OsmoMSC » History » Version 6

Version 5 (laforge, 10/21/2017 03:12 PM) → Version 6/18 (laforge, 10/21/2017 03:12 PM)

h1. OsmoMSC

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:]]
* Osmocom GSUP towards an HLR such as [[OsmoHLR:]]
* 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

h2. Position in a typical network

digraph G {
rankdir = LR;
OsmoBTS -> OsmoBSC [label="Abis/IP"];
OsmoBSC -> OsmoMSC [label="3GPP AoIP"];
OsmoMSC -> OsmoHLR [label="GSUP"];
OsmoMSC -> OsmoSIP [label="MNCC"];
OsmoMSC [color=red];
OsmoSIP [label="osmo-sip-connector"];

h2. History

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":

h2. Contact

* Contact us via the openbsc@ mailing list, see [[Cellular Infrastructure:Mailing Lists]].
* Contributions are welcome via [[Cellular Infrastructure:Gerrit]].
* Git repository browser at
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