Overview
DISA (which stands for Direct Inward System Access) 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.

The security implications of DISA are obviuous! Make sure you have a proper authentication scheme in place so that unautherized callers cannot abuse your system!

Changelog

V2.0 - Added Response Timeout, Digit Timeout and Reuqire Confirmation

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! You can, if you must, leave it blank. The voice
  prompt will still say 'Enter Password', but you won't need to. This is
  on the list of minor annoyances that need to be fixed.
• Caller ID: You can change the outgoing caller ID for this DISA by setting an override value.
• Response Timeout: The maxium amount of time it will wait before hanging up if the user has dialed an incomplete or invalid extension
• Digit Timeout: The maximum time delay between digits
• Require Confirmation: Before prompting for
  password, it will say 'Press 1' every 3 seconds until a digit
  (anything, it doesn't have to be '1') is pressed. It will then continue
  on and ask for a password. This is mainly useful if dialling out
  through a device (eg, X100P, TDM400, or a poorly configured VSP) that
  doesn't tell you when the call is actually answered.
• 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)
• Allow Hangup:When checked allows the current call to be ended and return the
  caller to the dial tone by pressing the Hangup feature code. (**)