BT Versatility - Getting started - basic call features; Making and answering calls

To Locate the Digital Line Module (ISDN 2) in the PORTS module:
Remove the Ports Module by firstly opening the Ports MDF cover.
Open the Ports module and remove it from the MDF.
Insert the Digital Line Module (or modules) on the MDF connectors.
The upper slot is the first module position.
The top connector is for the first module that connects to the Network only.
The lower connector is for the second module. This can be an ISDN 2 Network
connection or an internal ISDN S-bus connection.
BT Versatility
Installation and Maintenance Manual
Analogue line module
18
First network
module
Second Module.
Can be external T or
internal S