Types of Telephone Lines UK

Analogue, Digital and IP 

Traditionally BT was the main telephone line and telephony service provider, with the vast majority of lines and numbers being provided from the ‘local BT exchange’. However things have now changed!

So we thought it might be good to know the following simple breakdown of line types.

Analogue PSTN (Public Switched Telephone Network)

Is a standard voice line, the same as you would have at home

Analogue PSTN Aux (Auxiliary) Group

A number of analogue lines all grouped under one main number (as used for businesses)

Digital ISDN 2E

One ISDN 2E line provides 2 speech channels / lines. An ISDN circuit can be one ISDN 2E line or a few grouped together.
Example: Two ISDN 2E lines, grouped together would provide a circuit of 4 speech channels / lines

Digital ISDN 30E

One ISDN 30E circuit provides a minimum of 8 speech channels / lines which can be increased to a maximum of 30 without the need for additional hardware (interface boxes).

All the above lines are in the majority, provided via BT OpenReach and numbered from the local BT Exchange

IP, VoIP, SIP, Cloud and ‘Internet Lines’

Basically lines that are delivered over a data connection i.e. broadband, lease line etc..
These services are provided by an increasing number of service providers (including Avalon Telecom) and unlike traditional ‘OpenReach’ lines and services are NOT restricted to being numbered form the local exchange. That is to say you can use a Taunton telephone number even if you based in Bridgwater.

We will go into more detail about ISDN and ‘Internet lines’ in a future news blog