DISA's managed interface to the Public Switch Telephone Network (PSTN), which serves as DoD's primary interface for off-netting to - toll-free commercial numbers from OCONUS locations, is being enhanced for better customer service. DSN users will now be able to dial directly to toll-free commercial numbers without operator intervention or a second dial tone and long digit strings.

DISA has implemented the PSTN's four toll-free area codes — 800, 888, 866, and 877 — as DSN area codes to enable this direct dialing capability. DSN users can now dial US PSTN toll-free numbers by simply dialing 94 + the 10-digit toll-free number.

Although the operations and maintenance organizations of all services have been notified that this change is to be implemented, global implementation of the toll-free area codes at the base, post, camp, and station level may take some time and may not be technically feasible in some locations if the local DSN telephone switch is operating an outdated version of software.

Authorized uses of this interface are:

• government contractors and vendors with 1-800 numbers;
• help desk numbers for hardware/software;
• Non-toll PSTN number with a 1-800 numbers for credit card calling, where the toll charges are applied to the credit card (credit card calling can be made with either government-provided calling cards (FTS) or personal calling cards); and
• reverse billing to call recipient via "1-800-call-collect" services.

How to use the 800,  855, 866, 877, 888 service:

• Dial DSN 94+ toll free number (e.g., 94-800-555-1212)
• This access is for OCONUS locations that do not have access to CONUS toll-free dialing.