Full Forms of Telecommunications (Telecom) Terms
| Telecom Acronym | Telecom Full Forms |
|---|---|
| 10 GbE | 10 Gigabit Ethernet |
| 10 GFC | 10 Gigabit Fibre Channel (Same as FC1200) |
| 2F | Two-Fiber |
| 3G | 3rd Generation |
| 4C | Consortium of Intel, IBM, Matsushita, and Toshiba |
| 4F | Four-Fiber |
| 5C | Consortium of Intel, Sony, Matsushita, Toshiba, and Hitachi |
| A/D | Analog-to-Digital |
| AAL | ATM Adaptation Layer |
| AAL0 | ATM Adaptation Layer Type 0 |
| AAL1 | ATM Adaptation Layer Type 1 |
| AAL2 | ATM Adaptation Layer 2 Transport |
| AAL3/4 | ATM Adaptation Layer Type 3 and 4 |
| AAL5 | ATM Adaptation Layer 5 |
| ABR | Available Bit Rate |
| ABT | Advanced BiCMOS Technology |
| AC | Alternating Current; Administrative Complex; Atomic Clock |
| AC-3 | Audio Coding Revision 3 |
| ACAC | Actual Call Admission Control |
| ACEG | Alternating Current Equipment Ground |
| ACK | Acknowledge |
| ACL | Active Control List; Access Control List |
| ACO | Alarm Cutoff |
| ACQ | Acquire |
| ACR | Allowed Cell Rate |
| ACS | Automatic Channel Shutdown; Alarm Correlation and Suppression |
| ACSE | Association Control Service Element |
| ACSS | Automatic Channel Shutdown Suppression; Automatic Channel Shutdown State |
| ACT | Active |
| ACTS | Advanced Communication Technology Satellite (NASA) |
| ADC | Analog-to-Digital Converter; Add/Drop Coupler |
| ADI | Asset Distribution Interface |
| ADM | Add/Drop Multiplexer |
| ADP | Actual Departure Potential |
| ADSL | Asymmetric Digital Subscriber Line |
| ADT | Actual Departure Time |
| AE | Automation Engine |
| AES | Advanced Encryption Standard |
| AESA | ATM End System Address |
| AFC | Automatic Frequency Control |
| AFI | Authority and Format Identifier |
| AFM | APS Mode Mismatch Failure |
| AGC | Automatic Gain Control |
| AGGR | Aggregate |
| AID | Access Identifier |
| AIM | Auto Image Management; Active Inventory Map |
| AINI | ATM Inter-Network Interface |
| AINS | Automatic in Service State |
| AIR | Additive Increase Rate |
| AIS | Alarm Indication Signal |
| AISDP | Alarm Indication Signal Decay Period |
| AISIP | Alarm Indication Signal Integration Period |
| AIS-L | Alarm Indication Signal – Line |
| AIS-P | Alarm Indication Signal – Path |
| AIS-S | Alarm Indication Signal – Section |
| AIS-V | VT Alarm Indication Signal |
| ALMLED2U | Alarm LED 2 RU (Online Edge Platform) |
| ALS | Automatic Laser Shutdown |
| AM | Amplitude Modulation; Application Manager |
| AMF | APS Mode Mismatch Failure |
| AMI | Access Method Interface; Alternate Mark Inversion |
| AMM | Alarm Management Module; Auxiliary Management Module |
| AMP | Amplifier |
| AMPS | Advanced Mobile Phones System |
| AMS | Asset Management System |
| ANSI | American National Standards Institute |
| AO | Autonomous Output |
| AOD | Advertising on Demand |
| APC | Angled Physical Contact |
| APD | Avalanche PhotoDiode |
| API | Application Program Interface |
| APS | Automatic Protection Switching |
| APSBF | Automatic Protection Switching Byte Failure |
| APSCM | Automatic Protection Switching Channel Mismatch |
| APSMM | Automatic Protection Switching Mode Mismatch |
| ARC | Alarm Reporting Control |
| ARP | Address Resolution Protocol |
| ARPU | Average Revenue per Unit (or User) |
| AS | Autonomous System |
| ASAP | Alarm Severity Assignment Profile |
| ASCII | American Standard Code for Information Interchange |
| ASD | Access Security Device |
| ASE | Amplified Spontaneous Emission |
| ASI | Asynchronous Serial Interface |
| AsiaPac | Asia Pacific |
| ASIC | Application-Specific Integrated Circuit |
| ASN.1 | Abstract Syntax Notation One |
| ASP | Applications Service Provider; Average Selling Price |
| ASYNC | Asynchronous |
| AT | Advanced Technology |
| AT&T | American Telephone and Telegraph Company |
| ATA | Advanced Technology Attachment |
| ATAF | ATM Test Access Function |
| ATAG | Autonomous Tag |
| ATAGSEQ | Autonomous Tag Sequence |
| ATC | Alarm Traffic Controller |
| ATDMA | Asynchronous Time Division Multiple Access |
| A-TDMA | Advanced Time Division Multiple Access |
| ATM | Asynchronous Transfer Mode |
| ATM SAM | ATM Service Access Multiplexer |
| ATMVCL | ATM Virtual Channel Link |
| ATMVPL | ATM Virtual Path Link |
| ATTN | Attenuator |
| AU/AU-x | Administrative Unit |
| AUG | Administrative Unit Group |
| AU-n | Administrative Unit “n” |
| AUX | Auxiliary |
| AVC | Attribute Value Change |
| AWG | American Wire Gauge |
| AWGN | Additive White Gaussian Noise |
| B/P | Backplane |
| B3ZS | Bipolar With 3-Zero Substitution |
| B6ZS | Bipolar With 6-Zero Substitution |
| B8ZS | Bipolar With 8-Zero Substitution |
| BA | Booster Amplifier |
| BB | Broadband |
| BBE | Background Block Error |
| BBER | Background Block Error Ratio |
| BBE-RS | Background Block Error Regenerator Section (an SDH regenerator section error) |
| BC | Business Continuity |
| BCD | Binary-Coded Decimal |
| BCST | Broadcast |
| B-DCS | Broadband Digital Cross-connect System |
| BDFB | Battery Distribution Fuse Bay |
| BE | Block Error; Best Effort |
| BECN | Backward Explicit Congestion Notification |
| BELLCORE | BELL Communications Research, Inc. |
| BER | Bit Error Rate |
| BE-RS | Block Errors-Regenerative Section |
| BER-SD-P | Path Signal Degrade BER |
| BER-SF-P | Path Signal Failure BER |
| BERT | Bit Error Rate Test |
| BFP | Back Facet Power |
| BGP | Border Gateway Protocol |
| BGP4 | Border Gateway Protocol, version 4 |
| BICI | Broadband Inter-Carrier Interfaces; B-ISDN Inter-carrier Interface |
| BICSI | Building Industry Consulting Services International |
| BIOS | Basic Input/Output System |
| BIP | Bit Interleaved Parity |
| BIT | Built-In Test |
| BITS | Building Integrated Timing System |
| bits/sym | Bits per Symbol |
| BLSR | Bidirectional Line Switched Ring |
| BML | Business Management Layer |
| BNC | Bayonet Neill-Concelman |
| BOC | Bell Operating Company |
| BOD | Bandwidth on Demand |
| BOL | Beginning of Life |
| BOM | Bill of Materials |
| BONDING | Bandwidth ON Demand Interoperability Group |
| BOOTP | Bootstrap Protocol |
| BOT | Build Operate Transfer |
| BP | Backplane |
| BPI | Baseline Privacy Interface |
| BPI+ | Baseline Privacy Interface Plus |
| B-PON | Broadband Passive Optical Network |
| BPP | Backplane Protocol |
| bps | bits per second |
| BPSR | Bidirectional Path Switched Ring |
| BPT | Band Pass-Through |
| BPV | BiPolar Violations |
| B-RAS | Broadband Remote Access Server |
| BRI | Basic Rate Interface |
| BRM | Backward RM |
| BSC | Board SC Connector |
| BSP | Board Support Package |
| BSS | Business Support System |
| BT | British Telecom; Burst Tolerance |
| Btag | Beginning Tag |
| BTM | Bits Termination Circuit Pack |
| BTS | Business Telecom Services |
| BTU/hr | British Thermal Unit per hour |
| BW | Bandwidth |
| BWDM | Band Wavelength Division Multiplexer |
| BYT | Total Byte Count |
| C | Celsius; Critical |
| C/I | Carrier-to-Interface Ratio |
| C2O | Cable to Optic |
| CA | Content Archived |
| CAB | Conformity Assessment Body |
| CAC | Connection Admission Control; Call Admission Control |
| CAD | Computer Aided Design |
| CALA | Central America and Latin America |
| CAM | Content Addressable Memory |
| CAP | Competitive Access Provider |
| CAPEX | Capital Expenditure |
| CAS | Channel Associated Signaling |
| CATV | Community Antenna Television; Cable Television |
| CB, C/B | Circuit Breaker |
| C-BAE | C-Band Amplifier Equalizer |
| C-BAM | C-Band Amplifier Monitor |
| CBN | Common Bonding Network |
| CBR | Constant Bit Rate |
| CC | Cross Connection; Clear Channel |
| CCB | Configuration Control Board |
| CCC | Cross Connect Controller |
| CCC768 | Cross Connect Fabric with 768×768 STS-1 capacity |
| CCCG | Cross Connection and Control Group |
| CCC-PC | CCC Processor Card |
| CCC-XC | CCC Cross Connect Card |
| CCDF | Complementary Cumulative Distribution Function |
| CCI | Content Control Information |
| CCITT | Consultative Committee on International Telegraphy and Telephony |
| CCK | Complimentary Code Keying |
| CCW | Counterclockwise |
| CD | Compact Disc; CoreDirector®; Chromatic Dispersion |
| CDD | CoreDirector® Designer Software Tool |
| CDE | Common Desktop Environment (UNIX) |
| CDE | Common Desktop Environment |
| CDMA | Code Division Multiple Access |
| CDP | Contracted Deadline Potential |
| CDR | Call Detail Recording; Clock and Data Recovery |
| CD-ROM | Compact Disc Read Only Memory |
| CDT | Connection Dropping Threshold |
| CDTS | Chromatic Dispersion Test Set |
| CDV | Cell Delay Variation |
| CDVT | Cell Delay Variation Tolerance |
| CD-WO | Compact Disc – Write One |
| CE | Consumer Electronics |
| CEA | Consumer Electronics Association |
| CER | Cell Error Ratio; Codeword Error Ration |
| CES | Circuit Emulation Service |
| CEV | Controlled Environmental Vault |
| CFG | Configuration |
| CFM | Cubic Feet per Minute |
| CFU | Cooling Fan Unit |
| CH | Channel |
| CHASEH | Environmentally Hardened Chassis |
| CHASSIS-e | Old Chassis Type |
| CHASYNC | Chassis with Sync |
| CI | Compact Intelligence; Craft Interface; Customer Interface; Certified Integrator |
| CID | Circuit Identification; Craft Interface Device |
| CIF | Client Interface |
| CIFS | Common Internet File System |
| CIM | Client Interface Module |
| CINOT | Ciena Optical Transport System |
| CIR | Customer Information Release |
| CIT | Craft Interface Terminal; Craft Interface Tool |
| CL | Coupling Loss; Cleared |
| CLASS | Custom Local Area Signaling Services |
| CLEC | Competitive Local Exchange Carrier |
| CLEI | Common Language Equipment Identifier |
| CLEITM | Common Language Equipment Identifier |
| CLFI | Common Language Facility Identifier |
| CLI | Command Line Interface |
| CLIP | Calling Line Identification Presentation |
| CLIR | Calling Line Identification Restriction |
| CLLI | Common Language Location Identifier |
| CLNP | Connectionless Network Layer Protocol |
| CLNS | Connectionless Network Service |
| CLP | Cell Loss Priority |
| CLR | Cell Loss Ratio |
| CLTP | Connectionless Transport Protocol |
| cm | centimeter |
| CM | Control Module; Cable Modem |
| CM-CLI | Control Module Command Line Interface |
| CMF | Channel Mismatch Failure; Client Management Frame |
| CMIP | Common Management Information Protocol |
| CMIS | Common Management Information Services |
| CMISE | Common Management Information Service Element |
| CMO | Ciena Management Object |
| CMR | Cell Misinsertion Rate |
| CMS | Call Management Server |
| CMTS | Cable Modem Termination System |
| CMU | Clock Multiplier Unit |
| C-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 Ratio |
| CNMP | Customer Network Management Portal |
| CNR | Carrier-to-Noise Ration |
| CO | Central Office |
| COADM | Configurable Optical Add/Drop Multiplexer |
| COBRA | Copper and Optical Broadband Remote Access |
| CODEC | Coder/Decoder |
| COE | Central Office Equipment |
| COFA | Change of Frame Alignment |
| COLD | Central Office Layout Design |
| COLL | Collision Count |
| COM | Ciena’s inter-processor communications system |
| CONDTYPE | Condition Type |
| CONS | Connection Oriented Network Service |
| COO | Chief Operating Officer |
| COPS | Common Open Policy Services |
| CORBA | Common Object Request Broker Architecture |
| CoS | Class of Service |
| COS | Class of Service; Common Object Services |
| COT | Central Office Terminal |
| COTS | Commercial off the Shelf |
| CP | Circuit Pack; Control Processor; Connection Provisioner; Call Processing; Customer Premise |
| CPCI | Compact Peripheral Component Interconnect |
| CPD | Common Path Distortion |
| CPE | Customer Premises Equipment; Customer Provided Equipment |
| C-Plane | Control Plane |
| CPLD | Complex Programmable Logic Device |
| CPM | Cross-Phase Modulation |
| CPRM | Content Protection for Recordable Media |
| CPT | Channel Pass-Through |
| CPTTAG | Connection Termination Point Tag |
| CPU | Central Processing Unit |
| CR | Circuit Reliability; Carriage Return; Critical Alarm |
| CRC | Cyclic Redundancy Check |
| CRG | Circuit Restoration Group |
| CRIP | CIENA Routing Information Protocol |
| CR-LDP | Constraint-based Routing Label Distribution Protocol |
| CRS | Cross Connect |
| CRT | Cathode Ray Tube |
| CRx Line | Client Receive Line |
| CS | Control Sub-span; Convergence Sublayer; CoreStream |
| CSA | Canadian Standards Association |
| CSD | Core Switching Division |
| CSES | Consecutive Severely Errored Seconds |
| Csh | C Shell |
| CSH | Common Signal Header |
| CSI | Convergence Sublayer Indicator |
| CSM | Core Switching Manager |
| C-SMF | Conventional Single Mode Fiber |
| CSO | Composite Second Order |
| CSP | Customer Service Profile |
| CSR | Customer Service Representative |
| CS-RZ | Carrier-Suppressed Return-to-Zero |
| CST | Central Standard Time |
| CSU | Channel Service Unit; Customer Service Unit |
| CSV | Comma-Separated Value |
| CT | Critical |
| Ctag | Correlation Tag |
| CTAM | Cable & Telecommunications Association for Marketing |
| CTB | Composite Triple Beat |
| CTC | Common Transmit Clock |
| CTD | Cell Transfer Delay |
| CTG | Cradle-To-Grave |
| CTM | Core Transport Manager |
| CTN | Core Transmission Network |
| CTP | Connection Termination Point |
| CTS | Clear To Send |
| CTx Line | Client Transmit Line |
| CUG | Closed User Group |
| CV | Code Violation |
| CV-FE | Code violation – Far End |
| CV-L | Code Violation – Line |
| CV-P | Code Violation – Path |
| CV-PFE | Code Violation – Path Far End |
| CV-S, CVS | Code Violation – Section; Code Violation — Seconds |
| CW | Clockwise; Continuous Wave |
| CWDM | Coarse Wave Division Multiplexing; Coarse Wavelength Division Multiplex |
| CWDM-U | Coarse Wavelength Division Multiplexing – UPSR |
| D&C | Drop and Continue |
| D/A | Digital-to-Analog |
| D/I | Drop and Insert |
| DAC | Digital to Analog Converter; Digital Addressable Controller |
| DACS | Digital Access and Cross-Connect System |
| DAD | Direct Access Devise |
| DADM | Data Add/Drop Multiplexer |
| DAS | Direct Attached Storage |
| DATE | Duly Authorised Telecommunications Entity |
| dB | decibel |
| DB | Database |
| DB-9 | Data Bus 9 Pin Connector |
| DBA | Dynamic Bandwidth Assignment |
| dBc | Decibel referenced to the carrier |
| dBm | Decibel reference in milliwatts |
| DBMS | Database Management System |
| DBPSK | Differential Binary Phase Shift Keying |
| DBS | Direct Broadcast Satellite |
| DC | Direct Current; Data Connection |
| DCC | Data Communications Channel |
| DCE | Data Communications Equipment; Data Circuit Terminating Equipment |
| DCF | Dispersion-Compensating Fiber |
| DCG | Dispersion Compensation Grating |
| DCM | Dispersion Compensation Module |
| DCME | Digital Compressed Multiplication Equipment |
| DCN | Data Communication Network |
| DCOM | Distributed Component Object Model |
| DCP | Digital Communications Protocol; Device Control Protocol |
| DCS | Digital Cross-connect System; Digital Connection System |
| DDI | Direct Dialing Inward |
| DDS | Digital Data Storage; Digital Data Service; Digital Data System; Digital Data Stream |
| DE | Discard Eligible |
| DEC | Digital Electrical Carrier |
| DEG | Degraded Signal |
| DEMUX | Demultiplexer |
| DENI | Digital Entertainment Networking Initiative |
| DENY | Transaction Denier |
| DFB | Distributed Feedback |
| DG | Disc Group |
| DGD | Differential Group Delay |
| DHCP | Dynamic Host Configuration Protocol |
| DHWG | Digital Home Working Group |
| DID | Direct Inward Dialing |
| DiffServ | Differentiated Services |
| DIO | Digital Input/Output |
| DIP | Dual In-line Package (switch) |
| DIR | Direction |
| Div | Division |
| DLC | Digital Loop Carrier |
| DLCI | Data Link Connection Identifier |
| DLL | Dynamic Link Library; Data Lind Layer (driver); Downline Load |
| DLT | Digital Linear Tape Drives |
| DM | Degraded Minute; Dispersion Mitigation |
| DMA | Direct Memory Access |
| DMACS | Distributed Monitoring and Control System |
| DMB | Digital Multipoint Bridge; Document Maintenance Bulletin |
| DMC | Dual Modem Cards |
| DMH | Degraded Modem Hours |
| DMM | Digital Multi-Meter |
| DMOP | Detailed Method of Procedure |
| DMS | Dispersion-managed Solution |
| DMUX | [Optical] Demultiplexer |
| DN | Data Node |
| DNCS | Digital Network Control System |
| DNR | Do Not Revert |
| DNS | Domain Name Server; Domain Name System |
| DOCSIS | Data-Over-Cable Service Interface Specifications |
| DOS | Disk Operating System |
| DoS | Denial of Service |
| DP | Data Processing |
| DPDT | Double-Pole, Double-Throw |
| DPFI | Data Plane Fault Isolation |
| DPI | Digital Program Insertion |
| DPR | Dedicated Protection Ring |
| DPRAM | Dual Port Random Access Memory |
| DPT | Dynamic Packet Transport |
| DQ | Degraded Quality Level |
| DQDB | Distributed Queue Dual Bus |
| DQoS | Dynamic Quality of Service; Deploying Quality of Service |
| DQPSK | Differential Quadrature Phase Shift Keying |
| DR | Disaster Recovery |
| DRAM | Dynamic Random Access Memory |
| DRM | Digital Rights Management |
| DS | Digital Signal; Downstream |
| DS0 | Digital Signal Level 0 (64 Kb/s data/voice channel) |
| DS1 | Digital Signal Level 1 (T1 equivalent) |
| DS3 | Digital Signal Level 3 (T3 equivalent) |
| DSCP | Differentiated Service Code Point |
| DSCRDS | Discard Count |
| DSF | Dispersion Shifted Fiber |
| DSL | Digital Subscriber Line; Digital Subscriber Loop |
| DSLAM | Digital Subscriber Line Access Multiplexer |
| DS-n | Digital Signal, level n |
| DSP | Digital Signal Processor |
| DSS | Direct Satellite Services |
| DSS2 | Digital Subscriber Signaling 2 |
| DSTB | Digital Set-top Box |
| DSX | Digital Side Interface |
| DS-x | Digital Signal where N denotes multiple of 51.84 Mb/s |
| DSX-1 | Digital Signal Level 1 Cross Connect |
| DSX-3 | Digital Signal Level 3 Cross Connect |
| DT | Decision Technology; Direct Termination |
| DTCP | Digital Transmission Content Protection |
| DTE | Data Terminal Equipment |
| DTH | Direct-to-Home |
| DTL | Designated Transit List |
| DTMF | Dual Tone Multi-Frequency |
| DTS | Dynamic Transport System |
| DTV | Digital Television |
| DUART | Dual Universal Asynchronous Receiver Transmitter |
| DUP | Data User Part |
| DUS | Don’t Use Synchronization |
| DV | Digital Video |
| DVB-ASI | Digital Video Broadcast Asynchronous Serial Interface |
| DVC | Dynamic Virtual Concatenation |
| DVD | Digital Versatile Disc |
| DVD+R | Recordable Digital Versatile Disc |
| DVD+RW | Rewritable Digital Versatile Disc |
| DVI | Display Visual Interface |
| DVM | Digital Voltmeter |
| DVOW | Digital Voice Orderwire |
| DVR | Digital Video Recorder |
| DW | Datawire |
| DWDM | Dense Wavelength Division Multiplexing |
| DXC | Digital Cross-Connect |
| DXI | Data Exchange Interface |
| E1 | European Equivalent of T1 (2.048 Mb/s signal speed) |
| E2E | End To End |
| E2PROM | Electrically Erasable Programmable Read Only Memory |
| E3 | European data signal at a rate of 34.368 Mb/s |
| EAI | Enterprise Application Integration |
| EAL | Events, Alarms, and Logging |
| EAP | Extensible Authentication Protocol |
| EAS | Emergency Alert System |
| EB | Error Block; Eastbound |
| EBEM | Enhanced Bus Extender Module |
| EC-1 | Electrical Carrier Level 1 (STS1 Equivalent) |
| ECC | Edge Card Control; Embedded Communications Channel |
| ECI | Equipment Catalog Item |
| ECLR | Egress Cell Loss Ratio |
| ECn | Electrical Carrier, level n; 0=64 kb/s, 2=6,312 Mb/s, 3=44,736 Mb/s |
| ECN | Engineering Change Notice |
| ECO | Engineering Change Order |
| ED | Equipment Degrade |
| EDF | Erbium-Doped Fiber |
| EDFA | Erbium-Doped Fiber Amplifier |
| eDOCSIS | Embedded Data-Over-Cable Service Interface Specifications |
| EEE | Electronic Equipment Enclosure |
| EEPROM | Electrically Erasable Programmable Read Only Memory |
| EF | Equipment Failure |
| EF&I | Engineer, Furnish and Install |
| EFCI | Explicit Forward Congestion Indication |
| EFD | Event Forwarding Discriminator |
| EFEC | Enhanced Forward Error Correction |
| EFP | Equipment Fault Protection |
| EH | Environmentally Hardened |
| EIA | Electronic Industries Alliance; Electronic Industries Association |
| EID | Equipment Identifier |
| EIDE | Enhanced Integrated Drive Electronics |
| EIRP | Effective Isotropic Radiated Power |
| EJB | Enterprise Java Beans |
| ELAN | Emulated Local Area Network |
| ELR | Extra Long Reach |
| EM | Element Manager |
| EMBS | Egress Maximum Burst Size |
| EMC | ElectroMagnetic Compatibility |
| EMD | Extended Management Domain |
| EMEA | Europe, Middle East and Africa |
| EMG | Extended Management Gateway |
| EMI | Electromagnetic Interference |
| EML | Element Management Layer; Electro-Absorptive Modulated Laser |
| EMP | Expiring Maintenance Process |
| EMS | Element Management System |
| EMT | Expiring Maintenance Tool |
| eMTA | Embedded Multimedia Terminal Adapter |
| EMX | ESCON MUX |
| END | Extended Management Domain |
| ENE | End Network Element |
| ENUT | Enhanced Non-preemptable Unprotected Traffic |
| EO | Equipment Order |
| EOC | Embedded Operations Channel |
| EoD | Everything on Demand |
| EOF | End of Frame |
| EOL | End of Life |
| EOM | End of Message |
| EoS | Ethernet over SONET/SDH |
| EOW | Engineered Orderwire; Express Orderwire |
| EPA | Environmental Protection Agency |
| EPCR | Egress Peak Cell Rate |
| EPD | Early Packet Discard |
| EPG | Equipment Protection Group |
| EPL | Ethernet Private Line |
| EPLD | Erasable Programmable Logic Device |
| E-PON | Ethernet Passive Optical Network |
| EPROM | Erasable Programmable Read Only Memory |
| EQPT | Equipment |
| ER | Extended Reach |
| ERDI | Enhanced Remote Defect Indicator |
| EREI-P | Enhanced Path Remote Error Indication |
| Errcde | Error Code |
| ES | Errored Second |
| ESA | EDFA Saturation Algorithm; End System Address |
| ESCBND | ESCON Bundle |
| ESCON | Enterprise System Connection; IBM Enterprise systems connection protocol |
| ESCR | Egress Sustainable Cell Rate |
| ESD | Electrostatic Discharge |
| ESDS | Electrostatic Discharge Sensitive |
| ESF | Extended Super Frame; Extended Superframe Format |
| ES-FE | Errored Seconds – Far End |
| ESI | End System Identifier |
| ES-IS | End System to Intermediate System |
| ES-L | Errored Seconds – Line |
| ES-LFE | Errored Second-Line Far End |
| ESMOP | Electronic Service Method of Procedure |
| ES-MS | Errored Seconds at the Mulitplexor Section |
| ESN | Extended Subnetwork |
| ES-P | Errored Seconds – Path |
| ES-PFE | Errored Seconds – Path Far End |
| ESR | Errored Second Ratio |
| ES-RS | Errored Second Regenerator Section |
| ES-S | Errored Seconds – Section |
| EST | Eastern Standard Time |
| ES-V | Errored Second-Virtual Tributary (VT) Path; Errored Second-VT Path Far End |
| ESx | Errored Second Count |
| ET | End Terminal; Entitlement Tracker |
| Etag | Ending Tag |
| ETH | 10/100 Ethernet |
| ETHBND | Ethernet Bundle |
| ETLMI | ESCON Trib Laser Manager Interface |
| ETR | External Timing Reference |
| ETSI | European Telecommunications Standards Institute |
| EU | European Union |
| EVM | Error Vector Magnitude |
| EVPL | Ethernet Virtual Private Line |
| EVPLAN | Ethernet Virtual Private Local Area Network |
| EWO | Engineering Work Order |
| EXER-R | Exercise – Ring |
| EXER-S | Exercise – Span (SONET) |
| EXP | Experimental |
| EXZ | Excessive Zone |
| F | Fahrenheit |
| F&I | Furnish and Install |
| FA, F/A | Fuse Alarm; Fault Alarm |
| FAB | Field Alert Bulletin |
| FAD | Functional Access Domain |
| FAF | Facility Failure |
| FAT | Factory Acceptance Test |
| FC | Failure Code; Failure Count; Fiber Channel; Fibre Channel |
| FC Switch | Fiber Channel Switch |
| FC100 | Fibre Channel 1 Gb/s |
| FC10000 | Fibre Channel 10 Gb/s (same as 10GFC) |
| FC200 | Fibre Channel 2 Gb/s |
| FC400 | Fibre Channel 4 Gb/s |
| FCAPS | Fault, Configuration, Accounting, Performance (or Provisioning), Security management |
| FCC | Federal Communications Commission |
| FC-FE | Failure Count – Far End |
| FCIP | Fiber Channel over Internet Protocol |
| FC-L | Failure Count – Line |
| FC-LFE | Failure Count – Line Far End |
| FCM | Fan Control Module |
| FCP | Fiber Channel Protocol |
| FC-P | Failure Count – Path |
| FC-PFE | Failure Count – Path Far End |
| FCS | Frame Check Sequence |
| FCS32 | Count of FCS-32 Error |
| FC-V | Failure Count – VT |
| FC-VFE | Failure Count – VT Far End |
| FDA | Food and Drug Administration |
| FDD | Frequency Division Duplexed |
| FDDI | Fiber Distributed Data Interface |
| FDF | Fiber Distributing Frame |
| FDL | Facilities Data Link |
| FDM | Frequency Division Multiplexing; Fast Ethernet |
| FDMA | Frequency Division Multiple Access |
| FDP | Fiber Distribution Panel |
| FDRP | Frame Drop |
| FE | Far End; Fast Ethernet; Forward Error Correction |
| FEAC | Far End Alarm Channel |
| FEACT | Far-End Terminal Alarm Condition |
| FEALM | Far-End Alarm |
| FEB | Fast Ethernet Bridging |
| FEBE | Far End Block Error |
| FEC | Forward Error Correction; Forwarding Equivalence Class |
| FECN | Forward Explicit Congestion Notification |
| FECS | Forward Error Correction Seconds |
| FEDS | FICON Extended Storage over Distance |
| FEP | Far End Protection |
| FEPLF | Far End Protection Line Failure |
| FEPM | Far End Performance Monitor |
| FERF | Far End Receive Failure |
| FET | Field-Effect Transistor |
| FF | Fast Forward |
| FFA | First Field Application |
| FFP | Facility Fault Protection |
| FFT | Fast Fourier Transform |
| FIB | Forwarding Information Base |
| FIC | Frame Identification Code |
| FICON | Fiber Connection |
| FIL | Fiber in the Loop |
| FIT | Failure in Time |
| FITB | Fiber in the Building |
| FITL | Fiber in the Loop |
| FITR | Fiber in the Riser |
| FLAG | Fibre Link Around the Globe |
| FM | Fan Module; Fault Management; Forwarding Module; Frequency Modulation |
| FMA | Failure Modes Analysis |
| FMECA | Failure Mode and Effects and Criticality Analyses |
| FMS | Fault Management System |
| FO | Fiber Optics |
| FOADM | Fixed Optical Add/Drop Multiplexer; Flexible Optical Add/Drop Multiplexer |
| FOB | Free On Board |
| FOD | Free on Demand |
| FOSC | Fiber Optic Splice Course |
| FOTS | Fiber Optic Transmission System |
| FP | Fabry-Perot (type of laser); Frame Pulse (NEC) |
| FPG | Facility Protection Group |
| FPGA | Field Programmable Gate Array |
| FPM | Fan Power Module |
| FPP | Fast Pattern Processor |
| FPS | Frames per Second |
| FR | Frame Relay |
| FRC | Force |
| FRD | Functional Requirements Document; Feature Requirements Definition |
| FREQ | Frequency |
| FRF | Frame Relay Forum |
| FRF.12 | Frame Relay Forum Implementation Agreement 12 |
| FRF.13 | Frame Relay Forum Implementation Agreement 13 |
| FRF.5 | Frame Relay Forum Implementation Agreement 5 |
| FRF.8.1 | Frame Relay Forum Implementation Agreement 8.1 |
| FRG | Fragment Count |
| FRM | Forward Resource Management; Frame Count |
| FRMS | Dropped Frames |
| FRU | Field Replacement Unit |
| FS | File System |
| FSA | Field Service Application |
| FSAN | Full Services Access Network (consortium) |
| FSB | Field Service Bulletin |
| FSO | Free Space Optical |
| FS-P | Forced Switch – Protection |
| FS-R | Forced Switch – Ring |
| FSS | Fixed Satellite Service |
| FS-S | Forced Switch – Span |
| FS-W | Forced Switch – Working |
| FT-2000 | SONET OC-48 lightwave system (AT&T) |
| FTA | Fault Tree Analysis |
| FTAM | File Transfer and Access Management |
| FTC | Fabric and Timing Card |
| FTM | Fabric Timing Module |
| FTP | File Transfer Protocol |
| FTTB | Fiber to the Building; Fiber to the Business |
| FTTC | Fiber to the Curb |
| FTTD | Fiber to the Desk |
| FTTH | Fiber to the Home |
| FTTP | Fiber to the Premise; Maintenance Channel Transparent Termination Point |
| FTTx | Fiber to the [endpoint] |
| FUNI | Frame-based User-Network Interface |
| FW | Firmware; Firewall |
| FWHM | Full Width at Half Maximum |
| FWM | Four-Wave Mixing |
| GA | General Availability |
| Gb | Gigabit |
| GB | Gigabyte |
| GbE | Gigabit Ethernet |
| GbE VFTP | Gigabit Ethernet Virtual Facility Termination Point |
| GbE WAN | Gigabit Ethernet Wide Area Network |
| GbE WIF | Gigabit Ethernet Wide Area Network Interface |
| GBIC | Gigabit Interface Converter |
| Gbps, Gbits | Gigabits per second |
| Gbytes/s | Gigabytes per second |
| GC | Gateway Controller |
| GCAC | Generic Connection Admission Control |
| GCC0 | General Communications Channel 0 (similar to SDH/SONET DCC) |
| GCIT | Graphical Craft Interface Terminal |
| GCM | General Control Module |
| GCRA | Generic Cell Rate Algorithm |
| GDMO | Guidelines for the Definition of Managed Objects |
| GE | Gigabit Ethernet; Greater than or equal to |
| GEB | Gigabit Ethernet Bridge |
| GEO or GSO | Geostationary Earth Orbit |
| GET | Gigabit Ethernet Tunneling |
| GFA | Gain Flattened Amplifier |
| GFC | Generic Flow Control |
| GFF | Gain Flattening Filter (used in EDFA) |
| GFP | Generic Framing Procedure |
| GFR | Guaranteed Frame Rate |
| GHz | Gigahertz; One billion cycles per second |
| GMPLS | Generalized Multi-Protocol Label Switching |
| GMT | Greenwich Mean Time; Grasshoppers Made for Telecommunications (GMT fuses) |
| GN | Gateway Network Element |
| GND | Ground |
| GNE | Gateway Network Element |
| GOS | Grade of Service |
| GP | Gateway Platform |
| GPI | General Purpose Input |
| GPIN | General Purpose Input |
| GPO | General Purpose Output |
| G-PON | Gigabit Passive Optical Network |
| GPRS | General Packet Radio Service |
| GPS | Global Positioning System; Global Positioning Satellite |
| GR | Generic Requirement; Geographic Redundancy |
| GRDM | Gigabit Rate Data Multiplexer |
| GRTES | General Requirements for Transmission Equipment Specification |
| GSM | Global System for Mobile communication |
| GT | Gain Transfer; Grating Temperature |
| GT | Gain Transfer; Grating Temperature |
| GTP | Group Termination Point |
| GUI | Graphical User Interface |
| GW | Gateway |
| GWC | Gateway Controller |
| HA | High Availability |
| HCFM | High-speed Cell Forwarding Module |
| HCSFI | High-speed Central Switch Fabric Interface |
| HD | High Definition |
| HDB3 | High Density Bipolar 3 |
| HDCP | High-bandwidth Digital Content Protection |
| HDLC | High-speed/level Data Link Control |
| HDMI | High Definition Multimedia Interface |
| HD-SDI | High Definition Serial Digital Interface |
| HDSF | High-speed Distributed Switch Fabric |
| HDSL | High-Speed Digital Subscriber Line |
| HDT | Host Digital Terminal |
| HDTV | High Definition Television |
| HE | Headend |
| HEC | Header Error Control; Headend Controller |
| HEM | Headend Modem |
| HEPA | High Efficiency Particulate Arrester |
| HFC | Hybrid Fiber Coax |
| HFM | High-speed Forwarding Module |
| HGW | Home Gateway |
| HHP | Households Passed |
| HI | Hardware/Software Interface; Hardware-Software Integration; High Speed Internet |
| HISSA | High Speed Serial Application Specific Integrated Circuit (ASIC) |
| HMS | Hybrid Management Sub-layer |
| HNv1 | Home Networking Version 1 |
| HO | Higher Order |
| HOD | HBO on Demand |
| HO-DSP | High Order-Domain Specific Part |
| HO-DXC | Higher Order Digital Cross Connect |
| HOM | High-Order Modulation |
| HomePNA | Home Phoneline Networking Alliance |
| HOP | High Order Path |
| HO-POH | Higher Order – Path Overhead |
| HOVC | Higher Order Virtual Concatenation |
| HP | Hairpin; Higher Order Path; Homes Passed |
| HPF | High Pass Filter |
| HPFM | High-speed Packet Forwarding Module |
| HPNA | Home Phoneline Networking Alliance |
| HPOV | Hewlett Packard Open View |
| HP-UX | Hewlett Packard’s UNIX-based OS that runs on HP’s enterprise servers |
| HRD | Hardware Release Document; Hardware Requirements Document |
| HS | High Speed |
| HSB | High Speed Bus |
| HSD | High Speed Data |
| HSSI | High Speed Serial Interface |
| HT | High Threshold |
| HTML | Hyper Text Markup Language |
| HTTP | Hypertext Transfer Protocol |
| HVAC | Heating, Ventilation, and Air-Conditioning |
| HW | Hardware |
| Hz | Hertz |
| I/O | Input/Output |
| I/O | Input/Output |
| IAD | Integrated Access Device; Interface Access Device |
| IAS | Internet Access Service; Internet Authentication Service |
| IBCC | In-Band Communication Channel |
| IC | Integrated Circuit |
| ICB | Independent Customer Builds |
| ICD | International Code Designator |
| ICLR | Ingress Cell Loss Ratio |
| ICMP | Internet Control Message Protocol |
| ICNV | Input- Command Not Valid |
| ICP | IMA Control Protocol |
| ICPT | Installed Circuit Pack Type |
| ICR | Initial Cell Rate |
| ID | Identifier; Identification |
| IDE | Integrated Device Electronics |
| IDF | Intermediate Distribution Frame; Invalid Data Flag |
| IDH | Identification High byte |
| IDI | Initial Domain Identifier |
| IDL | Interface Definition Language |
| IDNV | Input- Data Not Valid |
| IDP | Initial Domain Part |
| IDS | Intrusion Detection System |
| IDT | Inter-DXC Trunk |
| IE | Information Element |
| IEC | Incoming Error Count; InterExchange Carrier |
| IEEE | Institute of Electrical and Electronics Engineers |
| IETF | Internet Engineering Task Force |
| IF | Intermediate Frequency |
| IFC | Initial First Cost |
| IG | Information Group |
| IGMP | Internet Group Multicast Protocol |
| IIAC | Input – Invalid Access Identifier |
| IIOP | CORBA Internet Inter-ORB Protocol |
| IISP | Interim Interface Signaling Protocol |
| ILA | Intermediate Light Amplification; Integrated Line Amplifier; In-Line Amplifier |
| ILEC | Incumbent Local Exchange Carrier |
| ILM | Integrated Laser Module; Integrated Laser Modulator |
| ILMI | Interim Link Management Interface; Interim Local Management Interface |
| ILOG | Information Log; Incoming Log |
| ILR | Issues List Report |
| IM | Instant Messaging |
| IMA | Inverse Multiplexing over ATM |
| IMBS | Ingress Maximum Burst Size |
| IMD | Intermodulation Distortion |
| IME | Interface Management Entity |
| IMT | Inter Machine Trunk |
| IN | Intelligent Network |
| I-NET | Institutional Network |
| INM | Integrated Network Manager |
| INMS | Integrated Network Management Suite; Integrated Network Management System |
| INT | Internal; Internal Clock |
| INTAP | Interoperability Technology Association for information Processing |
| INTP | Internodal Tunneling Protocol |
| IntServ | Integrated Services |
| INVW | Invalid Word Count |
| IOA | Input/Output Adapter |
| IOF | Inter-office Fiber |
| IOR | Interoperable Object Reference |
| IP | Internet Protocol |
| IPC | Inter-process Communications; InterProcess or InterProcesser Control |
| IPCR | Ingress Peak Cell Rate |
| IPG | Inter-Packet Gap |
| IPM | Interested Party Multicast |
| IPMS | Interested Party Multicast Service |
| IPOA | Internet Protocol over ATM |
| IPPV | Impulse Pay per View |
| IPsec | Internet Protocol Security |
| IPTA | Internet Protocol Transport Agreement |
| IPTV | IP Television |
| IR | Intermediate Reach |
| IRD | Integrated Receiver/Decoder |
| IRT | Integrated Receiver/Transcoder |
| IS | In Service; Intermediate System |
| ISA | Industry Standard Architecture |
| IS-ANR | In Service – Abnormal |
| IS-ANRST | In Service – Abnormal and Restricted |
| ISCC | InterSwitch Communications Channel |
| ISCR | Ingress Sustainable Cell Rate |
| iSCSI | Internet Small Computer System Interface; SCSI Protocol over TCP/IP |
| ISD | Idle Signal Detection |
| ISDN | Integrated Services Digital Network |
| IS-IS | Intermediate System to Intermediate System |
| ISM | Industrial Scientific Medical |
| IS-NR | In Service – Normal |
| ISO | International Standards Organization |
| ISP | Internet Service Provider; Inside Plant |
| IS-RST | In Service – Restricted |
| ISTP | Internet Signaling Transport Protocol |
| ISV | Independent Software Vendor |
| IT | Information Technology |
| ITA | Installation, Test, and Acceptance |
| ITC | Independent Transmit Clock |
| ITE | Information Technology Equipment |
| ITL | International Telecommunications Union |
| ITS | Intelligent Transportation System; Institute for Telecommunications Sciences |
| ITT | International Telephone and Telegraph |
| ITU | International Telecommunication Union |
| ITU-T | International Telecommunications Union – Telecommunications Standards Section |
| IUC | Interval Usage Code |
| IWF | Interworking Function |
| IXC | Inter-exchange Carrier |
| J0 | J Zero; Section trace byte in performance monitoring (J-zero) |
| J2EE | Java 2 Enterprise Edition |
| JBR | Jabber Count |
| JDBC | Java Database Connectivity |
| JDK | Java Development Kit |
| JDMK | Java Dynamic Management Kit |
| JEM | JAVA™ Element Manager |
| JMS | JAVA™ Messaging System |
| JNDI | Java Naming and Directory Interface |
| JPEG | Joint Photographic Experts Group |
| JRE | Java Runtime Environment |
| JTAG | Joint Test Action Group |
| JVM | Java Virtual Machine |
| K1 | SONET or SDH overhead byte of VLSR or MSP/MS-SPRing (see K2) |
| K2 | Used with K1-SONET or SDH overhead byte for VLSR or MSP/MS-SPRing |
| Kb | Kilobit |
| KB | Kilobyte |
| Kb/s | Kilobits per second |
| KB/s | Kilobytes per second |
| Kbit/s | Kilobits per second |
| Kbps | Kilobits per second |
| KBps | Kilobytes per second |
| kHz | KiloHertz |
| Km | Kilometer |
| Ksh | Korn Shell |
| ksym/s | Kilosymbols per Second |
| ksym/sec | Kilosymbols per Second |
| kVA | 1000 Volt Amperes |
| kW | Kilowatt |
| L | Current |
| L2TP | Layer 2 Tunneling Protocol |
| L3 | Layer 3 |
| LA | Line Adapter |
| LAC | Local Access Concentrator |
| LADM | Linear Add/Drop Multiplexer |
| LAN | Local Area Network |
| LANE | Local Area Network Emulation |
| LAP | Link Access Procedure; Link Access Protocol |
| LAPB | Link Access Procedure Balanced |
| LAPD | Link Access Procedure-D Channel (X 25) |
| LAPF | Link Access Procedure for Frame-Mode Bearer Services |
| LAPS | Link Access Procedure |
| LASER | Light Amplification by Stimulated Emission of Radiation |
| LATA | Local Access and Transport Area |
| LBC | Laser Bias Current |
| LBCL | Laser Bias Current Level |
| LBCN | Normalized Laser Bias Current |
| LBO | Line Build Out |
| LC | Lucent Connector; Line Card |
| LCAP | Local Craft Access Panel |
| LCAS | Link Capacity Adjustment Scheme |
| LCC | Life-Cycle cost; Link Control Channel |
| LCD | Liquid Crystal Display |
| LCL | Lower Confidence Limit |
| LCN | Local Computer Network; Logical Channel Number; Local Communications Network |
| LCR | Least Cost Routing |
| LCT | Large Capacity Terminal |
| LD | Laser Diode |
| LDAP | Lightweight Directory Access Protocol |
| LDCC | Line Data Communications Channel |
| LDP | Label Distribution Protocol |
| LDS | Local Digital Switch |
| LEAF | Large Effective Area Fiber |
| LEC | Local Exchange Carrier |
| LECS | LAN Emulation Configuration Server |
| LED | Light Emitting Diode |
| LEO | Low Earth Orbit |
| LER | Label Edge Router |
| LES | LAN Emulation Server |
| LF | Line Fail |
| LFE | Line Far End |
| LGN | Logical Group Node |
| LGX | Light-Guide Crossconnects |
| LH | Logical Host |
| LIC | Line Interface Card |
| LIF | Line Interface |
| LIM | Line Interface Module |
| LIP | Local Information Packet |
| LIU | Line Interface Unit |
| LLC | Logical Link Control |
| LLSDCC | Lower-Layer Section DCC |
| LM | Line Module |
| LMI | Local Management Interface |
| LMP | Link Management Protocol |
| LO | Low Order |
| LOADM | Lightweight Optical Add/Drop Multiplexer |
| LOC | Loss of Clock |
| Locn | Location |
| LO-DXC | Low Order Digital Cross Connect |
| LOF | Loss of Frame |
| LOF-P | Path Loss of Frame |
| LOH | Line Overhead |
| LOM | Loss of Multiframe; List of Materials |
| LOP | Loss of Pointer |
| LOPDP | Loss of Pointer Decay Period |
| LOPI | Loss of Pointer Inhibit |
| LOPIP | Loss of Pointer Integration Period |
| LOP-P | Loss of Pointer – Path |
| LOP-V | VT Loss of Pointer |
| LOS | Loss of Signal |
| LOSS | Loss of Signal Seconds |
| LOVC | Low-Order VC |
| LOW | Local Orderwire |
| LP | Line Processor; Lockout of Protection; Low Order Path |
| Lport | Logical port |
| LP-S | Lockout of Protection – Span |
| LP-S/SF-P | Lockout of Protection – Span/Signal Fail – Protection |
| LR | Long Reach (fiber); Line Regeneration Equipment |
| LRDC | Long Reach Daughter Card |
| LSA | Low Speed ADM |
| LSA-E-EH | Low Speed ADM Electrical (10/100 Base-T) Environmentally Hardened |
| LSA-O-EH | Low Speed ADM Optical (100 Base-FX) Environmentally Hardened |
| LSB | Least Significant Bit |
| LSF | Loss of Signal or Frame indication signal |
| LSL | Lower Specification Limit |
| LSM | Loss of Sync Message |
| LSN | Logical Subnetwork |
| LSP | Label Switched Path; Local Service Provider |
| LSR | Label Switch Router |
| LSSGR | LATA Switching System Generic Requirements |
| LT | Low Threshold; Laser Temperature |
| LTE | Line Terminating Equipment |
| LTN | Local Transport Network (fiber ring) |
| LTP | Link Termination Point; Logical Termination Point |
| LTS | Loop Testing System; Long Term Storage |
| LU | Line Unit |
| LVD | Low-Voltage Distribution |
| LWP | Low Water Peak |
| LZS | Lempel Ziv Stac |
| M12 | MUX DS-1 into DS2 |
| M13 | MUX DS-1 into DS3 |
| M23 | MUX DS-2 into DS3 |
| MAC | Media Access Control; Medium Access Control |
| MAN | Metropolitan Area Network |
| MAP | Main Audio Program |
| MAU | Media Access Unit |
| Mb | Megabit |
| MB | Megabyte |
| Mb/s | Megabits per second |
| MB/s | Megabytes per second |
| Mbaud | Megabaud |
| Mbits/s | Megabits per second |
| Mbps | Megabits per second |
| MBps | Megabytes per second |
| MBS | Maximum Burst Size |
| MCP | Management Control Processor |
| MCR | Minimum Cell Rate; Minimum Cost Routing |
| MCT | Maintenance Channel Transparency |
| MCTF | Motion Compensated Temporal Filtering |
| MD | MetroDirector K2 Platform |
| MDF | Main Distribution Frame |
| MDU | Multiple Dwelling Unit |
| mDVR | Multi-TV Digital Video Recorder |
| MEA | Mismatch of Equipment and Attributes |
| MEGACO | Media Gateway Control Protocol |
| MER | Modulation Error Ratio |
| MFR | Multilink Frame Relay |
| MG | Media Gateway |
| MGC | Media Gateway Controller |
| MGCP | Media Gateway Control Protocol |
| MGN | Management Gateway Node |
| MHz | Megahertz |
| MIB | Management Information Base |
| MID | Message Identifier |
| MIPS | Millions of Instructions per Second |
| MIT | Management Information Tree |
| MiTTs | Minutes of Telecommunications Traffic |
| MJ | Major |
| ML | Mediation Layer |
| MLMD | Multiplexer/Demultiplexer |
| MLPPP | Multi-Link Point-to-Point Protocol |
| mm | millimeter |
| MM | Multimode; Multimedia |
| MME | Multiwave Management Element |
| MMF | Multi-Mode Fiber |
| MML | Man Machine Language |
| MMO | Main Material Order |
| MMP | Multiwave Management Element |
| MN | Minor |
| MO | Managed Object |
| MOD | Module; Movies on Demand |
| MODEM | Modulator-Demodulator |
| MOF | Managed Object Framework |
| MOP | Method of Procedure |
| MOR | Multi-wavelength Optical Repeater |
| MOS | Mean Opinion Score |
| MP | Management Portal |
| MP3 | MPEG-2 Layer 3 |
| MPCKTS | Multicast Packet Count |
| MPEG | Moving Pictures Expert Group |
| MPI | Multi-Path Interface; Multi-Path Interference |
| M-Plane | Management Plane |
| MPLmS | Multi-Protocol Lambda Switching |
| MPLS | Multi Protocol Label Switching |
| MPLS-CP | MPLS Control Plane |
| MPN | Mode Partition Noise |
| MPOA | Multi Protocol over Asynchronous Transfer Mode |
| MPS | Modeling and Planning Suite |
| MPS | Modeling and Planning System; Modeling and Planning Suite |
| MPT | Multiplex Pass-Through |
| MPTS | Multiple Program Transport Stream |
| MR | Modification Request; Material Request; Medium Reach |
| MRRB | Maintenance Requirements Review Board; Material Release Review Board |
| ms | Milliseconds |
| MS | Multiplex Section |
| MSA | Mediation Services Administrator |
| MS-AIS | Multiplex Section – Alarm Indication Signal |
| MSB | Most Significant Bit |
| MSC | Metro Shelf Controller; Microsoft Cluster Server |
| MSF | Multiservice Switching Forum |
| MSM | Metro Switching Manager; Metro Switching Mismatch |
| MSN | Multi-Subnetwork |
| MSNM | Metro Switching Network Manager |
| MSNM ML | Metro Switching Network Manager Mediation Layer |
| MSO | Multiple System Operator |
| MSOH | Multiplexer Section Overhead |
| MSP | Multiplex Section Protection; Multiservice Switching Path |
| MS-P | Manual Switch – Protection |
| MSPP | Multiservice Provisioning Platform |
| MSPVC | Management Soft Permanent Virtual Circuit |
| MS-R | Manual Switch – Ring |
| MS-RDI | Multiplex Section – Remote Defect Indication |
| MS-REI | Multiplex Section Remote Error Indication |
| MS-S | Manual Switch – Span |
| MS-Spring/MSPR | Multiplex Section Shared Protection Ring |
| MST | Mountain Standard Time; Multiplex Section Termination |
| MSTE | Multiplex Section Terminating Equipment |
| MS-W | Manual Switch – Working |
| MTA | Multimedia Terminal Adapter |
| MTBF | Mean Time between Failure |
| MTIE | Maximum Time Interval Error |
| MTM | Metro Transport Manager |
| MTTP | Transparent Connection Termination Point |
| MTTR | Mean Time to Repair |
| MTTU | Mean Time to Understand |
| MTU | Maximum Transmission Unit |
| MUX | Multiplexer |
| MUXCVR | Muxceiver |
| mV | Millivolt |
| MVOA | Miniature Variable Optical Attenuator |
| MW | MultiWave® |
| MZ | Mach-Zehnder |
| NA | No Alarm; Not Alarmed; Not Applicable; Not Available; Numerical Aperture |
| NAD | Network Access Domain |
| NAP | Network Access Point |
| NAPT | Network Address and Protocol Translation |
| NAS | Network Access Server; Network Attached Storage |
| NAT | Network Address Translation |
| NBI | Northbound Interface |
| NBK | No Backup |
| NC | Nodal Controller; Normally Closed (contacts) |
| NCC | Network Control Center |
| NCCI | Network Call Correlation Identification |
| NCP | Nodal Control Point; Nodal Control Processor |
| NCP&D | Network Capacity Planning and Delivery |
| NCR | Non-Conformance Report |
| NCS | Network Computing System; Network Control System; Network Call Signaling |
| NCTA | National Cable & Telecommunications Association |
| NDC | National Destination Code |
| NDF | New Data Flag |
| NDIS | Network Design and Inventory System |
| NDMH | Non-Degraded Modem Hours |
| NDP | Network Discovery Protocol; Neighbor Discovery Protocol |
| NDSF | Non-Dispersion Shifted Fiber |
| NDVR | Network Digital Video Recording |
| NE | Network Element |
| NE/FE | Near End/Far End |
| NEBS | Network Equipment Building Standards; Network Equipment Building Systems |
| NEC | National Electric Code |
| NEF | Network Element Function |
| NEG | Negative Terminal |
| NEID | Network Element Identification |
| NEIR | Network Element Information Request |
| NEMA | National Electrical Manufacturers Association |
| NFS | Networked File System |
| NGDLC | Next Generation Digital Loop Carrier |
| NG-L1 | Next Generation Layer 1 |
| NGNA | Next Generation Network Architecture |
| NI | Network Interface |
| NIC | Network Interface Card |
| NID | Network Interface Device |
| NIDU | Network Interface Data Unit |
| NIS | Network Infrastructure Solutions |
| NIU | Network Interface Unit |
| NLA | Network Layer Address; Network Layer Agent |
| NLC | Node Line Card |
| NLD | Neighbor Link Discovery |
| NLPI | Network Layer Protocol Identifier |
| nm | nanometer |
| NM | Network Management; Network Manager; Network Management; Node Manager |
| NMA | Network Monitoring and Analysis |
| NME | Network Management Ethernet |
| NMF | Node-level Management Function |
| NML | Network Management Layer |
| NMS | Network Management System |
| NN | N key on keyboard for a no response |
| NNI | Network to Network Interface; Network Node Interface |
| NNIF | Network to Network Interface |
| NNM | Network Node Manager |
| NNTP | Network News Transfer Protocol |
| NO | Network Object; Normally Open (contacts) |
| NOC | Network Operations Center |
| NOCC | Network Operations Control Center |
| NPC | Network Parameter Control |
| NPR | Noise Power Ratio |
| NR | No Reply |
| NRT | Non-Real Time |
| NRTL | Nationally Recognized Test Laboratory |
| NRTVBR | Non Real-Time Variable Bit Rate |
| NRZ | Non-Return to Zero |
| ns | Nanosecond |
| NSA | Non Service Affecting |
| NSAP | Network Service Access Point |
| NSI | Network Side Interface |
| NSN | Nationally Significant Number |
| NSP | Node Switch Provider; Node Switch Processor |
| NT | Window New Technology |
| NTF | No Trouble Found |
| NTFCNCDE | Notification Codes (TL1) |
| NTFS | New Technology File System |
| NTP | Network Time Protocol |
| NTS | Near Term Storage; Network Time Synchronization |
| NTSC | National Television Standards Committee |
| NUT | Non-preemptive Unprotected Traffic |
| NVM | Non-Volatile Memory |
| NVRAM | Nonvolatile Random Access Memory |
| NZDSF | Non-Zero Dispersion Shifted Fiber |
| OA | Optical Amplifier |
| OADM | Optical Add/Drop Multiplexer |
| OAM | Operations, Administration and Maintenance |
| OAMCell | Operations, Administration and Maintenance Cell |
| OAMP | Operation, Administration, Maintenance and Provisioning |
| O-BLSR | Optical-Bidirectional Line Switched Ring |
| OC | Optical Carrier |
| OC-1 | Optical Carrier level 1, SONET bit rate = 51.84 Mb/s |
| OC-12 | Optical Carrier level 12, SONET bit rate = 622.08 Mb/s |
| OC-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 |
| OC-48 | Optical Carrier level 48, SONET bit rate = 2.488 Gb/s |
| OCAP | OpenCable Application Platform |
| OCH | Optical Channel |
| OCI | Open Connection Indication |
| OC-n | Optical Carrier-number; Optical Carrier where N denotes a multiple of 51.84 Mb/s |
| OCT | Octet Count |
| OCTU | Optical Channel Transport Unit |
| OCXO | Oven-Controlled Crystal Oscillator |
| ODA | Outlet Digital Adapter |
| ODACS | Optical Data Acquisition and Control System |
| ODBMS | Object Database Management System |
| ODF | Optical Distribution Frame |
| ODPR | Optically Dedicated Protection Ring |
| ODUk | Optical channel Data Unit where k is 1 or 2 |
| OEO | Optical-to-Electronic-to-Optical |
| OEPL | Optical Ethernet Private Line |
| OEPLAN | Optical Ethernet Private Local Area Network |
| OEVPL | Optical Ethernet Virtual Private Line |
| OEVPLAN | Optical Ethernet Virtual Private Local Area Network |
| OFC | Open Fiber Control; Optical Fiber Communication |
| OFDM | Orthogonal Frequency Division Multiplexing |
| OFS | Out of Frame Second |
| OID | Object Identifier |
| OIU | Operator Interface Unit; Optical Interface Unit; Office Interface Unit |
| OLA | Optical Line Amplifier; Optical Link Analysis |
| OLB | Optical Link Budget |
| OLM | Optical Link Module |
| OLMP | Optical Link Management Protocol |
| OLS | Optical Line System |
| OLT | Optical Line Termination; Optical Line Terminal |
| OLTP | OSRP Link Termination Point |
| OM | Optical Module |
| OMC | Operation and Maintenance Center |
| OMG | Object Management Group |
| OMS | ON-Center Management Suite |
| ON | Optical Network |
| ONE | Optical Network Element |
| ONM | ON-Center Network Manager |
| ONT | Optical Network Terminal |
| ONU | Optical Network Unit |
| OO | Optical-to-Optical |
| OOB | Out of Band |
| OOF | Out of Frame |
| OOK | On-Off Keying |
| OOM1 | Out of Multi Frame Stage 1 |
| OOM2 | Out of Multi Frame Stage 2 |
| OOO | Optical – Optical – Optical |
| OOR | Out of Range |
| OOS | Out of Service |
| OOS-MA | Out of Service-Management |
| OOS-MAANR | Out of Service-Management and Abnormal |
| OpEx | Operations Expenditure |
| OPM | Optical Performance Monitoring; Optical Power Meter |
| OPR | Optical Power Received |
| OPS/INE | Operations Provisioning System/Intelligent Network Element |
| OPT | Optical Power Transmit |
| OPTORL | Optical Return Loss |
| OPTX AE | OPTX Automation Engine |
| OPTX NM | OPTX Network Manager |
| OpUk | Optical channel payload Unit where k is 1 or 2 |
| OPVC | Optical channel Payload Virtual Container (timeslot) |
| ORB | Object Request Broker |
| ORIG | Original; Originating |
| ORL | Optical Return Loss |
| ORP | Optical Routing Protocol |
| OS | Operating System |
| OSA | Optical Spectrum Analyzer |
| OSC | Optical Supervisory Channel; Optical Service Channel |
| OSDS | Operations Systems Data Server |
| OSGI | Open Services Gateway Initiative |
| OSHA | Occupational Safety and Health Act |
| OSI | Open Systems Interconnection |
| OSM | OSC Splitter Module |
| OSMINE | Operations Systems Modifications for the Integration of Network Elements |
| OSNR | Optical Signal-to-Noise Ratio; Open Signal-to-Noise Ratio |
| OSP | Optical Signaling Protocol; Outside Plant |
| OSPF | Open Shortest Path First |
| OSPR | Optically Shared Protection Ring |
| OSRP | Optical Signaling and Routing Protocols |
| OSS | Operations Support System |
| OSSAN | Operations Support System Access Nodes |
| OSS-AU | Out of Service-Autonomous |
| OSS-AUMA | Out of Service-Autonomous and Management |
| OSS-AURST | Out of Service-Autonomous and Restricted |
| OSWF | On-site Work Force |
| OTC | Operations Technical Center; Optical Transport Card |
| OTDR | Optical Time Domain Reflectometer |
| OTGR | Operations Technology Generic Requirements |
| OTN | Optical Transport Network |
| OTS | Optical Transport System |
| OTS RPTR | OTS Repeater |
| OTU | Optical Transport Unit |
| OUI | Organizationally Unique Identifier |
| OUNI | Optical User Network Interface |
| O-UPSR | Optical-Unidirectional Path Switched Ring |
| OUSM | Optical Utility Services Manager |
| OUSP | Optical Utility Services Platform |
| OW | Order Wire |
| OXC | Optical Cross Connect |
| P2P | Peer to Peer |
| PA | Port Adapter; Pre-Amplifier |
| PAD | Power Attenuation Device |
| PAN | Personal Area Networking |
| PARP | Proxy ARP |
| PAT | Program Association Table |
| PAX | Path Adaptation and X-Connect |
| PB | Petabyte |
| PBOR | Primary-Backup Object Replication |
| PBX | Private Branch Exchange |
| PC | Personal Computer; Physical Contact; Processor Card |
| PCA | Protection Channel Access |
| PCB | Printed Circuit Board |
| PCC | Processor Communication Channel |
| PCI | Peripheral Component Interconnect |
| PCM | Pulse Code Modulation |
| PCMCIA | Personal Computer Memory Card Interface Adaptor |
| PCMM | PacketCable Multimedia |
| PCN | Program Change Notice; Product Change Notice |
| PCO | Pre-Conditioned Order |
| P-Code | Product Code |
| PCR | Peak Cell Rate |
| PCS | Provincial Civil Service & Personal Communication Service |
| PDA | Personal Digital Assistant |
| PDAP | Power Distribution and Alarm Panel |
| PDC | Passive Dispersion Compensator |
| Portable Document Format | |
| PDH | Pleisiochronous Digital Hierarchy |
| PDI | Payload Defect Indication |
| PDL | Polarization Dependent Loss |
| PDP | Policy Decision Point |
| PDU | Power Distribution Unit; Protocol Data Unit |
| PEG | Public, Education, Government |
| PEM | Processor Enhancement Module; Processor Element Module |
| PEP | Policy Enforcement Point |
| PESQ | Perceptual Evaluation of Speech Quality |
| PFE | Path Far End |
| PFM | Packet Forwarding Module |
| PFO | Premium Feature Open |
| PG | Peer Group; Protection Group |
| PGID | Peer Group Identifier |
| PGL | Peer Group Leader |
| PHY | Physical Layer Device; Physical |
| PIC | Programmable Interrupt Controller |
| pid | Password Identifier |
| PID | Personally Identifiable Data; Protocol Identifier; Packet Identifier; Personal Identification |
| PIF | Packet Interface FPGA |
| PIN | Photo Intrinsic; Positive-Intrinsic Negative; Personal Identification Number |
| PING | Packet Internet Groper |
| PIP | Plug-In Provisioning |
| PJ | Pointer Justification |
| PL | Packet Loss |
| PLC | Packet Loss Concealment |
| PLCN | Pilot Line Change Notification |
| PLCP | Physical Layer Convergence Protocol |
| PLD | Programmable Logic Device |
| PLL | Phase Locked Loop |
| PLM | Payload Label Mismatch |
| PLM-P | Payload Label Mismatch – Path |
| PLM-V | Payload Label Mismatch – VT |
| PLN | PNNI Logical Node |
| PLO | Path Layer Overhead |
| PM | Performance Management; Performance Monitoring; Program Manager; Project Manager |
| PMA | Power Management Algorithm |
| PMBB | Performance Monitoring Building Block |
| PMD | Polarization Mode Dispersion |
| PMDC | PMD Compensator |
| PMM | Power Management Module |
| PMP | Point-to-MultiPoint |
| PN | Physical Node |
| PNC | Physical Node Controller |
| PNNI | Private Network-to-Network Interface; Private Network Node Interface |
| PO | Purchase Order |
| POC | Point Of Contact |
| POH | Path Overhead |
| POM | Project Office Manager |
| PON | Passive Optical Network |
| POP | Point of Presence |
| POR | Power on Reset |
| POS | Packet over SONET; Positive Terminal |
| POST | Power on Self Test |
| POTS | Plain Old Telephone Service |
| PPC | Power PC |
| PPD | Partial Packet Discard |
| PPJC | Positive Pointer Justification Count |
| PPL | Point-to-Point Link |
| ppm | Pulse Position Modulation; Pulses per Million |
| PPM | Parts per Minute; Parts per Million; Pulses per Million |
| Pport | Physical port |
| PPP | Point-to-Point Protocol |
| PPS | Path Protection Switched; Pulses per Second |
| PPT | Power Passing Tap |
| PRBS | Pseudo Random Bit Sequence |
| PRC | Primary Reference Clock |
| PRI | Primary Rate Interface |
| PRNG | Pseudo Random Number Generators |
| PROM | Programmable Read Only Memory |
| PROT | Protocol; Protection |
| PRS | Primary Reference Source |
| PS | Power Supply; Policy Server |
| ps/nm-km | Pico-second |
| PSA | PacketCable Service Agreement |
| PSBF | Protection Switching Byte Failure |
| PSC | Protection Switching Count |
| PSD | Protection Switching Duration |
| PSEL | Presentation Suite |
| PSI | Program Specific Information |
| PSL | Path Signal Label |
| PSM | Persistent Stored Module |
| PSN | Packet Switch Node; Packet Switched Network |
| P-SNC | Permanent SNC |
| PSQM | Perceptual Speech Quality Measurement |
| PSR | Protection Side Regeneration; Path Switched Ring |
| PST | Primary State; Pacific Standard Time |
| PSTN | Public Switched Telephone Network |
| PSU | Power Supply Unit; Packet Switch Unit |
| PT | Pass-Through; Payload Type |
| PTE | Path Terminating Equipment |
| PTI | Payload Type Indicator |
| PTP | Physical Termination Point; Point-To-Point; Path Termination Point |
| PTSE | PNNI Topology State Element |
| PTSP | PNNI Topology State Packet |
| PV | Protocol Violation |
| PVC | Permanent Virtual Circuit; Poly Vinyl Chloride; Private Virtual Circuit |
| PVR | Personal Video Recorder |
| PWB | Printed Wire Board |
| PWM | Pulse Width Modulation |
| PWR | Power |
| Q3 | Telecommunications Management Network (TMN) Interface |
| QAM | Quadrature Amplitude Modulation |
| QL | Quality Level |
| QMC | QUICC Multichannel Controller |
| QoS | Quality of Service |
| QPSK | Quadrature Phase Shift Keying |
| QUICC | Quad Integrated Communications Controller |
| R&D | Research and Development |
| R.H. | Relative Humidity |
| R/W | Read/Write |
| R/W | Read/Write |
| RADIUS | Remote Authentication Dial-In User Service |
| RAI | Remote Alarm Indication |
| RAID | Redundant Array of Inexpensive Disk; Redundant Array of Independent Disk |
| RAIG | Resource Availability Information Group |
| RAM | Random Access Memory |
| RAN | Regional Area Network |
| RBF | Reconfigurable Blocking Filter |
| RBM | Regional Business Manager |
| RBOC | Regional Bell Operating Company |
| RBW | Resolution Bandwidth |
| RCC | Routing Control Channel |
| RCV | Receiver |
| RCVR | Receiver |
| RDF | Rate Decrease Factor |
| RDI | Remote Defect Indication |
| RDI-L | Remote Defect Indication – Line |
| RDI-P | Remote Defect Indication – Path |
| RED | Random Early Detection; Random Early Discard |
| REF | Reference |
| REI | Remote Error Indication |
| REI-L | Remote Error Indication – Line |
| REI-P | Remote Error Indication – Path |
| Rev. | Revision |
| RF | Radio Frequency |
| RFC | Request for Comment |
| RFI | 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) |
| RFT | Radio Frequency Transmitter |
| RG | Residential Gateway |
| RHC | Regional Holding Company |
| RIB | Routing Information Base |
| RIN | Relative Intensity Noise |
| RIP | Routing Information Protocol |
| RJ | Registered Jack |
| RKS | Record Keeping Server |
| RMA | Return Material Authorization; Replace Material Authorization |
| RMAN | Recovery Manager |
| RMI | Remote Method Invocation |
| RMS | Root Mean Square |
| RNR | Not Ready to Receive; Remote Failure Indication |
| ROADM | Re-configurable Optical Add/Drop Multiplexer |
| ROC | Regional Operations Center |
| ROI | Return on Investment |
| ROM | Read Only Memory |
| ROW | Return Order Wire |
| RPM | Revolutions per Minute |
| RPR | Resilient Packet Ring |
| RR | Ready to Receive; Reverse Request |
| RRB | Reliability Review Board |
| RRO | Record Route Object |
| RR-R | Reverse Request – Ring |
| RR-S | Reverse Request – Span |
| RS | Regenerator Section; Reed-Solomon |
| RS-E | Ring Switch – East |
| RSOH | Regenerator Section Overhead |
| RSP | Route Switch Processor |
| RST | Regenerator Section Terminating |
| RSVP | Resource Reservation Protocol |
| RSVP-TE | Resource Reservation Protocol with Traffic Engineering |
| RS-W | Ring Switch – West |
| RT | Remote Terminal; Real Time |
| RTC | Real-Time Clock |
| RTI | Real-Time Ingest |
| RTN | Return (voltage return) |
| RTOS | Real-Time Operating System |
| RTP | Routing Table Protocol; Real-Time Transport Protocol; Routine Task Procedure |
| RTRV | Retrieve |
| RTS | Ready to Send; Request to Send; Real Time Operation System |
| RTSP | Real Time Streaming Protocol |
| RTT | Round-trip Time |
| RTU | Right to Use |
| RTVBR | Real-Time Variable Bit Rate Traffic |
| RU | Rack Unit |
| RW | Rewind |
| RWA | Routing and Wavelength Assignment |
| RX | Receive |
| Rx Line | Receive Line |
| RZ | Return to Zero |
| RZ-DPSK | Return to Zero Differential Phase Shift Keying |
| s | Second |
| s.f. | Square Foot |
| S/IMP | Signal to Impulse Ratio |
| S/N | Signal to Noise Ratio |
| SA | Service-Affecting |
| SAAL | Signaling ATM Adaptation Layer |
| SABLIME | Product Administration System (AT&T) |
| SADM04-e | SONET/SDH Add/Drop Multiplexer (ONLINE Edge Platform) |
| SAN | Storage Area Network |
| SAP | Secondary Audio Program |
| SAR | Segmentation and Reassembly |
| SARP | Switching Address Resolution Protocol |
| SAS | Severely Errored Frame and AIS Seconds |
| SASE | Standalone Synchronization |
| SATA | Serial AT Attachment |
| SATCOM | Satellite Communications |
| SATT | Synchronization, Alarms, and Telemetry Termination |
| SAW | Surface Acoustic Wave |
| SBLK | Errored Superblocks |
| SBS | Stimulated Brillouin Scattering |
| SBV | Switched Broadcast Video |
| SBW | Signal Bandwidth |
| SC | Service Channel; Square Connector; Shelf Controller |
| SCC | Serial Communications Controller; Serial Communications Channels |
| SCCI | Small Computer System Interface |
| S-CDMA | Synchronous Code Division Multiple Access |
| SCM | Service Channel Modem; Sub-carrier Multiplexing |
| SCN | Service Channel Network; Shared Content Network |
| SCR | Sustainable Cell Rate; Silicon Controlled Rectifier |
| SCSI | Small Computer System Interface |
| SCTE | Society of Cable Telecommunications Engineers |
| SD | Signal Degrade; Signal Detect; Standard Definition |
| SDCC | Section Data Communications Channel |
| SDH | industries_cable Synchronous Digital Hierarchy |
| SDI | Secure Digital Interface; Serial Digital Interface |
| SDL | Synchronous Data Link; Synchronous Delay Line |
| SDLC | Synchronous Data Link Control |
| SDMH | Severely Degraded Modem Hours |
| SDP | Session Description Protocol |
| SD-P | Signal Degrade – Path |
| SD-R | Signal Degrade – Ring |
| SDRAM | Synchronized Dynamic Random Access Memory |
| SD-S | Signal Degrade-Span |
| SDTV | Standard Definition Television |
| SDU | Service Data Unit |
| SE | Systems Engineer |
| SEAL | Simple and Efficient Adaptation Layer |
| SEC | Secondary |
| SEF | Severely Errored Framing |
| SEFS | Severely Errored Frame Seconds |
| SEFS-S | Severely Errored Framing Seconds – Section |
| SEM | Service Entitlement Manager |
| SEMS | Severely Errored Multi-frame Seconds |
| SerDes | Serializer/DeSerializer |
| SES | Severely Errored Seconds |
| SES-L | Severely Errored Seconds – Line |
| SES-LFE | Severely Errored Seconds – Line Far End |
| SES-P | Severely Errored Seconds – Path |
| SES-PFE | Severely Errored Seconds – Path Far End |
| SESR | Severely Errored Second Ratio |
| SES-RS | Severely Errored Seconds – Regenerator Section |
| SES-S | Severely Errored Seconds – Section |
| SES-V | Severely Errored Seconds – VT |
| SES-VFE | Severely Errored Seconds – VT Far End |
| SETS | Synchronous Equipment Timing Source |
| SF | Signal Failure; Super Frame |
| SFD | Start of Frame Delimiter |
| SFDADM02-e | SONET/SDH Framed Data Add/Drop Multiplexer (ONLINE Edge Platform) |
| SFF | Small Form Factor (connector) |
| SFO | Sync Frequency Offset |
| SFP | Small Form-factor Pluggable |
| SF-R | Signal Failure – Ring |
| SF-S | Signal Failure – Span |
| SG | Signaling Gateway |
| SGC | Signaling Gateway Controller |
| sh | Bourne Shell |
| SHx | Shelf Number |
| SI | Serial Interface; Service Independent |
| SIC | System Integrity Control; Standard Industrial Classification |
| SID | System Identification number; Source Identifier |
| SIF | SONET Interoperability Forum; Switch Interface FPGA |
| SIM | Service Interface Module |
| SIP | Session Initiation Protocol |
| SLA | Service Level Agreement |
| SLIP | Serial Line Internet Protocol |
| SLM | Service Layer Manager |
| SLOSS | Synchronization Loss |
| SLR | Service Level Report |
| SM | Single Mode; Switching Module; Shelf Manager |
| SMB | Small and Medium Business |
| SMC | Serial Management Controllers; Standard Management Committee |
| SMDS | Switched Multimegabit Data Service |
| SME | Small and Medium Enterprise |
| SMF | Single Mode Fiber |
| SMIR | Single Mode Intermediate Reach |
| SML | Service Management Layer |
| SMLR | Single Mode Long Reach |
| SMM | Service Mediation Module |
| SMON | Switch Monitor |
| SMOP | Service Method of Procedure |
| SMS | Service Management Suite |
| SMT | Surface Mount Technology; Self-Monitoring Task |
| S-MTA | Standalone Multimedia Terminal Adaptor |
| SNA | Systems Network Architecture |
| SNC | Subnetwork Connection; Subnetwork Controller |
| SNCP | Subnetwork Connection Protection |
| SNCP/I | Subnetwork Connection Protection/Inherent monitoring |
| SNCP/N | Subnetwork Connection Protection/Non-intrusive monitoring |
| SNM | Switching Network Manager |
| SNMP | Simple Network Management Protocol |
| SNP | Sequence Number Protection |
| SNR | Signal-to-Noise Ratio |
| SNTP | Simple Network Time Protocol |
| SOA | Semiconductor Optical Amplifier |
| SOADM | Select Optical Add/Drop Multiplexer |
| SOF | Start of Frame |
| SOH | Section Overhead; State of Health |
| SOHO | Small Office/Home Office |
| SONET | industries_cable Synchronous Optical Network |
| SOP | Standard Operating Procedure |
| SP | Shelf Processor; Shelf Pump |
| SPC | SONET Permanent Circuit |
| SPE | Synchronous Payload Envelope |
| SPF | Shortest Path First |
| SPI | Serial Peripheral Interface; Service Provider Interface |
| SPM | Self-Phase Modulation |
| SPR/SPRing | Shared Protection Ring |
| SPTP | Service Path Termination Point |
| SPVC | Soft Permanent Virtual Connection; Soft Permanent Virtual Circuit |
| SQL | Structured Query Language |
| SR | Short Reach (fiber) |
| SRAM | Static Random Access Memory |
| SRD | Software Release Document |
| SRN | Software Release Notice |
| SRS | Stimulated Raman Scattering |
| SRTS | Synchronous Residual Time Stamp |
| SRVEFF | Service Affecting (TL1) |
| SSB | Single Sideband |
| SSCOP | Service Specific Connection Oriented Protocol |
| SSCS | Service-Specific Convergence Sublayer |
| SSEL | Session Selector |
| SSF | Server Signal Failure |
| SSL | Secure Sockets Layer |
| SSM | Synchronization-Status Messages |
| SSMF | Standard Single Mode Fiber |
| SST | Secondary Service State |
| SSTUR | Site-Specific Turn-Up Report |
| SSU | Synchronization Supply Unit |
| ST | Straight Terminus; Straight Tip |
| ST1 | Stratum 1 |
| ST2 | Stratum 2 |
| ST3 | Stratum 3 |
| ST3E | Stratum 3 Enhanced |
| ST4 | Stratum 4 (Asynchronous) |
| STB | Set-Top Box |
| STC | Stacking and Timing Card |
| STE | Section Terminating Equipment; Section Terminating Element |
| STII (2) | Type of optical connector |
| STM | Synchronous Transfer Mode |
| STM-0 | Synchronous Transfer Mode level 0, SDH bit rate = 51.84 Mb/s |
| STM-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/s |
| STM-4 | Synchronous Transfer Mode level 4, SDH bit rate = 622.08 Mb/s |
| STM-64 | Synchronous Transfer Mode level 64, SDH bit rate = 9953.28 Mb/s |
| STM-n | Synchronous Transport Module “n” |
| STM-nC | Synchronous Transport Module of level n concatenated |
| STMX | SONET/SDH Thin Multiplexer |
| STP | Spanning Tree Protocol; Shielded Twisted Pair |
| STS | Synchronous Transport Signal |
| STS-1 | Synchronous Transport Signal Level 1 |
| STS-3 | Synchronous Transport Signal Level 3 |
| STS-3c | Synchronous Transport Signal Level 3, concatenated |
| STS-n | Synchronous Transport Signal “n” |
| STS-Nc | Contiguous Concatenation of N STS-1 SPEs |
| STS-N-Xv | Virtual Concatenation of X STS-N SPEs |
| STU | Secure Telephone Unit; Synchronized, Traceability Unknown; Stratum Traceability Unknown |
| STU-P | Stratum Traceability Unknown-Provisioned |
| SVC | Switched Virtual Circuit |
| SVCC | Switched Virtual Channel Connection |
| SVOD | Subscription Video on Demand |
| SVP | Secure Video Processor |
| SVPC | Switched Virtual Path Connection |
| SW | Software |
| SWCA | Split Working Channel Access |
| SWID | Software Identifier |
| SWOD | Software ODACS |
| SX | Short Reach as in 1000Base-SX |
| SYNC | Synchronization |
| SYNCIO | Synchronized Input/Output |
| SYSLOG | System Log |
| T1 | Service or line operation at the DS-1 rate |
| T3 | Digital Carrier System for DS3 Signals |
| TAC | Transport Aggregated Circuit; Technical Assistance Center |
| TACS | Total Access Communications Systems |
| TADR | Target Address |
| TADRMAP | Target Address Map |
| TAP | Test Access Port; Technician Access Port |
| TARP | Target Identifier Address Resolution Protocol |
| TB | Terabyte |
| TBOS | Telemetry Byte Oriented Serial Protocol |
| TBU | Transport Bandwidth Unit |
| TBUS | Timing Bus |
| TC | Transmission Convergence; Transport Complex; Transport Channel |
| TCA | Threshold Crossing Alert; Timing Control and Access |
| TCBE | Total Corrected Bit Error |
| TCM | Trellis Coded Modulation; Transport Channel Members |
| TCMO | Transport Complex Managed Object |
| TCP | Transmission Control Protocol; Trouble Cleaning Procedure |
| TCP/IP | Transmission Control Protocol/Internet Protocol |
| TCTP | Transparent Connection Termination Point |
| TD | Traffic Director |
| TDEV | Time Deviation |
| TDM | Time Division Multiplexing |
| TE | Terminal Equipment |
| TEAL | CoreDirector® Events, Alarms, and Logging |
| TEC | Thermo-Electric Cooler |
| TED | Traffic Engineering Database |
| TEI | Terminal Endpoint Identifier; Terminal Equipment Identifier |
| Telco | Telephone Company |
| TELR | Talker Echo Loudness Rating |
| TEO | Telephone Equipment Order |
| TERM | Termination |
| TFT | Thin Film Transistor |
| TFTP | Trivial File Transfer Protocol |
| TG | Timing Generator |
| TGCP | Trunking Gateway Control Protocol |
| TGS | Time Generation System |
| THEC | Corrected Type Header Error Correction Code |
| THz | TeraHertz (1012 hertz) |
| TIA | Telecommunications Industry Association |
| TID | Target Identification; Terminal Identification |
| TIE | Time Interval Error |
| TIM | Trace Identifier Mismatch; Transmit Intermediate Multiplexer |
| TIM-S | Trace Identifier Mismatch – Section |
| TIRKS | Trunk Integrated Record Keeping System |
| TISSA | Time Space Switch Application-Specific Integrated Circuit |
| TKIP | Temporal Key Integrity Protocol |
| TL-1 | Transaction Language 1 |
| TL-1 CLI | Transaction Language One, Command Line Interface |
| TLC | Transport Logical Connection |
| TLI | Transaction Language Command Line Interface |
| TLS | Transparent LAN Services |
| TLSR | Transoceanic Line Switched Ring |
| TLV | Type-Length-Value |
| TM | Timing Module; Transaction Manager |
| TML | Telephony Markup Language |
| TMN | Telecommunications Management Network |
| TMO | Trans Metro Optical (platform) |
| tmout | Time Out |
| tmper | Time Period |
| TMUX | Terminal Multiplexer |
| TNL | Ethernet Tunneling |
| TNM | Transport Network Management |
| TOD | Television on Demand |
| ToD | Time of Day |
| TOH | Transport Overhead |
| TOP | Task Oriented Practice; Task Oriented Procedure |
| TOS | Type of Service |
| TP | Termination Point |
| TPFI | Timing Plane Fault Isolation |
| TR | Technical Reference |
| TRIB | Tributary |
| tRTO | TCP Retransmit Timeout |
| TrTOH | Transparent Transport Overhead |
| TS | Time Slot; Time Stamp; Time Synchronization |
| TSA | Time Slot Assignment |
| TSD | Transport System Division |
| TSE | Topology State Element |
| TSEL | Transport Selector |
| TSF | Transport Signal Failure |
| TSG | Timing Signal Generator |
| TSI | Time Slot Interchange; Time Switch Interchange |
| TSR | Technical Service Representative |
| TSX | Time-Space Switch ASIC |
| TTE | Transparent Terminal Equipment |
| TTL | Transistor Transistor Logic; Time to Live |
| TTP | Trail Termination Point |
| TTTP | Transparent Trail Termination Point |
| TU | Tributary Unit; Transmission Unit |
| TUG | Tributary Unit Group |
| TUG-n | Tributary Unit Group, level n |
| TU-n | Tributary Unit, level n |
| TV | Television |
| TW | TrueWave |
| TWC | TrueWave Classic |
| TX | Transmit |
| Tx Line | Transmit Line |
| UART | Universal Asynchronous Receiver/Transmitter |
| UAS | Unavailable Seconds |
| UASL | Unavailable Second Count-Line |
| UAS-L | Unavailable Seconds – Line |
| UAS-LFE | Unavailable Seconds – Line Far End |
| UASP | Unavailable Second Count-Path |
| UAS-P | Unavailable Seconds – Path |
| UAS-PFE | Unavailable Seconds – Path Far End |
| UAS-RS | Unavailable Seconds – Regenerator Section |
| UAS-S | Unavailable Seconds – Section |
| UAS-V | Unavailable Seconds – VT |
| UAS-VFE | Unavailable Seconds – VT Far End |
| UAT | Unavailable Time |
| UB | Uncorrected Block |
| UBR | Undefined Bit Rate; Unspecified Bit Rate |
| UBRVBR | Unspecified Bit Rate Variable Bit Rate |
| UC | User Channel |
| UCA | Unswitched Channel Access |
| UCBE | Uncorrectable Block Error |
| UCD | Upstream Channel Descriptor |
| UD | Unconditional Disconnect |
| UDLR | Unidirectional Link Routing |
| UDP | User Datagram Protocol |
| UDR | Unconditional Disconnect Response |
| UEQ | Unequipped |
| UFEC | Ultra Forward Error Correction |
| UGC | Universal Gateway Carrier |
| UGS | Unsolicited Grant Service |
| UHD | Ultra High Density |
| UHF | Ultra High Frequency |
| UI | User Interface |
| UID | User Identifier |
| UITS | Unacknowledged Information Transfer Service |
| UL | Underwriters Laboratories |
| ULH | Ultra Long Haul |
| ULSDCC | Upper Layer Section Data Communications Channel |
| UMTS | Universal Mobile Telecommunications System |
| UNEQ | Unequipped Path; Unequipped |
| UNEQ-P | Unequipped Path |
| UNEQ-V | Unequipped VT |
| UNEs | Unbundled Network Elements |
| UNI/UNIF | User Network Interface |
| UNII | Unlicensed National Information Infrastructure |
| UOG | Universal OSS Gateway |
| UPC | Ultra Physical Contact; Universal Packet Carrier; Usage Parameter Control |
| UPnP | Universal Plug and Play |
| UPS | Uninterrupted Power Supply |
| UPSR | Unidirectional Path Switched Ring |
| URI | Universal Resource Identifier |
| URL | Universal Resource Locator |
| US | Upstream |
| USA | Universal Shelf Amplifier |
| USB | Universal Serial Bus |
| USEPA | United States Environmental Protection Agency |
| UTC | Universal Time Coordinated; Universal Transport Carrier |
| UTOPIA | Universal Test and Operations Physical Interface for ATM |
| UTP | Unprotected Termination Point; Unshielded Twisted Pair |
| UV | Ultraviolet |
| UVC | Universal Voice Carrier; Universal Video Carrier |
| V | Voltage |
| V/A | Video/Audio |
| VAC | Volts Alternating Current |
| VAD | Voice Activity Detection |
| VAP | Virtual Access Partitioning |
| VBI | Vertical Blanking Interval |
| VBR | Variable Bit Rate |
| VC | Virtual Circuit; Virtual Channel; Virtual Container; Virtual Concatenation |
| VCAT | Virtual Concatenation |
| VCC | Virtual Channel Connection |
| VCG | Virtual Concatenation Group |
| VCI | Virtual Channel Identifier |
| VCL | Virtual Channel Link |
| VCM | Virtual Concatenation-group Member |
| VC-N | Virtual Container Level N (N=11, 12, 2, 3, 4) |
| VC-N-Xc | Contiguous Concatenation of X Virtual Containers at Level N |
| VC-N-Xv | Virtual Concatenation of X Virtual containers at Level N |
| VCO | Voltage Controlled Oscillator |
| VCR | Video Cassette Recorder |
| VCSEL | Vertical Cavity Surface-Emitting Laser |
| VCXO | Voltage Controlled Crystal Oscillator |
| VDC | Volts Direct Current |
| VDSL | Very-high-bit-rate Digital Subscriber Line |
| VF | Virtual Fiber; Virtual Facility |
| VFTP | Virtual Facility Termination Point |
| VG | Virtual Group |
| VGA | Variable Gain Amplifier |
| VHF | Very High Frequency |
| VLAN | Virtual Local Area Network |
| VLR | Very Long Reach |
| VLSR | Virtual Line Switched Ring |
| VM | Voice Mail; Virtual Memory |
| VOA | Variable Optical Attenuator |
| VOD | Video on Demand |
| VoIP | Voice over Internet Protocol |
| VOM | Volt-Ohm Meter |
| VOQ | Virtual Output Queuing |
| VOW | Voice Order Wire |
| VP | Virtual Path |
| VPC | Virtual Path Connection |
| VPCI | Virtual Path Connection Identifier |
| VPG | Virtual Path Group |
| VPI | Virtual Path Identifier |
| VPI/VCI | Combined, VPI and VCI identify a connection on an ATM Network |
| VPL | Virtual Path Link |
| VPLS | Virtual Private LAN Service |
| VPN | Virtual Private Network |
| VPS | Voice Processing System |
| VPSP | Virtual Path Switch Protection |
| VRRP | Virtual Router Redundancy Protocol |
| VSA | Virtual-Scheduling Algorithm; Vector Signal Analyzer |
| VSAT | Very Small Aperture Terminal |
| VSI | Vendor-Specific Information |
| VSR | Very Short Reach |
| VT | Virtual Tributary |
| VT-100 | Terminal Emulation System |
| VTG | Virtual Tributary Group |
| V-UNI | Virtual User Network Interface |
| W | Watt; Working |
| WAD | Wavelength Add and Drop |
| WAN | Wide Area Network |
| WB | Working Band; Westbound |
| WCA | Working Channel Access |
| WCI | Wavelength Converter Interface |
| WCI RT | Wavelength Converter Interface Rate Tunable |
| WCIRT-e | Wavelength Converter Interface Rate Tunable (ONLINE Edge Platform) |
| WCSS | WDM Capable Switching System |
| W-DCS | Wideband Digital Cross-Connect System |
| WDM | Wavelength Division Multiplexing |
| WDT | Watchdog timer |
| 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 |
| 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 |
| WTR | Wait to Restore |
| WWN | World Wide Name |
| 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 |
| ZAC | Zero Administration Client |
| ZWP | Zero Water Peak |