| msc { |
| hscale=3; |
| ms [label="MS/BTS"], bsc_lchan[label="BSC lchan FSM"], |
| bsc_gscon[label="BSC conn FSM"], bsc_mgcp[label="BSC mgcp FSM"], mgw_msc[label="MGW/MSC"]; |
| |
| ms note mgw_msc [label="lchan allocation sequence for BSSMAP Assignment Request"]; |
| |
| bsc_gscon <= mgw_msc [label="BSSMAP Assignment Request"]; |
| bsc_gscon abox bsc_gscon [label="ST_ASSIGNMENT_\nWAIT_LCHAN"]; |
| |
| bsc_lchan <- bsc_gscon [label="lchan_select_by_chan_mode(chan_mode)"]; |
| |||; |
| --- [label="IF returned lchan is NULL"]; |
| bsc_gscon => mgw_msc [label="BSSMAP Assignment Failure"]; |
| bsc_gscon abox bsc_gscon [label="ST_ACTIVE"]; |
| ---; |
| |||; |
| bsc_gscon box bsc_gscon [label="store lchan pointer in conn->lchan_for_assignment"]; |
| bsc_lchan <- bsc_gscon [label="lchan_activate(FOR_ASSIGNMENT)"]; |
| ...; |
| |||; |
| --- [label="on lchan FSM error or timeout"]; |
| bsc_lchan -> bsc_gscon [label="GSCON_EV_LCHAN_ALLOC_ERROR"]; |
| bsc_gscon box bsc_gscon [label="'forget' all about conn->lchan_for_assignment"]; |
| bsc_gscon => mgw_msc [label="BSSMAP Assignment Failure"]; |
| bsc_gscon abox bsc_gscon [label="ST_ACTIVE"]; |
| --- [label="END: 'on error'"]; |
| ...; |
| ...; |
| |
| --- [label="IF lchan FSM decides that it is an lchan for speech"]; |
| bsc_lchan -> bsc_gscon [label="GSCON_EV_ENSURE_MGW_ENDPOINT"]; |
| --- [label="IF there is an MGW endpoint for the BTS already (conn->user_plane.fi_bts)"]; |
| bsc_gscon -> bsc_lchan [label="LCHAN_EV_MGW_ENDPOINT_AVAILABLE"]; |
| --- [label="ELSE: no MGW endpoint for the BTS side yet"]; |
| bsc_gscon abox bsc_gscon [label="ST_ASSIGNMENT_\nWAIT_CRCX_BTS"]; |
| bsc_gscon box bsc_gscon [label="assignment_created_mgw_endpoint = true"]; |
| bsc_gscon -> bsc_mgcp [label="mgcp_conn_create()"]; |
| bsc_mgcp abox bsc_mgcp [label="ST_CRCX_RESP (MGCP_MGW_TIMEOUT = 4s)"]; |
| bsc_mgcp => mgw_msc [label="CRCX (for BTS)"]; |
| bsc_gscon note bsc_mgcp [label="conn FSM relies on mgcp FSM timeout"]; |
| ...; |
| --- [label="On Timeout"]; |
| bsc_mgcp note bsc_mgcp [label="On timeouit, the MGCP FSM will terminate, emitting the parent_term |
| event set upon mgcp_conn_create():"]; |
| bsc_mgcp -> bsc_gscon [label="GSCON_EV_MGW_FAIL_BTS"]; |
| bsc_gscon note bsc_gscon [label="GSCON_EV_MGW_FAIL_BTS is handled by the conn FSM allstate |
| handler. It sets conn->user_plane.fi_bts = NULL."]; |
| bsc_gscon -> bsc_lchan [label="LCHAN_EV_MGW_ENDPOINT_ERROR"]; |
| bsc_lchan note bsc_gscon [label="conn FSM timeout handler exits and relies on the lchan FSM |
| signalling error, which should actually happen immediately:"]; |
| bsc_gscon <- bsc_lchan [label="GSCON_EV_LCHAN_ALLOC_ERROR"]; |
| bsc_gscon abox bsc_gscon [label="ST_ACTIVE"]; |
| bsc_gscon box bsc_gscon [label="'forget' all about conn->lchan_for_assignment"]; |
| bsc_gscon => mgw_msc [label="BSSMAP Assignment Failure"]; |
| --- [label="END: 'On Timeout'"]; |
| ...; |
| |
| bsc_mgcp <= mgw_msc [label="CRCX OK (for BTS)"]; |
| bsc_mgcp box bsc_mgcp [label="libosmo-mgcp-client fsm_crcx_resp_cb()"]; |
| bsc_mgcp abox bsc_mgcp [label="ST_READY"]; |
| bsc_mgcp -> bsc_gscon [label="GSCON_EV_MGW_CRCX_RESP_BTS"]; |
| bsc_gscon abox bsc_gscon [label="ST_ASSIGNMENT_\nWAIT_LCHAN"]; |
| bsc_gscon -> bsc_lchan [label="LCHAN_EV_MGW_ENDPOINT_AVAILABLE"]; |
| --- [label="END: lchan FSM decides that it is an lchan for speech"]; |
| ...; |
| ...; |
| |
| bsc_lchan -> bsc_gscon [label="GSCON_EV_LCHAN_ACTIVE"]; |
| bsc_gscon abox bsc_gscon [label="ST_ASSIGNMENT_\nWAIT_COMPLETE\nT10, 6s"]; |
| ms <= bsc_gscon [label="RR Assignment"]; |
| ...; |
| --- [label="On Timeout"]; |
| bsc_gscon => mgw_msc [label="BSSMAP Assignment Failure"]; |
| bsc_gscon -> bsc_lchan [label="LCHAN_EV_LCHAN_RELEASE"]; |
| bsc_gscon box bsc_gscon [label="'forget' all about conn->lchan_for_assignment"]; |
| --- [label="IF assignment_created_mgw_endpoint == true"]; |
| bsc_gscon -> bsc_mgcp [label="mgcp_conn_delete()"]; |
| bsc_gscon note bsc_mgcp [label="If the MGW endpoint didn't exist before the Assignment, release |
| it now. If there was one before this, it is probably still in use by a previous lchan, so |
| keep it in place."]; |
| bsc_gscon abox bsc_gscon [label="ST_ACTIVE"]; |
| --- [label="END: 'On Timeout'"]; |
| ...; |
| ms => bsc_gscon [label="RR Assignment Complete"]; |
| bsc_gscon -> bsc_lchan [label="OLD lchan: LCHAN_EV_LCHAN_RELEASE"]; |
| bsc_gscon box bsc_gscon [label="conn->lchan = conn->lchan_for_assignment"]; |
| --- [label="IF: chan_mode a speech mode?"]; |
| bsc_gscon abox bsc_gscon [label="ST_WAIT_MDCX_BTS"]; |
| bsc_gscon -> bsc_mgcp [label="mgcp_conn_modify()"]; |
| bsc_mgcp note bsc_mgcp [label="same mgcp FSM as above, for BTS side"]; |
| bsc_mgcp abox bsc_mgcp [label="ST_MDCX_RESP"]; |
| bsc_mgcp => mgw_msc [label="MDCX (for BTS)"]; |
| ...; |
| --- [label="On Timeout"]; |
| bsc_gscon -> bsc_lchan [label="LCHAN_EV_RELEASE"]; |
| bsc_gscon -> bsc_mgcp [label="mgcp_conn_delete()"]; |
| bsc_gscon => mgw_msc [label="BSSMAP Assignment Failure"]; |
| bsc_gscon abox bsc_gscon [label="ST_WAIT_CLEAR_CMD"]; |
| bsc_gscon => mgw_msc [label="BSSMAP Clear Request"]; |
| --- [label="END: 'On Timeout'"]; |
| ...; |
| bsc_mgcp <= mgw_msc [label="MDCX OK"]; |
| bsc_mgcp abox bsc_mgcp [label="ST_READY"]; |
| bsc_mgcp -> bsc_gscon [label="GSCON_EV_MGW_MDCX_RESP_BTS"]; |
| bsc_gscon abox bsc_gscon [label="ST_WAIT_CRCX_MSC"]; |
| bsc_gscon -> bsc_mgcp [label="mgcp_conn_create()"]; |
| bsc_mgcp note bsc_mgcp [label="second mgcp FSM for MSC side"]; |
| bsc_mgcp => mgw_msc [label="CRCX (for MSC)"]; |
| ...; |
| --- [label="On Timeout"]; |
| bsc_gscon -> bsc_lchan [label="LCHAN_EV_RELEASE"]; |
| bsc_gscon -> bsc_mgcp [label="mgcp_conn_delete()"]; |
| bsc_gscon => mgw_msc [label="BSSMAP Assignment Failure"]; |
| bsc_gscon abox bsc_gscon [label="ST_WAIT_CLEAR_CMD"]; |
| bsc_gscon => mgw_msc [label="BSSMAP Clear Request"]; |
| --- [label="END: 'On Timeout'"]; |
| ...; |
| bsc_mgcp <= mgw_msc [label="CRCX OK (for MSC)"]; |
| bsc_gscon <- bsc_mgcp [label="GSCON_EV_MGW_CRCX_RESP_MSC"]; |
| --- [label="END: chan_mode a speech mode?"]; |
| |
| bsc_gscon => mgw_msc [label="BSSMAP Assignment Complete"]; |
| |
| bsc_gscon abox bsc_gscon [label="ST_ACTIVE"]; |
| } |