OsmoMSC is the Osmocom implementation of a Mobile Switching Center (MSC).It implements the following interfaces:
- 3GPP AoIP over M3UA or SUA towards BSCs, for example OsmoBSC, possibly via a STP like OsmoSTP
- 3GPP IuCS over M3UA or SUA towards RNCs or HNBGWs, for example OsmoHNBGW, possibly via a STP like OsmoSTP
- Osmocom GSUP (alternative to SS7/TACP/MAP) towards an HLR such as OsmoHLR
- Subscriber management
- Supplementary Services (SS/USSD)
- Short Message Service (SMS)
- inter-MSC handover
- SMPP v3.4 for external SMS entities (minimal SMSC is built-in)
- MGCP for controlling an external Media Gateway like OsmoMGW
- MNCC for external call-control handlers, such as osmo-sip-connector for SIP trunks
- Osmocom VTY interface for configuration + introspection
- Osmocom CTRL interface for programmatic access to internal state/configuration
Position in a typical network¶
OsmoMSC was the result of splitting OsmoNITB into three parts during the 2017 NITB-split. Parts of OsmoNITB became OsmoBSC, other parts became OsmoHLR, while the mobility management, call control and SMS handling became OsmoMSC. At the time of the rewrite, the entire MSC and VLR state machines have been properly re-implemented using osmo-fsm
Osmocom provides binary packages for several flavors of Debian and Ubuntu GNU/Linux on a variety of architectures (i586, x86_64, armhf, armv7l). Unless you are a software developer interested in developing on Osmocom, it is recommended you use those packages instead of building from source.
For more details see Binary_Packages
The source code is available from
Public read-only access is available via
git clone https://gitea.osmocom.org/cellular-infrastructure/osmo-msc
You can browse it via gitea: https://gitea.osmocom.org/cellular-infrastructure/osmo-msc
Contributions are welcome via Gerrit.
Test Suite¶We have a TTCN-3 test suite as part of our Titan_TTCN3_Testsuites
- source code: https://gitea.osmocom.org/ttcn3/osmo-ttcn3-hacks/src/branch/master/msc
- results: https://jenkins.osmocom.org/jenkins/view/TTCN3/job/ttcn3-msc-test/
- Contact us via the openbsc@ mailing list, see Mailing Lists.
- Contributions are welcome via Gerrit.
- Git repository browser at https://gitea.osmocom.org/cellular-infrastructure/osmo-msc
Commercial support as well as development, system integration and training services for this project are available from sysmocom