McAlester Army Ammunition Plant uses DSN as the provider of long-distance communications service for the Department of Defense (DoD). Every installation has a special DSN number and the numbers vary by world-wide location. In order to place a call using DSN, the caller must be using a military phone on an installation. Cell phones cannot dial DSN numbers. When dialing a DSN number from a United States installation to another United States installation, it is unnecessary to dial the DSN 312 area code. When dialing a DSN number to/from overseas locations, the DSN area code must be included. Army Community Service (ACS) Office can be reached at 918-420-6523/ DSN 956-6523 for more information. Please note that long distance charges may be incurred.