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Using ISDN2 and ISDN2e | BT Business
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Using ISDN2 and ISDN2e

A single, high-quality, ISDN2e line has two 64k channels. Usually you’d use these separately, so you can make two calls at once. These could be two simultaneous voice calls, two data calls or one voice call and one data call.

You can also add more ISDN2e circuits to your installation, increasing the number of simultaneous connections and/or available data bandwidth.

Charges for voice calls are the same as for analogue lines, as are data calls within the UK. There are different rates for international 64k data calls.

For more information on how ISDN2/2e works and getting started, go to our Getting started with ISDN2 and ISDN2e guide.

ISDN User Guides

For more information on ISDN2e:

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Differences between point-to-point and point-to-multipoint configuration

The main differences between point-to-multipoint (Standard Access or S/T reference point) and point-to-point (System Access or T reference point) configurations are:

1. The number of devices that you can plug into the box on the wall:

  • Point-to-multipoint allows you to connect up to eight separate devices to the box on the wall.
  • Point-to-point allows you to connect just one device. This is usually a PBX.

2. The type of telephone number range that you can use:

  • Point-to-multipoint allows up to eight MSN telephone numbers.
  • Point-to-point uses DDI numbers, which come in blocks of 10. There is no maximum to the number of DDIs you can have.

Features and benefits of ISDN2e explained

Help using features of ISDN2e.

Diverting an individual DDI number on your ISDN2e line

Presenting a DDI number in place of your outgoing CLI

Options for forwarding calls made to your number

The difference between Customer Controlled Call Forwarding (CCCF) and Admin Controlled Call Forwarding (ACCF)

Available call-barring options

Viewing the phone number of the person you’re talking to

Preventing a caller from finding out the number they’ve connected to

Malicious Call Indication (MCID)

Sending alphanumeric characters down the ISDN line, along with the number you’re dialling

Video-conferencing

Upgrading from ISDN2 to ISDN2e

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