Adodo's Concise Glossary of Telecoms

Telecommunications is an industry fraught with complicated terminology and
three letter acronyms.
To help with your understanding of some of the more frequently used terms, here
is Adodo's glossary of telecoms.

ADSL - Asymmetric Digital Subscriber Line

A broadband technology that delivers very high data transfer speeds over
existing telephone lines within the traditional copper wire telephone network. It
downloads faster than you can upload them due to there being more bandwidth
available on the downstream. It is up to nine times faster than a 56k modem
connection. Ideal for residential connections or for businesses not running a
server.

Analogue Lines

The original telephone lines. They are still a common option for smaller
businesses. However, technology is shifting rapidly towards digital options like
ISDN and SIP trunking which prove to be more cost effective.

Auto Attendant

An automated answering system that directs the caller to their destination using
prompts. For example, "For the Accounts Department, please press 1".

Bandwidth

A measurement that gives us the capacity to know how much data can be sent
through a connection. It is measured either in frequency range eg) 3 kHz, or
transmission rate (in bits per second) eg) 63 Kps.

Blackberry

A handheld device which enables wireless access to phone, email,
corporate data and other organiser features whilst your away from the office.

Bluetooth

A new technology designed to be embedded in electronic devices in order to
provide wireless and seamless connections over short distances of up to 10
meters. Named after a Danish king.

Broadband

Any permanent connection to another network (usually the internet) that has the
ability to send and receive large amounts of information in a short period of time.

Call Forwarding

This feature allows incoming calls to be redirected to another destination, such
as a mobile phone or a home number.

Centrex

A PBX-like service providing switching at the central office instead of at the
customer's premises. Typically, the telephone company owns and manages all
the communications equipment and software necessary to implement the
Centrex service.

Channel

Is another word used to describe a telephone line, usually used in the context of
digital lines.

CLI - Calling Line Identification

Technology that provides the identity information of the incoming call on the
receivers phone display.

CoS - Class of Service

A means of managing traffic over a network by identifying types of traffic and
prioritising certain groups.

DASS - The Digital Access Signalling System

The first incarnation DASS1 is now obsolete and has been replaced by
DASS II. This itself will become obsolete over the coming years.
DASS II is purely a protocol used to control data flow across the ISDN
doing a similar job to the protocols used with modems when sending the data over the analogue PSTN. It is more highly specified and controlled and
operates at higher speeds.

DDI - Direct Dialling Inward or Direct Dial In

Gives the ability to route a call to the desired destination within an organisation
directly through the switchboard bypassing the receptionist. The telephone
company can allocate a range of numbers associated with the PBX and assign
each seven digit number to individuals, faxes or computers.

DECT - Digital Enhanced Cordless Telephony

Are cordless handsets that provide wireless communications within an office,
building or site, and they can be fully integrated into the company telephone
system.

DSL - Digital Subscriber Line

Once called digital subscriber loop, this is a family of technologies that provide
digital data transmission over telephone lines. It can carry both data and voice
signals.

Ethernet

One of the oldest Local Area Networks technologies which has been highly
successful and is still popular.

Fixed Line

Is a telephone line which travels through a solid medium, either metal wire or
optical fibre.

GPRS - General Packet Radio Services

A technology that allows customers to remain connected to the network between
calls for the receipt and transmission of data.

IP - Internet Protocol

A standard set of rules that dictate how data is structured and
controlled to ensure an accurate transfer of information.

IP PBX - Internet Protocol, Private Branch Exchange

Is a business telephone system designed to deliver voice over a data
network.

IP Telephony

Also known as Internet Telephony or Voice over IP (VoIP). Use of Internet
Protocol to carry and route two-way voice communications. IP Telephony can
support telephone to telephone links through suitable adapters but also voice
communications from telephone to IP terminal (such as a PC with sound card) or
from IP terminal to IP terminal.

IP/VoIP Gateway

A gateway for existing telephone systems, that converts traditional traffic into IP
so that it can be transmitted over a data network. Using an IP gateway can be
considered 'migration path' towards IP Telephony. This means that you can
gradually transfer to IP Technology thus adding longevity to your existing system.

ISDN - Integrated Services Digital Network

A Digital public network for voice and data communications. The key feature of
the ISDN is that it integrates speech and data on the same lines, adding features
that were not available in the classic telephone system It is available as ISDN2e,
where the lines come in pairs, or as ISDN30e which comes in groups of up to 30
lines, the minimum order being 30.

ISP - Internet Service Provider

Point of access to the Internet for small business and individual users.

LAN - Local Area Network

A computer network covering a small physical area such as a school, a group of
offices or a home.

Leased Line

Also known as a 'private circuit'. It is ideal for larger business that have mission
critical applications to run across the circuit. They may require large bandwidth
and high reliability, this option also includes a service level agreement. The
leased line provides a direct connection between your premises and another site
of choice.

LLU - Local Loop Unbundling

Is where a carrier provides their own broadband service from a local
telephone exchange. They are buying the right to run their services
over the copper cables and install their equipment in the exchange.

Network

A network is a collection of two or more computers all linked together to share
data and resources.

OFTEL - Office of Telecommunications

The UK regulator for the telecommunications industry.

PBX - Private Branch Exchange

Is a telephone exchange that serves a particular business or office, as opposed
to one that a common carrier or telephone company operates for many
businesses or for the general public. Sometimes referred to as PABX private
automatic branch exchange or EPABX electronic private automatic branch
exchange.

PSTN - Public Switched Telephone Network

The public switched telephone network which was traditionally analogue, but now
is almost entirely digital. On a PSTN line two way conversations travel down a
telephone line in a straight line, rather like traffic flowing up and down a
motorway in opposite directions.

Portal

A gateway or entry point to the Internet incorporating significant function.

QoS - Quality of Service

This is used to provide acceptable voice quality across IP networks.

SDSL - Symmetric Digital Subscriber Line

Broadband technology that delivers very high data transfer speeds over existing
telephone lines. The main difference between ADSL and SDSL is that SDSL has
the same upstream data rate as downstream (symmetrical), whereas ADSL
always has smaller upstream bandwidth (asymmetrical). However, unlike ADSL,
it can't co-exist with a conventional voice service on the same pair as it takes
over the entire bandwidth.

SIP Trunking

These lines allow a pure IP connection to be formed between enterprises
and telephone carriers and make it possible for businesses to make and
receive calls over broadband circuits or other data connections.

Smartphone

A mobile phone offering advanced capabilities beyond a typical mobile phone,
often with PC-like functionality.

Soft PBX - Soft Phone

A software application providing server-based telephony, for example, a soft
phone on your laptop allows you to make calls from it.

Trunk

Another way of saying 'line' or 'channel'.

Unified Messaging

Provides a centralised mailbox for all email, fax and voice messages. Through
this system, messages can be viewed, replied to, saved and deleted in this one
inbox.

Voicemail

Callers are enabled to leave messages on personalised mailboxes. Messages
can also be retrieved remotely.

VoIP - Voice over Internet Protocol

A protocol that is optimised for the transmission of voice through the Internet or
other packet switched networks, and is now considered part of the backbone of
every day telecommunications.

VPN - Virtual Private Network

A Virtual Private Network is a private network built on Internet Protocol (IP) that
helps extend the reach of your company's network either nationally or globally to
connect remote sites or users together.

WAN - Wide Area Network

A computer network that covers a larger area rather than being limited
to one building or site.