Double-Throw DPFI Data Plane Fault IsolationDPI Digital Program Insertion; Dots Per InchDPR Dedicated Protection RingDPRAM Dual Port Random Access MemoryDPT Dynamic Packet TransportDQ Degraded Quality LevelDQDB Distributed Queue Dual BusDQoS Direct Memory AccessDQPSK Differential Quadrature Phase Shift

KeyingDR Disaster RecoveryDRAM Dynamic Random Access MemoryDRM Digital Rights ManagementDS Digital Signal; DownstreamDS0 Digital Service, Level 0, 64kbpsDS1 Digital Service, Level 1, 1.544 Mb/s

;Digital Signal LevelDS3 Digital Signal Level 3 (T3 equivalent)DSCP Differentiated Service Code PointDSCRDS Discard CountDSF Dispersion Shifted FiberDSI Digital Speech InterpolationDSL Digital Subscriber Line; Digital

Subscriber Loop

7

DSLAM Digital Subscriber Line Access Multiplexer

DS-n Digital Signal, level n DSP Digital Signal ProcessorDSS Direct Satellite ServicesDSS2 Digital Subscriber Signaling 2DSTB Digital Set-top BoxDSX Digital Side InterfaceDS-x Digital Signal where N denotes

multiple of 51.84 Mb/sDSX-1 Digital Signal Level 1 Cross ConnectDSX-3 Digital Signal Level 3 Cross ConnectDT Decision Technology; Direct Termina-

tionDTCP Digital Transmission Content ProtectionDTE Data Terminal EquipmentDTH Direct-to-Home, usually satellite

television broadcastingDTL Designated Transit ListDTMF Dual Tone Multiple FrequencyDTS Dynamic Transport SystemDTV Digital TelevisionDUART Dual Universal Asynchronous Receiver

TransmitterDUP Data User PartDUS Don’t Use SynchronizationDV Digital VideoDVB-ASI Digital Video Broadcast Asynchronous

Serial InterfaceDVC Dynamic Virtual ConcatenationDVD Digital Versatile DiscDVD+R Recordable Digital Versatile DiscDVD+RW Rewritable Digital Versatile DiscDVI Display Visual InterfaceDVM Digital VoltmeterDVOW Digital Voice OrderwireDVR Digital Video RecorderDW DatawireDWDM Dense Wavelength Division

MultiplexingDXC Digital Cross-ConnectDXI Data Exchange Interface

E E&M Ear & Mouth

E1 European Equivalent of T1 (2.048 Mb/s signal speed)

E2E End To EndE2PROM Electrically Erasable Programmable

Read Only MemoryE3 European data signal at a rate of

34.368 Mb/sEAI Enterprise Application IntegrationEAL Events, Alarms, and LoggingEAP Extensible Authentication ProtocolEAS Emergency Alert SystemEB Error Block; EastboundEb/No Energy per Bit to Noise ratioEC Enhanced Capacity ; European

CommissionEC-1 Electrical Carrier Level 1 (STS1

Equivalent)ECC Edge Card Control; Embedded

Communications ChannelECI Equipment Catalog ItemECLR Egress Cell Loss RatioECn Electrical Carrier, level n; 0=64 kb/s,

2=6,312 Mb/s, 3=44,736 Mb/sECN Engineering Change NoticeECO Engineering Change OrderECTRA European Committee for

Telecommunications Regulatory AffairsED Equipment DegradeEDF Erbium-Doped FiberEDFA Erbium-Doped Fiber AmplifierEDI Electronic Data InterchangeeDOCSIS Embedded Data-Over-Cable Service

Interface SpecificationsEEE Electronic Equipment EnclosureEEPROM Electrically Erasable Programmable

Read Only MemoryEF Equipment FailureEF&I Engineer, Furnish and Install EFCI Explicit Forward Congestion IndicationEFD Event Forwarding DiscriminatorEFP Equipment Fault ProtectionEH Environmentally HardenedEIA Electronic Industries Alliance; Electronic

Industries AssociationEID Equipment IdentifierEIDE Enhanced Integrated Drive Electronics

8

EII European Information InfrastructureEIR Excess Information RateEIRP Effective Isotropic Radiated Power;

Equivalent Isotropic Radiated PowerEJB Enterprise Java BeansELAN Emulated Local Area NetworkELR Extra Long ReachEM Element ManagerEMBS Egress Maximum Burst SizeEMC ElectroMagnetic CompatibilityEMD Extended Management DomainEMEA Europe, Middle East and AfricaEMG Extended Management GatewayEMI Electromagnetic InterferenceEML Element Management Layer;

Electro-Absorptive Modulated LaserEMP Expiring Maintenance Process EMS Element Management System EMT Expiring Maintenance Tool eMTA Embedded Multimedia Terminal

AdapterEMX ESCON MUXEND Extended Management DomainENE End Network ElementENUT Enhanced Non-preemptable

Unprotected TrafficEO Equipment OrderEOC Embedded Operations ChannelEoD Everything on DemandEOF End of FrameEOL End of LifeEOM End of MessageEoS Ethernet over SONET/SDHEOW Engineered Orderwire; Express

OrderwireEPA Environmental Protection AgencyEPCR Egress Peak Cell RateEPD Early Packet DiscardEPG Equipment Protection GroupEPL Ethernet Private LineEPLD Erasable Programmable Logic DeviceE-PON Ethernet Passive Optical NetworkEPR Engineering Progress ReportEPROM Erasable Programmable Read Only

Memory

EQPT EquipmentER Extended ReachERDI Enhanced Remote Defect IndicatorEREI-P Enhanced Path Remote Error IndicationErrcde Error CodeES Errored SecondESA EDFA Saturation Algorithm; End Sys-

tem AddressESCBND ESCON BundleESCON Enterprise Systems ConnectionESCR Egress Sustainable Cell RateESD Electrostatic DischargeESDS Electrostatic Discharge SensitiveESF Extended Super Frame; Extended

Superframe FormatES-FE Errored Seconds - Far EndESI End System IdentifierES-IS End System to Intermediate SystemES-L Errored Seconds - LineES-LFE Errored Second-Line Far EndESMOP Electronic Service Method of ProcedureES-MS Errored Seconds at the Mulitplexor

SectionESN Extended SubnetworkES-P Errored Seconds - PathES-PFE Errored Seconds - Path Far EndESR Errored Second RatioES-RS Errored Second Regenerator SectionES-S Errored Seconds - SectionEST Eastern Standard TimeES-V Errored Second-Virtual Tributary (VT)

Path; Errored Second-VT Path Far EndESx Errored Second CountET End TerminalEtag Ending TagETH 10/100 EthernetETHBND Ethernet BundleETLMI ESCON Trib Laser Manager InterfaceETR External Timing ReferenceETSI European Telecommunications

Standards InstituteEU European UnionEVC Ethernet Virtual CircuitEVM Error Vector MagnitudeEVPL Ethernet Virtual Private Line

9

EVPLAN Ethernet Virtual Private Local Area Network

EWO Engineering Work OrderEXER-R Exercise - RingEXER-S Exercise - Span (SONET)EXP ExperimentalEXZ Excessive Zone

F F FahrenheitF&I Furnish and InstallFA, F/A Fuse Alarm; Fault AlarmFAB Field Alert BulletinFAD Functional Access DomainFAF Facility FailureFAT Factory Acceptance TestFC Failure Code; Failure Count; Fiber

Channel; Fibre ChannelFC Switch Fibre Channel SwitchFC100 Fibre Channel 1 Gb/sFC10000 Fibre Channel 10 Gb/s (same as

10GFC) FC200 Fibre Channel 2 Gb/sFC400 Fibre Channel 4 Gb/sFCAPS Fault, Configuration, Accounting,

Performance (or Provisioning), Security management

FCC Federal Communications CommissionFC-FE Failure Count - Far EndFCIP Fibre Channel over Internet

ProtocolFC-L Failure Count - LineFC-LFE Failure Count - Line Far EndFCM Fan Control ModuleFCP Fibre Channel ProtocolFC-P Failure Count - PathFC-PFE Failure Count - Path Far EndFCS Frame Check Sequence; Fibre Channel

StandardFCS32 Count of FCS-32 ErrorFC-V Failure Count - VTFC-VFE Failure Count - VT Far EndFDD Frequency Division DuplexedFDDI Fiber Distributed Data InterfaceFDF Fiber Distributing Frame

FDL Facilities Data LinkFDM Frequency Division Multiplexing; Fast

Ethernet ; Frequency Division Modulation

FDMA Frequency Division Multiple AccessFDP Fiber Distribution PanelFDRP Frame DropFE Far End; Fast Ethernet; Forward Error

CorrectionFEAC Far End Alarm ChannelFEACT Far-End Terminal Alarm ConditionFEALM Far-End AlarmFEB Fast Ethernet BridgingFEBE Far End Block ErrorFEC Forward Error Correction; Forwarding

Equivalence ClassFECN Forward Explicit Congestion

NotificationFECS Forward Error Correction SecondsFEDS FICON Extended Storage over

DistanceFEP Front End Processor; Far End

ProtectionFEPLF Far End Protection Line FailureFEPM Far End Performance MonitorFERF Far End Receive FailureFET Field-Effect TransistorFF Fast ForwardFFA First Field ApplicationFFP Facility Fault ProtectionFFT Fast Fourier TransformFIB Forwarding Information BaseFIC Frame Identification CodeFICON Fiber ConnectionFIL Fiber in the LoopFIT Failure in TimeFITB Fiber in the BuildingFITL Fiber in the LoopFITR Fiber in the RiserFLAG Fiber Link Around the GlobeFM Fan Module; Fault Management;

Forwarding Module; Frequency Modulation

FMA Failure Modes AnalysisFMECA Failure Mode and Effects and Criticality

Analyses

10

FMS Fault Management SystemFNCS Foreign National Control SystemFO Fiber OpticsFOADM Fixed Optical Add/Drop Multiplexer;

Flexible Optical Add/Drop MultiplexerFOB Free On BoardFOC Final Operating ConfigurationFOD Free on DemandFOS Follow on Satellite, Intelsat designationFOSC Fiber Optic Splice CourseFOTS Fiber Optic Transmission SystemFOW Forward OrderWireFP Fabry-Perot (type of laser); Frame

Pulse (NEC)FPG Facility Protection GroupFPGA Field Programmable Gate ArrayFPLMTS Future Public Land Mobile

Telecommunications SystemsFPM Fan Power ModuleFPP Fast Pattern ProcessorFPS Frames per SecondFR Frame RelayFRAD Frame Relay Access DeviceFRC ForceFRD Functional Requirements Document;

Feature Requirements DefinitionFREQ FrequencyFRF Frame Relay ForumFRF.12 Frame Relay Forum Implementation

Agreement 12FRF.13 Frame Relay Forum Implementation

Agreement 13FRF.5 Frame Relay Forum Implementation

Agreement 5FRF.8.1 Frame Relay Forum Implementation

Agreement 8.1FRG Fragment CountFRM Forward Resource Management; Frame

CountFRMS Dropped FramesFRS Frame Relay ServiceFRU Field Replacement UnitFS File SystemFSA Field Service ApplicationFSAN Full Services Access Network

(consortium)

FSB Field Service BulletinFSO Free Space OpticalFS-P Forced Switch - ProtectionFS-R Forced Switch - RingFSS Fixed Satellite ServiceFS-S Forced Switch - SpanFS-W Forced Switch - WorkingFT France TelecomFT1 Fractional T1GT Gain Transfer; Grating TemperatureFTA Fault Tree AnalysisFTAM File Transfer and Access ManagementFTC Fabric and Timing CardFTM Fabric Timing ModuleFTP File Transfer ProtocolFTTB Fiber to the Building; Fiber to the

BusinessFTTC Fibre to the Curb (Kerb), linked to VDSL

in deploymentFTTD Fiber to the DeskFTTH Fiber to the HomeFTTP Fiber to the Premise; Maintenance

Channel Transparent Termination PointFTTx Fiber to the [endpoint]FUNI Frame-based User-Network InterfaceFW Firmware; FirewallFWHM Full Width at Half MaximumFWM Four-Wave MixingFXO Foreign Exchange OfficeFXS Foreign Exchange Service

G G/T Gain to System Noise Temperature

RatioGA General AvailabilityGb GigabitGB GigabyteGbE Gigabit EthernetGbE VFTP Gigabit Ethernet Virtual Facility

Termination PointGbE WAN Gigabit Ethernet Wide Area NetworkGbE WIF Gigabit Ethernet Wide Area Network

InterfaceGBIC Gigabit Interface ConverterGbit Gigabit

11

Gbps, Gbits Gigabits per secondGbytes/s Gigabytes per secondGC Gateway ControllerGCAC Generic Connection Admission ControlGCC0 General Communications Channel 0

(similar to SDH/SONET DCC)GCIT Graphical Craft Interface TerminalGCM General Control ModuleGCRA Generic Cell Rate AlgorithmGDMO Guidelines for the Definition of

Managed ObjectsGE Gigabit Ethernet; Greater than or

equal to ; General Electric Corporation

GEB Gigabit Ethernet BridgeGEO Geostationary Earth OrbitGESS General Electric Satellite ServicesGET Gigabit Ethernet TunnelingGFA Gain Flattened AmplifierGFC Generic Flow ControlGFF Gain Flattening Filter (used in EDFA)GFP Generic Framing ProcedureGFR Guaranteed Frame RateGHz Gigahertz (Billion hertz)GigE Gigabit EthernetGII Global Information InfrastructureGMDSS Global Maritime Distress and Safety

SystemGMPLS Generalized Multi-Protocol Label

SwitchingGMT Greenwich Mean Time; Grasshoppers

Made for Telecommunications (GMT fuses)

GN Gateway Network ElementGND GroundGNE Gateway Network ElementGOS Grade of ServiceGP Gateway PlatformGPI General Purpose InputGPIN General Purpose InputGPO General Purpose OutputG-PON Gigabit Passive Optical NetworkGPS Global Positioning System; Global

Positioning SatelliteGR Generic Requirement; Geographic

RedundancyGRDM Gigabit Rate Data Multiplexer

GRTES General Requirements for Transmission Equipment Specification

GSM Global System for Mobile communications, originally: Groupe Spéciale Mobile

GSO Geostationary Earth OrbitGT Gain Transfer; Grating TemperatureGTF Global Traffic Forecast (Intelsat)GTM Global Traffic Meeting (Intelsat)GTP Group Termination PointGTS General TeleSystems GroupGUI Graphical User InterfaceGW GatewayGWC Gateway Controller

H HA High AvailabilityHCSFI High-speed Central Switch Fabric

InterfaceHD High DefinitionHDB3 High Density Bipolar 3HDCP High-bandwidth Digital Content Pro-

tectionHDLC High-speed/level Data Link ControlHDMI High Definition Multimedia InterfaceHD-SDI High Definition Serial Digital InterfaceHDSF High-speed Distributed Switch FabricHDSL High-speed Digital Subscriber LineHDT Host Digital TerminalHDTV High Definition TelevisionHE HeadendHEC Header Error Control; Headend

ControllerHEM Headend ModemHEPA High Efficiency Particulate ArresterHFC Hybrid Fiber CoaxHFM High-speed Forwarding ModuleHGW Home GatewayHHP Households PassedHI Hardware/Software Interface;

Hardware-Software Integration; High Speed Internet

HISSA High Speed Serial Application Specific Integrated Circuit (ASIC)

HMS Hybrid Management Sub-layerHNv1 Home Networking Version 1

12

HO Higher OrderHOD HBO on DemandHO-DSP High Order-Domain Specific PartHO-DXC Higher Order Digital Cross ConnectHOM High-Order ModulationHomePNA Home Phoneline Networking AllianceHOP High Order PathHO-POH Higher Order - Path OverheadHOVC Higher Order Virtual ConcatenationHP Hairpin; Higher Order Path; Homes

PassedHPA High Power AmplifierHPF High Pass FilterHPNA Home Phoneline Networking AllianceHPOV Hewlett Packard Open ViewHPPI High Performance Parallel InterfaceHP-UX Hewlett Packard’s UNIX-based OS that

runs on HP’s enterprise serversHRD Hardware Release Document; Hard-

ware Requirements DocumentHS High SpeedHSB High Speed BusHSD High Speed DataHSSI High Speed Serial InterfaceHT High ThresholdHTML Hyper Text Markup LanguageHTTP Hypertext Transfer ProtocolHVAC Heating, Ventilation, and

Air-Conditioning HVS Hospitality Voice ServicesHW HardwareHz Hertz

I I/B Inbound/Outroute (also known as

the return link), from remote terminal to hub

I/O Input/OutputIAD Integrated Access Device; Interface

Access DeviceIAS Internet Access Service; Internet

Authentication ServiceIBCC In-Band Communication ChannelIBS Intelsat Business ServiceIBT International Business TravellerIC Integrated Circuit

ICB Independent Customer BuildsICD International Code DesignatorICLR Ingress Cell Loss RatioICMP Internet Control Message ProtocolICNV Input- Command Not ValidICP IMA Control ProtocolICPT Installed Circuit Pack TypeICR Initial Cell RateID Identifier; IdentificationIDB International Development BankIDE Integrated Device ElectronicsIDF Intermediate Distribution Frame;

Invalid Data FlagIDH Identification High byteIDI Initial Domain IdentifierIDL Interactive Distance Learning;

Interface Definition LanguageIDNV Input, Data Not ValidIDP Initial Domain PartIDR Intermediate Data RateIDS Intrusion Detection SystemIDT Inter-DXC TrunkIDU Indoor UnitIE Information ElementIEC Incoming Error Count;

InterExchange CarrierIEEE Institute for Electrical and

Electronics EngineersIETF Internet Engineering Task ForceIF Intermediate FrequencyIFC Initial First CostIG Information GroupIGMP Internet Group Multicast ProtocolIIAC Input - Invalid Access IdentifierIIOP CORBA Internet Inter-ORB ProtocolIISP Interim Interface Signaling ProtocolILA Intermediate Light Amplification;

Integrated Line Amplifier; In-Line Amplifier

ILEC Incumbent Local Exchange CarrierILM Integrated Laser Module;

Integrated Laser ModulatorILMI Interim Link Management Interface;

Interim Local Management Interface

ILOG Information Log; Incoming Log

13

ILR Issues List ReportIM Instant MessagingIMA Inverse Multiplexing over ATMIMBS Ingress Maximum Burst SizeIMD Intermodulation DistortionIME Interface Management EntityIMT Inter Machine TrunkIN Intelligent NetworkINAP Intelligent Network Application Part

ProtocolI-NET Institutional NetworkINM Integrated Network ManagerInroute see I/BINT Internal; Internal ClockINTAP Interoperability Technology

Association for information Processing

INTP Internodal Tunneling ProtocolIntServ Integrated ServicesINVW Invalid Word CountIOA Input/Output AdapterIOC Initial Operating ConfigurationIOF Inter-office FiberIOR Interoperable Object Reference

;Indian Ocean RegionIP Intelligent Peripheral, IN block;

Internet ProtocolIPC Inter-process Communications;

InterProcess or InterProcesser Control

IPCR Ingress Peak Cell RateIPCU DAMA IP Channel UnitIPG Inter-Packet GapIPM Interested Party MulticastIPMI Internet Protocol Multicasting

InitiativeIPMS Interested Party Multicast ServiceIPOA Internet Protocol over ATMIPPV Impulse Pay per ViewIPR Intellectual Property RightsIPsec Internet Protocol SecurityIPSL Integrated IP Software LicenseIPTA Internet Protocol Transport

AgreementIPTV IP TelevisionIPX Internet Package Exchange

IR Intermediate ReachIRD Integrated Receiver/DecoderIRT Integrated Receiver/TranscoderIS In Service; Intermediate SystemISA Industry Standard ArchitectureIS-ANR In Service - AbnormalIS-ANRST In Service - Abnormal and

RestrictedISCC InterSwitch Communications

ChannelISCR Ingress Sustainable Cell RateiSCSI Internet Small Computer System

Interface; SCSI Protocol over TCP/IP

ISD Idle Signal DetectionISDN Integrated Services Digital NetworkIS-IS Intermediate System to

Intermediate SystemISM Industrial Scientific MedicalIS-NR In Service - NormalISO International Standards

OrganizationISOC the Internet SocietyISP Internet Service Provider; Inside

PlantIS-RST In Service - RestrictedISTP Internet Signaling Transport

ProtocolISV Independent Software VendorIT Information TechnologyITA Installation, Test, and AcceptanceITC Independent Transmit ClockITE Information Technology EquipmentITL International Telecommunications

UnionITS Intelligent Transportation System;

Institute for Telecommunications Sciences

ITT International Telephone and TelegraphITU International Telecommunication UnionITU-T ITU Telecommunications standards

bodyIUC Interval Usage CodeIVPN International VPNIWF Interworking FunctionIXC Inter-exchange Carrier

14

J J0 J ZeroJ2EE Java 2 Enterprise EditionJBR Jabber CountJDBC Java Database ConnectivityJDK Java Development KitJDMK Java Dynamic Management KitJDS-HR Japan Digital Services - Half RateJEM JAVA™ Element ManagerJMS JAVA™ Messaging SystemJNDI Java Naming and Directory InterfaceJPEG Joint Photographic Experts GroupJRE Java Runtime EnvironmentJTAG Joint Test Action GroupJVM Java Virtual Machine

K k kilo (thousand)K1 SONET or SDH overhead byte of MSP/

MS-SPRing (see K2)K2 Used with K1-SONET or SDH overhead

byte for MSP/MS-SPRingKb KilobitKB KilobyteKb/s Kilobits per secondKB/s Kilobytes per secondKbit/s Kilobits per secondKbps Kilobits per secondKBps Kilobytes per secondkBPS kilo Bits Per Secondkft Kilofeet (USA cable length

measurement)kHz kilohertz (thousand hertz)Km KilometerKsh Korn Shellksym/s Kilosymbols per Secondksym/sec Kilosymbols per SecondkVA 1000 Volt AmpereskW Kilowatt

L L2TP Layer 2 Tunneling ProtocolL3 Layer 3LA Line Adapter; Latin America

LAC Local Access ConcentratorLADM Linear Add/Drop MultiplexerLAN Local Area NetworkLANE Local Area Network EmulationLAP Link Access Procedure; Link Access

ProtocolLAPB Link Access Procedure BalancedLAPD Link Access Procedure-D Channel

(X 25)LAPF Link Access Procedure for Frame-Mode

Bearer ServicesLAPS Link Access ProcedureLASER Light Amplification by Stimulated

Emission of RadiationLATA Local Access and Transport AreaLATM Local ATMLBC Laser Bias CurrentLBCL Laser Bias Current LevelLBCN Normalized Laser Bias CurrentLBO Line Build OutLC Lucent Connector; Line CardLCAP Local Craft Access PanelLCAS Link Capacity Adjustment SchemeLCC Life-Cycle cost; Link Control ChannelLCD Liquid Crystal DisplayLCL Lower Confidence LimitLCN Local Computer Network;

Logical Channel Number; Local Communications Network

LCR Least Cost RoutingLCT Large Capacity TerminalLD Laser DiodeLDAP Lightweight Directory Access ProtocolLDCC Line Data Communications ChannelLDCELP Low Delay CELPLDP Label Distribution ProtocolLDS Local Digital SwitchLEAF Large Effective Area FiberLEC Local Exchange CarrierLECS LAN Emulation Configuration ServerLED Light Emitting DiodeLEO Low Earth OrbitLER Label Edge RouterLES LAN Emulation ServerLF Line Fail

15

LFE Line Far EndLGN Logical Group NodeLGX Light-Guide CrossconnectsLH Logical HostLIC Line Interface CardLIF Line InterfaceLIM Line Interface ModuleLIP Local Information PacketLIU Line Interface UnitLLC Logical Link ControlLLSDCC Lower-Layer Section DCCLM Line ModuleLMDS Local Multipoint Distribution ServiceLMI Local Management InterfaceLMP Link Management ProtocolLNA Low Noise AmplifierLNB Low Noise Block LO Low OrderLOADM Lightweight Optical Add/Drop

MultiplexerLOC Loss of ClockLocn LocationLO-DXC Low Order Digital Cross ConnectLOF Loss of FrameLOF-P Path Loss of FrameLOH Line OverheadLOM Loss of Multiframe; List of Materials LOP Loss of PointerLOPDP Loss of Pointer Decay PeriodLOPI Loss of Pointer InhibitLOPIP Loss of Pointer Integration PeriodLOP-P Loss of Pointer - PathLOP-V VT Loss of PointerLOS Loss of SignalLOSS Loss of Signal SecondsLOVC Low-Order VCLOW Local OrderwireLP Line Processor; Lockout of Protection;

Low Order PathLport Logical portLP-S Lockout of Protection - SpanLP-S/SF-P Lockout of Protection - Span/Signal Fail

- ProtectionLR Long Reach (fiber); Line Regeneration

Equipment

LRDC Long Reach Daughter CardLSA Low Speed ADMLSB Least Significant BitLSF Loss of Signal or Frame indication

signalLSL Lower Specification LimitLSM Loss of Sync MessageLSN Logical SubnetworkLSP Label Switched Path; Local Service

ProviderLSR Label Switch RouterLSSGR LATA Switching System Generic

RequirementsLT Low Threshold; Laser TemperatureLTE Line Terminating Equipment; Long

Terminal EvolutionLTN Local Transport Network (fiber ring)LTP Link Termination Point; Logical

Termination PointLTS Loop Testing System; Long Term

StorageLU Line UnitLVD Low-Voltage DistributionLWP Low Water PeakLZS Lempel Ziv Stac

M M&C Monitor and ControlM12 MUX DS-1 into DS2M13 MUX DS-1 into DS3M23 MUX DS-2 into DS3MAC Media Access Control; Medium Access

ControlMAN Metropolitan Area NetworkMAP Main Audio Program; Mobile

Application Part ProtocolMAU Media Access UnitMb MegabitMB MegabyteMb/s Megabits per secondMB/s Megabytes per secondMbaud MegabaudMbits/s Megabits per secondMb/s Megabits per secondMb/s Megabytes per secondMb/s Million Bits Per Second

16

MBS Maximum Burst SizeMCC Master Control Center / ComputerMCP Management Control ProcessorMCPC Multiple Channels Per CarrierMCR Minimum Cell Rate; Minimum Cost

RoutingMCS Master Control StationMCT Maintenance Channel TransparencyMCTF Motion Compensated Temporal

FilteringMDF Main Distribution FrameMDU Multiple Dwelling UnitmDVR Multi-TV Digital Video RecorderME Middle EastMEA Mismatch of Equipment and AttributesMEGACO Media Gateway Control ProtocolMEO Medium Earth OrbitMER Modulation Error RatioMFR Multilink Frame RelayMG Media GatewayMGC Media Gateway ControllerMGCP Media Gateway Control ProtocolMGN Management Gateway NodeMHz Megahertz (million hertz)MIB Management Information BaseMID Message IdentifierMIPS Millions of Instructions per SecondMIT Management Information TreeMiTTs of Telecommunications TrafficMJ MajorML Mediation LayerMLMD Multiplexer/DemultiplexerMLPPP Multi-Link Point-to-Point Protocolmm millimeterMM Multimode; MultimediaMMCS Meridian Multi Media Center SwitchMME Multiwave Management ElementMMF Multi-Mode FiberMML Man Machine LanguageMMO Main Material OrderMMP Multiwave Management ElementMN MinorMNO Mobile Network OperatorMNC Multi-National Company

MO Managed ObjectMOD Module; Movies on DemandMODEM Modulator-DemodulatorModem Modulator/DemodulatorMOF Managed Object FrameworkMOP Method of ProcedureMOR Multi-wavelength Optical RepeaterMOS Mean Opinion ScoreMP Management PortalMP3 MPEG-2 Layer 3MPCKTS Multicast Packet CountMPEG Moving Pictures Expert GroupMPI Multi-Path Interface; Multi-Path

InterferenceM-Plane Management PlaneMPLmS Multi-Protocol Lambda SwitchingMPLS Multi Protocol Label SwitchingMPLS-CP MPLS Control PlaneMPN Mode Partition NoiseMPOA Multi Protocol over Asynchronous

Transfer ModeMPS Multiple Priority SystemMPT Multiplex Pass-ThroughMPT Ministry of Posts and

TelecommunicationsMPTS Multiple Program Transport StreamMR Modification Request; Material

Request; Medium ReachMRRB Maintenance Requirements Review

Board; Material Release Review Boardms MillisecondsMS Multiplex SectionMSA Mediation Services AdministratorMS-AIS Multiplex Section - Alarm Indication

SignalMSB Most Significant BitMSC Metro Shelf Controller; Microsoft

Cluster ServerMSF Multiservice Switching ForumMSN Multi-SubnetworkMSNM Metro Switching Network ManagerMSNM ML Metro Switching Network Manager

Mediation LayerMSO Multiple System OperatorMSOH Multiplexer Section Overhead

17

MSP Multiplex Section Protection; Multiservice Switching Path

MS-P Manual Switch - ProtectionMSPP Multiservice Provisioning PlatformMSPVC Management Soft Permanent Virtual

CircuitMS-R Manual Switch - RingMS-RDI Multiplex Section - Remote Defect

IndicationMS-REI Multiplex Section Remote Error

IndicationMSS Mobile Satellite ServiceMS-S Manual Switch - SpanMS-Spring/MSPR

Multiplex Section Shared Protection Ring

MST Mountain Standard Time; Multiplex Section Termination

MSTE Multiplex Section Terminating Equipment

MS-W Manual Switch - WorkingMTA Multimedia Terminal AdapterMTBF Mean Time between FailureMTIE Maximum Time Interval ErrorMTP Message Transfer PartMTTP Transparent Connection Termination

PointMTTR Mean Time to RepairMTTU Mean Time to UnderstandMTU Maximum Transmission UnitMUX MultiplexerMUXCVR MuxceivermV MillivoltMVOA Miniature Variable Optical AttenuatorMZ Mach-Zehnder

N NA No Alarm; Not Alarmed; Not

Applicable; Not Available; Numerical Aperture

NAD Network Access DomainNAP Network Access PointNAPT Network Address and Protocol |Transla-

tionNAS Network Access Server; Network

Attached Storage

NASA National Aeronautical and Space Agency (US)

NAT Network Address TranslationNBI Northbound InterfaceNBK No BackupNC Nodal Controller; Normally Closed

(contacts)NCB National Computer BoardNCC Network Control Center/ComputerNCCC Network Control Coordination ChannelNCCI Network Call Correlation IdentificationNCP Nodal Control Point; Nodal Control

ProcessorNCP&D Network Capacity Planning and

DeliveryNCR Non-Conformance ReportNCS Network Computing System; Network

Control System; Network Call SignalingNCT Network Control TerminalNCTA National Cable & Telecommunications

AssociationNDC National Destination CodeNDF New Data FlagNDIS Network Design and Inventory SystemNDMH Non-Degraded Modem HoursNDP Network Discovery Protocol; Neighbor

Discovery ProtocolNDSF Non-Dispersion Shifted FiberNDVR Network Digital Video RecordingNE Network ElementNE/FE Near End/Far EndNEBS Network Equipment Building

Standards; Network Equipment Building Systems

NEC National Electric CodeNEF Network Element FunctionNEG Negative TerminalNEID Network Element IdentificationNEIR Network Element Information RequestNEMA National Electrical Manufacturers

AssociationNFS Networked File SystemNGDLC Next Generation Digital Loop CarrierNG-L1 Next Generation Layer 1NGNA Next Generation Network Architecture

18

NGSO Non-Geostationary Earth Orbit, used as a general descriptive for LEO and MEO systems.

NGW National GatewayNI Network InterfaceNIC Network Interface CardNID Network Interface DeviceNIDU Network Interface Data UnitNII National Information Infrastructure

(for the USA, see also GII and EII)NIS Network Infrastructure SolutionsNISC National Information Services CouncilNIU Network Interface UnitNLA Network Layer Address; Network Layer

AgentNLC Node Line CardNLD Neighbor Link DiscoveryNLPI Network Layer Protocol Identifiernm nanometerNM Network Management; Network

Manager; Network Management; Node Manager

NMA Network Monitoring and AnalysisNME Network Management EthernetNMF Node-level Management FunctionNML Network Management LayerNMS Network Management SystemNN N key on keyboard for a no responseNNI Network to Network Interface;

Network Node InterfaceNNIF Network to Network InterfaceNNM Network Node ManagerNNTP Network News Transfer ProtocolNO Network Object; Normally Open

(contacts)NOC Network Operations CenterNOCC Network Operations Control CenterNPC Network Parameter ControlNPR Noise Power RatioNR No ReplyNRT Non-Real TimeNRTL Nationally Recognized Test LaboratoryNRTVBR Non Real-Time Variable Bit RateNRZ Non-Return to Zerons NanosecondNSA Non Service Affecting

NSAP Network Service Access PointNSF National Science Foundation (US)NSI Network Side InterfaceNSN Nationally Significant NumberNSP Node Switch Provider; Node Switch

ProcessorNT Window New TechnologyNTE Network Terminating EquipmentNTF No Trouble FoundNTFCNCDE Notification Codes (TL1)NTFS New Technology File SystemNTP Network Time ProtocolNTS Near Term Storage; Network Time

SynchronizationNTSC National Television Standards

CommitteeNUT Non-preemptive Unprotected TrafficNVM Non-Volatile MemoryNVRAM Nonvolatile Random Access MemoryNZDSF Non-Zero Dispersion Shifted Fiber

O O&M Operations and ManagementOA Optical AmplifierOA&M Operations Administration and

ManagementOADM Optical Add/Drop MultiplexerOAM Operations, Administration and

Maintenance OAMCell Operations, Administration and

Maintenance CellOAMP Operation, Administration,

Maintenance and Provisioning O-BLSR Optical-Bidirectional Line Switched

RingOC Optical CarrierOC-1 Optical Carrier level 1, SONET bit rate

= 51.84 Mb/s OC1 Optical Carrier level 1 (51.84 Mb/s)OC-12 Optical Carrier level 12, SONET bit rate

= 622.08 Mb/sOC-192 Optical Carrier level 192, SONET bit

rate = 9.953 Gb/s OC-3 Optical Carrier level 3, SONET bit rate

= 155.52 Mb/s

19

OC-48 Optical Carrier level 48, SONET bit rate = 2.488 Gb/s

OCAP OpenCable Application PlatformOCH Optical ChannelOCI Open Connection IndicationOC-n Optical Carrier-number; Optical Carrier

where N denotes a multiple of 51.84 Mb/s

OCT Octet CountOCTU Optical Channel Transport UnitOCXO Oven-Controlled Crystal OscillatorODA Outlet Digital AdapterODBMS Object Database Management SystemODF Optical Distribution FrameODPR Optically Dedicated Protection RingODU Outdoor UnitODUk Optical channel Data Unit where k is

1 or 2OEM Original Equipment ManufacturerOEO Optical-to-Electronic-to-OpticalOEPL Optical Ethernet Private LineOEPLAN Optical Ethernet Private Local Area

NetworkOEVPL Optical Ethernet Virtual Private LineOEVPLAN Optical Ethernet Virtual Private Local

Area NetworkOFC Open Fiber Control; Optical Fiber

CommunicationOFDM Orthogonal Frequency Division

MultiplexingOFS Out of Frame SecondOFTEL Office of Telecommunications (UK

Regulator)OID Object IdentifierOIU Operator Interface Unit; Optical

Interface Unit; Office Interface UnitOLA Optical Line Amplifier; Optical Link

AnalysisOLB Optical Link BudgetOLM Optical Link ModuleOLMP Optical Link Management ProtocolOLS Optical Line SystemOLT Optical Line Termination; Optical Line

TerminalOLTP OSRP Link Termination PointOM Optical ModuleOMC Operation and Maintenance Center

OMG Object Management GroupOMT Orthogonal Mode TransducerON Optical NetworkONE Optical Network ElementONP Open Network ProvisionONT Optical Network TerminalONU Optical Network UnitOO Optical-to-OpticalOOB Out of BandOOF Out of FrameOOK On-Off KeyingOOM1 Out of Multi Frame Stage 1OOM2 Out of Multi Frame Stage 2OOO Optical - Optical - OpticalOOR Out of RangeOOS Out of ServiceOOS-MA Out of Service-ManagementOOS-MAANR

Out of Service-Management and Abnormal

OpEx Operations ExpenditureOPM Optical Performance Monitoring;

Optical Power MeterOPR Optical Power ReceivedOPS/INE Operations Provisioning System/

Intelligent Network ElementOPT Optical Power TransmitOPTORL Optical Return LossOpUk Optical channel payload Unit where k is

1 or 2OQPSK Offset Quaternary Phase-shift KeyingORB Object Request BrokerOribital Slot

longitude position above the equator at which a satellite is located

ORIG Original; OriginatingORL Optical Return LossORP Optical Routing ProtocolOS Operating SystemOSA Optical Spectrum AnalyzerOSC Optical Supervisory Channel; Optical

Service ChannelOSDS Operations Systems Data ServerOSGI Open Services Gateway InitiativeOSHA Occupational Safety and Health ActOSI Open Systems Interconnection

20

OSM OSC Splitter ModuleOSMINE Operations Systems Modifications for

the Integration of Network ElementsOSNR Optical Signal-to-Noise Ratio; Open

Signal-to-Noise RatioOSP Optical Signaling Protocol; Outside

PlantOSPF Open Shortest Path FirstOSPR Optically Shared Protection RingOSRP Optical Signaling and Routing

ProtocolsOSS Operations Support SystemOSSAN Operations Support System Access

NodesOSS-AU Out of Service-AutonomousOSS-AUMA Out of Service-Autonomous and

ManagementOSS-AURST Out of Service-Autonomous and

RestrictedOSWF On-site Work ForceOTC Operations Technical Center; Optical

Transport CardOTDR Optical Time Domain ReflectometerOTGR Operations Technology Generic

RequirementsOTN Optical Transport NetworkOTS Optical Transport SystemOTS RPTR OTS RepeaterOTU Optical Transport UnitOUI Organizationally Unique IdentifierOUNI Optical User Network InterfaceO-UPSR Optical-Unidirectional Path Switched

RingOUSM Optical Utility Services ManagerOUSP Optical Utility Services PlatformOutbound see O/BOutroute see O/BOW Order WireOXC Optical Cross Connect

P P2P Peer to PeerP6 Pentium 6PA Port Adapter; Pre-AmplifierPA Power AmplifierPABX Private Automatic Branch Exchange

PAD Power Attenuation DevicePAMA Permanent Assignment Multiple AccessPAN Personal Area NetworkingPARP Proxy ARPPAS PanAmSatPAT Program Association TablePAX Path Adaptation and X-ConnectPB PetabytePBOR Primary-Backup Object ReplicationPPB-TE Provider Backbone Bridging -

Traffic EngineeringPBT Provider Backbone TransportPBX Private Branch ExchangePC Personal Computer; Physical Contact;

Processor CardPC Personal ComputerPCA Protection Channel AccessPCB Printed Circuit BoardPCC Processor Communication ChannelPCCA Pacific Century Corporate AccessPCG Pacific Century GroupPCI Peripheral Component InterconnectPCM Pulse Code ModulationPCMCIA Personal Computer Memory Card

Interface AdaptorPCMM PacketCable MultimediaPCN Program Change Notice; Product

Change Notice ;Personal Communications Network

PCO Pre-Conditioned OrderP-Code Product CodePCP Primary Cross-connection Point, street

cabinet/flexibility pointPCR Peak Cell RatePCS Personal Communication SystemPDA Personal Digital AssistantPDAP Power Distribution and Alarm PanelPDC Passive Dispersion CompensatorPDF Portable Document FormatPDH Pleisiochronous Digital HierarchyPDH Plesiochronous Digital HierarchyPDI Payload Defect IndicationPDL Polarization Dependent LossPDP Policy Decision PointPDU Power Distribution Unit; Protocol Data

Unit

21

PEG Public, Education, GovernmentPEM Processor Enhancement Module;

Processor Element ModulePEP Policy Enforcement PointPESQ Perceptual Evaluation of Speech

QualityPFE Path Far EndPFM Packet Forwarding ModulePFO Premium Feature OpenPG Peer Group; Protection GroupPGID Peer Group IdentifierPGL Peer Group LeaderPHY Physical Layer Device; PhysicalPIC Programmable Interrupt ControllerPID Personally Identifiable Data; Protocol

Identifier; Packet Identifier; Personal Identification

PIF Packet Interface FPGAPIN Photo Intrinsic; Positive-Intrinsic

Negative; Personal Identification Number

PING Packet Internet GroperPIP Plug-In ProvisioningPJ Pointer JustificationPL Packet LossPLC Packet Loss ConcealmentPLCN Pilot Line Change NotificationPLCP Physical Layer Convergence ProtocolPLD Programmable Logic DevicePLDT Philippines Long Distance Telephone

CompanyPLL Phase Locked LoopPLM Payload Label MismatchPLM-P Payload Label Mismatch - PathPLM-V Payload Label Mismatch - VTPLN PNNI Logical NodePLO Path Layer OverheadPM Performance Management;

Performance Monitoring; Program Manager; Project Manager

PMA Power Management AlgorithmPMBB Performance Monitoring Building BlockPMD Polarization Mode DispersionPMDC PMD CompensatorPMM Power Management ModulePMO Program Management Office

PN Pseudo Noise; physical nodePNC Physical Node ControllerPNNI Private Network-to-Network Interface;

Private Network Node InterfacePO Purchase OrderPOC Point Of ContactPOH Path OverheadPOM Project Office ManagerPON Passive Optical NetworkPOP/PoP Point of Presence, usually referring to

an Internet service provider/access point

POR Power on ResetPOS Packet over SONET; Positive TerminalPOST Power on Self TestPOTS Plain Old Telephone ServicePPC Power PCPPD Partial Packet DiscardPPJC Positive Pointer Justification CountPPL Point-to-Point LinkPPM Parts per Minute; Parts per Million;

Pulses per MillionPport Physical portPPP Point-to-Point ProtocolPPS Path Protection Switched; Pulses per

SecondPPT Power Passing TapPRB Project Review BoardPRBS Pseudo Random Bit SequencePRC Primary Reference ClockPRI Primary Rate InterfacePRNG Pseudo Random Number GeneratorsPROM Programmable Read Only MemoryPROT Protocol; ProtectionPRS Primary Reference SourcePS Power Supply; Policy Serverps/nm-km Pico-secondPSA PacketCable Service AgreementPSBF Protection Switching Byte FailurePSC Protection Switching Count; Project

Steering CommitteePSD Protection Switching DurationPSEL Presentation SuitePSI Program Specific InformationPSL Path Signal Label

22

PSM Persistent Stored ModulePSN Packet Switch Node; Packet Switched

NetworkP-SNC Permanent SNCPSQM Perceptual Speech Quality

MeasurementPSR Protection Side Regeneration; Path

Switched RingPST Primary State; Pacific Standard TimePSTN Public Switched Telephone NetworkPSU Power Supply Unit; Packet Switch UnitPT Pass-Through; Payload TypePTE Path Terminating EquipmentPTI Payload Type IndicatorPTO Private Telecommunications OperatorPTP Physical Termination Point;

Point-To-Point; Path Termination PointPTS Per Trunk SignalingPTSE PNNI Topology State ElementPTSP PNNI Topology State PacketPTT Posts, Telegraph and Telephone

company (usually a government monopoly operator)

PV Protocol ViolationPVC Permanent Virtual Circuit; Poly Vinyl

Chloride; Private Virtual CircuitPVR Personal Video RecorderPWB Printed Wire BoardPWM Pulse Width ModulationPWR Power

Q Q3 Telecommunications Management

Network (TMN) InterfaceQAM Quadrature Amplitude ModulationQL Quality LevelQMC QUICC Multichannel ControllerQoS Quality of ServiceQPM Quarterly Progress MeetingQPR Quarterly Progress ReportQPSK Quadrature Phase Shift KeyingQUICC Quad Integrated Communications Con-

trollerR R&D Research and Development;

Research and DesignR.H. Relative Humidity

R/W Read/WriteRADIUS Remote Authentication Dial-In User

ServiceRAI Remote Alarm IndicationRAID Redundant Array of Inexpensive Disk;

Redundant Array of Independent DiskRAIG Resource Availability Information GroupRAITN Regional Arab Information Technology

NetworkRAM Random Access MemoryRAN Regional Area Network; Radio Access

NetworkRASCOM Regional African Satellite

Communications OrganisationRBF Reconfigurable Blocking FilterRBM Regional Business Manager RBOC Regional Bell Operating CompanyRBW Resolution BandwidthRCC Routing Control ChannelRCV ReceiverRCVR ReceiverRDF Rate Decrease FactorRDI Remote Defect IndicationRDI-L Remote Defect Indication - LineRDI-P Remote Defect Indication - PathRED Random Early Detection; Random Early

DiscardREF ReferenceREI Remote Error IndicationREI-L Remote Error Indication - LineREI-P Remote Error Indication - PathRev. RevisionRF Radio FrequencyRFC Request for CommentRFFP Request For Final ProposalsRFI Radio Frequency Interference;

Remote Failure Indication; Request for Information

RFI-L Remote Failure Indication (detected at the line-layer)

RFI-P Remote Failure Indication(detected at the path-layer)

RFP Request for ProposalRFT Radio Frequency Transmitter used to

describe large antennas with associated receive/transmit equipment

RG Residential Gateway

23

RHC Regional Holding CompanyRIB Routing Information BaseRIN Relative Intensity NoiseRIP Routing Information ProtocolRJ Registered JackRJ-11 Registered Jack –11RKS Record Keeping ServerRMA Return Material Authorization; Replace

Material AuthorizationRMAN Recovery ManagerRMI Remote Method InvocationRMS Root Mean SquareRNR Not Ready to Receive; Remote Failure

IndicationROADM Re-configurable Optical Add/Drop

MultiplexerROC Regional Operations CenterROI Return on InvestmentROM Read Only MemoryROW Return OrderWireRPM Revolutions per MinuteRPR Resilient Packet RingRR Ready to Receive; Reverse RequestRRB Reliability Review BoardRRO Record Route ObjectRR-R Reverse Request - RingRR-S Reverse Request - SpanRS Regenerator Section; Reed-SolomonRS232 Recommended Standard –232RS-E Ring Switch - EastRSOH Regenerator Section OverheadRSP Route Switch ProcessorRSTP Resilient Spanning Tree ProtocolRST Regenerator Section TerminatingRSVP Resource Reservation ProtocolRSVP-TE Resource Reservation Protocol with

Traffic EngineeringR/W Read/WriteRS-W Ring Switch - WestRT Remote Terminal; Real TimeRTC Real-Time ClockRTI Real-Time IngestRTN Return (voltage return)RTO Recovery Time ObjectiveRTOS Real-Time Operating System

RTP Routing Table Protocol; Real-Time Transport Protocol; Routine Task Procedure

RTPS Real Time Streaming ProtocolRTRV RetrieveRTS Ready to Send;

Request to Send; Real Time Operation System

RTSP Real Time Streaming ProtocolRTT Round-trip TimeRTU Right to UseRTVBR Real-Time Variable Bit Rate TrafficRU Rack UnitRW RewindRWA Routing and Wavelength AssignmentRX ReceiveRx Line Receive LineRZ Return to ZeroRZ-DPSK Return to Zero Differential Phase Shift

KeyingS s Seconds.f. Square FootS/IMP Signal to Impulse RatioS/N Signal to Noise RatioSA Service-AffectingSAAL Signaling ATM Adaptation LayerSABLIME Product Administration System (AT&T)SAN Storage Area NetworkSAP Secondary Audio ProgramSAR Segmentation and ReassemblySARP Switching Address Resolution ProtocolSAS Severely Errored Frame and AIS

SecondsSAAS Software As A ServiceSASE Standalone SynchronizationSATA Serial AT AttachmentSATCOM Satellite Communications Satellite

CapacitySATT Synchronization, Alarms, and

Telemetry Termination SAW Surface Acoustic WaveS-band frequency bandSBLK Errored SuperblocksSBS Stimulated Brillouin Scattering

24

SBV Switched Broadcast VideoSBW Signal BandwidthSC Service Channel; Square Connector;

Shelf ControllerSCADA Supervisory Control and Data

AcquisitionSCC Serial Communications Controller;

Serial Communications ChannelsSCCI Small Computer System InterfaceSCCP Signalling Connection Control Part,

part of SS7S-CDMA Synchronous Code Division Multiple

AccessSCE Service Creation Environment, IN blockSCEP Service Creation Environment Point, IN

blockSCF Service Control Function, IN blockSCM Service Channel Modem; Sub-carrier

MultiplexingSCN Service Channel Network; Shared

Content NetworkSCP Service Control Point, IN blockSCPC Single Channel per CarrierSCR Sustainable Cell Rate; Silicon Con-

trolled RectifierSCSI Small Computer System InterfaceSCTE Society of Cable Telecommunications

EngineersSD Signal Degrade; Signal Detect;

Standard DefinitionSDA System Design AuthoritySDCC Section Data Communications ChannelSDF Service Data Function, IN blockSDH Synchronous Digital HierarchySDI Secure Digital Interface; Serial Digital

InterfaceSDL Synchronous Data Link; Synchronous

Delay LineSDLC Synchronous Data Link ControlSDMA Space Domain Multiple AccessSDMH Severely Degraded Modem HoursSDP Service Data Point, IN blockSD-P Signal Degrade - PathSD-R Signal Degrade - RingSDRAM Synchronized Dynamic Random Access

MemorySD-S Signal Degrade-Span

SDTV Standard Definition TelevisionSDU Service Data UnitSE Systems EngineerSEAL Simple and Efficient Adaptation LayerSEC SecondarySEF Severely Errored FramingSEFS Severely Errored Frame SecondsSEFS-S Severely Errored Framing Seconds -

SectionSEM Service Entitlement Manager SEMS Severely Errored Multi-frame SecondsSerDes Serializer/DeSerializerSES Severely Errored SecondsSES-L Severely Errored Seconds - LineSES-LFE Severely Errored Seconds -

Line Far EndSES-P Severely Errored Seconds - PathSES-PFE Severely Errored Seconds -

Path Far EndSESR Severely Errored Second RatioSES-RS Severely Errored Seconds -

Regenerator SectionSES-S Severely Errored Seconds - SectionSES-V Severely Errored Seconds - VTSES-VFE Severely Errored Seconds - VT Far EndSETS Synchronous Equipment Timing SourceSF Signal Failure; Super FrameSFD Start of Frame DelimiterSFF Small Form Factor (connector)SFO Sync Frequency OffsetSFP Small Form-factor PluggableSF-R Signal Failure - RingSF-S Signal Failure - SpanSG Signaling GatewaySGC Signaling Gateway Controllersh Bourne ShellSHx Shelf NumberSI Serial Interface; Service Independent ;

System IntegratorSIB Service Independent Building Block,

IN blockSIC System Integrity Control; Standard

Industrial ClassificationSID System Identification number; Source

Identifier

25

SIF SONET Interoperability Forum; Switch Interface FPGA

SIM Service Interface ModuleSIP Session Initiation ProtocolSITA Société Internationale de

Télécommunications AéronautiqueSLA Service Level AgreementSLIP Serial Line Internet ProtocolSLM Service Layer ManagerSLOSS Synchronization LossSLR Service Level ReportSM Single Mode; Switching Module; Shelf

ManagerSMAP Service Management Access Point,

IN blockSMB Small and Medium BusinessSMC Serial Management Controllers; Stan-

dard Management CommitteeSMCS Short Message Service CenterSMDS Switched Multimegabit Data ServiceSME Small and Medium Enterprise; Short

Message EntitySMF Single Mode FiberSMIR Single Mode Intermediate ReachSML Service Management LayerSMLR Single Mode Long ReachSMM Service Mediation ModuleSMON Switch MonitorSMOP Service Method of ProcedureSMP Service Management Point, IN blockSMS Service Management System, IN block;

Service Management Suite; Short Message Service

SMSC Short Message Service Centre, part of GSM messaging system

SMT Surface Mount Technology; Self-Monitoring Task

S-MTA Standalone Multimedia Terminal Adaptor

SN Service Node, IN blockSNA Systems Network ArchitectureSNC Subnetwork Connection; Subnetwork

ControllerSNCP Subnetwork Connection ProtectionSNCP/I Subnetwork Connection Protection/

Inherent monitoring

SNCP/N Subnetwork Connection Protection/Non-intrusive monitoring

SNG Satellite News GatheringSNM Switching Network ManagerSNMP Simple Network Management ProtocolSNP Sequence Number ProtectionSNR Signal-to-Noise RatioSNTP Simple Network Time ProtocolSOA Semiconductor Optical AmplifierSOF Start of FrameSOH Section Overhead; State of HealthSOHO Small Office/Home OfficeSONET Synchronous Optical Network, US

equivalent to SDHSOP Standard Operating Procedure;

Service ProviderSP Shelf Processor; Shelf Pump; Service

ProviderSPC SONET Permanent CircuitSPCN Satellite Personal Communications

NetworkSPE Synchronous Payload EnvelopeSPF Shortest Path FirstSPI Serial Peripheral Interface; Service

Provider InterfaceSPM Self-Phase ModulationSPR/SPRing Shared Protection RingSPTP Service Path Termination PointSPVC Soft Permanent Virtual Connection;

Soft Permanent Virtual CircuitSQL Structured Query LanguageSR Short Reach (fiber)SRAM Static Random Access MemorySRC/DST Source/DestinationSRD Software Release DocumentSRF Specialised Resource Function, IN

blockSRN Software Release NoticeSRS Stimulated Raman ScatteringSRTS Synchronous Residual Time StampSRVEFF Service Affecting (TL1)SS/TDMA Satellite Switched Time Division

Multiple Access, Intelsat serviceSS5 Signaling System 5SS7 Signalling System 7, supported by the

ITU-T, also known as CCITT 7

26

SSB Single SidebandSSCOP Service Specific Connection Oriented

ProtocolSSCS Service-Specific Convergence SublayerSSEL Session SelectorSSF Server Signal Failure ; Service

Switching FunctionSSL Secure Sockets LayerSSM Synchronization-Status MessagesSSMF Standard Single Mode FiberSSP Service Switching Point, IN blockSSPA Solid State Power AmplifierSST Secondary Service StateSSTUR Site-Specific Turn-Up ReportSSU Synchronization Supply Unit ;

Subscriber TerminalsST Straight Terminus; Straight TipST1 Stratum 1; Switched T1ST2 Stratum 2ST3 Stratum 3ST3E Stratum 3 EnhancedST4 Stratum 4 (Asynchronous)STB Set-Top BoxSTC Stacking and Timing CardSTE Section Terminating Equipment;

Section Terminating ElementSTII (2) Type of optical connectorSTM Synchronous Transfer Mode, or

ModuleSTM-0 Synchronous Transfer Mode level 0,

SDH bit rate = 51.84 Mb/sSTM-1 Synchronous Transfer Mode level 1,

SDH bit rate = 155.52 Mb/s STM-16 Synchronous Transfer Mode level 16,

SDH bit rate = 2488.32 Mb/sSTM-4 Synchronous Transfer Mode level 4,

SDH bit rate = 622.08 Mb/sSTM-64 Synchronous Transfer Mode level 64,

SDH bit rate = 9953.28 Mb/sSTM-n Synchronous Transport Module nSTM-nC Synchronous Transport Module of level

n concatenatedSTMX SONET/SDH Thin MultiplexerSTP Spanning Tree Protocol; Shielded

Twisted PairSTS Synchronous Transport SignalSTS-1 Synchronous Transport Signal Level 1

STS-3 Synchronous Transport Signal Level 3STS-3c Synchronous Transport Signal Level 3,

concatenatedSTS-n Synchronous Transport Signal nSTS-Nc Contiguous Concatenation of N STS-1

SPEsSTS-N-Xv Virtual Concatenation of X STS-N SPEsSTU Secure Telephone Unit; Synchronized,

Traceability Unknown; Stratum Traceability Unknown

STU-P Stratum Traceability Unknown-Provisioned

SVC Switched Virtual CircuitSVCC Switched Virtual Channel ConnectionSVOD Subscription Video on DemandSVP Secure Video ProcessorSVPC Switched Virtual Path ConnectionSW SoftwareSWCA Split Working Channel AccessSWID Software IdentifierSWOD Software ODACSSX Short Reach as in 1000Base-SXSYNC SynchronizationSYNCIO Synchronized Input/OutputSYSLOG System Log

T T1 Service or line operation at the

DS-1 rateT1 1.544 Mb/s (US orientated)T3 Digital Carrier System for DS3 SignalsTAC Transport Aggregated Circuit; Technical

Assistance CenterTACACS Terminal Access Controller Access

Control SystemsTACS Total Access Communications Systems

(Analogue)TADR Target AddressTADRMAP Target Address MapTAM Total Available MarketTAP Test Access Port; Technician Access

PortTARP Target Identifier Address Resolution

ProtocolTAS Telecommunications Authority of

SingaporeTB Terabyte

27

TBD To Be DeterminedTBOS Telemetry Byte Oriented Serial ProtocolTBUS Timing BusTC Transmission Convergence; Transport

Complex; Transport ChannelTCA Threshold Crossing Alert; Timing

Control and AccessTCBE Total Corrected Bit ErrorTCM Trellis Coded Modulation; Transport

Channel MembersTCMO Transport Complex Managed ObjectTCP Transmission Control Protocol; Trouble

Cleaning ProcedureTCP/IP Transmission Control Protocol/Internet

ProtocolTCTP Transparent Connection Termination

PointTD Traffic DirectorTDEV Time DeviationTDM Time Division MultiplexingTDMA Time Division Multiple AccessTE Terminal EquipmentTEC Thermo-Electric CoolerTED Traffic Engineering DatabaseTEI Terminal Endpoint Identifier; Terminal

Equipment IdentifierTelco Telephone CompanyTELR Talker Echo Loudness RatingTEO Telephone Equipment OrderTERM TerminationTFT Thin Film TransistorTFTP Trivial File Transfer ProtocolTG Timing GeneratorTGCP Trunking Gateway Control ProtocolTGS Time Generation SystemTHEC Corrected Type Header Error

Correction CodeTHz TeraHertz (1012 hertz)TI Terrestrial InterferenceTIA Telecommunications Industry

AssociationTID Target Identification; Terminal Identifi-

cationTIE Time Interval ErrorTIM Trace Identifier Mismatch; Transmit

Intermediate MultiplexerTIM-S Trace Identifier Mismatch - Section

TIRKS Trunk Integrated Record Keeping System

TISSA Time Space Switch Application-Specific Integrated Circuit

Hz HertzTKIP Temporal Key Integrity ProtocolTL-1 Transaction Language 1TL-1 CLI Transaction Language One,

Command Line InterfaceTLC Transport Logical ConnectionTLI Transaction Language Command Line

InterfaceTLS Transparent LAN ServicesTLSR Transoceanic Line Switched RingTLV Type-Length-ValueTM Timing Module; Transaction ManagerIN Intelligent NetworkTMC Terminal Monitor and ControlTML Telephony Markup LanguageTMN Telecommunications Management

NetworkTMO Trans Metro Optical (platform)tmout Time Outtmper Time PeriodTMUX Terminal MultiplexerTNL Ethernet TunnelingTNM Transport Network ManagementTOD Television on DemandToD Time of Day TOH Transport OverheadTOP Task Oriented Practice; Task Oriented

ProcedureTOS Type of ServiceTP Termination PointTPFI Timing Plane Fault IsolationTQM Total Quality ManagementTR Technical ReferenceTRIB TributaryTRM Technical Review MeetingtRTO TCP Retransmit TimeoutTrTOH Transparent Transport OverheadTS Time Slot; Time Stamp; Time Synchro-

nizationTSA Time Slot AssignmentTSD Transport System DivisionTSE Topology State Element

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TSEL Transport SelectorTSF Transport Signal FailureTSG Timing Signal GeneratorTSI Time Slot Interchange; Time Switch

InterchangeTSR Technical Service RepresentativeTSX Time-Space Switch ASICTTE Transparent Terminal EquipmentTTL Transistor Transistor Logic; Time to LiveTTP Trail Termination PointTTTP Transparent Trail Termination PointTU Tributary Unit; Transmission UnitTUG Tributary Unit GroupTUG-n Tributary Unit Group, level nTU-n Tributary Unit, level nTV TelevisionTVRO Television Receive Only earth stationTW TrueWave – fiber brandTWC TrueWave Classic – fiber brandTX TransmitTx Line Transmit Line

U UAE United Arab EmiratesUART Universal Asynchronous Receiver/Trans-

mitterUAS Unavailable SecondsUASL Unavailable Second Count-LineUAS-L Unavailable Seconds - LineUAS-LFE Unavailable Seconds - Line Far EndUASP Unavailable Second Count-PathUAS-P Unavailable Seconds - PathUAS-PFE Unavailable Seconds - Path Far EndUAS-RS Unavailable Seconds - Regenerator

SectionUAS-S Unavailable Seconds - SectionUAS-V Unavailable Seconds - VTUAS-VFE Unavailable Seconds - VT Far EndUAT Unavailable TimeUB Uncorrected BlockUBR Undefined Bit Rate; Unspecified

Bit RateUBRVBR Unspecified Bit Rate Variable Bit RateUC User ChannelUCBE Uncorrectable Block Error

UCD Upstream Channel DescriptorUD Unconditional DisconnectUDLR Unidirectional Link RoutingUDP User Datagram ProtocolUDR Unconditional Disconnect ResponseUEM Universal Equipment ModulesUEQ UnequippedUGC Universal Gateway CarrierUGS Unsolicited Grant ServiceUHD Ultra High DensityUHF Ultra High FrequencyUI User InterfaceUIC User Interface ClientUID User IdentifierUITS Unacknowledged Information Transfer

ServiceUL Underwriters LaboratoriesULH Ultra Long HaulULSDCC Upper Layer Section Data

Communications ChannelUMTS Universal Mobile Telecommunications

SystemUNEQ Unequipped Path; UnequippedUNEQ-P Unequipped PathUNEQ-V Unequipped VTUNEs Unbundled Network ElementsUNI User Network InterfaceUNI/UNIF User Network InterfaceUNII Unlicensed National Information

InfrastructureUOG Universal OSS GatewayUPC Ultra Physical Contact; Universal Packet

Carrier; Usage Parameter ControlUPN Universal Personal NumberUPnP Universal Plug and PlayUPS Uninterrupted Power SupplyUPSR Unidirectional Path Switched RingUPT Universal Personal TelecommunicationsURI Universal Resource IdentifierURL Universal Resource LocatorUS UpstreamUSB Universal Serial BusUSEPA United States Environmental Protection

AgencyUTC Universal Time Coordinated; Universal

Transport Carrier

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UTOPIA Universal Test and Operations Physical Interface for ATM

UTP Unprotected Termination Point; Un-shielded Twisted Pair

UV UltravioletPRI Primary Rate InterfaceUVC Universal Voice Carrier; Universal

Video Carrier

V V VoltagePSTN Public Switched Telephone NetworkV/A Video/AudioVAC Voltage Alternating CurrentVAD Voice Activity DetectionVADSL or Very high speed (Asymmetric) VDSL Digital Subscriber LineVAP Virtual Access PartitioningV-band 50/40 GHzVBI Vertical Blanking IntervalVBR Variable Bit RateVC Virtual Circuit; Virtual Channel; Virtual

Container; Virtual ConcatenationVCAT Virtual ConcatenationVCC Virtual Channel ConnectionVCG Virtual Concatenation GroupVCI Virtual Channel IdentifierVCL Virtual Channel LinkVCM Virtual Concatenation-group MemberVC-N Virtual Container Level N (N=11, 12, 2,

3, 4)VC-N-Xc Contiguous Concatenation of X Virtual

Containers at Level NVC-N-Xv Virtual Concatenation of X Virtual

containers at Level NVCO Voltage Controlled OscillatorVCR Video Cassette RecorderVCSEL Vertical Cavity Surface-Emitting LaserVCXO Voltage Controlled Crystal OscillatorVDC Volts Direct CurrentVDSL Very-high-bit-rate

Digital Subscriber LineVEC Voice Equivalent CircuitVF Virtual Fiber; Virtual FacilityVFCU Voice/FAX Channel UnitVFTP Virtual Facility Termination Point

VG Virtual GroupVGA Variable Gain AmplifierVHF Very High FrequencyVLAN Virtual Local Area NetworkVLR Very Long ReachVM Voice Mail; Virtual Memory;

Virtual MachineVME Versa Module EurocardVMM Voice/Modem ModuleVOA Variable Optical AttenuatorVOD Video on DemandVoIP Voice over Internet ProtocolVOM Volt-Ohm MeterVOQ Virtual Output QueuingVOW Voice Order WireVP Virtual PathVPC Virtual Path ConnectionVPCI Virtual Path Connection IdentifierVPG Virtual Path GroupVPI Virtual Path IdentifierVPI/VCI Combined, VPI and VCI identify a

connection on an ATM NetworkVPL Virtual Path LinkVPLS Virtual Private LAN ServiceVPN Virtual Private NetworkV-pole Vertical-poleVPS Voice Processing SystemVPSP Virtual Path Switch ProtectionVRRP Virtual Router Redundancy ProtocolVSA Virtual-Scheduling Algorithm; Vector

Signal AnalyzerVSAT Very Small Aperture TerminalVSI Vendor-Specific InformationVSR Very Short ReachVSSP Virtual Service Switching PointVT Virtual TributaryVT-100 Terminal Emulation SystemVTG Virtual Tributary GroupV-UNI Virtual User Network Interface

W W Watt; WorkingWAD Wavelength Add and DropWAN Wide Area Network

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WB Working Band; WestboundWBS Work Breakdown StructureWC Watts per channelWCA Working Channel AccessWCSS WDM Capable Switching SystemW-DCS Wideband Digital Cross-Connect

SystemWDM Wavelength Division MultiplexingWDT Watchdog timerWE Western EuropeWECA Wireless Ethernet Compatibility

AllianceWEP Wired Equivalency PrivacyWFA Workforce AutomationWFM Workforce ManagementWFQ Weighted Fair QueuingWIF Wide Area Network InterfaceWiFi Wireless FidelityWiMedia An alliance for Wireless MultimediaWLAN Wireless Local Area NetworkWLL/WiLL Wireless Local Loop, WiLL is also Mo-

torola’s WLL product line nameWM9 Windows Media Player Version 9WPA Wireless (WiFi) Protected AccessWPS Working/Protect SplitterWRED Weighted Random Early Discard;

Weighted Random Early DetectionWSS Wavelength Selective SwitchWTO World Trade OrganisationVPN Virtual Private NetworkWTR Wait to RestoreWWN World Wide NameWWW World Wide Web

X X.25 Packet Switched Communications

InterfaceXC Cross ConnectXCVR TransceiverXDSL See DSL (Digital Subscriber Line)XFP 10 Gb/s small form-factor pluggable

transceiverXML Extensible Markup LanguageXMTR TransmitterXPM Cross-Phase Modulation

Z ZAC Zero Administration ClientZWP Zero Water Peak

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Notes

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Notes

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