diff options
| -rw-r--r-- | include/osmocom/bsc/handover_fsm.h | 6 | ||||
| -rw-r--r-- | src/osmo-bsc/handover_fsm.c | 183 |
2 files changed, 104 insertions, 85 deletions
diff --git a/include/osmocom/bsc/handover_fsm.h b/include/osmocom/bsc/handover_fsm.h index 4db08901d..7c2145e84 100644 --- a/include/osmocom/bsc/handover_fsm.h +++ b/include/osmocom/bsc/handover_fsm.h @@ -28,10 +28,10 @@ enum handover_fsm_state { HO_ST_NOT_STARTED, HO_ST_WAIT_LCHAN_ACTIVE, + HO_ST_WAIT_MGW_ENDPOINT_TO_MSC, HO_ST_WAIT_RR_HO_DETECT, HO_ST_WAIT_RR_HO_COMPLETE, HO_ST_WAIT_LCHAN_ESTABLISHED, - HO_ST_WAIT_MGW_ENDPOINT_TO_MSC, /* The inter-BSC Outgoing Handover FSM has completely separate states, but since it makes sense for it * to also live in conn->ho.fi, it should share the same event enum. From there it is merely @@ -46,11 +46,11 @@ enum handover_fsm_event { HO_EV_LCHAN_ACTIVE, HO_EV_LCHAN_ESTABLISHED, HO_EV_LCHAN_ERROR, + HO_EV_MSC_MGW_OK, + HO_EV_MSC_MGW_FAIL, HO_EV_RR_HO_DETECT, HO_EV_RR_HO_COMPLETE, HO_EV_RR_HO_FAIL, - HO_EV_MSC_MGW_OK, - HO_EV_MSC_MGW_FAIL, HO_EV_CONN_RELEASING, HO_OUT_EV_BSSMAP_HO_COMMAND, diff --git a/src/osmo-bsc/handover_fsm.c b/src/osmo-bsc/handover_fsm.c index c044407bb..442f7bebb 100644 --- a/src/osmo-bsc/handover_fsm.c +++ b/src/osmo-bsc/handover_fsm.c @@ -162,10 +162,10 @@ struct gsm_subscriber_connection *ho_fi_conn(struct osmo_fsm_inst *fi) static const struct osmo_tdef_state_timeout ho_fsm_timeouts[32] = { [HO_ST_WAIT_LCHAN_ACTIVE] = { .T = 23042 }, + [HO_ST_WAIT_MGW_ENDPOINT_TO_MSC] = { .T = 23042 }, [HO_ST_WAIT_RR_HO_DETECT] = { .T = 23042 }, [HO_ST_WAIT_RR_HO_COMPLETE] = { .T = 23042 }, [HO_ST_WAIT_LCHAN_ESTABLISHED] = { .T = 23042 }, - [HO_ST_WAIT_MGW_ENDPOINT_TO_MSC] = { .T = 23042 }, [HO_OUT_ST_WAIT_HO_COMMAND] = { .T = 7 }, [HO_OUT_ST_WAIT_CLEAR] = { .T = 8 }, }; @@ -878,10 +878,24 @@ void handover_end(struct gsm_subscriber_connection *conn, enum handover_result r static void ho_fsm_wait_lchan_active(struct osmo_fsm_inst *fi, uint32_t event, void *data) { struct gsm_subscriber_connection *conn = ho_fi_conn(fi); + struct handover *ho = &conn->ho; switch (event) { case HO_EV_LCHAN_ACTIVE: - ho_fsm_state_chg(HO_ST_WAIT_RR_HO_DETECT); + /* - If the lchan is voiceless, no need to even think about the MGW. + * - If this is an intra-BSC Handover, we already have an RTP stream towards the MSC and aren't + * touching it. + * - If we're on SCCPlite, the MSC manages the MGW endpoint, all we do is the BTS side CI, so we can + * skip the part that would CRCX towards the MSC. + * So create an MSC side endpoint CI only if a voice lchan is established for an incoming inter-BSC + * handover on AoIP. Otherwise go on to send a Handover Command and wait for the Detect. + */ + if (ho->new_lchan->activate.info.requires_voice_stream + && (ho->scope & HO_INTER_BSC_IN) + && gscon_is_aoip(conn)) + ho_fsm_state_chg(HO_ST_WAIT_MGW_ENDPOINT_TO_MSC); + else + ho_fsm_state_chg(HO_ST_WAIT_RR_HO_DETECT); return; case HO_EV_LCHAN_ERROR: @@ -894,6 +908,75 @@ static void ho_fsm_wait_lchan_active(struct osmo_fsm_inst *fi, uint32_t event, v } } +/* Only for voice, only for inter-BSC Handover into this BSC, and only for AoIP: + * + * Establish the MGW endpoint CI that points towards the MSC. This needs to happen after the lchan (lchan_rtp_fsm) has + * created an MGW endpoint with the first CRCX, so that an endpoint is available, and before sending the Handover + * Request Acknowledge, so that the RTP address and port established towards the MSC can be included in the Handover + * Request Acknowledge message. + * (For SCCPlite, the MSC manages the CN side endpoint CI itself, and we don't need to send any RTP address in the + * Handover Request Acknowledge.) + * + * Actually, it should be possible to kick this off even above in handover_start_inter_bsc_in(), to do the CRCX towards + * the MSC at the same time as establishing the lchan. The gscon_ensure_mgw_endpoint() doesn't care which one of + * lchan_rtp_fsm or handover_start_inter_bsc_in() calls it first. The benefit would be that we'd send out the Handover + * Command ever so slightly sooner -- which isn't critical really, because a) how long does a CRCX take, milliseconds? + * and b) the time critical part is *after* the Handover Command was kicked off to keep the transition between cells as + * short as possible. The drawback of doing this earlier is code complexity: receiving the HO_EV_MSC_MGW_OK / + * HO_EV_MSC_MGW_FAIL events would need to be juggled in between the HO_EV_LCHAN_ACTIVE / HO_EV_LCHAN_ERROR. So the + * decision for now is to leave it here. + */ +static void ho_fsm_wait_mgw_endpoint_to_msc_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state) +{ + struct gsm_subscriber_connection *conn = ho_fi_conn(fi); + struct handover *ho = &conn->ho; + + if (!gscon_connect_mgw_to_msc(conn, + ho->new_lchan, + ho->inter_bsc_in.msc_assigned_rtp_addr, + ho->inter_bsc_in.msc_assigned_rtp_port, + fi, + HO_EV_MSC_MGW_OK, + HO_EV_MSC_MGW_FAIL, + NULL, + &ho->created_ci_for_msc)) { + ho_fail(HO_RESULT_ERROR, + "Unable to connect MGW endpoint to the MSC side"); + } +} + +static void ho_fsm_wait_mgw_endpoint_to_msc(struct osmo_fsm_inst *fi, uint32_t event, void *data) +{ + struct gsm_subscriber_connection *conn = ho_fi_conn(fi); + const struct mgcp_conn_peer *mgw_info; + + switch (event) { + + case HO_EV_MSC_MGW_OK: + /* Ensure the endpoint is really there, and log it. This state is only entered for AoIP connections, see + * ho_fsm_wait_lchan_active() above. */ + mgw_info = osmo_mgcpc_ep_ci_get_rtp_info(conn->user_plane.mgw_endpoint_ci_msc); + if (!mgw_info) { + ho_fail(HO_RESULT_ERROR, + "Unable to retrieve RTP port info allocated by MGW for" + " the MSC side."); + return; + } + LOG_HO(conn, LOGL_DEBUG, "MGW's MSC side CI: %s:%u\n", + mgw_info->addr, mgw_info->port); + ho_fsm_state_chg(HO_ST_WAIT_RR_HO_DETECT); + return; + + case HO_EV_MSC_MGW_FAIL: + ho_fail(HO_RESULT_ERROR, + "Unable to connect MGW endpoint to the MSC side"); + return; + + default: + OSMO_ASSERT(false); + } +} + static void ho_fsm_wait_rr_ho_detect_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state) { int rc; @@ -1011,88 +1094,24 @@ static void ho_fsm_wait_rr_ho_complete(struct osmo_fsm_inst *fi, uint32_t event, } } -static void ho_fsm_post_lchan_established(struct osmo_fsm_inst *fi); - static void ho_fsm_wait_lchan_established_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state) { struct gsm_subscriber_connection *conn = ho_fi_conn(fi); if (conn->ho.fi && lchan_state_is(conn->ho.new_lchan, LCHAN_ST_ESTABLISHED)) { LOG_HO(conn, LOGL_DEBUG, "lchan already established earlier\n"); - ho_fsm_post_lchan_established(fi); + ho_success(); } } static void ho_fsm_wait_lchan_established(struct osmo_fsm_inst *fi, uint32_t event, void *data) { - switch (event) { - - case HO_EV_LCHAN_ESTABLISHED: - ho_fsm_post_lchan_established(fi); - break; - - default: - OSMO_ASSERT(false); - } -} - -static void ho_fsm_post_lchan_established(struct osmo_fsm_inst *fi) -{ struct gsm_subscriber_connection *conn = ho_fi_conn(fi); - struct handover *ho = &conn->ho; - if (ho->new_lchan->activate.info.requires_voice_stream - && (ho->scope & HO_INTER_BSC_IN)) - ho_fsm_state_chg(HO_ST_WAIT_MGW_ENDPOINT_TO_MSC); - else - ho_success(); -} - -static void ho_fsm_wait_mgw_endpoint_to_msc_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state) -{ - struct gsm_subscriber_connection *conn = ho_fi_conn(fi); - struct handover *ho = &conn->ho; - - if (!gscon_connect_mgw_to_msc(conn, - ho->new_lchan, - ho->inter_bsc_in.msc_assigned_rtp_addr, - ho->inter_bsc_in.msc_assigned_rtp_port, - fi, - HO_EV_MSC_MGW_OK, - HO_EV_MSC_MGW_FAIL, - NULL, - &ho->created_ci_for_msc)) { - ho_fail(HO_RESULT_ERROR, - "Unable to connect MGW endpoint to the MSC side"); - } -} - -static void ho_fsm_wait_mgw_endpoint_to_msc(struct osmo_fsm_inst *fi, uint32_t event, void *data) -{ - struct gsm_subscriber_connection *conn = ho_fi_conn(fi); switch (event) { - - case HO_EV_MSC_MGW_OK: - /* For AoIP, we created the MGW endpoint. Ensure it is really there, and log it. */ - if (gscon_is_aoip(conn)) { - const struct mgcp_conn_peer *mgw_info; - mgw_info = osmo_mgcpc_ep_ci_get_rtp_info(conn->user_plane.mgw_endpoint_ci_msc); - if (!mgw_info) { - ho_fail(HO_RESULT_ERROR, - "Unable to retrieve RTP port info allocated by MGW for" - " the MSC side."); - return; - } - LOG_HO(conn, LOGL_DEBUG, "MGW's MSC side CI: %s:%u\n", - mgw_info->addr, mgw_info->port); - } + case HO_EV_LCHAN_ESTABLISHED: ho_success(); - return; - - case HO_EV_MSC_MGW_FAIL: - ho_fail(HO_RESULT_ERROR, - "Unable to connect MGW endpoint to the MSC side"); - return; + break; default: OSMO_ASSERT(false); @@ -1187,6 +1206,19 @@ static const struct osmo_fsm_state ho_fsm_states[] = { , .out_state_mask = 0 | S(HO_ST_WAIT_LCHAN_ACTIVE) + | S(HO_ST_WAIT_MGW_ENDPOINT_TO_MSC) + | S(HO_ST_WAIT_RR_HO_DETECT) + , + }, + [HO_ST_WAIT_MGW_ENDPOINT_TO_MSC] = { + .name = "WAIT_MGW_ENDPOINT_TO_MSC", + .onenter = ho_fsm_wait_mgw_endpoint_to_msc_onenter, + .action = ho_fsm_wait_mgw_endpoint_to_msc, + .in_event_mask = 0 + | S(HO_EV_MSC_MGW_OK) + | S(HO_EV_MSC_MGW_FAIL) + , + .out_state_mask = 0 | S(HO_ST_WAIT_RR_HO_DETECT) , }, @@ -1224,20 +1256,7 @@ static const struct osmo_fsm_state ho_fsm_states[] = { .in_event_mask = 0 | S(HO_EV_LCHAN_ESTABLISHED) , - .out_state_mask = 0 - | S(HO_ST_WAIT_MGW_ENDPOINT_TO_MSC) - , - }, - [HO_ST_WAIT_MGW_ENDPOINT_TO_MSC] = { - .name = "WAIT_MGW_ENDPOINT_TO_MSC", - .onenter = ho_fsm_wait_mgw_endpoint_to_msc_onenter, - .action = ho_fsm_wait_mgw_endpoint_to_msc, - .in_event_mask = 0 - | S(HO_EV_MSC_MGW_OK) - | S(HO_EV_MSC_MGW_FAIL) - , }, - [HO_OUT_ST_WAIT_HO_COMMAND] = { .name = "inter-BSC-OUT:WAIT_HO_COMMAND", .action = ho_out_fsm_wait_ho_command, |