DISA Overview:

DISA allows you to provide an internal dialtone to external callers. When you configure a DISA destination, you can use it as a menu destination within a Digital Receptionist, so that you can get an internal Asterisk dialtone. This means you could call into your Asterisk system and dial out as if you were using an extension connected to the Asterisk box itself.

Configuration DISA Name: A friendly name to help you identify the DISA destination.
PIN: A code required to be input by the remote user to access the dialtone. You should always require a PIN for security purposes[[BR]] Caller ID: You can change the outgoing caller ID for this DISA by setting an override value.
Context: By default, internal context (from-internal) is used. You could provide a custom context to limit the access for this DISA. (Only for the experienced)