Osmocom's Mobile Switching Center for 2G and 3G mobile networks

 The Mobile Switching Center (MSC) is the heart of 2G/3G
 circuit-switched services. It terminates the A-interface links from the
 Base Station Controllers (BSC) and handles the MM and CC sub-layers of
 the Layer 3 protocol from the phones (MS).
 .
 This Osmocom implementation of the MSC handles A interfaces via 3GPP
 AoIP in an ASP role. It furthermore implements IETF MGCP against an
 external media gateway, such as OsmoMGW. It does *not* implement MAP
 towards a HLR, but the much simpler Osmocom GSUP protocol, which can
 be translated to MAP if needed.