The Acronyms Guide

edited by Erin Malone Chris 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 or Optical Communications Certification programs please contact [email protected]. Table of Contents

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

Acronym Guide ADI Asset Distribution Interface Numerics ADM Add/Drop Multiplexer 2F Two-Fiber ADP Actual Departure Potential; Automatic 10 GbE 10 Data Processing ADSL 10 GFC 10 Gigabit Fibre Channel (Same as Asymmetric Digital Subscriber Line FC1200) ADT Actual Departure Time; Automatic Data 100G 100 Gigabits Transmission AE 16-QAM 16 (points) Quadrature Amplitude Automation Engine; Automation Envi- Modulation ronment AES 3D Three Dimensional Advanced Encryption ; Application Environment Specific 3G 3rd Generation AESA ATM End System Address; ATM End 40G 40 Gigabits Station Address 4C Consortium of , IBM, Matsushita, AFI Authority and Format Identifier and Toshiba AFM APS Mode Mismatch Failure 4F Four-Fiber AGC Automatic Gain Control; Access Group 5C Consortium of Intel, Sony, Matsushita, Controller Toshiba, and Hitachi AGGR Aggregate A AID Access Identifier; Application Identifier A/D Analog-to-Digital AIM Auto Image Management; Active AAL ATM Adaptation Layer Inventory Map AAL0 ATM Adaptation Layer Type 0 AIN Advanced Intelligent Network AAL1 ATM Adaptation Layer Type 1 AINI ATM Inter-Network Interface AAL2 ATM Adaptation Layer 2 Transport AINS Automatic in Service State AAL3/4 ATM Adaptation Layer Type 3 and 4 AIR Additive Increase Rate AAL5 ATM Adaptation Layer 5 AIS Alarm Indication Signal ABR Available AISDP Alarm Indication Signal Decay Period ABT Advanced BiCMOS Technology AISIP Alarm Indication Signal Integration AC Alternating Current; Administrative Period Complex; Atomic Clock AIS-L Alarm Indication Signal - Line AC-3 Audio Coding Revision 3 AIS-P Alarm Indication Signal - Path ACAC Actual Call Admission Control AIS-S Alarm Indication Signal - Section ACEG Alternating Current Equipment Ground AIS-V VT Alarm Indication Signal ACK Acknowledge ALS Automatic Laser Shutdown; Application ACL Active Control List; Access Control List Layer Service ACO Alarm Cutoff AM Amplitude Modulation; Application ACQ Acquire Manager ACR Allowed Cell Rate AMF APS Mode Mismatch Failure ACS Automatic Channel Shutdown; Alarm AMI Access Method Interface; Alternate Correlation and Suppression Mark Inversion ACSE Association Control Service Element AMP Amplifier; Amperes ACSS Automatic Channel Shutdown AMS Asset Management System; Agent Suppression; Automatic Channel Management System Shutdown State ANSI American National Standards Institute ACT Active AO Autonomous Output ADC Analog-to-Digital Converter; Add/Drop AOD Advertising on Demand Coupler APC Angled Physical Contact

1 APD Avalanche PhotoDiode AU-n Administrative Unit n API Application Program Interface AUX Auxiliary APS Automatic Protection Switching AVC Attribute Value Change APSBF Automatic Protection Switching Byte AWG American Wire Gauge Failure AWGN Additive White Gaussian Noise APSCM Automatic Protection Switching Channel Mismatch B APSMM Automatic Protection Switching Mode Mismatch B/P Backplane ARC Alarm Reporting Control B3ZS Bipolar With 3-Zero Substitution ARP Address Resolution Protocol B6ZS Bipolar With 6-Zero Substitution ARPU Average Revenue per Unit (or User) B8ZS Bipolar With 8-Zero Substitution AS Autonomous System BA Booster Amplifier ASAP Alarm Severity Assignment Profile BB Broadband ASCII American Standard Code for Informa- BBE Background Block Error tion Interchange BBER Background Block Error Ratio ASD Access Security Device BBE-RS Background Block Error Regenerator ASE Amplified Spontaneous Emission; Ap- Section (an SDH regenerator section plication Service Element error) ASI Asynchronous Serial Interface; BC Business Continuity; Broadcast Asynchronous SCSI Interface BCD Binary-Coded Decimal ASIC Application-Specific Integrated Circuit BCST Broadcast ASN.1 Abstract Syntax Notation One B-DCS Broadband Digital Cross-connect ASP Applications Service Provider; Average System Selling Price BDFB Battery Distribution Fuse Bay; Battery ASYNC Asynchronous Distribution Fuse Board AT Advanced Technology BE Block Error; Best Effort AT&T American Telephone and Telegraph BECN Backward Explicit Congestion Notifica- Company tion ATA Advanced Technology Attachment BELLCORE BELL Communications Research, Inc. ATAF ATM Test Access Function BER Bit Error Rate ATAG Autonomous Tag BE-RS Block Errors-Regenerative Section ATAGSEQ Autonomous Tag Sequence BER-SD-P Path Signal Degrade BER ATC Alarm Traffic Controller BER-SF-P Path Signal Failure BER ATDMA Asynchronous Time Division Multiple BERT Bit Error Rate Test Access BFP Back Facet Power; Basic Format Packet A-TDMA Advanced Time Division Multiple BGP Border Gateway Protocol Access BGP4 Border Gateway Protocol, version 4 ATM Asynchronous Transfer Mode BICI Broadband Inter-Carrier Interfaces; ATM SAM ATM Service Access Multiplexer B-ISDN Inter-carrier Interface ATMVCL ATM Virtual Channel Link BICSI Building Industry Consulting Services ATMVPL ATM Virtual Path Link International ATTN Attenuator BIOS Basic Input/Output System AU/AU-x Administrative Unit BIP Bit Interleaved Parity; Breaker Interface Panel AUG Administrative Unit Group B-ISDN Broadband ISDN AUI Autonomous Unit Interface

2 BIT Built-In Test; Binary Digit CA Content Archived; Carrier Access BITS Building Integrated Timing System CAB Conformity Assessment Body bits/sym Bits per Symbol CAC Connection Admission Control; Call BLSR Bidirectional Line Switched Ring Admission Control BML Business Management Layer CAD Aided Design BNC Bayonet Neill-Concelman British CALA Central America and Latin America National Connector CAM Content Addressable Memory BOC Bell Operating Company CANARIE Canadian Network for Advancement of BOD Bandwidth on Demand Research BOL Beginning of Life CAP Competitive Access Provider BOM Bill of Materials CAPEX Capital Expenditure BONDING Bandwidth ON Demand CAS Channel Associated Signaling Interoperability Group CATV Community Antenna Television; Cable BOOTP Bootstrap Protocol Television BP Backplane CB, C/B Circuit Breaker BPI Baseline Privacy Interface CBDS Connectionless Broadband Data Service BPI+ Baseline Privacy Interface Plus CBN Common Bonding Network B-PON Broadband Passive Optical Network CBR Constant Bit Rate BPP Backplane Protocol CC Cross Connection; Clear Channel; bps bits per second Calling Centers BPSR Bidirectional Path Switched Ring CCAF Call Control Agent Function, IN block BPT Band Pass-Through CCB Configuration Control Board BPV BiPolar Violations CCC Cross Connect Controller B-RAS Broadband Remote Access Server CCC768 Cross Connect Fabric with 768x768 BRI Basic Rate Interface STS-1 capacity BRM Backward RM CCCG Cross Connection and Control Group BSC Board SC Connector CCC-PC CCC Processor Card BSP Board Support Package CCDF Complementary Cumulative BSS Business Support System Distribution Function BT British Telecom; Burst Tolerance CCI Content Control Information Btag Beginning Tag CCITT Consultative Committee on Interna- tional Telegraphy and Telephony BTM Bits Termination Circuit CCK Complimentary Code Keying BTO Build Transfer Operate CCW Counterclockwise BTS Business Telecom Services CDE Common () BTU/hr British Thermal Unit per hour CDMA Code Division Multiple Access BW Bandwidth CDP Contracted Deadline Potential BWDM Band Wavelength Division Multiplexer CDR Call Detail Recording; Clock and Data BYT Total Byte Count Recovery CD-ROM Compact Disc Read Only Memory C CDT Connection Dropping Threshold C Celsius; Critical CDTS Chromatic Dispersion Test Set C/I Carrier-to-Interface Ratio CDV Cell Delay Variation C/N Carrier-to-Noise Ratio CDVT Cell Delay Variation Tolerance C2O Cable to Optic CD-WO Compact Disc - Write One

3 CE Consumer Electronics CME Compressed Multiplication Equipment CEA Consumer Electronics Association CMF Channel Mismatch Failure; Client CELP Code Excited Linear Predictive Management Frame CER Cell Error Ratio; Codeword Error Ration CMIP Common Management Information Protocol CES Circuit Emulation Service CMIS Common Management Information CEV Controlled Environmental Vault Services CFDM Command Frequency Division CMISE Common Management Information Multiplexer Service Element CFG Configuration CMR Cell Misinsertion Rate CFM Cubic Feet per Minute CMS Call Management Server CFU Cooling Fan Unit CMTS Termination System CH Channel CMU Clock Multiplier Unit CHASEH Environmentally Hardened Chassis C-n Container C-11=1,544 Mb/s; CHASYNC Chassis with Sync C-12=2,048 Mb/s; C-2=6,312 Mb/s; CI Compact Intelligence; Craft Interface; C-3=34,368 Mb/s and 44,736 Mb/s; Customer Interface; Certified Integrator C-4=139,264 Mb/s CID Circuit Identification; Craft Interface CNIPS Core Network Integrated Planning Device System CIF Client Interface CNIR Carrier-to-Noise/Ingress Ratio CIFS Common CNMP Customer Network Management Portal CIM Client Interface Module CNR Carrier-to-Noise Ratio CINOT Ciena Optical Transport System CO Central Office CIT Craft Interface Terminal; Craft COAX Coaxial Cable Interface Tool COBRA Copper and Optical Broadband Re- CL Coupling Loss; Cleared mote Access CLASS Custom Local Area Signalling Services CODEC Coder/Decoder CLEC Competitive Local Exchange Carrier COE Central Office Equipment CLEI Common Language Equipment COFA Change of Frame Alignment Identifier COLD Central Office Layout Design CLEITM Common Language Equipment COLL Collision Count Identifier CONDTYPE Condition Type CLFI Common Language Facility Identifier CONS Connection Oriented Network Service CLI Command Line Interface COO Chief Operating Officer CLIP Calling Line Identification Presentation COPS Common Open Policy Services CLIR Calling Line Identification Restriction CORBA Common Object Request Broker CLLI Common Language Location Identifier Architecture CLNP Connectionless Network Layer Protocol COS Class of Service; Common Object CLNS Connectionless Network Service Services; CORBA Object Services CLP Cell Loss Priority CoS Class of Service CLR Cell Loss Ratio COT Central Office Terminal CLTP Connectionless Transport Protocol COTS Commercial off the Shelf cm centimeter CP Circuit Pack; Control Processor; Connection Provisioner; Call CM Control Module; Cable Modem Processing; Customer Premise CM-CLI Control Module Command Line CPCI Compact Peripheral Component Interface Interconnect

4 CPD Common Path Distortion CTG Cradle-To-Grave CPE Customer Premises Equipment; Cus- CTN Core Transmission Network tomer Provided Equipment CTP Connection Termination Point C-Plane Control Plane CTS Clear To Send CPLD Complex Programmable Logic Device CTx Line Client Transmit Line CPM Cross-Phase Modulation CUG Closed User Group CPRM Content Protection for Recordable CV Code Violation Media CV-FE Code violation - Far End CPT Channel Pass-Through CV-L Code Violation - Line CPTTAG Connection Termination Point Tag CV-P Code Violation - Path CPU CV-PFE Code Violation - Path Far End CR Circuit Reliability; Carriage Return; Critical Alarm CV-S, CVS Code Violation - Section; Code Violation -- Seconds CRC Cyclic Redundancy Check CW Clockwise; Continuous Wave CRG Circuit Restoration Group CR-LDP Constraint-based Routing Label Distribution Protocol D CRS Cross Connect D&C Drop and Continue CRT Cathode Ray Tube D/A Digital-to-Analog CRx Line Client Receive Line D/I Drop and Insert CS Control Sub-span; Convergence DAC Digital to Analog Converter; Digital Sublayer; CoreStream Addressable Controller CSA Canadian Standards Association DACS Digital Access and Cross-Connect System CSC Command Signal and Control DAD Direct Access Device CSD Core Switching Division DADM Data Add/Drop Multiplexer CSES Consecutive Severely Errored Seconds DARPA Defense Advanced Research Projects Csh C Agency (US) CSH Common Signal DAS Direct Attached Storage CSI Convergence Sublayer Indicator DATE Duly Authorised Telecommunications CSM Core Switching Manager Entity C-SMF Conventional Single Mode Fiber dB decibel CSO Composite Second Order DB Database CSP Customer Service Profile DB-9 Data Bus 9 Pin Connector CSR Customer Service Representative DBA Database Administrator CS-RZ Carrier-Suppressed Return-to-Zero dBc Decibel referenced to the carrier CST Central Standard Time dBm Decibel reference to milliwatts CSU Channel Service Unit; Customer Service DBMS Database Management System Unit DBPSK Differential Binary Phase Shift Keying CSV Comma-Separated Value DBS Direct Broadcast Satellite CT Critical dBW Decibels referenced to Watts CTAM Cable & Telecommunications DC Direct Current; Data Connection Association for Marketing DCC Data Communications Channel CTB Composite Triple Beat DCE Data Communications Equipment; CTC Common Transmit Clock Data Circuit Terminating Equipment CTD Cell Transfer Delay DCF Dispersion-Compensating Fiber

5 DCG Dispersion Compensation Grating DMACS Distributed Monitoring and Control DCM Dispersion Compensation Module System DCME Digital Compressed Multiplication DMB Digital Multipoint Bridge; Document Equipment Maintenance Bulletin DCMS Digital Circuit Multiplication System DMC Dual Modem Cards DCN Data Communication Network DMH Degraded Modem Hours DCOM Distributed Component Object Model DMM Digital Multi-Meter DCP Digital Communications Protocol; DMOP Detailed Method of Procedure Device Control Protocol DMS Dispersion-managed Solution DCS Digital Cross-connect System; Digital DMUX [Optical] Demultiplexer Connection System DNCS Digital Network Control System DCS 1800 Digital Cellular System, GSM variant at DNR Do Not Revert 1800 MHz DNS Domain Name Server; Domain Name DCU Dial up Data Channel Unit System DDI Direct Dialing Inward DOCSIS Data-Over-Cable Service Interface DDS Digital Data Storage; Digital Data Specifications Service; Digital Data System; Digital DOD Department of Defense Data Stream DOS Disk DE Discard Eligible DoS Denial of Service DEC Digital Electrical Carrier DP Distribution Point; Data Processing DECT Digital European Cordless Telephone/ Telecommunication DPDT Double-Pole, Double-Throw DEG Degraded Signal DPFI Data Plane Fault Isolation DEMUX Demultiplexer DPI Digital Program Insertion; Dots Per Inch DENI Digital Entertainment Networking DPR Dedicated Initiative DPRAM Dual Port Random Access Memory DENY Transaction Denier DPT Dynamic Packet Transport DFB Distributed Feedback DQ Degraded Quality Level DG Disc Group DQDB Distributed Queue Dual Bus DGD Differential Group Delay DQoS Direct Memory Access DHCP Dynamic Host Configuration Protocol DQPSK Differential Quadrature Phase Shift DHWG Digital Home Working Group Keying DID Direct Inward Dialer DR Disaster Recovery DiffServ Differentiated Services DRAM Dynamic Random Access Memory DIO Digital Input/Output DRM Digital Rights Management DIP Dual In-line Package (switch) DS Digital Signal; Downstream DIR Direction DS0 Digital Service, Level 0, 64kbps Div Division DS1 Digital Service, Level 1, 1.544 Mb/s ;Digital Signal Level DLC Digital Loop Carrier DS3 Digital Signal Level 3 (T3 equivalent) DLCI Data Link Connection Identifier DSCP Differentiated Service Code Point DLL Dynamic Link Library; Data Lind Layer (driver); Downline Load DSCRDS Discard Count DLT Digital Linear Tape Drives DSF Dispersion Shifted Fiber DM Degraded Minute; Dispersion DSI Digital Speech Interpolation Mitigation DSL Digital Subscriber Line; Digital DMA Direct Memory Access Subscriber Loop

6 DSLAM Digital Subscriber Line Access E1 European Equivalent of T1 (2.048 Mb/s Multiplexer signal speed) DS-n Digital Signal, level n E2E End To End DSP Digital Signal Processor E2PROM Electrically Erasable Programmable DSS Direct Satellite Services Read Only Memory DSS2 Digital Subscriber Signaling 2 E3 European data signal at a rate of 34.368 Mb/s DSTB Digital Set-top Box EAI Enterprise Application Integration DSX Digital Side Interface EAL Events, Alarms, and Logging DS-x Digital Signal where N denotes multiple of 51.84 Mb/s EAP Extensible Authentication Protocol DSX-1 Digital Signal Level 1 Cross Connect EAS Emergency Alert System DSX-3 Digital Signal Level 3 Cross Connect EB Error Block; Eastbound DT Decision Technology; Direct Termina- Eb/No Energy per Bit to Noise ratio tion EC Enhanced Capacity ; European DTCP Digital Transmission Content Protection Commission DTE Data Terminal Equipment EC-1 Electrical Carrier Level 1 (STS1 Equivalent) DTH Direct-to-Home, usually satellite television broadcasting ECC Edge Card Control; Embedded Communications Channel DTL Designated Transit List ECI Equipment Catalog Item DTMF Dual Tone Multiple Frequency ECLR Egress Cell Loss Ratio DTS Dynamic Transport System ECn Electrical Carrier, level n; 0=64 kb/s, DTV Digital Television 2=6,312 Mb/s, 3=44,736 Mb/s DUART Dual Universal Asynchronous Receiver ECN Engineering Change Notice Transmitter ECO Engineering Change Order DUP Data User Part ECTRA European Committee for DUS Don’t Use Synchronization Telecommunications Regulatory Affairs DV Digital ED Equipment Degrade DVB-ASI Digital Video Broadcast Asynchronous EDF Erbium-Doped Fiber Serial Interface EDFA Erbium-Doped Fiber Amplifier DVC Dynamic Virtual Concatenation EDI Electronic Data Interchange DVD Digital Versatile Disc eDOCSIS Embedded Data-Over-Cable Service DVD+R Recordable Digital Versatile Disc Interface Specifications DVD+RW Rewritable Digital Versatile Disc EEE Electronic Equipment Enclosure DVI Display Visual Interface EEPROM Electrically Erasable Programmable DVM Digital Voltmeter Read Only Memory DVOW Digital Voice Orderwire EF Equipment Failure DVR Digital Video Recorder EF&I Engineer, Furnish and Install DW Datawire EFCI Explicit Forward Congestion Indication DWDM Dense Wavelength Division EFD Event Forwarding Discriminator Multiplexing EFP Equipment Fault Protection DXC Digital Cross-Connect EH Environmentally Hardened DXI Data Exchange Interface EIA Electronic Industries Alliance; Electronic Industries Association E EID Equipment Identifier E&M Ear & Mouth EIDE Enhanced Integrated Drive Electronics

7 EII European Information Infrastructure EQPT Equipment EIR Excess Information Rate ER Extended Reach EIRP Effective Isotropic Radiated Power; ERDI Enhanced Remote Defect Indicator Equivalent Isotropic Radiated Power EREI-P Enhanced Path Remote Error Indication EJB Enterprise Java Beans Errcde Error Code ELAN Emulated Local Area Network ES Errored Second ELR Extra Long Reach ESA EDFA Saturation Algorithm; End Sys- EM Element Manager tem Address EMBS Egress Maximum Burst Size ESCBND ESCON Bundle EMC ElectroMagnetic Compatibility ESCON Enterprise Systems Connection EMD Extended Management Domain ESCR Egress Sustainable Cell Rate EMEA Europe, Middle East and Africa ESD Electrostatic Discharge EMG Extended Management Gateway ESDS Electrostatic Discharge Sensitive EMI Electromagnetic Interference ESF Extended Super Frame; Extended EML Element Management Layer; Superframe Format Electro-Absorptive Modulated Laser ES-FE Errored Seconds - Far End EMP Expiring Maintenance ESI End System Identifier EMS Element Management System ES-IS End System to Intermediate System EMT Expiring Maintenance Tool ES-L Errored Seconds - Line eMTA Embedded Multimedia Terminal ES-LFE Errored Second-Line Far End Adapter ESMOP Electronic Service Method of Procedure EMX ESCON MUX ES-MS Errored Seconds at the Mulitplexor END Extended Management Domain Section ENE End Network Element ESN Extended Subnetwork ENUT Enhanced Non-preemptable ES-P Errored Seconds - Path Unprotected Traffic ES-PFE Errored Seconds - Path Far End EO Equipment Order ESR Errored Second Ratio EOC Embedded Operations Channel ES-RS Errored Second Regenerator Section EoD Everything on Demand ES-S Errored Seconds - Section EOF End of Frame EST Eastern Standard Time EOL End of Life ES-V Errored Second-Virtual Tributary (VT) EOM End of Message Path; Errored Second-VT Path Far End EoS Ethernet over SONET/SDH ESx Errored Second Count EOW Engineered Orderwire; Express ET End Terminal Orderwire Etag Ending Tag EPA Environmental Protection Agency ETH 10/100 Ethernet EPCR Egress Peak Cell Rate ETHBND Ethernet Bundle EPD Early Packet Discard ETLMI ESCON Trib Laser Manager Interface EPG Equipment Protection Group ETR External Timing Reference EPL Ethernet Private Line ETSI European Telecommunications EPLD Erasable Programmable Logic Device Standards Institute E-PON Ethernet Passive Optical Network EU European Union EPR Engineering Progress Report EVC Ethernet Virtual Circuit EPROM Erasable Programmable Read Only EVM Error Vector Magnitude Memory EVPL Ethernet Virtual Private Line

8 EVPLAN Ethernet Virtual Private Local Area FDL Facilities Data Link Network FDM Frequency Division Multiplexing; Fast EWO Engineering Work Order Ethernet ; Frequency Division EXER-R Exercise - Ring Modulation EXER-S Exercise - Span (SONET) FDMA Frequency Division Multiple Access EXP Experimental FDP Fiber Distribution Panel EXZ Excessive Zone FDRP Frame Drop FE Far End; ; Forward Error Correction F FEAC Far End Alarm Channel F Fahrenheit FEACT Far-End Terminal Alarm Condition F&I Furnish and Install FEALM Far-End Alarm FA, F/A Fuse Alarm; Fault Alarm FEB Fast Ethernet Bridging FAB Field Alert Bulletin FEBE Far End Block Error FAD Functional Access Domain FEC Forward Error Correction; Forwarding FAF Facility Failure Equivalence Class FAT Factory Acceptance Test FECN Forward Explicit Congestion FC Failure Code; Failure Count; Fiber Notification Channel; Fibre Channel FECS Forward Error Correction Seconds FC Switch Fibre Channel Switch FEDS FICON Extended Storage over FC100 Fibre Channel 1 Gb/s Distance FC10000 Fibre Channel 10 Gb/s (same as FEP Front End Processor; Far End 10GFC) Protection FC200 Fibre Channel 2 Gb/s FEPLF Far End Protection Line Failure FC400 Fibre Channel 4 Gb/s FEPM Far End Performance Monitor FCAPS Fault, Configuration, Accounting, FERF Far End Receive Failure Performance (or Provisioning), Security FET Field-Effect Transistor management FF Fast Forward FCC Federal Communications Commission FFA First Field Application FC-FE Failure Count - Far End FFP Facility Fault Protection FCIP Fibre Channel over Internet Protocol FFT Fast Fourier Transform FC-L Failure Count - Line FIB Forwarding Information Base FC-LFE Failure Count - Line Far End FIC Frame Identification Code FCM Fan Control Module FICON Fiber Connection FCP Fibre Channel Protocol FIL Fiber in the Loop FC-P Failure Count - Path FIT Failure in Time FC-PFE Failure Count - Path Far End FITB Fiber in the Building FCS Frame Check Sequence; Fibre Channel FITL Fiber in the Loop Standard FITR Fiber in the Riser FCS32 Count of FCS-32 Error FLAG Fiber Link Around the Globe FC-V Failure Count - VT FM Fan Module; Fault Management; FC-VFE Failure Count - VT Far End Forwarding Module; Frequency Modulation FDD Frequency Division Duplexed FMA Failure Modes Analysis FDDI Fiber Distributed Data Interface FMECA Failure Mode and Effects and Criticality FDF Fiber Distributing Frame Analyses

9 FMS Fault Management System FSB Field Service Bulletin FNCS Foreign National Control System FSO Free Space Optical FO Fiber Optics FS-P Forced Switch - Protection FOADM Fixed Optical Add/Drop Multiplexer; FS-R Forced Switch - Ring Flexible Optical Add/Drop Multiplexer FSS Fixed Satellite Service FOB Free On Board FS-S Forced Switch - Span FOC Final Operating Configuration FS-W Forced Switch - Working FOD Free on Demand FT France Telecom FOS Follow on Satellite, Intelsat designation FT1 Fractional T1 FOSC Fiber Optic Splice Course GT Gain Transfer; Grating Temperature FOTS Fiber Optic Transmission System FTA Fault Tree Analysis FOW Forward OrderWire FTAM File Transfer and Access Management FP Fabry-Perot (type of laser); Frame FTC Fabric and Timing Card Pulse (NEC) FTM Fabric Timing Module FPG Facility Protection Group FTP File Transfer Protocol FPGA Field Programmable Gate Array FTTB Fiber to the Building; Fiber to the FPLMTS Future Public Land Mobile Business Telecommunications Systems FTTC Fibre to the Curb (Kerb), linked to VDSL FPM Fan Power Module in deployment FPP Fast Pattern Processor FTTD Fiber to the Desk FPS Frames per Second FTTH Fiber to the Home FR Frame Relay FTTP Fiber to the Premise; Maintenance FRAD Frame Relay Access Device Channel Transparent Termination Point FRC Force FTTx Fiber to the [endpoint] FRD Functional Requirements Document; FUNI Frame-based User-Network Interface Feature Requirements Definition FW Firmware; FREQ Frequency FWHM Full Width at Half Maximum FRF Frame Relay Forum FWM Four-Wave Mixing FRF.12 Frame Relay Forum Implementation FXO Foreign Exchange Office Agreement 12 FXS Foreign Exchange Service FRF.13 Frame Relay Forum Implementation Agreement 13 FRF.5 Frame Relay Forum Implementation G Agreement 5 G/T Gain to System Noise Temperature FRF.8.1 Frame Relay Forum Implementation Ratio Agreement 8.1 GA General Availability FRG Fragment Count Gb Gigabit FRM Forward Resource Management; Frame GB Gigabyte Count GbE Gigabit Ethernet FRMS Dropped Frames GbE VFTP Gigabit Ethernet Virtual Facility FRS Frame Relay Service Termination Point FRU Field Replacement Unit GbE WAN Gigabit Ethernet Wide Area Network FS File System GbE WIF Gigabit Ethernet Wide Area Network FSA Field Service Application Interface FSAN Full Services Access Network GBIC Gigabit Interface Converter (consortium) Gbit Gigabit

10 Gbps, Gbits Gigabits per second GRTES General Requirements for Transmission Gbytes/s Gigabytes per second Equipment Specification GC Gateway Controller GSM Global System for Mobile communications, originally: Groupe GCAC Generic Connection Admission Control Spéciale Mobile GCC0 General Communications Channel 0 GSO Geostationary Earth Orbit (similar to SDH/SONET DCC) GT Gain Transfer; Grating Temperature GCIT Graphical Craft Interface Terminal GTF Global Traffic Forecast (Intelsat) GCM General Control Module GTM Global Traffic Meeting (Intelsat) GCRA Generic Cell Rate Algorithm GTP Group Termination Point GDMO Guidelines for the Definition of Managed Objects GTS General TeleSystems Group GE Gigabit Ethernet; Greater than or GUI Graphical equal to ; GW Gateway Corporation GWC Gateway Controller GEB Gigabit Ethernet Bridge GEO Geostationary Earth Orbit H GESS General Electric Satellite Services HA High Availability GET Gigabit Ethernet Tunneling HCSFI High-speed Central Switch Fabric GFA Gain Flattened Amplifier Interface GFC Generic Flow Control HD High Definition GFF Gain Flattening Filter (used in EDFA) HDB3 High Density Bipolar 3 GFP Generic Framing Procedure HDCP High-bandwidth Digital Content Pro- GFR Guaranteed tection GHz Gigahertz (Billion hertz) HDLC High-speed/level Data Link Control GigE Gigabit Ethernet HDMI High Definition Multimedia Interface GII Global Information Infrastructure HD-SDI High Definition Serial Digital Interface GMDSS Global Maritime Distress and Safety HDSF High-speed Distributed Switch Fabric System HDSL High-speed Digital Subscriber Line GMPLS Generalized Multi-Protocol Label HDT Host Digital Terminal Switching HDTV High Definition Television GMT Greenwich Mean Time; Grasshoppers HE Headend Made for Telecommunications (GMT fuses) HEC Header Error Control; Headend Controller GN Gateway Network Element HEM Headend Modem GND Ground HEPA High Efficiency Particulate Arrester GNE Gateway Network Element HFC Hybrid Fiber Coax GOS Grade of Service HFM High-speed Forwarding Module GP Gateway Platform HGW Home Gateway GPI General Purpose Input HHP Households Passed GPIN General Purpose Input HI Hardware/Software Interface; GPO General Purpose Output Hardware-Software Integration; G-PON Gigabit Passive Optical Network High Speed Internet GPS Global Positioning System; Global HISSA High Speed Serial Application Specific Positioning Satellite Integrated Circuit (ASIC) GR Generic Requirement; Geographic HMS Hybrid Management Sub-layer Redundancy HNv1 Home Networking Version 1 GRDM Gigabit Rate Data Multiplexer 11 HO Higher Order ICB Independent Customer Builds HOD HBO on Demand ICD International Code Designator HO-DSP High Order-Domain Specific Part ICLR Ingress Cell Loss Ratio HO-DXC Higher Order Digital Cross Connect ICMP Internet Control Message Protocol HOM High-Order Modulation ICNV Input- Command Not Valid HomePNA Home Phoneline Networking Alliance ICP IMA Control Protocol HOP High Order Path ICPT Installed Circuit Pack Type HO-POH Higher Order - Path Overhead ICR Initial Cell Rate HOVC Higher Order Virtual Concatenation ID Identifier; Identification HP Hairpin; Higher Order Path; Homes IDB International Development Bank Passed IDE Integrated Device Electronics HPA High Power Amplifier IDF Intermediate Distribution Frame; HPF High Pass Filter Invalid Data Flag HPNA Home Phoneline Networking Alliance IDH Identification High byte HPOV Hewlett Packard Open View IDI Initial Domain Identifier HPPI High Performance Parallel Interface IDL Interactive Distance Learning; HP-UX Hewlett Packard’s UNIX-based OS that Interface Definition Language runs on HP’s enterprise servers IDNV Input, Data Not Valid HRD Hardware Release Document; Hard- IDP Initial Domain Part ware Requirements Document IDR Intermediate Data Rate HS High Speed IDS Intrusion Detection System HSB High Speed Bus IDT Inter-DXC Trunk HSD High Speed Data IDU Indoor Unit HSSI High Speed Serial Interface IE Information Element HT High Threshold IEC Incoming Error Count; HTML Hyper Text Markup Language InterExchange Carrier HTTP Hypertext Transfer Protocol IEEE Institute for Electrical and HVAC Heating, Ventilation, and Electronics Engineers Air-Conditioning IETF Internet Engineering Task Force HVS Hospitality Voice Services IF Intermediate Frequency HW Hardware IFC Initial First Cost Hz Hertz IG Information Group IGMP Internet Group Multicast Protocol I IIAC Input - Invalid Access Identifier I/B Inbound/Outroute (also known as IIOP CORBA Internet Inter-ORB Protocol the return link), from remote IISP Interim Interface Signaling Protocol terminal to hub ILA Intermediate Light Amplification; I/O Input/Output Integrated Line Amplifier; In-Line IAD Integrated Access Device; Interface Amplifier Access Device ILEC Incumbent Local Exchange Carrier IAS Internet Access Service; Internet ILM Integrated Laser Module; Authentication Service Integrated Laser Modulator IBCC In-Band Communication Channel ILMI Interim Link Management Interface; IBS Intelsat Business Service Interim Local Management IBT International Business Traveller Interface IC Integrated Circuit ILOG Information Log; Incoming Log

12 ILR Issues List Report IR Intermediate Reach IM Instant Messaging IRD Integrated Receiver/Decoder IMA Inverse Multiplexing over ATM IRT Integrated Receiver/Transcoder IMBS Ingress Maximum Burst Size IS In Service; Intermediate System IMD Intermodulation Distortion ISA Industry Standard Architecture IME Interface Management Entity IS-ANR In Service - Abnormal IMT Inter Machine Trunk IS-ANRST In Service - Abnormal and IN Intelligent Network Restricted INAP Intelligent Network Application Part ISCC InterSwitch Communications Protocol Channel I-NET Institutional Network ISCR Ingress Sustainable Cell Rate INM Integrated Network Manager iSCSI Internet Small Computer System Interface; SCSI Protocol over Inroute see I/B TCP/IP INT Internal; Internal Clock ISD Idle Signal Detection INTAP Interoperability Technology ISDN Integrated Services Digital Network Association for information Processing IS-IS Intermediate System to Intermediate System INTP Internodal Tunneling Protocol ISM Industrial Scientific Medical IntServ Integrated Services IS-NR In Service - Normal INVW Invalid Word Count ISO International Standards IOA Input/Output Adapter Organization IOC Initial Operating Configuration ISOC the Internet Society IOF Inter-office Fiber ISP Internet Service Provider; Inside IOR Interoperable Object Reference Plant ;Indian Ocean Region IS-RST In Service - Restricted IP Intelligent Peripheral, IN block; ISTP Internet Signaling Transport Internet Protocol Protocol IPC Inter-process Communications; ISV Independent Software Vendor InterProcess or InterProcesser Control IT Information Technology IPCR Ingress Peak Cell Rate ITA Installation, Test, and Acceptance IPCU DAMA IP Channel Unit ITC Independent Transmit Clock IPG Inter-Packet Gap ITE Information Technology Equipment IPM Interested Party Multicast ITL International Telecommunications Union IPMI Internet Protocol Multicasting Initiative ITS Intelligent Transportation System; Institute for Telecommunications IPMS Interested Party Multicast Service Sciences IPOA Internet Protocol over ATM ITT International Telephone and Telegraph IPPV Impulse Pay per View ITU International Telecommunication Union IPR Intellectual Property Rights ITU-T ITU Telecommunications standards IPsec Internet Protocol Security body IPSL Integrated IP Software License IUC Interval Usage Code IPTA Internet Protocol Transport IVPN International VPN Agreement IWF Interworking Function IPTV IP Television IXC Inter-exchange Carrier IPX Internet Package Exchange

13 J LAC Local Access Concentrator J0 J Zero LADM Linear Add/Drop Multiplexer J2EE Java 2 Enterprise Edition LAN Local Area Network JBR Jabber Count LANE Local Area Network Emulation JDBC Java Database Connectivity LAP Link Access Procedure; Link Access Protocol JDK Java Development Kit LAPB Link Access Procedure Balanced JDMK Java Dynamic Management Kit LAPD Link Access Procedure-D Channel JDS-HR Japan Digital Services - Half Rate (X 25) JEM JAVA™ Element Manager LAPF Link Access Procedure for Frame-Mode JMS JAVA™ Messaging System Bearer Services JNDI Java Naming and Directory Interface LAPS Link Access Procedure JPEG Joint Photographic Experts Group LASER Light Amplification by Stimulated JRE Java Runtime Environment Emission of Radiation JTAG Joint Test Action Group LATA Local Access and Transport Area JVM Java Virtual Machine LATM Local ATM LBC Laser Bias Current K LBCL Laser Bias Current Level k kilo (thousand) LBCN Normalized Laser Bias Current K1 SONET or SDH overhead byte of MSP/ LBO Line Build Out MS-SPRing (see K2) LC Lucent Connector; Line Card K2 Used with K1-SONET or SDH overhead LCAP Local Craft Access Panel byte for MSP/MS-SPRing LCAS Link Capacity Adjustment Scheme Kb Kilobit LCC Life-Cycle cost; Link Control Channel KB Kilobyte LCD Liquid Crystal Display Kb/s Kilobits per second LCL Lower Confidence Limit KB/s Kilobytes per second LCN Local ; Kbit/s Kilobits per second Logical Channel Number; Kbps Kilobits per second Local Communications Network KBps Kilobytes per second LCR Least Cost Routing kBPS kilo Bits Per Second LCT Large Capacity Terminal kft Kilofeet (USA cable length LD Laser Diode measurement) LDAP Lightweight Directory Access Protocol kHz kilohertz (thousand hertz) LDCC Line Data Communications Channel Km Kilometer LDCELP Low Delay CELP Ksh Korn Shell LDP Label Distribution Protocol ksym/s Kilosymbols per Second LDS Local Digital Switch ksym/sec Kilosymbols per Second LEAF Large Effective Area Fiber kVA 1000 Volt Amperes LEC Local Exchange Carrier kW Kilowatt LECS LAN Emulation Configuration Server LED Light Emitting Diode L LEO Low Earth Orbit L2TP Layer 2 Tunneling Protocol LER Label Edge Router L3 Layer 3 LES LAN Emulation Server LA Line Adapter; Latin America LF Line Fail

14 LFE Line Far End LRDC Long Reach Daughter Card LGN Logical Group Node LSA Low Speed ADM LGX Light-Guide Crossconnects LSB Least Significant Bit LH Logical Host LSF Loss of Signal or Frame indication LIC Line Interface Card signal LIF Line Interface LSL Lower Specification Limit LIM Line Interface Module LSM Loss of Sync Message LIP Local Information Packet LSN Logical Subnetwork LIU Line Interface Unit LSP Label Switched Path; Local Service Provider LLC Logical Link Control LSR Label Switch Router LLSDCC Lower-Layer Section DCC LSSGR LATA Switching System Generic LM Line Module Requirements LMDS Local Multipoint Distribution Service LT Low Threshold; Laser Temperature LMI Local Management Interface LTE Line Terminating Equipment; Long LMP Link Management Protocol Terminal Evolution LNA Low Noise Amplifier LTN Local Transport Network (fiber ring) LNB Low Noise Block LTP Link Termination Point; Logical LO Low Order Termination Point LOADM Lightweight Optical Add/Drop LTS Loop Testing System; Long Term Multiplexer Storage LOC Loss of Clock LU Line Unit Locn Location LVD Low-Voltage Distribution LO-DXC Low Order Digital Cross Connect LWP Low Water Peak LOF Loss of Frame LZS Lempel Ziv Stac LOF-P Path Loss of Frame LOH Line Overhead M LOM Loss of Multiframe; List of Materials M&C Monitor and Control LOP Loss of Pointer M12 MUX DS-1 into DS2 LOPDP Loss of Pointer Decay Period M13 MUX DS-1 into DS3 LOPI Loss of Pointer Inhibit M23 MUX DS-2 into DS3 LOPIP Loss of Pointer Integration Period MAC Media Access Control; LOP-P Loss of Pointer - Path MAN Metropolitan Area Network LOP-V VT Loss of Pointer MAP Main Audio Program; Mobile LOS Loss of Signal Application Part Protocol LOSS Loss of Signal Seconds MAU Media Access Unit LOVC Low-Order VC Mb Megabit LOW Local Orderwire MB Megabyte LP Line Processor; Lockout of Protection; Mb/s Megabits per second Low Order Path MB/s Megabytes per second Lport Logical port Mbaud Megabaud LP-S Lockout of Protection - Span Mbits/s Megabits per second LP-S/SF-P Lockout of Protection - Span/Signal Fail - Protection Mb/s Megabits per second LR Long Reach (fiber); Line Regeneration Mb/s Megabytes per second Equipment Mb/s Million Bits Per Second

15 MBS Maximum Burst Size MO Managed Object MCC Master Control Center / Computer MOD Module; Movies on Demand MCP Management Control Processor MODEM Modulator-Demodulator MCPC Multiple Channels Per Carrier Modem Modulator/Demodulator MCR Minimum Cell Rate; Minimum Cost MOF Managed Object Framework Routing MOP Method of Procedure MCS Master Control Station MOR Multi-wavelength Optical Repeater MCT Maintenance Channel Transparency MOS Mean Opinion Score MCTF Motion Compensated Temporal MP Management Portal Filtering MP3 MPEG-2 Layer 3 MDF Main Distribution Frame MPCKTS Multicast Packet Count MDU Multiple Dwelling Unit MPEG Moving Pictures Expert Group mDVR Multi-TV Digital Video Recorder MPI Multi-Path Interface; Multi-Path ME Middle East Interference MEA Mismatch of Equipment and Attributes M-Plane Management Plane MEGACO Media Gateway Control Protocol MPLmS Multi-Protocol Lambda Switching MEO Medium Earth Orbit MPLS Multi Protocol Label Switching MER Modulation Error Ratio MPLS-CP MPLS Control Plane MFR Multilink Frame Relay MPN Mode Partition Noise MG Media Gateway MPOA Multi Protocol over Asynchronous MGC Media Gateway Controller Transfer Mode MGCP Media Gateway Control Protocol MPS Multiple Priority System MGN Management Gateway Node MPT Multiplex Pass-Through MHz Megahertz (million hertz) MPT Ministry of Posts and MIB Management Information Base Telecommunications MID Message Identifier MPTS Multiple Program Transport Stream MIPS Millions of Instructions per Second MR Modification Request; Material Request; Medium Reach MIT Management Information Tree MRRB Maintenance Requirements Review MiTTs of Telecommunications Traffic Board; Material Release Review Board MJ Major ms Milliseconds ML Mediation Layer MS Multiplex Section MLMD Multiplexer/Demultiplexer MSA Mediation Services Administrator MLPPP Multi-Link Point-to-Point Protocol MS-AIS Multiplex Section - Alarm Indication mm millimeter Signal MM Multimode; Multimedia MSB Most Significant Bit MMCS Meridian Multi Media Center Switch MSC Metro Shelf Controller; Microsoft MME Multiwave Management Element Cluster Server MMF Multi-Mode Fiber MSF Multiservice Switching Forum MML Man Machine Language MSN Multi-Subnetwork MMO Main Material Order MSNM Metro Switching Network Manager MMP Multiwave Management Element MSNM ML Metro Switching Network Manager Mediation Layer MN Minor MSO Multiple System Operator MNO Mobile Network Operator MSOH Multiplexer Section Overhead MNC Multi-National Company

16 MSP Multiplex Section Protection; NASA National Aeronautical and Space Multiservice Switching Path Agency (US) MS-P Manual Switch - Protection NAT Network Address Translation MSPP Multiservice Provisioning Platform NBI Northbound Interface MSPVC Management Soft Permanent Virtual NBK No Backup Circuit NC Nodal Controller; Normally Closed MS-R Manual Switch - Ring (contacts) MS-RDI Multiplex Section - Remote Defect NCB National Computer Board Indication NCC Network Control Center/Computer MS-REI Multiplex Section Remote Error NCCC Network Control Coordination Channel Indication NCCI Network Call Correlation Identification MSS Mobile Satellite Service NCP Nodal Control Point; Nodal Control MS-S Manual Switch - Span Processor MS-Spring/MSPR NCP&D Network Capacity Planning and Multiplex Section Shared Protection Delivery Ring NCR Non-Conformance Report MST Mountain Standard Time; Multiplex Section Termination NCS Network Computing System; Network Control System; Network Call Signaling MSTE Multiplex Section Terminating Equipment NCT Network Control Terminal MS-W Manual Switch - Working NCTA National Cable & Telecommunications Association MTA Multimedia Terminal Adapter NDC National Destination Code MTBF Mean Time between Failure NDF New Data Flag MTIE Maximum Time Interval Error NDIS Network Design and Inventory System MTP Message Transfer Part NDMH Non-Degraded Modem Hours MTTP Transparent Connection Termination Point NDP Network Discovery Protocol; Neighbor Discovery Protocol MTTR Mean Time to Repair NDSF Non-Dispersion Shifted Fiber MTTU Mean Time to Understand NDVR Network Digital Video Recording MTU Maximum Transmission Unit NE Network Element MUX Multiplexer NE/FE Near End/Far End MUXCVR Muxceiver NEBS Network Equipment Building mV Millivolt Standards; Network Equipment MVOA Miniature Variable Optical Attenuator Building Systems MZ Mach-Zehnder NEC National Electric Code NEF Network Element Function N NEG Negative Terminal NA No Alarm; Not Alarmed; Not NEID Network Element Identification Applicable; Not Available; Numerical NEIR Network Element Information Request Aperture NEMA National Electrical Manufacturers NAD Network Access Domain Association NAP Network Access Point NFS Networked File System NAPT Network Address and Protocol |Transla- NGDLC Next Generation Digital Loop Carrier tion NG-L1 Next Generation Layer 1 NAS Network Access Server; Network Attached Storage NGNA Next Generation Network Architecture

17 NGSO Non-Geostationary Earth Orbit, used as NSAP Network Service Access Point a general descriptive for LEO and NSF National Science Foundation (US) MEO systems. NSI Network Side Interface NGW National Gateway NSN Nationally Significant Number NI Network Interface NSP Node Switch Provider; Node Switch NIC Network Interface Card Processor NID Network Interface Device NT Window New Technology NIDU Network Interface Data Unit NTE Network Terminating Equipment NII National Information Infrastructure NTF No Trouble Found (for the USA, see also GII and EII) NTFCNCDE Notification Codes (TL1) NIS Network Infrastructure Solutions NTFS New Technology File System NISC National Information Services Council NTP Network Time Protocol NIU Network Interface Unit NTS Near Term Storage; Network Time NLA Network Layer Address; Network Layer Synchronization Agent NTSC National Television Standards NLC Node Line Card Committee NLD Neighbor Link Discovery NUT Non-preemptive Unprotected Traffic NLPI Network Layer Protocol Identifier NVM Non-Volatile Memory nm nanometer NVRAM Nonvolatile Random Access Memory NM Network Management; Network NZDSF Non-Zero Dispersion Shifted Fiber Manager; Network Management; Node Manager NMA Network Monitoring and Analysis O NME Network Management Ethernet O&M Operations and Management NMF Node-level Management Function OA Optical Amplifier NML Network Management Layer OA&M Operations Administration and Management NMS Network Management System OADM Optical Add/Drop Multiplexer NN N key on keyboard for a no response OAM Operations, Administration and NNI Network to Network Interface; Maintenance Network Node Interface OAMCell Operations, Administration and NNIF Network to Network Interface Maintenance Cell NNM Network Node Manager OAMP Operation, Administration, NNTP Network News Transfer Protocol Maintenance and Provisioning NO Network Object; Normally Open O-BLSR Optical-Bidirectional Line Switched (contacts) Ring NOC Network Operations Center OC Optical Carrier NOCC Network Operations Control Center OC-1 Optical Carrier level 1, SONET bit rate NPC Network Parameter Control = 51.84 Mb/s NPR Noise Power Ratio OC1 Optical Carrier level 1 (51.84 Mb/s) NR No Reply OC-12 Optical Carrier level 12, SONET bit rate = 622.08 Mb/s NRT Non-Real Time OC-192 Optical Carrier level 192, SONET bit NRTL Nationally Recognized Test Laboratory rate = 9.953 Gb/s NRTVBR Non Real-Time Variable Bit Rate OC-3 Optical Carrier level 3, SONET bit rate NRZ Non-Return to Zero = 155.52 Mb/s ns Nanosecond NSA Non Service Affecting

18 OC-48 Optical Carrier level 48, SONET bit rate OMG Object Management Group = 2.488 Gb/s OMT Orthogonal Mode Transducer OCAP OpenCable Application Platform ON Optical Network OCH Optical Channel ONE Optical Network Element OCI Open Connection Indication ONP Open Network Provision OC-n Optical Carrier-number; Optical Carrier ONT Optical Network Terminal where N denotes a multiple of 51.84 Mb/s ONU Optical Network Unit OCT Octet Count OO Optical-to-Optical OCTU Optical Channel Transport Unit OOB Out of Band OCXO Oven-Controlled Crystal Oscillator OOF Out of Frame ODA Outlet Digital Adapter OOK On-Off Keying ODBMS Object Database Management System OOM1 Out of Multi Frame Stage 1 ODF Optical Distribution Frame OOM2 Out of Multi Frame Stage 2 ODPR Optically Dedicated Protection Ring OOO Optical - Optical - Optical ODU Outdoor Unit OOR Out of Range ODUk Optical channel Data Unit where k is OOS Out of Service 1 or 2 OOS-MA Out of Service-Management OEM Original Equipment Manufacturer OOS-MAANR OEO Optical-to-Electronic-to-Optical Out of Service-Management and Abnormal OEPL Optical Ethernet Private Line OpEx Operations Expenditure OEPLAN Optical Ethernet Private Local Area Network OPM Optical Performance Monitoring; Optical Power Meter OEVPL Optical Ethernet Virtual Private Line OPR Optical Power Received OEVPLAN Optical Ethernet Virtual Private Local Area Network OPS/INE Operations Provisioning System/ Intelligent Network Element OFC Open Fiber Control; Optical Fiber Communication OPT Optical Power Transmit OFDM Orthogonal Frequency Division OPTORL Optical Return Loss Multiplexing OpUk Optical channel payload Unit where k is OFS Out of Frame Second 1 or 2 OFTEL Office of Telecommunications (UK OQPSK Offset Quaternary Phase-shift Keying Regulator) ORB Object Request Broker OID Object Identifier Oribital Slot OIU Operator Interface Unit; Optical longitude position above the equator Interface Unit; Office Interface Unit at which a satellite is located OLA Optical Line Amplifier; Optical Link ORIG Original; Originating Analysis ORL Optical Return Loss OLB Optical Link Budget ORP Optical Routing Protocol OLM Optical Link Module OS Operating System OLMP Optical Link Management Protocol OSA Optical Spectrum Analyzer OLS Optical Line System OSC Optical Supervisory Channel; Optical OLT Optical Line Termination; Optical Line Service Channel Terminal OSDS Operations Systems Data Server OLTP OSRP Link Termination Point OSGI Open Services Gateway Initiative OM Optical Module OSHA Occupational Safety and Health Act OMC Operation and Maintenance Center OSI Open Systems Interconnection

19 OSM OSC Splitter Module PAD Power Attenuation Device OSMINE Operations Systems Modifications for PAMA Permanent Assignment Multiple Access the Integration of Network Elements PAN Personal Area Networking OSNR Optical Signal-to-Noise Ratio; Open PARP Proxy ARP Signal-to-Noise Ratio PAS PanAmSat OSP Optical Signaling Protocol; Outside Plant PAT Program Association Table OSPF Open Shortest Path First PAX Path Adaptation and X-Connect OSPR Optically Shared Protection Ring PB Petabyte OSRP Optical Signaling and Routing PBOR Primary-Backup Object Replication Protocols PPB-TE Provider Backbone Bridging - OSS Operations Support System Traffic Engineering OSSAN Operations Support System Access PBT Provider Backbone Transport Nodes PBX Private Branch Exchange OSS-AU Out of Service-Autonomous PC Personal Computer; Physical Contact; OSS-AUMA Out of Service-Autonomous and Processor Card Management PC Personal Computer OSS-AURST Out of Service-Autonomous and PCA Protection Channel Access Restricted PCB Printed Circuit Board OSWF On-site Work Force PCC Processor Communication Channel OTC Operations Technical Center; Optical PCCA Pacific Century Corporate Access Transport Card PCG Pacific Century Group OTDR Optical Time Domain Reflectometer PCI Peripheral Component Interconnect OTGR Operations Technology Generic PCM Requirements Pulse Code Modulation PCMCIA OTN Optical Transport Network Personal Computer Memory Card Interface Adaptor OTS Optical Transport System PCMM PacketCable Multimedia OTS RPTR OTS Repeater PCN Program Change Notice; Product OTU Optical Transport Unit Change Notice ;Personal OUI Organizationally Unique Identifier Communications Network OUNI Optical User Network Interface PCO Pre-Conditioned Order O-UPSR Optical-Unidirectional Path Switched P-Code Product Code Ring PCP Primary Cross-connection Point, street OUSM Optical Utility Services Manager cabinet/flexibility point OUSP Optical Utility Services Platform PCR Peak Cell Rate Outbound see O/B PCS Personal Communication System Outroute see O/B PDA Personal Digital Assistant OW Order Wire PDAP Power Distribution and Alarm Panel OXC Optical Cross Connect PDC Passive Dispersion Compensator PDF Portable Document Format P PDH Pleisiochronous Digital Hierarchy P2P Peer to Peer PDH Plesiochronous Digital Hierarchy P6 Pentium 6 PDI Payload Defect Indication PA Port Adapter; Pre-Amplifier PDL Polarization Dependent Loss PA Power Amplifier PDP Policy Decision Point PABX Private Automatic Branch Exchange PDU Power Distribution Unit; Protocol Data Unit

20 PEG Public, Education, Government PN Pseudo Noise; physical node PEM Processor Enhancement Module; PNC Physical Node Controller Processor Element Module PNNI Private Network-to-Network Interface; PEP Policy Enforcement Point Private Network Node Interface PESQ Perceptual Evaluation of Speech PO Purchase Order Quality POC Point Of Contact PFE Path Far End POH Path Overhead PFM Packet Forwarding Module POM Project Office Manager PFO Premium Feature Open PON Passive Optical Network PG Peer Group; Protection Group POP/PoP Point of Presence, usually referring to PGID Peer Group Identifier an Internet service provider/access PGL Peer Group Leader point PHY Physical Layer Device; Physical POR Power on Reset PIC Programmable Controller POS Packet over SONET; Positive Terminal PID Personally Identifiable Data; Protocol POST Power on Self Test Identifier; Packet Identifier; Personal POTS Plain Old Telephone Service Identification PPC Power PC PIF Packet Interface FPGA PPD Partial Packet Discard PIN Photo Intrinsic; Positive-Intrinsic PPJC Positive Pointer Justification Count Negative; Personal Identification Number PPL Point-to-Point Link PING Packet Internet Groper PPM Parts per Minute; Parts per Million; Pulses per Million PIP Plug-In Provisioning Pport Physical port PJ Pointer Justification PPP Point-to-Point Protocol PL Packet Loss PPS Path Protection Switched; Pulses per PLC Packet Loss Concealment Second PLCN Pilot Line Change Notification PPT Power Passing Tap PLCP Physical Layer Convergence Protocol PRB Project Review Board PLD Programmable Logic Device PRBS Pseudo Random Bit Sequence PLDT Philippines Long Distance Telephone PRC Primary Reference Clock Company PRI Primary Rate Interface PLL Phase Locked Loop PRNG Pseudo Random Number Generators PLM Payload Label Mismatch PROM Programmable Read Only Memory PLM-P Payload Label Mismatch - Path PROT Protocol; Protection PLM-V Payload Label Mismatch - VT PRS Primary Reference Source PLN PNNI Logical Node PS Power Supply; Policy Server PLO Path Layer Overhead ps/nm-km Pico-second PM Performance Management; Performance Monitoring; Program PSA PacketCable Service Agreement Manager; Project Manager PSBF Protection Switching Byte Failure PMA Power Management Algorithm PSC Protection Switching Count; Project PMBB Performance Monitoring Building Block Steering Committee PMD Polarization Mode Dispersion PSD Protection Switching Duration PMDC PMD Compensator PSEL Presentation Suite PMM Power Management Module PSI Program Specific Information PMO Program Management Office PSL Path Signal Label

21 PSM Persistent Stored Module R/W Read/Write PSN Packet Switch Node; Packet Switched RADIUS Remote Authentication Dial-In User Network Service P-SNC Permanent SNC RAI Remote Alarm Indication PSQM Perceptual Speech Quality RAID Redundant Array of Inexpensive Disk; Measurement Redundant Array of Independent Disk PSR Protection Side Regeneration; Path RAIG Resource Availability Information Group Switched Ring RAITN Regional Arab Information Technology PST Primary State; Pacific Standard Time Network PSTN Public Switched Telephone Network RAM Random Access Memory PSU Power Supply Unit; Packet Switch Unit RAN Regional Area Network; Radio Access PT Pass-Through; Payload Type Network PTE Path Terminating Equipment RASCOM Regional African Satellite Communications Organisation PTI Payload Type Indicator RBF Reconfigurable Blocking Filter PTO Private Telecommunications Operator RBM Regional Business Manager PTP Physical Termination Point; Point-To-Point; Path Termination Point RBOC Regional Bell Operating Company PTS Per Trunk Signaling RBW Resolution Bandwidth PTSE PNNI Topology State Element RCC Routing Control Channel PTSP PNNI Topology State Packet RCV Receiver PTT Posts, Telegraph and Telephone RCVR Receiver company (usually a government RDF Rate Decrease Factor monopoly operator) RDI Remote Defect Indication PV Protocol Violation RDI-L Remote Defect Indication - Line PVC Permanent Virtual Circuit; Poly Vinyl RDI-P Remote Defect Indication - Path Chloride; Private Virtual Circuit RED Random Early Detection; Random Early PVR Personal Video Recorder Discard PWB Printed Wire Board REF Reference PWM Pulse Width Modulation REI Remote Error Indication PWR Power REI-L Remote Error Indication - Line REI-P Remote Error Indication - Path Q Rev. Revision Q3 Telecommunications Management RF Radio Frequency Network (TMN) Interface RFC Request for Comment QAM Quadrature Amplitude Modulation RFFP Request For Final Proposals QL Quality Level RFI Radio Frequency Interference; QMC QUICC Multichannel Controller Remote Failure Indication; QoS Quality of Service Request for Information QPM Quarterly Progress Meeting RFI-L Remote Failure Indication QPR Quarterly Progress Report (detected at the line-layer) QPSK Quadrature Phase Shift Keying RFI-P Remote Failure Indication (detected at the path-layer) QUICC Quad Integrated Communications Con- troller RFP Request for Proposal R RFT Radio Frequency Transmitter used to describe large antennas with associated R&D Research and Development; receive/transmit equipment Research and Design RG Residential Gateway R.H. Relative Humidity 22 RHC Regional Holding Company RTP Routing Table Protocol; RIB Routing Information Base Real-Time Transport Protocol; Routine Task Procedure RIN Relative Intensity Noise RTPS Real Time Streaming Protocol RIP Routing Information Protocol RTRV Retrieve RJ Registered Jack RTS Ready to Send; RJ-11 Registered Jack –11 Request to Send; RKS Record Keeping Server Real Time Operation System RMA Return Material Authorization; Replace RTSP Real Time Streaming Protocol Material Authorization RTT Round-trip Time RMAN Recovery Manager RTU Right to Use RMI Remote Method Invocation RTVBR Real-Time Variable Bit Rate Traffic RMS Root Mean Square RU Rack Unit RNR Not Ready to Receive; Remote Failure RW Rewind Indication RWA Routing and Wavelength Assignment ROADM Re-configurable Optical Add/Drop Multiplexer RX Receive ROC Regional Operations Center Rx Line Receive Line ROI Return on Investment RZ Return to Zero ROM Read Only Memory RZ-DPSK Return to Zero Differential Phase Shift Keying ROW Return OrderWire S RPM Revolutions per Minute s Second RPR Resilient Packet Ring s.f. Square Foot RR Ready to Receive; Reverse Request S/IMP Signal to Impulse Ratio RRB Reliability Review Board S/N Signal to Noise Ratio RRO Record Route Object SA Service-Affecting RR-R Reverse Request - Ring SAAL Signaling ATM Adaptation Layer RR-S Reverse Request - Span SABLIME Product Administration System (AT&T) RS Regenerator Section; Reed-Solomon SAN Storage Area Network RS232 Recommended Standard –232 SAP Secondary Audio Program RS-E Ring Switch - East SAR Segmentation and Reassembly RSOH Regenerator Section Overhead SARP Switching Address Resolution Protocol RSP Route Switch Processor SAS Severely Errored Frame and AIS RSTP Resilient Seconds RST Regenerator Section Terminating SAAS Software As A Service RSVP Resource Reservation Protocol SASE Standalone Synchronization RSVP-TE Resource Reservation Protocol with SATA Serial AT Attachment Traffic Engineering SATCOM Satellite Communications Satellite R/W Read/Write Capacity RS-W Ring Switch - West SATT Synchronization, Alarms, and RT Remote Terminal; Real Time Telemetry Termination RTC Real-Time Clock SAW Surface Acoustic Wave RTI Real-Time Ingest S-band frequency band RTN Return (voltage return) SBLK Errored Superblocks RTO Recovery Time Objective SBS Stimulated Brillouin Scattering RTOS Real-Time Operating System

23 SBV Switched Broadcast Video SDTV Standard Definition Television SBW Signal Bandwidth SDU Service Data Unit SC Service Channel; Square Connector; SE Systems Engineer Shelf Controller SEAL Simple and Efficient Adaptation Layer SCADA Supervisory Control and Data SEC Secondary Acquisition SEF Severely Errored Framing SCC Serial Communications Controller; Serial Communications Channels SEFS Severely Errored Frame Seconds SCCI Small Computer System Interface SEFS-S Severely Errored Framing Seconds - Section SCCP Signalling Connection Control Part, part of SS7 SEM Service Entitlement Manager S-CDMA Synchronous Code Division Multiple SEMS Severely Errored Multi-frame Seconds Access SerDes Serializer/DeSerializer SCE Service Creation Environment, IN block SES Severely Errored Seconds SCEP Service Creation Environment Point, IN SES-L Severely Errored Seconds - Line block SES-LFE Severely Errored Seconds - SCF Service Control Function, IN block Line Far End SCM Service Channel Modem; Sub-carrier SES-P Severely Errored Seconds - Path Multiplexing SES-PFE Severely Errored Seconds - SCN Service Channel Network; Shared Path Far End Content Network SESR Severely Errored Second Ratio SCP Service Control Point, IN block SES-RS Severely Errored Seconds - SCPC Single Channel per Carrier Regenerator Section SCR Sustainable Cell Rate; Silicon Con- SES-S Severely Errored Seconds - Section trolled Rectifier SES-V Severely Errored Seconds - VT SCSI Small Computer System Interface SES-VFE Severely Errored Seconds - VT Far End SCTE Society of Cable Telecommunications SETS Synchronous Equipment Timing Source Engineers SF Signal Failure; Super Frame SD Signal Degrade; Signal Detect; SFD Standard Definition Start of Frame Delimiter SFF SDA System Design Authority Small Form Factor (connector) SFO SDCC Section Data Communications Channel Sync Frequency Offset SFP SDF Service Data Function, IN block Small Form-factor Pluggable SF-R SDH Synchronous Digital Hierarchy Signal Failure - Ring SF-S SDI Secure Digital Interface; Serial Digital Signal Failure - Span Interface SG Signaling Gateway SDL Synchronous Data Link; Synchronous SGC Signaling Gateway Controller Delay Line sh Bourne Shell SDLC Synchronous Data Link Control SHx Shelf Number SDMA Space Domain Multiple Access SI Serial Interface; Service Independent ; SDMH Severely Degraded Modem Hours System Integrator SDP Service Data Point, IN block SIB Service Independent Building Block, SD-P Signal Degrade - Path IN block SIC SD-R Signal Degrade - Ring System Integrity Control; Standard Industrial Classification SDRAM Synchronized Dynamic Random Access SID Memory System Identification number; Source Identifier SD-S Signal Degrade-Span

24 SIF SONET Interoperability Forum; Switch SNCP/N Subnetwork Connection Protection/ Interface FPGA Non-intrusive monitoring SIM Service Interface Module SNG Satellite News Gathering SIP Session Initiation Protocol SNM Switching Network Manager SITA Société Internationale de SNMP Simple Network Management Protocol Télécommunications Aéronautique SNP Sequence Number Protection SLA Service Level Agreement SNR Signal-to-Noise Ratio SLIP Serial Line Internet Protocol SNTP Simple Network Time Protocol SLM Service Layer Manager SOA Semiconductor Optical Amplifier SLOSS Synchronization Loss SOF Start of Frame SLR Service Level Report SOH Section Overhead; State of Health SM Single Mode; Switching Module; Shelf SOHO Small Office/Home Office Manager SONET Synchronous Optical Network, US SMAP Service Management Access Point, equivalent to SDH IN block SOP Standard Operating Procedure; SMB Small and Medium Business Service Provider SMC Serial Management Controllers; Stan- SP Shelf Processor; Shelf Pump; Service dard Management Committee Provider SMCS Short Message Service Center SPC SONET Permanent Circuit SMDS Switched Multimegabit Data Service SPCN Satellite Personal Communications SME Small and Medium Enterprise; Short Network Message Entity SPE Synchronous Payload Envelope SMF Single Mode Fiber SPF Shortest Path First SMIR Single Mode Intermediate Reach SPI Serial Peripheral Interface; Service SML Service Management Layer Provider Interface SMLR Single Mode Long Reach SPM Self-Phase Modulation SMM Service Mediation Module SPR/SPRing Shared Protection Ring SMON Switch Monitor SPTP Service Path Termination Point SMOP Service Method of Procedure SPVC Soft Permanent Virtual Connection; SMP Service Management Point, IN block Soft Permanent Virtual Circuit SMS Service Management System, IN block; SQL Structured Query Language Service Management Suite; Short SR Short Reach (fiber) Message Service SRAM Static Random Access Memory SMSC Short Message Service Centre, part of SRC/DST Source/Destination GSM messaging system SRD Software Release Document SMT Surface Mount Technology; Self-Monitoring Task SRF Specialised Resource Function, IN block S-MTA Standalone Multimedia Terminal Adaptor SRN Software Release Notice SN Service Node, IN block SRS Stimulated Raman Scattering SNA Systems Network Architecture SRTS Synchronous Residual Time Stamp SNC Subnetwork Connection; Subnetwork SRVEFF Service Affecting (TL1) Controller SS/TDMA Satellite Switched Time Division SNCP Subnetwork Connection Protection Multiple Access, Intelsat service SNCP/I Subnetwork Connection Protection/ SS5 Signaling System 5 Inherent monitoring SS7 Signalling System 7, supported by the ITU-T, also known as CCITT 7

25 SSB Single Sideband STS-3 Synchronous Transport Signal Level 3 SSCOP Service Specific Connection Oriented STS-3c Synchronous Transport Signal Level 3, Protocol concatenated SSCS Service-Specific Convergence Sublayer STS-n Synchronous Transport Signal n SSEL Session Selector STS-Nc Contiguous Concatenation of N STS-1 SSF Server Signal Failure ; Service SPEs Switching Function STS-N-Xv Virtual Concatenation of X STS-N SPEs SSL Secure Sockets Layer STU Secure Telephone Unit; Synchronized, SSM Synchronization-Status Messages Traceability Unknown; Stratum Traceability Unknown SSMF Standard Single Mode Fiber STU-P Stratum Traceability Unknown- SSP Service Switching Point, IN block Provisioned SSPA Solid State Power Amplifier SVC Switched Virtual Circuit SST Secondary Service State SVCC Switched Virtual Channel Connection SSTUR Site-Specific Turn-Up Report SVOD Subscription Video on Demand SSU Synchronization Supply Unit ; SVP Secure Video Processor Subscriber Terminals SVPC Switched Virtual Path Connection ST Straight Terminus; Straight Tip SW Software ST1 Stratum 1; Switched T1 SWCA Split Working Channel Access ST2 Stratum 2 SWID Software Identifier ST3 Stratum 3 SWOD Software ODACS ST3E Stratum 3 Enhanced SX Short Reach as in 1000Base-SX ST4 Stratum 4 (Asynchronous) SYNC Synchronization STB Set-Top Box SYNCIO Synchronized Input/Output STC Stacking and Timing Card SYSLOG System Log STE Section Terminating Equipment; Section Terminating Element STII (2) Type of optical connector T STM Synchronous Transfer Mode, or T1 Service or line operation at the Module DS-1 rate STM-0 Synchronous Transfer Mode level 0, T1 1.544 Mb/s (US orientated) SDH bit rate = 51.84 Mb/s T3 Digital Carrier System for DS3 Signals STM-1 Synchronous Transfer Mode level 1, TAC Transport Aggregated Circuit; Technical SDH bit rate = 155.52 Mb/s Assistance Center STM-16 Synchronous Transfer Mode level 16, TACACS Terminal Access Controller Access SDH bit rate = 2488.32 Mb/s Control Systems STM-4 Synchronous Transfer Mode level 4, TACS Total Access Communications Systems SDH bit rate = 622.08 Mb/s (Analogue) STM-64 Synchronous Transfer Mode level 64, TADR Target Address SDH bit rate = 9953.28 Mb/s TADRMAP Target Address Map STM-n Synchronous Transport Module n TAM Total Available Market STM-nC Synchronous Transport Module of level TAP Test Access Port; Technician Access n concatenated Port STMX SONET/SDH Thin Multiplexer TARP Target Identifier Address Resolution STP Spanning Tree Protocol; Shielded Protocol Twisted Pair TAS Telecommunications Authority of STS Synchronous Transport Signal Singapore STS-1 Synchronous Transport Signal Level 1 TB Terabyte

26 TBD To Be Determined TIRKS Trunk Integrated Record Keeping TBOS Telemetry Byte Oriented Serial Protocol System TBUS Timing Bus TISSA Time Space Switch Application-Specific Integrated Circuit TC Transmission Convergence; Transport Complex; Transport Channel Hz Hertz TCA Threshold Crossing Alert; Timing TKIP Temporal Key Integrity Protocol Control and Access TL-1 Transaction Language 1 TCBE Total Corrected Bit Error TL-1 CLI Transaction Language One, TCM Trellis Coded Modulation; Transport Command Line Interface Channel Members TLC Transport Logical Connection TCMO Transport Complex Managed Object TLI Transaction Language Command Line TCP Transmission Control Protocol; Trouble Interface Cleaning Procedure TLS Transparent LAN Services TCP/IP Transmission Control Protocol/Internet TLSR Transoceanic Line Switched Ring Protocol TLV Type-Length-Value TCTP Transparent Connection Termination TM Timing Module; Transaction Manager Point IN Intelligent Network TD Traffic Director TMC Terminal Monitor and Control TDEV Time Deviation TML Telephony Markup Language TDM Time Division Multiplexing TMN Telecommunications Management TDMA Time Division Multiple Access Network TE Terminal Equipment TMO Trans Metro Optical (platform) TEC Thermo-Electric Cooler tmout Time Out TED Traffic Engineering Database tmper Time Period TEI Terminal Endpoint Identifier; Terminal TMUX Terminal Multiplexer Equipment Identifier TNL Ethernet Tunneling Telco Telephone Company TNM Transport Network Management TELR Talker Echo Loudness Rating TOD Television on Demand TEO Telephone Equipment Order ToD Time of Day TERM Termination TOH Transport Overhead TFT Thin Film Transistor TOP Task Oriented Practice; Task Oriented TFTP Trivial File Transfer Protocol Procedure TG Timing Generator TOS Type of Service TGCP Trunking Gateway Control Protocol TP Termination Point TGS Time Generation System TPFI Timing Plane Fault Isolation THEC Corrected Type Header Error TQM Total Quality Management Correction Code TR Technical Reference THz TeraHertz (10 12 hertz) TRIB Tributary TI Terrestrial Interference TRM Technical Review Meeting TIA Telecommunications Industry Association tRTO TCP Retransmit Timeout TID Target Identification; Terminal Identifi- TrTOH Transparent Transport Overhead cation TS Time Slot; Time Stamp; Time Synchro- TIE Time Interval Error nization TIM Trace Identifier Mismatch; Transmit TSA Time Slot Assignment Intermediate Multiplexer TSD Transport System Division TIM-S Trace Identifier Mismatch - Section TSE Topology State Element

27 TSEL Transport Selector UCD Upstream Channel Descriptor TSF Transport Signal Failure UD Unconditional Disconnect TSG Timing Signal Generator UDLR Unidirectional Link Routing TSI Time Slot Interchange; Time Switch UDP User Datagram Protocol Interchange UDR Unconditional Disconnect Response TSR Technical Service Representative UEM Universal Equipment Modules TSX Time-Space Switch ASIC UEQ Unequipped TTE Transparent Terminal Equipment UGC Universal Gateway Carrier TTL Transistor Transistor Logic; Time to Live UGS Unsolicited Grant Service TTP Trail Termination Point UHD Ultra High Density TTTP Transparent Trail Termination Point UHF Ultra High Frequency TU Tributary Unit; Transmission Unit UI User Interface TUG Tributary Unit Group UIC User Interface Client TUG-n Tributary Unit Group, level n UID User Identifier TU-n Tributary Unit, level n UITS Unacknowledged Information Transfer TV Television Service TVRO Television Receive Only earth station UL Underwriters Laboratories TW TrueWave – fiber brand ULH Ultra Long Haul TWC TrueWave Classic – fiber brand ULSDCC Upper Layer Section Data TX Transmit Communications Channel Tx Line Transmit Line UMTS Universal Mobile Telecommunications System UNEQ Unequipped Path; Unequipped U UNEQ-P Unequipped Path UAE United Arab Emirates UNEQ-V Unequipped VT UART Universal Asynchronous Receiver/Trans- mitter UNEs Unbundled Network Elements UAS Unavailable Seconds UNI User Network Interface UASL Unavailable Second Count-Line UNI/UNIF User Network Interface UAS-L Unavailable Seconds - Line UNII Unlicensed National Information Infrastructure UAS-LFE Unavailable Seconds - Line Far End UOG Universal OSS Gateway UASP Unavailable Second Count-Path UPC Ultra Physical Contact; Universal Packet UAS-P Unavailable Seconds - Path Carrier; Usage Parameter Control UAS-PFE Unavailable Seconds - Path Far End UPN Universal Personal Number UAS-RS Unavailable Seconds - Regenerator UPnP Universal Plug and Play Section UPS Uninterrupted Power Supply UAS-S Unavailable Seconds - Section UPSR Unidirectional Path Switched Ring UAS-V Unavailable Seconds - VT UPT Universal Personal Telecommunications UAS-VFE Unavailable Seconds - VT Far End URI Universal Resource Identifier UAT Unavailable Time URL Universal Resource Locator UB Uncorrected Block US Upstream UBR Undefined Bit Rate; Unspecified Bit Rate USB Universal Serial Bus UBRVBR Unspecified Bit Rate Variable Bit Rate USEPA United States Environmental Protection Agency UC User Channel UTC Universal Time Coordinated; Universal UCBE Uncorrectable Block Error Transport Carrier

28 UTOPIA Universal Test and Operations Physical VG Virtual Group Interface for ATM VGA Variable Gain Amplifier UTP Unprotected Termination Point; Un- VHF Very High Frequency shielded Twisted Pair VLAN Virtual Local Area Network UV Ultraviolet VLR Very Long Reach PRI Primary Rate Interface VM Voice Mail; ; UVC Universal Voice Carrier; Universal Virtual Machine Video Carrier VME Versa Module Eurocard VMM Voice/Modem Module V VOA Variable Optical Attenuator V Voltage VOD Video on Demand PSTN Public Switched Telephone Network VoIP Voice over Internet Protocol V/A Video/Audio VOM Volt-Ohm Meter VAC Voltage Alternating Current VOQ Virtual Output Queuing VAD Voice Activity Detection VOW Voice Order Wire VADSL or Very high speed (Asymmetric) VP Virtual Path VDSL Digital Subscriber Line VPC Virtual Path Connection VAP Virtual Access Partitioning VPCI Virtual Path Connection Identifier V-band 50/40 GHz VPG Virtual Path Group VBI Vertical Blanking Interval VPI Virtual Path Identifier VBR Variable Bit Rate VPI/VCI Combined, VPI and VCI identify a VC Virtual Circuit; Virtual Channel; Virtual connection on an ATM Network Container; Virtual Concatenation VPL Virtual Path Link VCAT Virtual Concatenation VPLS Virtual Private LAN Service VCC Virtual Channel Connection VPN Virtual Private Network VCG Virtual Concatenation Group V-pole Vertical-pole VCI Virtual Channel Identifier VPS Voice Processing System VCL Virtual Channel Link VPSP Virtual Path Switch Protection VCM Virtual Concatenation-group Member VRRP Virtual Router Redundancy Protocol VC-N Virtual Container Level N (N=11, 12, 2, 3, 4) VSA Virtual- Algorithm; Vector Signal Analyzer VC-N-Xc Contiguous Concatenation of X Virtual Containers at Level N VSAT Very Small Aperture Terminal VC-N-Xv Virtual Concatenation of X Virtual VSI Vendor-Specific Information containers at Level N VSR Very Short Reach VCO Voltage Controlled Oscillator VSSP Virtual Service Switching Point VCR Video Cassette Recorder VT Virtual Tributary VCSEL Vertical Cavity Surface-Emitting Laser VT-100 Terminal Emulation System VCXO Voltage Controlled Crystal Oscillator VTG Virtual Tributary Group VDC Volts Direct Current V-UNI Virtual User Network Interface VDSL Very-high-bit-rate Digital Subscriber Line W VEC Voice Equivalent Circuit W Watt; Working VF Virtual Fiber; Virtual Facility WAD Wavelength Add and Drop VFCU Voice/FAX Channel Unit WAN Wide Area Network VFTP Virtual Facility Termination Point

29 WB Working Band; Westbound Z WBS Work Breakdown Structure ZAC Zero Administration Client WC Watts per channel ZWP Zero Water Peak WCA Working Channel Access WCSS WDM Capable Switching System W-DCS Wideband Digital Cross-Connect System WDM Wavelength Division Multiplexing WDT Watchdog timer WE Western Europe WECA Wireless Ethernet Compatibility Alliance WEP Wired Equivalency Privacy WFA Workforce Automation WFM Workforce Management WFQ Weighted Fair Queuing WIF Wide Area Network Interface WiFi Wireless Fidelity WiMedia An alliance for Wireless Multimedia WLAN Wireless Local Area Network WLL/WiLL Wireless Local Loop, WiLL is also Mo- torola’s WLL product line name WM9 Windows Media Player Version 9 WPA Wireless (WiFi) Protected Access WPS Working/Protect Splitter WRED Weighted Random Early Discard; Weighted Random Early Detection WSS Wavelength Selective Switch WTO World Trade Organisation VPN Virtual Private Network WTR Wait to Restore WWN World Wide Name WWW World Wide Web

X X.25 Packet Switched Communications Interface XC Cross Connect XCVR Transceiver XDSL See DSL (Digital Subscriber Line) XFP 10 Gb/s small form-factor pluggable transceiver XML Extensible Markup Language XMTR Transmitter XPM Cross-Phase Modulation

30 Notes

31 Notes

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