The AN/TTC-56 is a mobile packet switch developed by the U.S. Army. It is a hybrid of a digital circuit switch, a commercial Internet Protocol Cisco 7206 router, digital multiplexer, security and network management equipment. It provides most of the functionality of the AN/TTC-39D, with more advanced data networking, in a smaller and easier-to-deploy package. The newer AN/TTC-56 (V)3 is part of the Area Common User System Modernization (ACUS-Mod), which also upgrades the AN/TTC-39 and Mobile Subscriber Equipment and other communications systems, as a replacement for the former WIN-T and JNN architecture.
The TTC-56 is also known in Army parlance as a SSS, "triple S," or "Single Shelter Switch."
It is housed in a S-788/G Lightweight Multi-Purpose Shelter, which, along with its power supplies, can be towed by two High Mobility Multipurpose Wheeled Vehicles (HMMWV), rather than the 5-ton trucks required by the AN/TTC-39. One AN/TSM-210 Electronic Shop is provided with each Single Shelter Switch (SSS).
- U.S. Army Communications-Electronics Research, Development and Engineering Center, Tactical Switching Systems
- Department of the Army (January 16, 2008), Procurement Programs, Committee Staff Procurement Backup Book, Fiscal Year (FY) 2009 Budget Estimates, Other Procurement, Army: Communications and Electronics Budget Activity 2
- Robert K. Ackerman (April 2000), "Tactical Signalers Learn to Pack Light, Travel Right", Signal