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Diffstat (limited to 'include/osmocom/msc/msc_ho.h')
| -rw-r--r-- | include/osmocom/msc/msc_ho.h | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/include/osmocom/msc/msc_ho.h b/include/osmocom/msc/msc_ho.h new file mode 100644 index 000000000..99956f1e6 --- /dev/null +++ b/include/osmocom/msc/msc_ho.h @@ -0,0 +1,104 @@ +/* MSC Handover API */ +/* + * (C) 2019 by sysmocom - s.m.f.c. GmbH <info@sysmocom.de> + * All Rights Reserved + * + * SPDX-License-Identifier: AGPL-3.0+ + * + * Author: Neels Hofmeyr + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as published by + * the Free Software Foundation; either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#pragma once + +#include <osmocom/gsm/gsm_utils.h> +#include <osmocom/core/sockaddr_str.h> + +#include <osmocom/mgcp_client/mgcp_client.h> + +#include <osmocom/msc/neighbor_ident.h> +#include <osmocom/msc/ran_msg.h> +#include <osmocom/msc/mncc_call.h> + + +struct gsm0808_handover_required; + +struct msc_a; +struct ran_dec_handover_required; + +#define LOG_HO(msc_a, level, fmt, args...) \ + LOGPFSML((msc_a)? ((msc_a)->ho.fi ? : (msc_a)->c.fi) : NULL, \ + level, "%s" fmt, (msc_a->ho.fi ? "" : "HO: "), ##args) + +enum msc_ho_fsm_state { + MSC_HO_ST_REQUIRED, + MSC_HO_ST_WAIT_REQUEST_ACK, + MSC_HO_ST_WAIT_COMPLETE, +}; + +enum msc_ho_fsm_event { + MSC_HO_EV_RX_REQUEST_ACK, + MSC_HO_EV_RX_DETECT, + MSC_HO_EV_RX_COMPLETE, + MSC_HO_EV_RX_FAILURE, + MSC_HO_EV_MNCC_FORWARDING_COMPLETE, + MSC_HO_EV_MNCC_FORWARDING_FAILED, +}; + +struct msc_ho_state { + struct osmo_fsm_inst *fi; + struct ran_handover_required info; + unsigned int next_cil_idx; + bool subsequent_ho; + bool ready_to_switch_rtp; + bool rtp_switched_to_new_cell; + + struct { + enum osmo_rat_type ran_type; + struct gsm0808_cell_id cid; + struct osmo_cell_global_id cgi; + enum msc_neighbor_type type; + union { + struct ran_peer *ran_peer; + const char *msc_ipa_name; + }; + + /* The RTP address from Handover Request Acknowledge. + * Might be from AoIP Transport Layer Address from a BSC RAN peer, + * or from MNCC forwarding for inter-MSC handover. */ + struct osmo_sockaddr_str ran_remote_rtp; + /* The codec from Handover Request Acknowledge. */ + bool codec_present; + enum mgcp_codecs codec; + + /* Inter-MSC voice forwarding via MNCC, to the remote MSC. The Prepare Handover Response sent us the + * Handover Number the remote MSC assigned. This is a call to that Handover Number, via PBX. + * (NULL if not an inter-MSC Handover) */ + struct mncc_call *mncc_forwarding_to_remote_ran; + } new_cell; + + struct { + /* Saved RTP IP:port and codec in case we need to roll back */ + struct osmo_sockaddr_str ran_remote_rtp; + enum mgcp_codecs codec; + } old_cell; +}; + +void msc_ho_start(struct msc_a *msc_a, const struct ran_handover_required *ho_req); + +enum msc_neighbor_type msc_ho_find_target_cell(struct msc_a *msc_a, const struct gsm0808_cell_id *cid, + const struct neighbor_ident_entry **remote_msc, + struct ran_peer **ran_peer_from_neighbor_ident, + struct ran_peer **ran_peer_from_seen_cells); |