The OsmoMSC arose by separating the BSC and HLR from the historical OsmoNITB. For 3G, we needed a standalone MSC without being tied to BSC, and for an asynchronous subscriber storage that can be used by both voice and data services, we needed a separate OsmoHLR, which also added support for Milenage authentication.

At the time of writing (March 2017), the OsmoMSC exists only on the vlr_3G branch of openbsc.git. However, future development of the Osmocom circuit-switched core network will center around the OsmoMSC, while OsmoNITB will be reduced to legacy. Read Osmocom 3G and 2G Now Support Milenage Authentication and watch this space...