Telephone Line Connection; Analogue Pstn Telephone Line Connection - CSL DualCom GSM Mk1 Installation Manual

Telephone Line Connection

There are several different types of telephone line available from different service
providers.
DualCom requires an analogue telephone line connection. 'Earth Loop Call-
ing' or 'Earth Calling' types of analogue telephone line can not be used.
DualCom can not be directly connected to any type of digital telephone line.
For Broadband connection see page 28.
Earth connection
DualCom does not require an Earth connection at the telephone line terminals
as per EN regulations. See item 4, page 24.
Analogue PSTN Telephone Line
The analogue PSTN is a communication network where the line from the ex-
change equipment and the service supplied to the subscriber is 'analogue', i.e.
not 'digital'. See Fig 8.
A telephone line is always terminated at the users premises by an NTP (Net-
work Termination Point) which is provided by the telecoms Service Provider.
This is a socket or connection where the users equipment can be connected.
Some NTPs provide a socket and terminals for connection. In many cases,
the NTP operates using power supplied from the exchange equipment via the
telephone line.
An analogue PSTN telephone line may be provided by BT or any of the other
44 telecomms service providers in UK. DualCom can be connected to any of
these company's PSTN analogue lines.
Analogue PSTN Telephone Line
Fig 8
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