Local telcos have charged relatively high rates for ISDN service-the 64 Kbps service which supports both voice and data. AT&T has recently filed ISDN tariffs in all 48 continental states to offer the service using its Switched Digital Services and Software Defined Data Network.
There are two potential benefits to the new AT&T service; it will be available virtually everywhere and the rates will be relatively low. Local telcos have offered ISDN only in selected cities at rates ranging from $30 to $200 per month for blocks of hours-rates which work out to 10 to 15 cents per minute. AT&T's tariffs work out to 6~6 to 9 cents per minute. However, local telcos may charge for the dedicated line connection to AT&T where AT&T cannot provide direct connectivity; therefore, the true cost of using AT&T can be 4 to 5 cents per minute higher.
[Contact: AT&T at 800-222-7956.]