Full M3UA SIGTRAN variant in libosmo-sccp
The M3UA+SCCP variant of SIGTRAN is used for spec-compliant AoIP and IuCS/IuPS interfaces. Osmocom libosmo-sccp currently only implements the SUA variant, and thus is not fully compatible with the lower protocol stacking of those standard interfaces.
#6 Updated by laforge about 1 month ago
- % Done changed from 0 to 50
see gerrit patches https://gerrit.osmocom.org/#/c/1803/ till https://gerrit.osmocom.org/#/c/1811/ for some preparatory work. The actual M3UA and SCCP code is following up to that, currently in a
laforge/sigtran branch of libosmo-sccp.git (see http://git.osmocom.org/libosmo-sccp/log/?h=laforge/sigtran)
- use osmo_prim to formally implement the SAP specified between protocol layers, e.g. MTP-SAP between M3UA and SCCP, or SCU-SAP between SCCP User and application
- use osmo_fsm to implement the state machines, e.g. ASP and AS FSM of M3UA
- use osmo_fsm to implement SCCP SCOC (connection oriented) per-connection state machine
- migrate existing SUA code to new SCOC FSM
- use parsed SUA (struct xua_msg) representation by default in all code, transcode from SCCP wire format to this for incoming messages, and from xua_msg to SCCP on outgoign messages. This helps keep the code more simple.
- untested but fairly complete osmo_fsm for SCOC
- definition for MTP SAP
- xUA ASP and AS osmo_fsm implementation
- SCCP <-> SUA transcoding with preliminary unit tests
More work is needed to pull the strings together and fix missing gaps.