A good way to prevent unauthorized outbound calling is to place restrictions on users' dialing permissions. You can change dialing permissions using access profiles in Outbound Routing and then assign that access profile at the user- or user-template level.
|
•
|
Disallow access to any number dialed during toll fraud. To find a list of numbers, search your call logs for frequent calls to international locations. |
|
•
|
Disallow dialing 011 and 00 to block all international calls (00 dials the international operator). |
|
•
|
Enable 011 for those individuals who are authorized to make international calls. Those individuals can then dial any country. |
|
•
|
Enable country codes for those foreign countries that are appropriate for users to call. To do so, enable 011xxx where xxx is the desired country code. |
The full list of country codes can be found in your phone book. The list is maintained by the ITU (International Telecommunication Union), a division of the United Nations. The ITU web site is http://www.itu.int and the most recently published list of country codes is available at http://www.itu.int/itudoc/itu-t/ob-lists/icc/e212_685.html (this list is valid as of January 2004, and some additional country codes have been assigned since then.)
|
•
|
Disallow dialing sequences that call for-pay services like 1900 or 1976, 976, etc. For information on additional numbers that should be blocked, see this website: |
|
•
|
Disallow dialing certain international North American area codes if desired, such as those in the Caribbean. For example, disallowing 1242 blocks calls to the Bahamas. |
The full list of North American area codes can be found in your phone book or at the web site for the North American Numbering Plan Administration: