Technicolor - Thomson SpeedTouchTM620 manual Isdn Backup, Action See

Chapter 9

The Integrated SpeedTouch™ ISDN Modem

9.3 ISDN Backup

ISDN Backup The SpeedTouch™ has an ISDN interface that can be used to create an ISDN backup for the ADSL line. The process is shown in the diagram below:

ADSL

ISDN

ISDN

INTERNET

When the ADSL line fails, the SpeedTouch™ establishes a dial-in connection towards the ISDN network. A PPP connection is then established over this ISDN connection which takes over the traffic from the failed ADSL line.

ISDN Callback If the SpeedTouch™ establishes the ISDN connection from the user end, the user will be charged with the connection cost. To avoid this, it is possible to use the callback option (if the other end supports it).

The SpeedTouch™ establishes a dial in connection and provides all necessary information, and disconnects. The system then waits for a callback to establish the ISDN connection over which the PPP connection is established.

Dial-In Modes The dial in connection line can operate in one of two modes:

Always on: the backup connection is always on

Dial on demand: the backup connection is established when necessary, i.e. when the ADSL line fails.

Configuring Callback In order to configure callback, you need to do the following:

Action	See
Configure the ISDN Dial-In Connection	9.3.1
Configure the PPP connection	9.3.2

E-DOC-CTC-20051017-0155 v1.0 117