Glossary Technology evolves at a rapid-fire pace. That’s why we’ve built an easy-to-use glossary to help you better understand the terms, technologies and trends that impact your business. 0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 100G testing 10G-EPON 2R 3R 3rd Generation Partnership Project — 3GPP 400G testing 5G 5G New Radio (NR) A-BGF ABR Absorption ABTS ACC Access Network Access Nodes ACK ACQ ACT Adapter Add-Drop Multiplexer (ADM) Address Resolution Protocol (ARP) Adjacent Channel ADM ADS ADSL Advanced Antenna System — AAS Aerial Cable AGW AIS AIS-L AIS-P AL_PA Algorithm ALS American National Standards Institute (ANSI) American Standard Code for Information Interchange (ASCII) American Wire Gauge (AWG) AMI Amplifier Amplitude AM ASK Analog ADC ANSI AP APC APD API APON APS ARB ARCNET ARFCN ARP AS ASCII ASP Asymmetric Digital Subscriber Line (ADSL) Asymmetric Digital Subscriber Line Transceiver Unit — Central or Remote (ATU-C and ATU-R) Asynchronous Asynchronous Transfer Mode (ATM) ATM Attenuation Attenuator ATU-C ATU-R AU AU PTR AU-LOP AUG Auto-Negotiation AWG b B B-ISDN B8ZS Backbone Backhaul Backoff Delay Backscatter Bandwidth BW Bandwidth Parts — BWP Base Station Controller (BSC) Base Transceiver Station (BTS) Baseband Baseband Unit Basic-Rate Integrated-Services Digital Network (BRI-ISDN) Baud Rate BB BB_Credit BB_Credit_CNT BBE BBER BBU Bc BCCH BDI Be Beamforming BEC BEI Bend Radius BERT BGC BGCF BGF BGP BIAE Big Data Binary 8 Zero Substitution (B8ZS) BIP-8 Bit Bit Error Ratio — BER Bit-Error-Rate Test (BERT) Bits per Second (bit/s or bps or b/s) BLEC BOD BOM Bonding Border Gateway Protocol (BGP) BPON BRI-ISDN Bridge Broadband Broadband Forum (BBF) Broadband Integrated-Services Digital Network (B-ISDN) Broadcast Broadcast Address Broadcast Domain BS BSC BTS Buffer-to-Buffer Credits (BBC) Byte (B) CA CA-Polar Calibration Call before You Dig (CBUD) CAP CAPEX Capital Expenditure (CAPEX) Carrier Carrier Ethernet 1.0 (CE 1.0) Carrier Ethernet 2.0 (CE 2.0) Carrier Ethernet Testing Carrier Sense Carrier Serving Area (CSA) Carrier-Sense Multi-Access with Collision Detection (CSMA/CD) Carrier-Sense Multiple-Access (CSMA) Carrier-Sense Multiple-Access with Collision Avoidance (CSMA/CA) CAS CBR CBS CC CCCH CCF CCS CD CDF CDMA CDN CE CE 1.0 CE 2.0 Central Office (CO) Central Offices Re-architected as Data Centers (CORD) CFM CFP Channel Channel Service Unit (CSU) CHAP CHAP cHEC Chromatic Dispersion (CD) CIR Circuit-Switched Network Citizens Broadband Radio Service (CBRS) CJTPAT Class of Service (CoS) CLEC CLP CLS CMF CMISE CMS CO Co-Channel Coarse Wavelength-Division Multiplexing (CWDM) Coaxial Cable Coherent Network Collision Collision Detect (CD) Collision Domain Commissioning Committed Information Rate (CIR) Common Public Radio Interface (CPRI) Competitive Local-Exchange Carrier (CLEC) Concentrator Conduit Connectivity fault management (CFM) Connector Connector Endface Contamination Contention Control Plane Converged network Converged Network CORESET CoS CP CP-OFDM CPE CPRI CQ CQI CRC Crossover Cable Crosstalk CRPAT CS_CTL CS/ES CSA CSCF CSI CSI-RS CSMA/CA CSMA/CD CSPAT CSR CSU CSU/DSU CTL Customer Premises Equipment (CPE) CVD CW CWDM Cyclic Redundancy Check (CRC) D_ID D-QoS DANL DAPI DAS Data Center Data Plane Data Service Unit (DSU) Data-Link Layer dB DBA dBc dBc/Hz dBd dBi dBm dBm/Hz DBS DC DCC DCCH DCE DCI DDN Dead Zone Dedicated Connection Deep Packet Inspection (DPI) Degree of Polarization (DOP) Delay Factor (DF) Dense Wavelength-Division Multiplexing (DWDM) Destination MAC Address DF DFB DFT DFT-s-OFDM DHCP DHD Dial-Up Connection Differential Phase Shift Keying (DPSK) Differentiated Services (DiffServ) Diffraction Grating DiffServ Digital coherent pluggables Digital Loop Carrier (DLC) Digital Signal Digital Subscriber Line (DSL) Digital Subscriber Line Access Multiplexer (DSLAM) Directivity Discrete Multitone Transmission (DMT) Distributed Antenna System Forum (DAS Forum) Distributed Antenna Systems (DAS) DIX DL DLC DMM DMRS DMT DNS Domain Name System (DNS) DOP Doppler Downstream DPI DPSK DR DRP DSL DSLAM DSP DSS DSU DTCH DTF DTMF Dual-port testing Dual-Tone Multifrequency Signaling (DTMF) Duplex DUT DVT DW DWDM DWS Dynamic Bandwidth Allocation (DBA) Dynamic Host Configuration Protocol (DHCP) Dynamic Range Distributed tap architecture (DTA) E_Port E-business or e-commerce E-LAN E-Line E-UTRAN E1 EARFCN EB EBS EC ECC Echo Cancellation ECN ECT EDFA EDGE EE_Credit EE_Credit_CNT EFM EFMA EFS eHEC EIA EIR EIRP Electromagnetic Spectrum Electronic Industry Association (EIA) Element Management System (EMS) eMBB EMF EMS End-to-end Network End-to-End Service Modeling ENIU eNodeB EOF EOW EPC EPG EPL EPLan EPON ER Erbium-Doped Fiber Amplifier Error Vector Magnitude (EVM) ES ESCON ESR Ethernet Ethernet in the First Mile (EFM) Ethernet Service OAM (SOAM) Ethernet Version 2 Ethernet Virtual Private Line (EVPL) ETSI European Telecommunications Standards Institute (ETSI) EVC EVDO EVM EVPL EVPLan Excessive Collision Error EXI EXP Explicit Congestion Notification (ECN) External passive intermodulation (PIM) Extranet f/s Far Field Region Far-End Crosstalk (FEXT) FAS Fast Ethernet Fast Link Pulse (FLP) Fault Management FBR FBT FC FC-0 FC-1 FC-2 FC-AL FC-PH FC-SW FCC FCP FCS FDD FDDI FDH FDM FDR FDT FDX FEBE FEC Feeder Network FEXT FFT FGT Fiber Cable Fiber Characterization Fiber Distributed Data Interface (FDDI) Fiber Distribution Hub (FDH) Fiber Monitoring Fiber-to-the-Antenna Fiber-to-the-Building (FTTB) Fiber-to-the-Cabinet (FTTCab) Fiber-to-the-Curb (FTTC) Fiber-to-the-Home (FTTH) Fiber-to-the-Node (FTTN) Fiber-to-the-Premises (FTTP) Fiber-to-the-x (FTTx) Fibre Channel (FC) Fibre Channel Protocol (FCP) Fibre Channel Switched Fabric (FC-SW) FICON Field intensity Field-Programmable Gate Array (FPGA) File Transfer Protocol (FTP) Filtering Filtering Rate FL_Port FLOGI Flow Control FM FMC FO Forward Error Correction (FEC) Forwarding Forwarding Rate FOTS FP FPGA FR1 FR2 Frame Frame Bursting Frame Check Sequence (FCS) Frame Relay Free Space Loss Frequency Frequency-Division Multiplexing (FDM) Fresnel Reflection FSAN FSK FSO FTFL FTP FTTA FTTB FTTC FTTCab FTTD FTTdp FTTH FTTH Council FTTH Testing FTTN FTTP FTTx Full-Duplex Full-stack assurance Fundamental Fusion Splice FUT FWA FWHM G_Port G.992.1 or G.DMT ADSL G.992.2 or G.Lite ADSL G.fast Gateway Gbit/s or Gb/s or Gbps GBR GCC GEM General Communication Channel (GCC) Generalized Multiprotocol Label Switching (GMPLS) Generic Framing Procedure (GFP) Geographic Information System (GIS) GFP GFP-F GFP-T Giants Gigabit Ethernet (GigE) Gigabyte (GB) gige GIS GMPLS GoB GPIB GPON Graded-Index Fiber Group Address GSCN GSM GUI Half-Duplex Harmonics HARQ HBA HDB3 HDD HDSL HDTV Head-end Headends Re-architected as Data Centers (HERD) Header Error Control (HEC) HEC Heterogeneous Network (HetNet) HetNet HFC HGW High Density Bipolar 3 (HDB3) High-Bit-Rate Digital Subscriber Line (HDSL) High-Definition Television (HDTV) High-Speed Packet Access (HSPA) HiPPI HO TCM HO VCAT HOA HOI Home Passed Home Subscriber Server (HSS) Host Host Bus Adapter (HBA) HPA HPBw HSDPA HSPA HSS HSUPA HTTP Hub Hybrid Fiber-Coaxial (HFC) Hybrid Networks Hydrogen Peak Hypertext Transfer Protocol (HTTP) I-BGF I-CSCF IAD IaDI IAE IBCF IBM ID IDSL IEC IEEE IEEE 802.1 IEEE 802.1ab IEEE 802.1ag IEEE 802.2 IEEE 802.3 IEEE 802.3ah IETF IF IFC IFG IKE IL ILEC IM-SSF IMS Imux Incumbent Local-Exchange Carrier (ILEC) Individual Address Insertion Loss (IL) Institute of Electrical and Electronics Engineers (IEEE) Integrated Access Device (IAD) Integrated-Services Digital Network (ISDN) Integrated-Services Digital Network Digital Subscriber Line (IDSL) Intelligent Hubs Interexchange Carrier (IXC) Interference Interframe Gap (IFG) Internal passive intermodulation (PIM) International Organization for Standardization (ISO) International Telecommunications Union (ITU) Internet Internet Engineering Task Force (IETF) Internet Key Exchange (IKE) Internet of Things (IoT) Internet Protocol (IP) Internet Protocol (IP) Address Internet Protocol Security (IPSec) Internet Protocol Television (IPTV) Internet Service Provider (ISP) Interpacket Gap (IPG) Interworking Function (IWF) Intranet Inverse Multiplexing (Imux) IORF IoT IP IP Multimedia Service Switching Function (IM-SSF) IP Multimedia Subsystem (IMS) IPG IPOA IPSec IPTV IQ Data IRB IrDI iSCSI ISDN ISI ISM ISO ISP ISUP ITU ITU Telecommunication Standardization Sector (ITU-T) ITU Y.1731 ITU-T IWF IXC Jabber Jitter Joint Photographic Experts Group (JPEG) JPEG Jumper Cable Kevlar Key Kilobit (kbit or kb) Kilobits per Second (kbit/s or kb/s) Kilobyte (KB) Kilometer KPI L_Port LAA Label-Switched Path (LSP) LAN LAPS Laser Laser Diode Last Mile Latency Layer 1 Layer 2 Layer 3 Layer 4 Layer 5 Layer 5 Layer 6 Layer 7 LCAS LCK Leased Line LED Legacy LFD LFn Light Source Light-Emitting Diode (LED) Link Link Aggregation Link Capacity Adjustment Scheme (LCAS) Link Loss Link Segment LIP LLC LLDP LO VCAT LOC Local Area Network (LAN) Local Loop LOCS LOF Logical Link Control (LLC) LOH LOI LOM Long-Term Evolution (LTE) Loop Qualification LOP LOS Loss Budget LP LPA LPB LPC LPE LPOM LPT LR LRn LRR LSP LSR LTE LTE V2V LTE SAE LTE V2X LTI LUG M2M MAC MAC Address Macrobend Macrocell Main Distribution Frame (MDF) MAN Manageable Hubs MAP MAPOS Massive MIMO - mMIMO Maximum Time Interval Error (MTIE) MB MB/s MBaud Mbit Mbit/s MBR MC MCF MCPPT MDF MDI MDU ME-LDPC Mean Opinion Score (MOS) Mean Time to Repair (MTTR) Mechanical Splice Media Media Access Control (MAC) Media Access Control (MAC) Address Media Access Control (MAC) Frame Media Gateway (MGW) Media Gateway Controller (MGC) Media Independent Interface (MII) Media Loss Rate (MLR) Media Resource Function Controller (MRFC) Media Resource Function Processor (MRFP) Medium Dependent Interface (MDI) MEF MEF 17 MEF 30.1 MEF 35 Megabit (Mbit or Mb) Megabits per Second (Mbit/s or Mb/s) Megabyte (MB) MEN Metropolitan Area Network (MAN) MFAS MFD MFI MGC MGCF MGW MIB Microbend MII Millions of Instructions per Second (MIPS) MIPS MISO ML-PPP MLM MLR MM MME MMF mMTC mmWave MNO Mobile Application Part (MAP) Mobile Backhaul Mobile Network Mobile Network Operator (MNO) Mode-Field Diameter Modem MON MOS Moving Pictures Experts Group (MPEG) MPEG MPI MPLS MPTS MRFC MRFP MRTIE MS MSA MSC MSO MSOH MSP MSPP MST MSTP MTA MTC MTIE MTTR MU-MIMO Multi-access edge computing (MEC) Multicast Multicast Address Multidwelling Unit (MDU) Multigigabit Ethernet Multilink Point-to-Point Protocol (ML-PPP or MP) Multimode Fiber (MMF) MultiNAT Multinetwork Address Translation (MultiNAT) Multipath Interference (MPI) Multiple input, multiple output (MIMO) Multiplexing Multiservice Testing MWM N_Port N-Way Narrowband NAS NASS National Institute of Standards and Technology (NIST) NATO NB NCITS NCS NDF NE Near-End Crosstalk (NEXT) NEF NEM Network Element (NE) Network Functions Virtualization (NFV) Network Interface Card (NIC) Network Interface Device (NID) Network monitoring Network Operations Center (NOC) Network Service Provider (NSP) Network Simulator Network slicing Network Switching Subsystem (NSS) Network Termination Equipment (NTE) NEXT NF NIC NID NIST NIU NL_Port NNI NOC Node Noise Noise Figure (NF) Non-Coherent Network Non-Return-to-Zero (NRZ) NOS NR-ARFCN NR-U NRZ NSP NSS NTE Numerical Aperture Numerology NUT OADM OAM OAM&P OBSAI OC OC-3 OccBW OCh OCI Octet ODN ODU OFC OFDM OFDMA OFM OH OHP OLA OLn OLP OLS OLT OLTS OMS ONT ONU OOF OOM OOM1 OOM2 OOSM Open Base Station Architecture Initiative (OBSAI) Open Fiber Control (OFC) Open Systems Interconnection (OSI) Operating Expenses (OPEX) Operations, Administration and Management (OAM) OPEX OPM OPNfr OPNyr OPNyx OPNyy OpS Optical Add/Drop Multiplexer (OADM) Optical Attenuator (OLA) Optical Carrier, Level 3 (OC-3) Optical Fiber Optical Fiber Multimeter (OFM) Optical Internetworking Forum (OIF) Optical Light Source Optical Line Terminal (OLT) Optical Network Optical Network Terminal (ONT) Optical Network Unit (ONU) Optical Power Meter (OPM) Optical Return Loss (ORL) Optical Signal-to-Noise Ratio (OSNR) Optical Spectrum Analysis Optical Spectrum Analyzer (OSA) Optical Splitter Optical Testing Optical Time-Domain Reflectometer (OTDR) Optical Transport Network (OTN) OPU Organizationally Unique Identifier (OUI) ORL ORR OSA OSC OSI OSNR OSP OTDR OTDR connectors or optical port OTL OTN OTS OTT OTU OUI OUT Outside Plant (OSP) Over-the-air (OTA) testing OX_ID P-CSCF P2MP P2P PABX Packet Packet Internet or Inter-Network Groper (PING) Packet Jitter Packet-Switched Network PAPR Parallel Detection PARAM Passive intermodulation (PIM) Passive Optical Local Area Network (PO-LAN or POL) Passive Optical Network (PON) PAT Pause Frames PBB-TE PBCH PBT PBX PC PCC PCFICH PCI PCR PCS PDCCH PDH PDL PDN-GW PDSCH PDU Per-Hop Behavior (PHB) Perceptual Evaluation of Speech Quality (PESQ) Performance Monitoring Peripheral Component Interconnect (PCI) PESQ pFCS PFI Phase PHB PHY Physical Address Physical Layer Physical Medium Dependent (PMD) PIN PING PJE Plain Old Telephone Service (POTS) Plain Old Telephone Service Splitter PLC Plesiochronous Digital Hierarchy (PDH) PLI PM PMA PMD PMF POH POI Point of Presence (PoP) Point-to-Multipoint Communication (P2MP) Point-to-Point Protocol (PPP) Point-to-Point Protocol over Ethernet (PPPoE) Point-to-Point Tunneling Protocol (PPTP) POL Pol-Mux POLAN Polarization Polarization Mode Dispersion (PMD) Polarization Multiplexing (Pol-Mux) Polarization-Maintaining Fiber (PMF) POLQA PON PoP Port PoS Postal, Telegraph and Telephone (PTT) POTS Power Meter PPI PPP PPPoE PPTP PRACH PRB PRBS PRBS31 Preamble Precision Time Protocol (PTP) PRI-IDSN Primary-Rate Integrated-Services Digital Network (PRI-IDSN) Private Branch Exchange (PBX) Propagation Delay Protocol Provider Backbone Bridge Traffic Engineering (PBB-TE) PSB PSD PSE PSI PSK PSP PSS PSTN PT PTE PTI PTN PTP PTT Public Switched Telephone Network (PSTN) Pulse Width PUSCH PVC QAM QoE QoS QPSK QSFP112 Quadruply Clad Fiber Quality of Experience (QoE) Quality of Service (QoS) R_CTL R_RDY RACS Radio Access Network Radio frequency (RF) signals Radio Frequency (RF) Radio Network Controller (RNC) RADSL RAID RAN RAR Rate-Adaptive Digital Subscriber Line (RADSL) Rayleigh Scattering RB RBOC RBW RCS RDI RDI-P Real-Time Transport Protocol (RTP) Rec Receiver Reconfigurable Optical Add-Drop Multiplexer (ROADM) Redundant Array of Independent Disk (RAID) Reflection Refraction Refraction Index Regional Bell Operating Company (RBOC) Registered Jack (RJ) REI-L Remote Access Remote Radio Heads (RRH) Remote Radio Unit Repeater RES Resilient Packet Ring (RPR) Resistance Fault Location (RFL) Return-to-Zero (RZ) RF RF Spectrum Analyzer RFC 2544 RFL RFTS Ribbon Cable RJ RJ-45 RL RLEC RMA RMON RMS RNC ROADM Round-Trip Delay Time (RTD) Router RPR RRC RRH RS RSOH RSRP RSRQ RSSI RST RT RTD RTP RTSA RTU Runt Frame Rx RX_ID RZ s S_ID S-CSCF S-GW SA SAE SAG SAN SAPI SBC SBS SBSMN SBus SC SC-FDMA SCS SCSI SD SDH SDL SDSL SDTV Segment SEQ_CNT SEQ_ID Service-Level Agreement (SLA) SES SESR Session Border Controller (SBC) Session Initiation Protocol (SIP) Set-Top Box (STB) SETG SETPI SETS SFN SFP SGF SGW Shared Ethernet SHDSL SIB Signal-to-Noise Ratio (SNR) Signaling Gateway (SGW) SIMO Simple Mail Transfer Protocol (SMTP) Simple Network Management Protocol (SNMP) Simplex Transmission Singlemode Fiber (SMF) SINR SIP SIP-AS SISO SLA SLF Slot Time SM Small Cell Small Computer System Interface (SCSI) SMF SMS SMTP SNI SNMP SNR SOF Softswitch (SS) Software-Defined Networking (SDN) SOH SONET SPA Spanning Tree SPDF SPE Spectrum SPI Splice Loss Splitter SQ SQM SS SS-RSRP SS-RSRQ SS-SINR SSB SSER SSMB SSS Standard-Definition Television (SDTV) Star Topology STAT Station Station Address STB STE STG STM Storage Area Network (SAN) STP STS SU-MIMO Submarine Network Subnet Subnet Mask SUI SUL SUT SVT Switch Symmetrical Digital Subscriber Line (SDSL) Symmetrical High-Speed Digital Subscriber Line (SHDSL) SYNC SyncE Synchronization Testing Synchronous Synchronous Digital Hierarchy (SDH) Synchronous Optical Network (SONET) System under Test (SUT) T_Port T-MGF T1 T1.413 T3 TA TCI TCM TCP Tcp: TDM TDMA TDR TE Telco Telecommunications Industry Association (TIA) Telecommunications Management Network (TMN) Telecommuting Terminal Adapter (TA) Terminal Multiplexer (TM) TFT Tg tHEC TIA Time Division Duplexing (TDD) Time to Live (TTL) Time-Division Multiple Access (TDMA) Time-Division Multiplexing (TDM) Time-Domain Reflectometry (TDR) TL TL_Port TLS TM TMN TNE TOH TOI ToS TPI Traceroute Transmission Control Protocol/Internet Protocol (TCP/IP) Transmitter Transparent LAN Service (TLS) Transport Layer Security (TLS) Ts TTI TTL TU Tu TUG Tunneling Turbo Codes Turn-up Twisted Pair Tx TXC TYPE U_Port UARFCN UAS UDP UE UL ULP UMTS UNI Unicast Address Uniform Resource Locator (URL) Universal Serial Bus (USB) Unshielded Twisted Pair (UTP) UPC UPI UR/LLC URL USB User Datagram Protocol (UDP) User Network Interface (UNI) User Plane UTP Variable Bit Rate (VBR) VBR VBW VC VC_RDY VCAT VDSL VDSL2 Vectoring Very-high-bit-rate digital subscriber line 2 (VDSL2) Very-High-Data-Rate Digital Subscriber Line (VDSL) VF VFL Video-on-Demand (VoD) Virtual Concatenation (VCAT) Virtual Local Area Network (VLAN) Virtual Private LAN Service (VPLS) Virtual Private Network (VPN) Virtualized Network Visual Fault Locator VLAN VNA VOA VoD VoDSL Voice over Digital Subscriber Line (VoDSL) Voice over Internet Protocol (VoIP) VoIP VoLTE VPI VPLS VPN VPSN VSWR VT Wall Jack WAN Wavelength Wavelength-Division Multiplexing (WDM) WB WDM Web-Scale Service Provider Webscale Operators WG Wide-Area Network (WAN) WiFi 6E WiMAX WiMAX MIMO Wireless Network Worldwide Interoperability for Microwave Access (WiMAX) WWN X.25 Data Protocol xDSL XGS-PON Y Coupler Zero-Dispersion Wavelength