Clear search
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
10 GbE 10 Gigabit Ethernet
10 GFC 10 Gigabit Fibre Channel (Same as FC1200)
A-TDMA Advanced Time Division Multiple Access
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
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
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
AIS-L Alarm Indication Signal - Line
AIS-P Alarm Indication Signal - Path
AIS-S Alarm Indication Signal - Section
AIS-V VT Alarm Indication Signal
AISDP Alarm Indication Signal Decay Period
AISIP Alarm Indication Signal Integration Period
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
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
ATDMA Asynchronous 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
AU-n Administrative Unit "n"
AUG Administrative Unit Group
AUX Auxiliary
AVC Attribute Value Change
AWG American Wire Gauge
AWGN Additive White Gaussian Noise
B-DCS Broadband Digital Cross-connect System
B-PON Broadband Passive Optical Network
B-RAS Broadband Remote Access Server
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
BBE-RS Background Block Error Regenerator Section (an SDH regenerator section error)
BBER Background Block Error Ratio
BC Business Continuity
BCD Binary-Coded Decimal
BCST Broadcast
BDFB Battery Distribution Fuse Bay
BE Block Error; Best Effort
BE-RS Block Errors-Regenerative Section
BECN Backward Explicit Congestion Notification
BELLCORE BELL Communications Research, Inc.
BER Bit Error Rate
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
BOL Beginning of Life
BOM Bill of Materials
BONDING Bandwidth ON Demand Interoperability Group
BOOTP Bootstrap Protocol
BP Backplane
BPI Baseline Privacy Interface
BPI+ Baseline Privacy Interface Plus
BPP Backplane Protocol
bps bits per second
BPSR Bidirectional Path Switched Ring
BPT Band Pass-Through
BPV BiPolar Violations
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
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
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
CCCG Cross Connection and Control Group
CCC-PC CCC Processor Card
CCDF Complementary Cumulative Distribution Function
CCI Content Control Information
CCITT Consultative Committee on International Telegraphy and Telephony
CCK Complimentary Code Keying
CCW Counterclockwise
CCC-XC CCC Cross Connect Card
CCC768 Cross Connect Fabric with 768x768 STS-1 capacity
CD Compact Disc; CoreDirector®; Chromatic Dispersion
CDD CoreDirector® Designer Software Tool
CDE Common Desktop Environment (UNIX)
CDR Call Detail Recording; Clock and Data Recovery
CD-ROM Compact Disc Read Only Memory
CDE Common Desktop Environment
CDMA Code Division Multiple Access
CDP Contracted Deadline Potential
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
C/I Carrier-to-Interface Ratio
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
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
COM Ciena's inter-processor communications system
COLD Central Office Layout Design
COLL Collision Count
CONDTYPE Condition Type
CONS Connection Oriented Network Service
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/A Digital-to-Analog
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
dB decibel
DB Database
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
DB-9 Data Bus 9 Pin Connector
DC Direct Current; Data Connection
D&C Drop and Continue
DCC Data Communications Channel
DCE Data Communications Equipment; Data Circuit Terminating Equipment
DCF Dispersion-Compensating Fiber
DCG Dispersion Compensation Grating
DCM Dispersion Compensation Module
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
D/I Drop and Insert
DIO Digital Input/Output
DIP Dual In-line Package (switch)
DIR Direction
DiffServ Differentiated Services
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
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
DSS2 Digital Subscriber Signaling 2
DSTB Digital Set-top Box
DSX Digital Side Interface
DSX-1 Digital Signal Level 1 Cross Connect
DS-x Digital Signal where N denotes multiple of 51.84 Mb/s
DSX-3 Digital Signal Level 3 Cross Connect
DT Decision Technology; Direct Termination
DTCP Digital Transmission Content Protection
DTE Data Terminal Equipment
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
EAL Events, Alarms, and Logging
EAI Enterprise Application Integration
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&I Engineer, Furnish and Install
EF Equipment Failure
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
EMC ElectroMagnetic Compatibility
EMD Extended Management Domain
EMEA Europe, Middle East and Africa
EMBS Egress Maximum Burst Size
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
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
E-PON Ethernet Passive Optical Network
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
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
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
ES-MS Errored Seconds at the Mulitplexor Section
ESMOP Electronic Service Method of Procedure
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
FA, F/A Fuse Alarm; Fault Alarm
FAB Field Alert Bulletin
FAD Functional Access Domain
FAF Facility Failure
F&I Furnish and Install
FC Failure Code; Failure Count; Fiber Channel; Fibre Channel
FC100 Fibre Channel 1 Gb/s
FC200 Fibre Channel 2 Gb/s
FC400 Fibre Channel 4 Gb/s
FC10000 Fibre Channel 10 Gb/s (same as 10GFC)
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
FC Switch Fiber Channel Switch
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
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
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
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
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
GNE Gateway Network Element
GND Ground
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
GPS Global Positioning System; Global Positioning Satellite
GR Generic Requirement; Geographic Redundancy
GRDM Gigabit Rate Data Multiplexer
GRTES General Requirements for Transmission Equipment Specification
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
HD-SDI High Definition Serial Digital Interface
HDB3 High Density Bipolar 3
HDCP High-bandwidth Digital Content Protection
HDLC High-speed/level Data Link Control
HDMI High Definition Multimedia Interface
HDSF High-speed Distributed Switch Fabric
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
HISSA High Speed Serial Application Specific Integrated Circuit (ASIC)
HMS Hybrid Management Sub-layer
HNv1 Home Networking Version 1
HO Higher Order
HOVC Higher Order Virtual Concatenation
HOD HBO on Demand
HOM High-Order Modulation
HomePNA Home Phoneline Networking Alliance
HO-DSP High Order-Domain Specific Part
HOP High Order Path
HO-POH Higher Order - Path Overhead
HO-DXC Higher Order Digital Cross Connect
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
HI Hardware/Software Interface; Hardware-Software Integration; High Speed Internet
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
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
INVW Invalid Word Count
IntServ Integrated Services
I/O Input/Output
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
IPPV Impulse Pay per View
IPOA Internet Protocol over ATM
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
ITL International Telecommunications Union
ITE Information Technology Equipment
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
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
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
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
LO-DXC Low Order Digital Cross Connect
LP Line Processor; Lockout of Protection; Low Order Path
LP-S/SF-P Lockout of Protection - Span/Signal Fail - Protection
Lport Logical port
LP-S Lockout of Protection - Span
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
Mbaud Megabaud
Mb/s Megabits per second
Mbits/s Megabits per second
Mbps Megabits per second
MBps Megabytes per second
MB/s Megabytes per second
MBS Maximum Burst Size
MCP Management Control Processor
MCT Maintenance Channel Transparency
MCTF Motion Compensated Temporal Filtering
MD MetroDirector K2 Platform
mDVR Multi-TV Digital Video Recorder
MCR Minimum Cell Rate; Minimum Cost Routing
MDF Main Distribution Frame
MDU Multiple Dwelling Unit
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
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
MP3 MPEG-2 Layer 3
MP Management Portal
MPCKTS Multicast Packet Count
MPEG Moving Pictures Expert Group
MPI Multi-Path Interface; Multi-Path Interference
MPLmS Multi-Protocol Lambda Switching
MPLS Multi Protocol Label Switching
MPLS-CP MPLS Control Plane
MPN Mode Partition Noise
MPS Modeling and Planning Suite
MPOA Multi Protocol over Asynchronous Transfer Mode
MPS Modeling and Planning System; Modeling and Planning Suite
MPT Multiplex Pass-Through
MPTS Multiple Program Transport Stream
M-Plane Management Plane
MR Modification Request; Material Request; Medium Reach
MRRB Maintenance Requirements Review Board; Material Release Review Board
ms Milliseconds
MS Multiplex Section
MS-AIS Multiplex Section - Alarm Indication Signal
MSA Mediation Services Administrator
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
MSPP Multiservice Provisioning Platform
MS-P Manual Switch - Protection
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
NEBS Network Equipment Building Standards; Network Equipment Building Systems
NEC National Electric Code
NEF Network Element Function
NE/FE Near End/Far End
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
OCAP OpenCable Application Platform
OCH Optical Channel
OCI Open Connection Indication
OCT Octet Count
OC-1 Optical Carrier level 1, SONET bit rate = 51.84 Mb/s
OC-3 Optical Carrier level 3, SONET bit rate = 155.52 Mb/s
OC-12 Optical Carrier level 12, SONET bit rate = 622.08 Mb/s
OC-48 Optical Carrier level 48, SONET bit rate = 2.488 Gb/s
OC-192 Optical Carrier level 192, SONET bit rate = 9.953 Gb/s
OC-n Optical Carrier-number; Optical Carrier where N denotes a multiple of 51.84 Mb/s
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
OSS-AU Out of Service-Autonomous
OSS-AUMA Out of Service-Autonomous and Management
OSS-AURST Out of Service-Autonomous and Restricted
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
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
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
PAT Program Association Table
PAX Path Adaptation and X-Connect
PB Petabyte
PBX Private Branch Exchange
PBOR Primary-Backup Object Replication
PC Personal Computer; Physical Contact; Processor Card
PCA Protection Channel Access
PCB Printed Circuit Board
PCC Processor Communication Channel
PCI Peripheral Component Interconnect
PCN Program Change Notice; Product Change Notice
PCM Pulse Code Modulation
PCMCIA Personal Computer Memory Card Interface Adaptor
PCMM PacketCable Multimedia
PCO Pre-Conditioned Order
P-Code Product Code
PCR Peak Cell Rate
PDA Personal Digital Assistant
PDAP Power Distribution and Alarm Panel
PDC Passive Dispersion Compensator
PDF 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
POH Path Overhead
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
PROM Programmable Read Only Memory
PROT Protocol; Protection
PRNG Pseudo Random Number Generators
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/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
RBOC Regional Bell Operating Company
RBM Regional Business Manager
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)
RG Residential Gateway
R.H. Relative Humidity
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
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
R/W Read/Write
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
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-4 Synchronous Transfer Mode level 4, SDH bit rate = 622.08 Mb/s
STM-16 Synchronous Transfer Mode level 16, SDH bit rate = 2488.32 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
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
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 CLI Transaction Language One, Command Line Interface
TL-1 Transaction Language 1
TLI Transaction Language Command Line Interface
TLC Transport Logical Connection
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 Line Transmit Line
TX Transmit
UART Universal Asynchronous Receiver/Transmitter
UAS Unavailable Seconds
UAS-L Unavailable Seconds - Line
UAS-LFE Unavailable Seconds - Line Far End
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
UASL Unavailable Second Count-Line
UASP Unavailable Second Count-Path
UAT Unavailable Time
UB Uncorrected Block
UBRVBR Unspecified Bit Rate Variable Bit Rate
UBR Undefined Bit Rate; Unspecified 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
UNEs Unbundled Network Elements
UNEQ Unequipped Path; Unequipped
UNEQ-P Unequipped Path
UNEQ-V Unequipped VT
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
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
VCAT Virtual Concatenation
VCC Virtual Channel Connection
VCG Virtual Concatenation Group
VCI Virtual Channel Identifier
VCL Virtual Channel Link
VCM Virtual Concatenation-group Member
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
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
VTG Virtual Tributary Group
VT-100 Terminal Emulation System
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
WDM Wavelength Division Multiplexing
WDT Watchdog timer
W-DCS Wideband Digital Cross-Connect System
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
WSS Wavelength Selective Switch
WRED Weighted Random Early Discard; Weighted Random Early Detection
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