Node Switch AN/TTC-47, also referred to as NCS (NODE CENTER SWITCH) provides automatic switching capability for the MSE system. It is the hub of the MSE network. Functional characteristics of the switch include automatic tandem switching, key generation, secure digital voice orderwire, and flood search routing. The node switch is configured in two S-250 shelters (an ON-306/TTC-47 switching shelter and an OL-413/TTC-47 operations shelter), each transported on a high mobility multipurpose wheeled vehicle (HMMWV). The switching shelter provides the external interface, circuit switching and associated functions. The operations shelter proves the central processing and operator interface functions. A PU-753/M 10-kw trailer-mounted diesel generator set provides power to both assemblages.