Glossary of Terms

Glossary

ADSL
Asymmetric Digital Subscriber Line - the broadband technology used to deliver standard copper broadband products. It is designed to be able to run over long copper cable lengths, sacrificing speed for distance, allowing wider data coverage with fewer DSLAMs across the network.

 

BNS
Backhaul Network Services. Backhaul Network Services (BNS) is a solution for communications providers who want to backhaul data from a number of outlying Local Loop Unbundling (LLU) or mobile Base Station Controller sites to their own network.

 

CLI
Calling Line Identity (also known as Caller ID, caller identification, CID, Calling Number identification, or CNID). A telephone service that transmits a caller's number to the receiving telephone equipment during the ringing signal, or when the call is being set up, but before the call is answered.

 

DACS
Digital Access Carrier System (also known as 0+2 Pair gain system). Modern ISDN technology based digital systems, made up of two normal subscriber lines over one copper pair.

 

DASS
Digital Access Signalling System. Our original ISDN30 offering used this as a signalling standard.

 

DDI
Direct Dialling In. A facility that lets callers dial direct into a firm's PABX extensions as if they were normal public telephone numbers. Most of our offices have DDI facilities.

 

DLM
Dynamic Line Management - this is a system that monitors each line in real time based on a set of rules within a defined policy to change the parameters of the line to achieve the best balance of speed and line stability. There are currently three policies which have different rules for managing the lines, Speed, Standard and Stable.

 

DMSU
Digital Main Switching Unit. These are the original long-distance exchanges. They are System X switches with the capacity to handle 30,000 simultaneous calls each. Every DMSU is connected to all the other DMSUs. This involves a much smaller number of links than would be required to link together the Digital Local Exchange.

 

DPNSS
Digital Private Network Signalling System. A network protocol used on digital trunk lines for connecting two PABX. It supports a defined set of inter-networking facilities.

 

DP
Distribution Point. A point within a network where the cable or fibre terminates. This provides a point of entry for engineers to terminate or test the network. Typically these points are located on telegraph poles.

 

DSLAM
Digital Subscriber Line Access Multiplexer. A network device, located in the telephone exchanges of the service providers,

 

DTMF
Dual Tone Multi Frequency. Used for telecommunication signalling over analogue telephone lines in the voice-frequency band between telephone handsets and other communications devices and the switching centre.

 

ETSI
European Telecommunications Standards Institute. An independent, non-profit, standardisation organization in the telecommunications industry in Europe with worldwide projection. ETSI has been successful in standardising the Low Power Radio, Short Range Device, GSM cell phone system and the TETRA professional mobile radio system.

 

EAD
Ethernet Access Direct. Offers permanently connected, point-to-point high speed data circuits that provide a secure and un-contended Ethernet service for Communications Providers between flexible network and customer nodes.

 

EBD
Ethernet Backhaul Direct. Offers permanently connected, point-to-point high speed data circuits that provide a secure and un-contended Ethernet backhaul service for Communications Providers over a defined network infrastructure.

 

FTTC
Fibre to the Cabinet - the term for the supply of data services over a fibre optic cable running between the local exchange and the local street cabinet, then using existing copper cable to deliver the data to the end user’s premises. In FTTC, the device which translates the data into a signal that can be carried over copper wire, the DSLAM, sits in a local street cabinet, rather than in the local exchange.

 

FTTP
Fibre to the Premises - the term for the supply of data services over a fibre optic cable running between the local exchange and the end user's premises. This technology completely replaces the need for copper cabling within the Openreach network.

 

FTTP ABBREVIATIONS

  • AN – Aggregation Node
  • BFT – Blown fibre tube
  • CBT - Connectorised block terminal
  • CMJ – Compact multi-function joint (used as small plitter or intermediate joint)
  • ELM – External locking mechanism (locking bollard)
  • FDP – Fibre DP
  • MMJ – Medium multi-function joint (used as medium splitter or intermediate joint)
  • NJ4A – Node Joint 4A
  • OTDR – Optical Time Domain Reflectometer
  • PM – Pole mounted
  • PMC – Pole mounted closure (interim pole mounted transition joint)
  • SN – Splitter Node
  • SST- Standard single tube (small profile cable)
  • ULW – Ultra Lightweight (36 fibre cable)
  • UN2 – Universal node 2 (used as large splitter or intermediate joint)

 

FTTx
Fibre to the (Cabinet - FTTC, Premises - FTTP, etc). Any broadband network architecture that uses optical fibre to replace all or part of the usual metal local loop used for last mile telecommunications.

 

GPON
Giggabit Passive Optical Node

 

HDSL
High Speed Digital Subscriber Line (also known as High-speed Digital Subscriber Loop). A copper delivered service on Copper Wideband Serving Section (CWSS). It is subject to reach limitations and is used primarily to provide 2 Mbit service to singleton sites.

 

ISDN
Integrated Services Digital Network. A digital network that lets a whole host of services be carried together on the same circuits. Considered an extension of the public switched telephone network, the key similarity is that it lets any two compatible pieces of connected equipment talk to each other. ISDN can carry any form of data, such as voice, video and computer files.

 

LAN
Local Area Network

 

L2C
Lead To Cash (provisioning). The lead to cash process goes from initial contact, to sale, to service delivery, to payment collection.

 

LLU
Local Loop Unbundling. Lets communications providers offer the full range of voice and broadband services, without having to route through our main network.

 

MDF
Main Distribution Frame. A point in a telephone exchange where cables from outside can be connected to the exchange equipment.

 

MSN
Multiple Subscriber Number. An ISDN version of Direct Dial In.

 

Multicast
A service within the Openreach network for distributing live television broadcasts to many users over broadband at the same time, in real time.

 

NGA
Next Generation Access (also known as Super Fast Fibre access). Our programme that is dedicated to shaping tomorrow's communications environment. We work with communications providers, the regulator, industry and other stakeholders to ensure that we build a clear picture of an access network that's fit for the future.

 

NTE5
Network Termination Equipment version 5 - also commonly known as the master socket, this is the copper termination point within the end user's premises and the place where the GEA over FTTC SSFP is installed. The master socket marks the demarcation point between the Openreach network and the end user's home network with respect to voice wiring.

 

NTE
Network Terminating Equipment. Equipment that is located in the home or office. Examples are set top boxes and LAN.

 

NTP
Network Terminating Point. The place where the network ends.

 

OHP
Openreach Handover Point. Mainly located in Metro Nodes, which are the breakout point for our Bulk Transport Link and Ethernet Backhaul Direct products.

 

ONBS
Openreach Network Backhaul Service. Offers connectivity between a communications providers' equipment (installed within Co-location, Netlocate or BT Locate at a BT MSAN Site) and their equipment (installed within Co-location, Netlocate or BT Locate at either the nearest BT MSAN Site, BT Metro Node Site or another BT MSAN Site or Metro Node Site which is within a distance of 15 radial kilometres of the first BT MSAN/Metro Site).

 

PBX
Private Branch Exchange. A telephone exchange that serves a particular business or office.

 

PCP
Primary Cross-connection Point - this is the local street cabinet in which cables extending out to local distribution points are aggregated and connected to larger copper and fibre optic cables to move the voice and data signals to and from the local exchange. The number of connections managed in a PCP depends on the number of end user premises in an area, but is usually several hundred (200-400) lines.

 

POTS
Plain Old Telephony Service (also known as an analogue telephone line). The basic services provided over the Public Switched Telephone Network (PSTN).

 

PSTN
Public Switched Telephone Network. It was originally a network of fixed-line analogue telephone systems but the switching (or telephone exchange) element of the PSTN is now digital. The mobile telephony networks are considered to be part of the PSTN.

 

PSU
Power Supply Unit (power supply). A power supply unit is a device that supplies electrical power to a device or group of devices.

 

PON
Passive Optical Node (Network)

 

SDSL
Symmetric Digital Subscriber Line (also known as Symmetric Digital Subscriber Loop). Uses a single wire pair to carry a few Mbit/s of data. However, unlike ADSL, upload and download speeds for the user are the same (hence symmetric versus asymmetric).

 

SFFA
Superfast Fibre Access - the marketing term used to describe Openreach's fibre optic access products

 

SNDDI
Single Number Direct Dialling In. An individual number DDI range, which means that for incoming calls the network will send, as default, 6 routing digits to the customer equipment so that calls can be directed to the correct channel.

 

TPON
Telephony over Passive Optical Networks. A technology that we have designed, it is made up of slim fibre optic cable instead of lots of copper wire pairs.

 

VDSL
Very high bit rate Digital Subscriber Line - the broadband technology used to deliver the higher speeds associated with FTTC compared to standard copper broadband products which are delivered over ADSL. VDSL is designed to work on shorter lengths of copper cable.

 

VIC
Virtual Interconnect Circuit. Allows for migration of interconnect routes from the DLE to the NGS.

 

VLAN
Virtual Local Area Network - a subdivision of the capacity within the network representing the "pipe" provided for a single end user’s data traffic through the Openreach network.

A
 
A/C
Aerial Cable
 
A&I
Accommodation and Infrastructure (planners)
 
ABB
Apartment Breakout Box
 
ABP
Address Based Premium
 
ACR
Access Capital Repair
 
ADSL
Asymmetric Digital Subscriber Line
 
ADSS
All-Dielectric Self-Supporting
 
AEC
Access Engineering Communications
 
AFM
Anticipated Faults Management system
 
AFS
Actual Faults Saved
 
AGC
Automatic Gain Control
 
Agg
Aggregation node (AKA an AN)
 
AICC
Assets In the Course of Construction
 
AIO
All In One (Cabinet)
 
AIRG
Accident & Incident Reporting Group
 
AJ
Aggregation Joint
 
AKA
Also Known As
 
ALP
Annual Learning Plan
 
AN
Aggregation Node. Fibre from the exchange is split and feeds Splitter nodes via mini cables. Also referred to as the Agg node
 
ANFP
Access Network Frequency Plan
 
AOC
Access Operation Centre (Bristol based Operations Control)
 
AOP
Annual Operating Plan
 
AOMP
Advanced Order Management Process
 
AONB
Areas of Outstanding Natural Beauty
 
AP
Address Point
 
APC
Angled Physical Contact
 
APT
All Ports Test
 
AR
Augmented Reality
 
ARENA
Audit Record of Engineering Network Activity
 
ASDH
Access Synchronous Digital Hierarchy
 
ASOW
As Seen On Workplace
 
n/a
Asset Assurance Team (now see Network Repair Team -  NRT)
 
ASU
Advanced Service Unit
 
ATA  
Analogue Telephony Adapter
 
ATE
Automatic Telephone Exchange
 
AVC
Aborted Visit Charges
 
AXE10
System Y type Exchange
 
ATM
Asynchronous Transfer Mode


B
 
BCD
Business and Corporate Delivery
 
B2B
Business to Business
 
BAU
Business As Usual
 
BB
Broadband
 
BB VAS
Broadband Value Added Services
 
BBU
Battery Back Up
 
BCD
Business & Corporate Delivery
 
BCMR
Business Connectivity Market Review
 
BCOF
Blown Cable Optical Fibre
 
BDF
Building Distribution Frame
 
BDUK
Broadband Delivery UK
 
BET
Broadband Enabling Technology
 
BFB
Blown Fibre Bundle
 
BFD
Blown Fibre Drop tubing
 
BFT 
Blown Fibre Tubing
 
BFU
Blown Fibre Unit
 
BLT
Bend Limiting Tubing
 
BNR
Bell Not Ringing
 
BPON
Business Passive Optical Network
 
BPS
Business and Public Sector
 
BR
Bell Ringing (continuous)
 
BT
Block Terminal
 
BTCC
BT Compliance Committee
 
BTD
BT Design
 
BTGS
BT Global Services
 
BTO 
BT Operate
 
BTTW
Build To The Wall
 
BTW
BT  Wholesale


C
 
C2M
Concept to Market
 
CA
Customer Apparatus
 
Cab
Short name for cross-connection street cabinet (See PCP)
 
CAD
Corporate Active Directory
 
CAL
Cabinet Assigned Loss
 
CARM
Compliance And Risk Management
 
CAT
Connectivity Allocation Tool - NewSite related developer tool
 
CAT
Cable Avoidance Tool
 
CBO
Cable Break Out
 
CBT
Connectorised Block Terminal
 
CCD
Customer Committed Date
 
CCJ
Cable Chamber Joint
 
CCN
Cross-CoNnection
 
CCT
Circuit
 
CCTV
Closed Circuit TeleVision
 
CDD
Contractual Delivery Date
 
CDDC
Connectorised Dual Drop Cable 
 
CDH
Cloud Data Hub
 
CDM
Construction Design Management
 
CDT
Continuous Dial Tone
 
CDTA
Conscious Decision to Appoint
 
CE 
Chief Engineer
 
CE 
Customer End
 
CEM
Chief Engineer Module
 
CEO
Chief Executive Officer
 
CET
Copper Enhanced Technologies
 
CFI
Customer Focused Investment
 
CFP
Community Fibre Partnership
 
CFU
Customer Facing Unit
 
CIDT
Copper Integrated Demand Test
 
CIO
Chief Information Officer
 
CJ
Cable Junction
 
CLI
Calling Line Identity
 
CLI
Customer Lead In
 
CMJ
Compact Multi-function Joint (Small Node)
 
CMN
Common
 
CMO
Compliance Monitoring Office
 
CMS CIS
Core Cable Maintenance Service. Common Infrastructure System
 
CMUX
Convertor MUltipleXer
 
CN
Civil Network (diagram)
 
CNF
Calling and Network Features
 
CNS
Customer Network Solutions
 
CO
Cuts Off
 
CO
Central Office (USA-Exchange)
 
COF
Cable Optical Fibre
 
COM
Completion
 
COMP
Completion
 
CONGO
Control Of New Greenfield Organisation
 
COTS
Commercial Off The Shelf
 
COW
Class Of Work
 
CoW
Clerk of Work
 
CP
Communications Provider
 
CP OCR
Communication Provider Optical Consolidation Rack
 
CPCA
CP controlled ATA
 
CPE
Customer Premises Equipment
 
CPE
Customer Provider Equipment
 
CPG
Core Planning Guide
 
CPI
Copper Pair Identification
 
CPW
CarPhone Warehouse
 
CR
Change Request
 
CRD
Customer Required By Date
 
Csat
Customer satisfaction
 
CSE
Customer Service Engineer
 
CSGS
Customer Service Guarantee Scheme
 
CSIM
Customer Service Insight Management
 
CSP
Customer Service Plan
 
CSP
Customer Splicing Point
 
CSP
Customer Service Point
 
CSPN
Connectorised SPlitter Node
 
CSS
Customer Service System
 
CST
Customer Service Team
 
CTD
Cumulative To Date
 
CTH
Central Test Head
 
CTIO
Chief Technology & Information Office
 
CuRe
Copper Rearrangement
 
CVF
Customer Verification Facility
 
CWSS
Copper Wideband Serving Section
 
CWWC
Confirm Working With Customer



 
D-side
Distribution side (of a Primary Cross-Connection Point - PCP)
 
D/W
Drop Wire
 
DACS
Digital Access Carrier System
 
Db
Decibel
 
DC
Data Centre
 
DC
Direct Currant
 
DCAT
(Now known as CAT) - Developers Connectivity Allocation Tool
 
DCN
Data Connection Network
 
DCR
ofcom Digital Communications Review
 
DCoE
Diagnostic Centre of Excellence (DCoE) teams
 
DCMS
Department for Culture Media & Sport
 
DCT
Data Centre Team
 
DCU
Damage Claims Unit (Now see Network Repair Team – NRT)
 
DEA
Digital Ethernet Access
 
DEL
Dedicated Exchange Line
 
DF
Dark Fibre
 
DF
Direct Fulfilment
 
DF1AL
Dark Fibre 1 Access Link
 
DF2AL
Dark Fibre 2 Access Link
 
DFA
Dark Fibre Access
 
DFE
Departure From Estimate
 
DFS
Dark Fibre Storage
 
DFS
Discrete Façade
 
DFW
Dual Fibre Working
 
DFX
Dark Fibre eXchange
 
DH
Data Hall
 
DHCP 
Dynamic Host Control Protocol (part of IP suite of protocols)
 
DIG
Direct In Ground
 
DILOR
Dropwires In Line Of Route
 
DIS
Disconnection
 
DLE
Digital Local Exchange
 
DMC
Data Management Centre
 
DN
Directory Number
 
DNA
Dense Network Access
 
DNO
Distribution Network Operator
 
DOA
Dead On Arrival
 
DP
Distribution Point (Often a telegraph pole)
 
DPA
Duct and Pole Access
 
DPNSS
Digital Private Network Signalling System
 
DPU
Distribution Point Unit
 
DSI
Developer Self Install
 
DSL
Digital Subscriber Line
 
DSLAM
Digital Subscriber Line Access Multiplexer
 
DSN
Distribution Splitter Node
 
DT
Diagnostic Test
 
DWAL
Directly Wired Access Line


E
 
E-Side
Exchange Side (of a Primary Cross-Connection Point - PCP, aka M-Side, Main Side)
 
EAD
Ethernet Access Direct
 
EBLC
EmBedded Line Card
 
ECC
Excess Construction Charges
 
ECC
Electronics Communications Code
 
ECD
Estimated Completion Date
 
ECI
DSLAM and modem vendor
 
EDFA
Erbium Doped Fibre Amplifier
 
EES
Ethernet Edge Switch
 
EIC
Electrical Installation Certificate
 
EICR
Electrical Installation Condition Report
 
ELF
Early Life Failures
 
ELM
External Locking Mechanism (Locking bollard)
 
EM
Element Manager
 
EMDL
Early Market Deployment Launch
 
eMLC
enhanced Managed Line Characteristics
 
EMP
Equivalence Management Platform
 
EMS
Environmental Management System
 
ENA
Equipment Network Access
 
ENA
Energy Networks Association
 
EO, E/O
Exchange Only (cable)
 
EOI
Equivalence Of Input
 
EoSL
End of Service Life
 
ES
Engineering Services, CPs can purchase the ES service from us
 
ESRI
Environmental Science Research Institute
 
ESV
Ethernet Single Visit
 
ETSI
European Telecommunications Standards Institute
 
EU
End User
 
EU
European Union
 
EU
Exchange Unit
 
EvoTAM
Evolutionary Test Access Matrix
 
EX
Exchange
 
EXFO
a type of Remote Test Unit (a hand-held tester)


F
  
F
Fibre
 
FACT
Front Access Connector Tray
 
FBC
Field Based Co-ordinator
 
FBWP
FaceBook WorkPlace
 
FDP
Fibre Distribution Point. Blown fibre feeds the premises
 
FDP
Floor Distribution Point
 
FDC
Fibre Drop Cable
 
FEN 
Field Engineering News
 
FFA
Future Fibre Architect
 
FFTC
Fibre From The Cabinet
 
FIRS
Fibre Integrated Reception Service
 
FJ
Faults man Jointer
 
FLL
First Line Leader
 
FLM
Fibre Locking Mechanism
 
FNC
Fiber Node Configurator
 
FND
Fibre and Network Delivery
 
FNF
Fault not Found
 
FNT
Faint Transmission
 
FOA
First Office Application
 
FoD
Fibre on Demand
 
FOD
First Occupation Date
 
FOD
Fibre Only Drop (Cable)
 
FODW
Fibre Only DropWire (aka FOD)
 
FPQ
Field Performance in Quality
 
FRAC
Fibre Repair Analysis Centre
 
FSD
First Service Dates
 
FT2
FastTest2
 
FTA
Freight Transport Association
 
FTTC
Fibre To The Cabinet 
 
FTTD
Fibre To The Door
 
FTTDP
Fibre To The Distribution Point
 
FTTP
Fibre To The Premises
 
FTTx
Fibre To The cabinet or premises (generic term)
 
FTTRN
Fibre To The Remote Node
 
FU
Frames Unit
 
FVA
Fibre Voice Access


G
 
G.fast
(Also known as G.9700 and G.9701 fast access to subscriber terminals)
 
GDPR
General Data Protection Regulation
 
GEA
Generic Ethernet Access
 
GigE
Gigabit Ethernet
 
GP
Ghost Plan
 
GPON
Gigabit Passive Optical Network
 
GQTT
Group Quality Task Time
 
GS
Global Services
 
GSP
Ground Support Person
 
GTCJ
Generic Test Controller - Java
 
GTCS
Generic Test Controller - Sun
 
GUI
Graphical User Interface
 
GUNPF

BT Group UK Numbering Policy Forum


H

HAWK
Hawk type Hand Held Tester
 
HBF
House Builders Federation
 
HCR
Heavy Cable Recovery
 
HCSA
Hydra Cable Storage Area
 
HCSC
High Capacity Single Circuit tray
 
HCSE
High Capacity Single Element tray
 
HD
High Density
 
HDD
Horizontal Directional Drilling
 
HDF
Handover Distribution Frame
 
HDTV
High Definition Television
 
HE
HeadEnd
 
HERS
Highway Electrical Registration Scheme
 
HEX
Heat Exchanger
 
HHT
Hand Held Terminal/Tester
 
HLD
High Level Design
 
HLSD
High Level Solution Design
 
HND
Holistic Network Design
 
HOF
Handover Frame
 
HOP
HandOver Pack
 
HOTAN
Health of the Access Network
 
HR
High Resistance (fault in the copper access network)
 
HRD
High-Reflectance Demarcation
 
HTTP
Hyper Text Transfer Protocol
 
HYDRA
Fibre optic cables used in the Optical connection rack
 
Hz
Hertz


I
 
ICB
Incoming Calls Barred
 
ICE
Infrastructure Clearance and Extraction
 
ICNIRP
International Commission on Non-ionizing Radiation Protection
 
ID
Infrastructure Delivery
 
IDC
Insulation Displacement Connection
 
IL2S
Integrated Layer 2 Switch
 
ILC
In Life Capacity
 
IMU
Integrated Market Review (2021)
 
IMUX
Inverse MUltipleXer
 
INS
Integrated Network Systems
 
IPA
IsoPropol Alcohol
 
IP
Internet Protocol
 
IPTV 
Internet Protocol Television
 
IS
Infrastructure Solutions
 
ISA
Information Sharing Agreements
 
ISDN
Integrated Service Digital Network
 
ISIS
Inland Services Information System
 
ISP
Internet Service Provider
 
ITT
Invitation To Tender
 
IVR
Interactive Voice Response


J
 
JB
Joint Box
 
JDSU
VIAVI (formally known as JDSU) – manufacturer of hand held tester
 
JF(x)
Joint Box Footway (size reference)
 
JP
Joint Post
 
JPPA
Job Pack Production Assistant
 
JRB
Joint Box Reinforced Brick - (Standard brick joint box)
 
JRC
Joint Box Reinforced Concrete - (Standard concrete joint box)
 
JUF
Joint box Unreinforced Footway


K
 

KBD
Knowledge Based Diagnostics
 
KCI
Keeping Customers Informed
 
KJC
Kit Joint Closure
 
kHz
KiloHertz
 
km
Kilometre


L
 
L2C
Lead To Cash (Income for business, previously known as Provision)
 
L2S  
Layer 2 Switch (Ethernet switch that is the connectivity point for CPs to the NGA Network)
 
L2W
Licence to Work
 
LA
Local Access
 
LA
Local Authority
 
LAD
Local Access Dataset
 
LAG
Link Aggregation Group
 
LAN
Local Area Network
 
LC
Line Card (also a type of fibre connector)
 
LDU
Loop Diagnostic Unit
 
LEA
Line Extenders Audio
 
LES
Line Extended Signalling
 
LFFN
Local Full Fibre Networks
 
LHS
Left-Hand-Side
 
LiC
Line interface Card
 
LIJ
Left In Jumpers
 
LJU
Line Jack Unit
 
LLC
Line Loss Calculator
 
LLEL
Low Loss Exchange Line
 
LLPP
Local Line Physical Protection
 
LLR
Light Loss Report
 
LLS
Low Level Solution
 
LLSD
Low Level Solution Design
 
LLT
Light Loss Task (Testing)
 
LLU
Local Loop Unbundling
 
LLUC
Local Loop Unbundling Commingling
 
LLUMS
Local Loop Unbundling Management System
 
LMA
Loop Management Area
 
LMTP
Let’s Make This Personal
 
LN
Line Network
 
LOB 
Line of Business
 
LP/APC
Lucent Connector/Angled Physical Contact
 
LRQA
Lloyds Register Quality Assessment
 
LRT
Long Reach Tails
 
LSBUD
Line Search Before yoU Dig
 
LSZH
Low Smoke Zero Halogen
 
LT
Line Test
 
LTDS
Line Test Dialogue Services
 
LTE
Line Terminating Equipment
 
LTOK
Line Test OK
 
LTOP
Line Test on Provision
 
LTOR
Line Test on Repair
 
LTS
Line Test System
 
LTU
Line Termination Unit
 
LV
Low Voltage



 
MBORC
Matters Beyond Our Reasonable Control
 
Mbps
Megabits per second
 
MBR
Minimum Bend Radii
 
MCJ
Mechanical Clip Joint
 
MDF
Main Distribution Frame
 
MDT
Manage Diagnostic Test
 
MDU
Multiple Dwelling Unit
 
MEAS
Mobile Ethernet Access Service
 
MET
Main Earth Terminal
 
MEMS
Micro-Electro-Mechanical Systems
 
MEWP
Mobile Elevating Work Platform
 
MFD
Mode Field Diameter
 
MFL
Main Fault Location
 
MFN
Multifunctional Node
 
M/H
Manhole
 
MI 
Managed Install
 
MiMo
Multiple input Multiple output
 
MIS 
Management Information Systems
 
MLC
Manage Line Characteristics
 
MLPA
Managed Line Plant Availability
 
mm
millimetre
 
MMJ
Medium Multi-function Joint (Medium Node)
 
MMPF
Multiple Metallic Path Facility
 
MMR
MeetMe Room (in a data centre)
 
MNSD
Manage Network and Service Diagnostic
 
MoBRA
Mounting BRAcket arm
 
MOU
Multiple Occupancy Unit
 
MPO
Multi-fibre Push On
 
MPA
Manage Product Availability
 
MPE
Multi-Purpose Enclosure (new name for UCAO)
 
MPF
Metallic Path Facility
 
MPI
Managed Physical Inventory
 
M-Side
Main Side (aka E-Side, Exchange Side)
 
MSAN
Multi-Service Access Node
 
MSL
Minimum Service Level
 
MTP
Medium Term Plan
 
MTTP
Mean Time To Provide
 
MTU
Multi-line Terminating Unit
 
MU/CJ
Main Underground/Cable Junction


N
 
NA
No Access
 
NA
Network Assessor
 
NAC
Network Analysis Centre team
 
NAD
Network Address Database
 
NAT
Node Analysis Tool
 
NATO
Neighbourhood Analysis Tool for Openreach
 
NC
Non-Compliance
 
NCSC
National Cyber Security Centre
 
NDS
Network Decision Support System
 
NDT
No dial tone
 
NED
Network Engineering Delivery
 
NED
Network Enhanced Device
 
NGA
Next Generation Access
 
NGN
Next Generation Network
 
NIMS
Network Information Management System
 
NIN
Northern Ireland Networks
 
NIT
Network Integration Test
 
NNI
Network Nodal Identifier
 
NOCR
Network Optical Consolidation Rack
 
NOPS
Network Operative Passport Scheme
 
NOT
Network Optimiser Tool (NewSites)
 
Not Spot
Areas of the country where there is currently no broadband coverage at all
 
NOU
Network Operations Unit
 
NR
No Reply
 
NRSWA
New Roads and Street Works Act
 
NSP
Non Served Premises
 
NSY
Noisy
 
NRT
Network Repair Team (03/06/19 now combines Asset Assurance team and Damage Claims Unit)
 
NT
No Tone
 
NTE
Network Terminating Equipment
 
NTP
Network Terminating Point
 
NTTP
Network Termination and Test Point
 
NTU
Network Terminating Unit
 
NU
Number Unobtainable
 
NUD
No Undue Discrimination


O
 
OBARCC
Openreach Board Audit, Risk and Compliance Committee
 
OCB
Outgoing Calls Barred
 
OCR
Optical Connection or Consolidation Rack
 
ODF
Optical Distribution Frame
 
ODN
Optical Distribution Network
 
Ofcom
Office of communications
 
OFF
Optical Flexibility Frame
 
OFN
One Fibre Network
 
OFNL
Open Fibre Networks Limited
 
OFR
Optical Flexibility Rack
 
O/H
Overhead
 
OHP
Openreach Homes Passed
 
OHR
Overhearing
 
OIB
Openreach Investment Board
 
OLO
Other Licensed Operators
 
OLT 
Optical Line Termination (generally network side)
 
OMP
Openreach Marketable Premises
 
OMU
Openreach Monitoring Unit
 
ON
Optical Network
 
ONSA
Openreach Network Services Agreement
 
ONT 
Optical Network Termination (Home equipment)
 
OPEX 
Operational Expenditure
 
OPM
Optical Power Meter
 
OPS
Optical Patching Shelf
 
OR
Openreach
 
ORMP
OpenReach Marketable Premises
 
ORSRIMS
OpenReach Service & Resource Inventory Management System
 
ORWFMT
OpenReach Work Flow Management Tool
 
OS
Ordnance Survey
 
OSA
Optical Spectrum Access
 
OSAS
Optical Stand Alone Survey
 
OSS 
Operating Support Systems
 
OTA
Office of the Telecommunications Adjudicator
 
OTDR
Optical Time Domain Reflectometer
 
OTH
Optical Test Head
 
OTIAN
Optical Telecommunication In the Access Network
 
OTU
Optical Test Unit
 
OWT
One Way Transmission


P
 
P&B 
Plan and Build
 
P2P (PTP)
Point To Point
 
P2MP
Point to MultiPoint
 
PAF
Postcode Address File
 
PAS
Public Availability Specification
 
PASMA
Prefabricated Access Suppliers' and Manufacturers' Association
 
PBX
Private Branch Exchange
 
PCP 
Primary Cross-connection Point (also referred to as a Cab (cabinet))
 
PCI
Pre-Construction Information
 
PDU
Power Distribution Unit
 
PDF (.pdf)
Portable Document Format
 
PE
PolyEthylene
 
PENC/S
Public Electronic Communications Network/Service
 
PER
Power Equipment Rack
 
PET
Permanently engaged tone
 
PeT 
Cable Polyethylene Twin
 
PEU
Pole Erection Unit
 
PeUT
Cable Polyethylene Unit Twin
 
PEW
Planned Engineering Works
 
PIA
Physical Infrastructure Access
 
PIMR
Passive Infrastructure Market Review
 
PINES
Planning Intelligent Notes Entry System
 
PIPeR
Physical Inventory of Plant and engineering Records
 
PJL
Post Joint Large (TfL equivalent of a jointing post)
 
PMC
Pole Mounted Closure
 
POC
Proof Of Concept
 
POE
Point Of Entry (box)
 
POI
Point Of Intervention
 
PON
Passive Optical Network
 
PoP
Point of Presence
 
POS
Provision Of Service
 
POTS
Plain Old Telephony Service
 
PPR
Proactive Pressure Repair
 
ppt
pair per tenancy
 
PQ
Pair Quality
 
PQT
Pail Quality Test
 
PSN
Primary Splitter Node
 
PSTN
Public Switched Telephone Network
 
PSU
Power Supply Unit
 
PTD
Permission To Dig
 
PTO
Precision Test Officer
 
PTP (P2P)
Point To Point
 
PTW
Permission To Work



 
QA
Quality assurance



 
RABiT
Rapid Assessment BT incident Tracker
 
RACI
Responsible Accountable Consulted Informed
 
RAMS
Risk And Method Statement
 
RARA
Ring Ahead - Ring After (Contacting the end user)
 
RAT
Request Automatic Test 
 
RBAT
Request Background Automatic Test
 
RBD 
Required By Date
 
RCKN
Reduced Cost Kilostream Network
 
RCR
Route Cause Repair
 
RDSLAM 
Remote Digital Subscriber Line Access Multiplexer (Remote DSLAM)
 
REIN
Repetitive Electrical Impulse Noise
 
REN
Ringing Equivalent Number
 
RET
Request Exchange Test
 
RFI
Request For Information
 
RFI
Ready For Install
 
RH
Relative Humidity
 
RFS
Ready For Service / Sending
 
RFT
Right First Time
 
RHS
Right-Hand-Side
 
RLT
Request Line Test
 
RMS
Root Mean Square
 
RO1
Resilience Option 1
 
RO2
Resilience Option 2
 
ROC
RoCDrop (Cable)
 
ROHS
Restriction of Hazardous Substances
 
RoI
Risk of Investment
 
ROSE
Routing Of Simple Exchange lines
 
RPA
Robotic Process Automation (RPA) recruits
 
RSA
Road Safety Audit
 
RSP
Report Spine Planner
 
RT
Ribbon Tray
 
RTP
Ring Trip
 
RTWF
Real Time Work Flow
 
RU
Remote Unit
 
RUE
Remote Unit Emulation
 
RWT
Right When Tested


S
  
SAC
Stand Alone Cabinet
 
SAM
Skill Alliance Module
 
SAPL
Single Address Point Locking Tray
 
SAS
Stand Alone Survey
 
SASA
Splitter Array Sub-Assemblies
 
SC
Shallow Climbable (Pole classification)
 
SC
Standard Connector
 
SC-APC
Subscriber Connector - Angled Physical Contact
 
SCBT
Splitter Connector Block Terminal
 
SCF
Security Critical Function
 
SCP
Secondary Cross-connection Point
 
SD 
Service Delivery
 
SDH
Synchronous Digital Hierarchy
 
SDP
Splitter Distribution Point
 
SDMB
SDMB - Sub Duct Mono Bore
 
SDEDS
Secure Data Exchange and Distribution System
 
SDP
Splitter Distribution Point
 
SDR
Standard Dimension Ratio
 
SDSL
Symmetric Digital Subscriber Line
 
SDU
Single Dwelling Unit
 
SEP
Superfast Extension Programme
 
SFA
Super Fast Access
 
SFFA
Super Fast Fibre Access
 
SFFB
Super Fast Fibre Broadband
 
SFP
Small Form-factor Pluggable
 
SFW
Single Fibre Working
 
SHDSL
Symmetric Hi-Speed Digital Subscriber Line
 
SHE
Subtended Head-End
 
SI
Self Install
 
SID
Strategic Infrastructure Development unit
 
SIN
Supplier Information Note (BT publication)
 
SLA
Service Level Agreement
 
SLG
Service Level Guarantee
 
SLU
Sub Loop Unbundling
 
SMC 
Service Management Centre
 
SME
Subject Matter Expert
 
SME
Small and Medium Enterprises
 
SMP
Significant Market Power
 
SMPF
Shared Metallic Path Facility
 
SMS
Short Message Service
 
SMT
Senior Management Team
 
SNAP
Single Network Accommodation Process
 
SNC
Significant Non-Compliance
 
SNOW
Service Notice Of Works
 
SOAP
Supplier Operational Auditor Process
 
SOC
Security Operation Centre
 
SOD
Service On Demand
 
SOF
Shelf Optical Fibre
 
SOGEA
Single Order VDSL
 
SOGFAST
Single Order G.fast
 
SoHo
Small office/Home office
 
SOR
Statement Of Requirement
 
SP & M
Sales, Product And Marketing
 
SPM
Subs Private Meter
 
SPN
Splitter Node
 
SRM
Sales and Relationship Manager
 
SRU
Small Remote Unit
 
SSFP
Service Specific Face Plate
 
SSSI
Site of Special Scientific Interest
 
SSRAMS
Site Specific Risk Assessment and Method Statement
 
SST
Standard Single Tube
 
SST  Y
Standard Single Tube (type) Y 
 
STAA
Strategic Transaction Automation Architecture
 
STC
Safe To Connect
 
STEM
Science, Technology, Engineering, Maths
 
SWF
Single Working Fibre
 
SYSX
System X type exchange
 
SYSY
System Y type exchange (also known as AXE10)


T
 
T & D 
Test And Diagnostics
 
T2R 
Trouble to Resolve (Cost to business, previously known as Maintenance)
 
TADDS
Test and Diagnostics Data Store
 
TAM
Test Access Matrix
 
TAN
Test Access Number
 
TCD
Target Completion Date
 
TCP
21st  ( T ) System Planning
 
TCP 
Transmission Control Protocol (part of Internet protocol suite)
 
TDFS
Technical Departure From Specification
 
TDR
Time Domain Reflectometer
 
TfL
Transport for London
 
TH
Test Head
 
THP
Total Homes Passed
 
TIJ
Tube Interception Joint
 
TJ
Tube Joint
 
TM
Termination Multi-function (TM series of nodes)
 
TMA
Traffic Management Act
 
TMS
TAM Management System
 
TN
Test Network
 
TNOK
Test Not OK (There is a fault on the line)
 
ToC
Test on Completion
 
TOK
Test OK
 
TOR 
Terms Of Reference
 
TOS
Temporary Out of Service
 
TPET
Third Party Engaged Tone
 
TPON
Telephony over Passive Optical Networks
 
TPR
Tie Pair Reconfiguration
 
TRC
Time Related Charge
 
TSC
Test System Controller
 
TSO
Technology, Service & Operations
 
TWP
Trialists Working Party



 
UAT
User Acceptance Testing
 
UBB
Ultra BroadBand
 
UBC
Universal Broadband Commitment
 
UCAO
Universal Closure Access Optical (now refer to MPE)
 
UFS
Universal Fibre Solution
 
UG
Underground
 
UII
Unified Inventory Interface
 
ULW
Ultra LightWeight
 
UPB
Universal Pole Bracket
 
UPRN
Unique Property Reference Number
 
USC
Universal Service Commitment
 
USO
Universal Service Obligation


V
 
VAL
Vulnerable Area Locator
 
VDS
Vendor Direct Shipped
 
VDSL
Very high speed Digital Subscriber Line
 
VIAVI
VIAVI (formally known as JDSU) – manufacturer of hand held tester
 
VMJ
View My Job
 
VoD
Video on Demand
 
VoIP
Voice over Internet Protocol
 
VTU
Vertical Termination Unit


W
 
W & V
Wholesale & Ventures
 
WAC
Work Allocation Control
 
WAN
Wide Area Network
 
WAU
Work Allocation Unit
 
WBC
Wholesale Broadband Connect
 
WD
Working Days
 
WDM
Wavelength Division Multiplexing
 
WFA 
Work Flow and Allocation
 
WIP
Work In Progress
 
WLAMR
Wholesale Local Access Market Review
 
WLA
Wholesale Local Access
 
WLR  
Wholesale Line Rental
 
WM
Work Manager
 
WO
Work Order
 
WOOSH
Web based Out Of Service Handling
 
WRF
Work Request Form
 
WTTC
Wireless to the Cab
 
WWR
While We’re There - service provided to CPs


X
 
xDSL
Digital Subscriber Line
 
XL
Crossed lines
 
XML
eXtensible Mark-up Language