Telecoms Terms Abbreviations

VoIP - Voice Over Internet Protocol
Telephone calls and voice traffic are converted in data (IP) and sent across data networks such as LANs, WANs and Internet. See also: QoS, PoE.

SIP - Session Initiation Protocol
SIP Trunks are the individual lines used to carry SIP data. SIP refers to the language used to carry voice traffic over data connections and the internet. To put it simply, SIP Trunks are just ISDN over the Internet.

ISDN - Intergrated Services Digital Network
The digital exchange and network infrastructure that currently transports the majority of voice calls across the UK. Available in 2 formats : ISDN2e & ISDN30e. See also: DDI, CLI, CTI.

ADSL - Asynchronous Digital Subscriber Line
ADSL is the popular format for broadband internet connections. Download speed is usually much higher than upload speed - the data bandwidths are Asynchronous.

FTTC - Fibre to the Cabinet
Fibre-to-the-Cabinet (FTTC) involves running fibre optic cables from the telephone exchange or distribution point to the street cabinets which then connect to a standard phone line to provide broadband.

FTTH - Fibre to the Home
Fibre-to-the-Home (FTTH) provides and end-to-end fibre optic connection the full distance from the exchange to the building and can deliver faster speeds than FTTC as there is no copper leg at all.

QoS - Quality Of Service
When using VoIP, QoS has to be configured on a data network to make sure call quality is preserved. Data networks without QoS risk degradation of phone call quality, and in some cases calls are cut off entirely.

EFM - Ethernet First Mile
EFM gives you a tough and reliable high-speed business internet connection. Unlike a standard leased line, EFM uses existing copper lines (instead of fibre) to connect you to the local BT exchange. It's cheaper and quicker to install than a standard leased line.

MPLS -  Multiprotocol Label Switching
A scalable private network, enabling multiple locations to connect to each other and transfer voice and data services via a private "cloud" arrangement.

PoE - Power Over Ethernet
VoIP telephones require electrical power. This power is usually provided by your ethernet switch (known as a PoE Switch), which powers the telephone as well as delivering the VoIP phone call data to it. If you don't have PoE Switches, you will need 3-pin electrical power adpaters for each telephone, with an associated power outlet at the workstation.

CTI - Computer Telephony Integration
The inbound CLI of the caller is delivered to a database, CRM or application on the PC. Traditionally the caller's data "pops" on screen when the phone rings. Also known as "Screen Popping".

ACD - Automated Call Distribution
Used in Contact Centres to distribute telephone calls evenly to available agents. The agent who has been waiting the longest gets the next call. Also known as "longest wait" or "most idle" call distribution. See also MIS, Skills-Based Routing.

LCR - Least Cost Routing
LCR software within the telephone system (or via an external "smart box" or "call router") adds a 3 or 4-digit code to each outbout telephone call, notifying the local PSTN exchange to route the call via a call services vendor. The customer will have a contract with thier particular call vendor/carrier already in place. LCR software can be re-programmed, making it easy for businesses to change call providers if required.

CPS - Carrier Pre-Selection
Removes the need for LCR. The local exchange is intelligent and knows the routing preferences of each telephone line connected, sending calls via the preferred call providers automatically without the need for software or telecoms equipment to be installed at the end-user premises.

BRI - Basic Rate ISDN
Another term for ISDN2e. Used often by IT professionals and telecoms engineers.

PRI - Primary Rate Primary Rate ISDN
Another term for ISDN30e. Used often by IT professionals and telecoms engineers.

DP - Distribution Point
Cabling connection and distribution box for 1308 block cabling systems.

DDI - Direct Dialling Inwards
DDI numbers are applied to ISDN lines, allowing selected staff, services and departments to have direct-dial facilities.

CLI - Calling Line Identity
The inbound caller's telephone number. Associated as a phone feature mainly with ISDN lines, however also presented over mobile and SIP Trunk networks.

NTE -  Network Termination Equipment
The NTE is the connection box for ISDN30 and other network services using ISDN protocols. An NTE can support up to 4 bearers, or trunks, of ISDN30 (ie. up to 120 phone lines). The ISDN30E connections are identified by RJ45 connections. NTEs supporting older DASS-type protocols have co-axial connections.