NBCN Networks

1 ADSL – Asymetric Digital Subscriber Line

Commonly referred to as ‘Broad Band Internet Access’, ADSL is a digital technology that allows the use of a standard analogue line to receive a large quantity of data.

Before ADSL was available internet users would connect to their Internet Service Provider (ISP) via a modem. Maximum speeds were limited to 56,000 bits per second.

ADSL is an ‘always on’ connection designed to exploit the nature of most multimedia communication in which large amounts of information flow towards the user and only a small amount of interactive control information is returned.

2 Analogue Lines

The best example of an Analogue line is the common residential home line. Analogue lines are compatible with the vast majority of telephones available from the ‘high street’ or DIY stores.

In addition most fax machines, alarm systems and modems are designed to work on Analogue lines.

A standard, single Analogue Line will have its own unique telephone number.

Analogue Lines can be grouped (see analogue group) or be stand alone, single Direct Exchange Lines (See Analogue DEL).

3 Analogue Group

Multiple Analogue Lines can be grouped at the local telephone exchange. This group can have just one published telephone number so that the called party can receive more than one call at a time on the same telephone number.

The owner of the analogue group can also make calls whilst receiving calls on the same number. e.g.

The ‘/’ indicates the number within the group i.e. 1st call will be presented to ‘/1’ 2nd call ‘/2’ etc. If the intended line is busy then the exchange ‘hunts’ to find the next available line in the group. If all lines are busy the caller will receive ‘busy’ tone.

4 Analogue DEL

An Analogue DEL (Direct Exchange Line) is a single Analogue Line (See Analogue Line)

5 Analogue Device

A device which can be attached to an ordinary analogue telephone line, such as a telephone, fax machine, cordless phone, answering machine, modem etc.

6 Auto-Attendant

A voicemail or intelligent network feature that allows callers to be automatically transferred to extensions or departments by dialling digits. A tone dialling phone is normally required to do this.

‘Thank you for calling ABC Trading for sales dial 1, service dial 2...etc’

7 Basic Rate

Abbreviated to BRI (basic rate interface) or ISDN2. An ISDN circuit providing 2 x 64 kbit/sec bearer channels for use by data or speech and one 16 kbit/sec control channel.

Two independent calls can be carried at the same time on one BRI circuit.

8 Centrex

Centrex is a service that allows a business to have their telephone lines adopt the features of a telephone system. In simple terms it’s like having a telephone system embedded in the public telephone network.

No special hardware is required in their offices yet they are able to make, hold and transfer calls on their Centrex exchange lines as if they were extensions on a telephone system. If they wish to make a call to an external party they are required to dial a prefix, typically 9.

BT’s version of Centrex for the SME customers is called Feature Line.

As the customer pays additional rental charges for this service calls between exchange lines in the companies Centrex service are often free or greatly reduced in cost. External calls are charged at normal rates and therefore benefit from least cost routing services.

8.1 Feature Line

FeatureLine is a BT brand name for their Centrex offering targeted at the small to medium sized enterprise (SME).

FeatureLine customers pay additional rental charges for the service. In return they are given free access to a number of the BT select services and calls between Feature Lines they own are free.

Calls can be held, transferred and diverted to other FeatureLines telephones as if they were extensions on a telephone system.

To dial a telephone number outside of the customer’s FeatureLine service the caller must prefix the call with a ‘9’. These calls are charged at BT rates and can benefit from the discount packages currently available to a normal BT telephone line. As with any BT customer Telecom Direct can offer the customer savings on their call charges.

8.2 Feature Line Hunt Number

FeatureLines can be grouped to give the customer an incoming hunting service. This is achieved by having a hunt group number. Each member of the group is referred to as an extension.

It is possible to have up to 10 hunt groups on one site.

Calls to the hunt group can be delivered using ‘Ordinary Hunting’ or ‘Cyclical Hunting’.

Ordinary Hunting (also known as Sequential Hunting) is where the calls are presented in a sequence starting with the first extension in the group. Calls will only be presented the second extension if the first is engaged and the third if the first 2 are engaged and so on. Therefore the majority of calls are answered by the extensions near the beginning of the group.

Cyclical Hunting is where the BT exchange will always attempt to connect an incoming call to the extension following the last extension to receive a call. This means calls are spread more evenly around the hunt group.

8.3 Feature-Line Bypass Number

FeatureLine Bypass gives the user a second telephone number on their line. If they have set up a divert on their FeatureLine the Bypass number will allow callers to bypass the diversion.