Before we allowed callers to use our DISA service again, we made significant changes in the process including blocking
IDDD, blocking access to a toll operator, restricting dial access outside our immediate calling area and assigning a "class of service" to our auth codes.
If you already have a special largescale tariff arrangement, such as Tariff 12, you're probably getting a good deal on IDDD. Don't overlook firms other than the Big Three, especially the updated representatives of overseas PTTs.
The company provides a discount IDDD service that takes advantage of the disparity in rates for dial-up calls from a foreign country to the U.S.