MOST4 MMHS is compliant with STANAG 4406 ed.2 - the NATO standard for military messaging - and related Annexes, supporting P772, PCT and S/MIME content types. The compliance with Annex D ensures interoperability with the legacy ACP127 SUPP-3 telegraphic networks (TMI-5). On the other hand, the compliance with Annex E, ACP142 (P_MUL) and STANAG 5066 is the basis for the new tactical messaging communications (TMI-1), the replacement of ACP127 SUPP-1.
Furthermore, MOST4 MMHS follows the NATO Integrated Interoperability Model (NIIM) recommendations for achieving full interconnectivity with NATO organizations and nations. The system is thus interoperable as far as messaging, directory and security services for fixed networks are concerned, being also interoperable in tactical environments, according to the NATO messaging standards for both MMHS and ACP127 protocols.
The system supports MMHS tactical messaging through STANAG 4406, Annex E mandatory TMI-1 protocol, including the ACP142 standard (P_MUL) for reliable multicast and EMCON support and makes use of STANAG 5066 for HF data communications. MOST4 MMHS also supports ACP127 tactical messaging according to ACP127 SUPP-1, covering broadcast, ship-shore and ship-to-ship communications.
MOST4 MMHS provides directory support for all organisational elements, according to the standard ACP133 definitions, including MMHS and ACP127 strategic and tactical operational organisations, users, roles and privileges, PKI public elements, system and network resources.