A system of telecommunications cables, cords and connecting hardware that can support the connection of information technology equipment.

Call Barring

The prevention of calls to certain destinations, e.g. overseas calls or calls to premium rate numbers may be barred.

Call Forwarding

A feature of telephone systems, call forwarding allows incoming calls to be diverted automatically to a different number, for example a mobile phone or a home office.

Call Logging

Data recorded about calls made or received through a telephone system. This data can then be used for reporting.

Call Management

The use of specialist software to analyse and report on call records which are output from a telephone system and recorded on computer disk. The results can identify misuse, allocate costs to departments and verify the adequacy of resources.

Call Park

A call can be parked by one user and then retrieved by another. Particularly useful when loudspeaker announcements are made, e.g. "Telephone call. Joe Smith dial 811". If Joe goes to any phone and dials 811 he will get the call that has been parked there for him.


Capital Expenditure


Telephone service provider.

Category 3

For cable and connecting hardware products with transmission characteristics specified to 16 MHz, typically used to support digital transmission of 10 Mb/s.

Category 5 (CAT5)

For cable and connecting hardware products with transmission characteristics specified to 100 MHz, typically used to support digital transmission of 100 Mb/s and above.

Category 5e

This is an enhanced version of Category 5, with additional parameters specified to enable parallel transmission with full duplex across the four pairs. Enhanced Category 5 specifications for cable and connecting hardware products with transmission characteristics specified to 100 MHz, intended to support digital transmission of 1000 Mb/s.

Category 6

For cable and connecting hardware products with transmission characteristics specified to 250 MHz, used to support digital transmission of 1 Gbp/s and above.

Category 7

For cable and connecting hardware products with transmission characteristics specified to 600 MHz. Category 7 is a cable standard only and will require a new connector standard to fully exploit transmission at the above frequencies.


Call Centre Management


Central Control Unit - The box or cabinet housing the central equipment that controls the telephone system.


Customer Experience Management
Software solutions that improve the effectiveness and performance of employees within customer service and contact centre environments. Performance management and eLearning packages which identify individual learning needs and offer immediate eLearning solutions to enhance the customer's experience.


A generic name for a feature offered by some Public Network Operators. Users have individual direct exchange lines but calls between users are free of charge and calls can be transferred between users. A limited set of features is provided to give something that approximates to a virtual telephone system.


A two-way communications path between electronic devices.


Calling Line Identity
The network will transmit the telephone number of the call originator to the recipient. One of the key ISDN features, CLI displays the phone number of the caller on the answering phone's display. CLI alpha tagging also shows the caller's name and company. CLI is the enabling feature of many computer telephony integration applications.


A software program that is used to contact and obtain data from a server software programme on another computer, often across a vast distance. Each client programme is designed to work with one or more specific kinds of server programme, and each server requires a specific kind of client. A web browser is a specific kind of client.


Calling Line Identity Presentation
A service that provides a called party with the Calling Line ID of the caller. Usually a paid-for option.


Calling Line Identification Restriction
Would stop your own CLI being presented to the called party.

Collapsed Backbone

A star-configured backbone system supported by a single root device – often a high-speed switch.

Collision Detection

The act of detecting when an Ethernet collision has occurred.


Connected Line Presentation
A service which provides the caller with the identity of the person he has connected to. For example you may dial 01234 567890 but that number may be diverted to another. COLP will provide you with the identity of the person you have actually connected to. The identity is typically the telephone number of the connected party. This is a paid-for service from the network provider and compatible equipment is required to make use of it.


A device that allows you physically to connect and disconnect copper wires or fibres in cable to equipment or to other wires or fibres. Copper wire and fibre optic connectors must often join transmission media to equipment or cross connects.


The joining together of more than two telephone users in a single call. Typically a call will be established between two persons, one will then hold the call, call a third party and then press a button to join all three parties in one call.

Contact Centre

A progression of the call centre merging customer calls with other media such as internet and email in conjunction with CRM applications. A unified approach to customer contact improving customer service levels leading to increased customer acquisition, satisfaction and retention.


The merging of voice and data hardware solutions such as the server based PBX. More efficiency and cost benefits becoming available through convergence. In addition Voice switched Over IP is driven by convergent technology.


Class of Service


Carrier Pre-selection
Carrier Pre-Selection uses network access technology, so voice traffic originating from your site will be routed directly to your chosen network with no need for prefix codes. The "selection" of the preferred provider is done automatically at point of entry (the local exchange) to the public voice network.


Customer Relations Management
Generic term for applications designed to streamline interactions with customers. CRM software allows call centre agents to access a customer's service history from the back-office customer account packages. Small businesses are waking up to the advantages of CRM solutions that integrate with their PCs. The Internet, Email, IVR, voice and interactive TV have sparked a seismic shift towards web-enabled call centres, opening up a new dimension in offering good service.


Carrier Sense Multiple Access with Collision Avoidance
 - A system used by Wireless LANs to warn other stations of an intended transmission, and hence prevents a collision.


Carrier Sense Multiple Access with Collision Detection
 - A system used in Ethernet where a station listens for the presence of a carrier before attempting to send, and detects the presence of a collision.


Computer Telephony Integration
 - The term used to describe the linking of the telephone system with a computer or network. The classic CTI application is "screen popping", which uses CLI to identify the caller and display his/her database records on the screen before the call is answered. CTI also enables calls to be made directly from a contact management package by simply clicking the call button.

Customer Service Mode

Used in voicemail to indicate a service where the caller hears a menu of choices from which he can choose by pressing buttons on his phone. These choices might transfer him to an extension, group of extensions, or the operator, enable him to leave a message or listen to information, or may offer him other menus.


A type of LAN switch which forwards incoming frames without storing and without error-checking.