High Quality Content by WIKIPEDIA articles! In telecommunications, Multi-Technology Operations System Interface (MTOSI) is a standard for implementing interfaces between OSSs. Service providers (carriers) use multiple Operational Support Systems (OSS) to manage complex networks. Since the various parts of the network must interact, so must the OSSs. It is standardized by the Telemanagement Forum (TM Forum). The TMF NGOSS provides a set of reference models that aid in analyzing and designing next generation BSS and OSS solutions that may utilize the MTOSI interface specifications.