bsc/BSC_Tests_VAMOS.ttcn

module BSC_Tests_VAMOS {

/* Integration Tests for OsmoBSC
 * (C) 2021 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
 * All rights reserved.
 *
 * Released under the terms of GNU General Public License, Version 2 or
 * (at your option) any later version.
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 *
 * This test suite tests OsmoBSC while emulating both multiple BTS + MS as
 * well as the MSC. See README for more details.
 *
 * There are test cases that run in so-called 'handler mode' and test cases
 * that run directly on top of the BSSAP and RSL CodecPorts.  The "handler mode"
 * tests abstract the multiplexing/demultiplexing of multiple SCCP connections
 * and/or RSL channels and are hence suitable for higher-level test cases, while
 * the "raw" tests directly on top of the CodecPorts are more suitable for lower-
 * level testing.
 */

import from BSC_Tests all;

import from Misc_Helpers all;
import from General_Types all;
import from Osmocom_Types all;
import from GSM_Types all;
import from IPL4asp_Types all;

import from BSSAP_Types all;
import from RAN_Adapter all;
import from BSSAP_LE_Adapter all;
import from BSSAP_LE_CodecPort all;
import from BSSAP_LE_Types all;
import from BSSLAP_Types all;
import from BSSAP_CodecPort all;
import from BSSMAP_Templates all;
import from IPA_Emulation all;
import from IPA_CodecPort all;
import from IPA_Types all;
import from IPA_Testing all;
import from RSL_Types all;
import from RSL_Emulation all;
import from MGCP_Emulation all;
import from MGCP_Templates all;
import from MGCP_Types all;
import from MGCP_CodecPort all;

import from Osmocom_CTRL_Functions all;
import from Osmocom_CTRL_Types all;
import from Osmocom_CTRL_Adapter all;

import from StatsD_Types all;
import from StatsD_CodecPort all;
import from StatsD_CodecPort_CtrlFunct all;
import from StatsD_Checker all;

import from Osmocom_VTY_Functions all;
import from TELNETasp_PortType all;

import from MobileL3_CommonIE_Types all;
import from MobileL3_Types all;
import from MobileL3_RRM_Types all;
import from L3_Templates all;
import from GSM_RR_Types all;

import from SCCP_Templates all;
import from BSSMAP_Templates all;
import from BSSMAP_LE_Templates all;

import from SCCPasp_Types all;

import from GSM_SystemInformation all;
import from GSM_RestOctets all;
import from TCCConversion_Functions all;

import from RAN_Emulation all;
import from MSC_ConnectionHandler all;

import from Native_Functions all;

const integer NUM_BTS := 3;
const integer NUM_MSC := 3;

private function f_rsl_chan_nr_to_subslot(RslChannelNr chan_nr)
return integer
{
	var integer subslot;
	select (chan_nr) {
		case (t_RslChanNr_Bm(?)) {
			/* TCH/F, always subslot 0 */
			subslot := 0;
		}
		case (t_RslChanNr_Lm(?, ?)) {
			/* TCH/H */
			subslot := chan_nr.u.lm.sub_chan;
		}
		case (t_RslChanNr_Osmo_VAMOS_Bm(?)) {
			/* TCH/F, always subslot 0 */
			subslot := 0;
		}
		case (t_RslChanNr_Osmo_VAMOS_Lm(?, ?)) {
			/* TCH/H */
			subslot := chan_nr.u.lm.sub_chan;
		}
		case else {
			setverdict(fail, "unsupported RslChannelNr type in f_rsl_chan_nr_to_subslot()");
			mtc.stop;
		}
	}
	return subslot;
}

private function f_rsl_chan_nr_to_rsl_cbits(RslChannelNr chan_nr)
return BIT5
{
	var BIT5 rsl_cbits;
	select (chan_nr) {
		case (t_RslChanNr_Bm(?)) {
			rsl_cbits := '00001'B;
		}
		case (t_RslChanNr_Lm(?, ?)) {
			rsl_cbits := int2bit(2 + chan_nr.u.lm.sub_chan, 5); /* '0001x'B */
		}
		case (t_RslChanNr_Osmo_VAMOS_Bm(?)) {
			rsl_cbits := '11101'B;
		}
		case (t_RslChanNr_Osmo_VAMOS_Lm(?, ?)) {
			rsl_cbits := int2bit(30 + chan_nr.u.lm.sub_chan, 5); /* '1111x'B */
		}
		case else {
			setverdict(fail, "unsupported RslChannelNr type in f_rsl_chan_nr_to_rsl_cbits()");
			mtc.stop;
		}
	}
	return rsl_cbits;
}

private function f_rsl_chan_nr_to_rr_cbits(RslChannelNr chan_nr)
return BIT5
{
	var BIT5 rr_cbits;
	select (chan_nr) {
		case (t_RslChanNr_Bm(?)) {
			rr_cbits := '00001'B;
		}
		case (t_RslChanNr_Lm(?, ?)) {
			rr_cbits := int2bit(2 + chan_nr.u.lm.sub_chan, 5); /* '0001x'B */
		}
		case (t_RslChanNr_Osmo_VAMOS_Bm(?)) {
			rr_cbits := '00001'B;
			/* In RR, there must *not* be Osmocom specific cbits */
		}
		case (t_RslChanNr_Osmo_VAMOS_Lm(?, ?)) {
			rr_cbits := int2bit(2 + chan_nr.u.lm.sub_chan, 5); /* '0001x'B */
			/* In RR, there must *not* be Osmocom specific cbits */
		}
		case else {
			setverdict(fail, "unsupported RslChannelNr type in f_rsl_chan_nr_to_rr_cbits()");
			mtc.stop;
		}
	}
	return rr_cbits;
}

private function f_rsl_chan_nr_to_chrt(RslChannelNr chan_nr, boolean vamos)
return RSL_ChanRateType
{
	var boolean fr;
	select (chan_nr) {
		case (t_RslChanNr_Bm(?)) {
			fr := true;
		}
		case (t_RslChanNr_Lm(?, ?)) {
				fr := false;
		}
		case (t_RslChanNr_Osmo_VAMOS_Bm(?)) {
			fr := true;
		}
		case (t_RslChanNr_Osmo_VAMOS_Lm(?, ?)) {
				fr := false;
		}
		case else {
			setverdict(fail, "unsupported RslChannelNr type in f_rsl_chan_nr_to_chrt()");
			mtc.stop;
		}
	}
	if (fr) {
		if (vamos) {
			return RSL_CHRT_OSMO_TCH_F_VAMOS;
		} else {
			return RSL_CHRT_TCH_F;
		}
	} else {
		if (vamos) {
			return RSL_CHRT_OSMO_TCH_H_VAMOS;
		} else {
			return RSL_CHRT_TCH_H;
		}
	}
}

private function f_lchan_str(integer bts_nr, integer trx_nr, RslChannelNr chan_nr)
return charstring
{
	var integer subslot := f_rsl_chan_nr_to_subslot(chan_nr);
	return "lchan " & int2str(bts_nr) & " " & int2str(trx_nr) & " " & int2str(chan_nr.tn) & " " & int2str(subslot);
}

private function f_long_lchan_str(integer bts_nr, integer trx_nr, RslChannelNr chan_nr)
return charstring
{
	var integer subslot := f_rsl_chan_nr_to_subslot(chan_nr);
	return "bts " & int2str(bts_nr) & " trx " & int2str(trx_nr) & " timeslot " & int2str(chan_nr.tn) & " sub-slot " & int2str(subslot);
}

private function f_lchan_ensure_established(TELNETasp_PT vty, integer bts_nr, integer trx_nr, RslChannelNr chan_nr)
{
	var charstring lchan_str := f_lchan_str(bts_nr, trx_nr, chan_nr);
	var charstring lchan_info := f_vty_transceive_ret(vty, "show " & lchan_str);
	if (f_strstr(lchan_info, "State: ESTABLISHED") < 0) {
		log("'show lchan' replied: ", lchan_info);
		setverdict(fail, "lchan " & lchan_str & " is not in state ESTABLISHED");
		mtc.stop;
	}
	setverdict(pass);
}

/* Activate a primary lchan in VAMOS speech mode */
testcase TC_chan_act_to_vamos() runs on test_CT {
	f_init_vty();

	f_logp(BSCVTY, "TC_chan_act_to_vamos");

	f_init(1, false);
	f_sleep(1.0);

	f_vty_transceive(BSCVTY, "bts 0 trx 0 timeslot 1 sub-slot 0 activate-vamos fr");

	var RSL_Message rsl;

	rsl := f_exp_ipa_rx(0, tr_RSL_MsgTypeD(RSL_MT_CHAN_ACTIV));

	var RSL_IE_Body chan_mode_ie;
	if (f_rsl_find_ie(rsl, RSL_IE_CHAN_MODE, chan_mode_ie) == false) {
		setverdict(fail, "Cannot find RSL_IE_CHAN_MODE");
		mtc.stop;
	}
	if (chan_mode_ie.chan_mode.ch_rate_type != RSL_CHRT_OSMO_TCH_F_VAMOS) {
		setverdict(fail, "expected chan_mode.ch_rate_type == RSL_CHRT_OSMO_TCH_F_VAMOS");
		mtc.stop;
	}

	var RSL_IE_Body osmo_tsc_ie;
	if (f_rsl_find_ie(rsl, RSL_IE_OSMO_TRAINING_SEQUENCE, osmo_tsc_ie) == false) {
		setverdict(fail, "Cannot find RSL_IE_OSMO_TRAINING_SEQUENCE");
		mtc.stop;
	}

	var RslChannelNr chan_nr := rsl.ies[0].body.chan_nr;
	f_ipa_tx(0, ts_RSL_CHAN_ACT_ACK(chan_nr, 23+10));

	f_sleep(1.0);
	f_lchan_ensure_established(BSCVTY, 0, 0, chan_nr);

	f_vty_transceive(BSCVTY, "bts 0 trx 0 timeslot 1 sub-slot 0 deactivate");

	f_shutdown_helper();
}

/* verify that DTAP passes through both ways with the right cbits */
private function f_verify_dtap() runs on MSC_ConnHdlr
{
	var octetstring l3_data := '00010203040506'O;
	var PDU_BSSAP rx_bssap_dtap;

	/* MS to NW */
	RSL.send(ts_RSL_DATA_IND(g_chan_nr, valueof(ts_RslLinkID_DCCH(0)), l3_data));
	BSSAP.receive(tr_BSSAP_DTAP) -> value rx_bssap_dtap;
	if (not match(rx_bssap_dtap.pdu.dtap, l3_data)) {
		setverdict(fail, "unexpected L3 data");
		mtc.stop;
	}

	/* NW to MS */
	l3_data := '0800dcba9876543210'O;
	BSSAP.send(ts_BSSAP_DTAP(l3_data, '00'O));
	RSL.receive(tr_RSL_DATA_REQ(g_chan_nr, tr_RslLinkID_DCCH(0), l3_data));
}


private function f_est_lchan_and_mode_modify_to_vamos() runs on MSC_ConnHdlr {
	var PDU_BSSAP ass_cmd := f_gen_ass_req(g_pars.use_osmux);
	var template PDU_BSSAP exp_compl := f_gen_exp_compl(g_pars.use_osmux);

	/* puzzle together the ASSIGNMENT REQ for given codec[s] */
	if (mp_bssap_cfg[0].transport == BSSAP_TRANSPORT_AoIP) {
		ass_cmd.pdu.bssmap.assignmentRequest.codecList := g_pars.ass_codec_list;
		exp_compl.pdu.bssmap.assignmentComplete.speechCodec.codecElements[0] :=
								g_pars.ass_codec_list.codecElements[0];
		if (isvalue(g_pars.expect_mr_s0_s7)) {
			exp_compl.pdu.bssmap.assignmentComplete.speechCodec.codecElements[0].s0_7 :=
								g_pars.expect_mr_s0_s7;
		}
	}
	ass_cmd.pdu.bssmap.assignmentRequest.channelType :=
				f_BSSMAP_chtype_from_codec(g_pars.ass_codec_list.codecElements[0]);
	log("expecting ASS COMPL like this: ", exp_compl);

	f_establish_fully(ass_cmd, exp_compl);

	f_lchan_ensure_established(BSCVTY, 0, 0, g_chan_nr);

	var charstring current_long_lchan_str := f_long_lchan_str(0, 0, g_chan_nr);
	f_vty_transceive(BSCVTY, current_long_lchan_str & " modify vamos tsc 2 3");

	var RSL_Message rsl_rr;
	RSL.receive(tr_RSL_DATA_REQ(g_chan_nr)) -> value rsl_rr;

	var PDU_ML3_NW_MS l3 := dec_PDU_ML3_NW_MS(rsl_rr.ies[2].body.l3_info.payload);

	var integer current_subslot := f_rsl_chan_nr_to_subslot(g_chan_nr);

	template PDU_ML3_NW_MS expect_rr_modify := tr_RRM_ModeModify(
		tr_ChannelDescription2_V(timeslotNumber := int2bit(g_chan_nr.tn, 3)),
		tr_ChannelMode_V(mode := 'C1'O /* 1 1 0 0 0 0 0 1 speech full rate or half rate version 1 in VAMOS mode (3GPP TS 44.018) */),
		extendedTSCSet := tr_ExtendedTSCSet_TV(cSDomainTSCSet := '01'B));

	if (not match(l3, expect_rr_modify)) {
		log("expected: ", expect_rr_modify);
		log("got: ", l3);
		setverdict(fail, "RR channelModeModify message is not as expected");
		mtc.stop;
	}
	f_rsl_reply(ts_RRM_ModeModifyAck(l3.msgs.rrm.channelModeModify.channelDescription,
					 l3.msgs.rrm.channelModeModify.channelMode,
					 l3.msgs.rrm.channelModeModify.extendedTSCSet), rsl_rr);

	var RSL_Message rsl;
	RSL.receive(tr_RSL_MODE_MODIFY_REQ_with_OSMO_TSC(g_chan_nr, tr_RSL_ChanMode(f_rsl_chan_nr_to_chrt(g_chan_nr, true), RSL_CMOD_SP_GSM1),
			    tsc_set := 1, /* 1 means TSC Set 2 (range 1-4 in spec tables and naming, 0-3 on the wire) */
			    tsc := 3));
	RSL.send(ts_RSL_MODE_MODIFY_ACK(g_chan_nr));
	f_sleep(1.0);

	f_lchan_ensure_established(BSCVTY, 0, 0, g_chan_nr);
	f_verify_dtap();
}

private function f_TC_mode_modify_to_vamos(charstring id) runs on MSC_ConnHdlr {
	f_est_lchan_and_mode_modify_to_vamos();
	f_perform_clear(RSL);
}

/* Modify a primary lchan into VAMOS speech mode */
testcase TC_mode_modify_to_vamos_fr() runs on test_CT {
	var TestHdlrParams pars := f_gen_test_hdlr_pars();
	var MSC_ConnHdlr vc_conn;

	f_init(1, true);
	f_sleep(1.0);

	pars.ass_codec_list := valueof(ts_BSSMAP_IE_CodecList({ts_CodecFR}));
	vc_conn := f_start_handler(refers(f_TC_mode_modify_to_vamos), pars);
	vc_conn.done;
	f_shutdown_helper();
}

/* Modify a primary lchan into VAMOS speech mode */
testcase TC_mode_modify_to_vamos_hr() runs on test_CT {
	var TestHdlrParams pars := f_gen_test_hdlr_pars();
	var MSC_ConnHdlr vc_conn;

	f_init(1, true);
	f_sleep(1.0);

	pars.ass_codec_list := valueof(ts_BSSMAP_IE_CodecList({ts_CodecHR}));
	vc_conn := f_start_handler(refers(f_TC_mode_modify_to_vamos), pars);
	vc_conn.done;
	f_shutdown_helper();
}

/* Establish a primary lchan, and then do a re-assignment to a VAMOS shadow lchan. */
private function f_reassign_secondary_to_primary_lchan(RslChannelNr new_chan_nr) runs on MSC_ConnHdlr
{
	var integer current_subslot := f_rsl_chan_nr_to_subslot(g_chan_nr);

	var integer new_subslot := f_rsl_chan_nr_to_subslot(new_chan_nr);
	var BIT5 new_rr_cbits := f_rsl_chan_nr_to_rr_cbits(new_chan_nr);

	activate(as_Media_mgw());

	f_rslem_register(0, new_chan_nr, RSL_PROC);
	log("f_rslem_register(0, new_chan_nr = ", new_chan_nr, ")");

	f_vty_transceive(BSCVTY, "bts 0 trx 0 timeslot " & int2str(g_chan_nr.tn) & " vamos-sub-slot " & int2str(current_subslot)
			 & " reassign-to trx 0 timeslot " & int2str(new_chan_nr.tn) & " sub-slot " & int2str(new_subslot));
	/* RSL CHAN ACT is ACKed by RSL emulation */

	var RSL_Message rsl;
	var RSL_IE_Body ie;
	var boolean b_unused;
	interleave {
	[] RSL.receive(tr_RSL_DATA_REQ(g_chan_nr)) -> value rsl {
		var PDU_ML3_NW_MS l3 := dec_PDU_ML3_NW_MS(rsl.ies[2].body.l3_info.payload);
		var template PDU_ML3_NW_MS expect_rr_assignment := tr_RR_AssignmentCommand(
			desc := tr_ChannelDescription2_V(timeslotNumber := int2bit(new_chan_nr.tn, 3),
					channelTypeandTDMAOffset := new_rr_cbits),
			mode := tr_ChannelMode_TV(mode := '01'O
						  /* 0 0 0 0 0 0 0 1 speech full rate or half rate version 1 (3GPP TS 44.018) */),
			extendedTSCSet := omit);
		if (not match(l3, expect_rr_assignment)) {
			log("expected: ", expect_rr_assignment);
			log("got: ", l3);
			setverdict(fail, "RR assignmentCommand message is not as expected");
			mtc.stop;
		}

		var PDU_ML3_MS_NW l3_tx := valueof(ts_RRM_AssignmentComplete('00'O));
		RSL.send(ts_RSL_EST_IND(new_chan_nr, valueof(ts_RslLinkID_DCCH(0)),
					enc_PDU_ML3_MS_NW(l3_tx)));

		}
	[] RSL.receive(tr_RSL_IPA_CRCX(new_chan_nr)) -> value rsl {
		var uint7_t rtp_pt := 0;
		if (f_rsl_find_ie(rsl, RSL_IE_IPAC_RTP_PAYLOAD, ie)) {
			rtp_pt := ie.ipa_rtp_pt;
		}
		RSL.send(ts_RSL_IPA_CRCX_ACK(new_chan_nr, 123,
						f_inet_addr("1.2.3.4"),
						4321,
						rtp_pt));
		}
	[] RSL.receive(tr_RSL_IPA_MDCX(new_chan_nr, ?)) -> value rsl{
		/* Extract conn_id, ip, port, rtp_pt2 from request + use in response */
		b_unused := f_rsl_find_ie(rsl, RSL_IE_IPAC_CONN_ID, ie);
		var uint16_t conn_id := ie.ipa_conn_id;
		/* mandatory */
		b_unused := f_rsl_find_ie(rsl, RSL_IE_IPAC_REMOTE_IP, ie);
		var HostPort peer;
		peer.host := f_inet_ntoa(ie.ipa_remote_ip);
		b_unused := f_rsl_find_ie(rsl, RSL_IE_IPAC_REMOTE_PORT, ie);
		peer.port_nr := ie.ipa_remote_port;
		var uint7_t rtp_pt := 0;
		/* optional */
		if (f_rsl_find_ie(rsl, RSL_IE_IPAC_RTP_PAYLOAD, ie)) {
			rtp_pt := ie.ipa_rtp_pt;
		}
		RSL.send(ts_RSL_IPA_MDCX_ACK(new_chan_nr, conn_id,
						f_inet_addr(peer.host),
						peer.port_nr,
						rtp_pt));
		}
	[] RSL.receive(tr_RSL_DEACT_SACCH(g_chan_nr)) {}
	[] RSL.receive(tr_RSL_RF_CHAN_REL(g_chan_nr)) {
		RSL.send(ts_ASP_RSL_UD(ts_RSL_RF_CHAN_REL_ACK(g_chan_nr),
				       IPAC_PROTO_RSL_TRX0));
		f_rslem_unregister(0, g_chan_nr, RSL_PROC);
		g_chan_nr := new_chan_nr;
		}
	/* (There must be no RSL_MT_REL_REQ on the old lchan.) */
	}

	setverdict(pass);

	f_sleep(1.0);
	f_vty_transceive(BSCVTY, "show lchan summary");

	f_verify_dtap();
}

private function f_est_and_reassign_to_secondary_lchan(RslChannelNr new_chan_nr) runs on MSC_ConnHdlr
{
	var integer new_subslot := f_rsl_chan_nr_to_subslot(new_chan_nr);
	var BIT5 new_rr_cbits := f_rsl_chan_nr_to_rr_cbits(new_chan_nr);

	var PDU_BSSAP ass_cmd := f_gen_ass_req();
	var template PDU_BSSAP exp_compl := f_gen_exp_compl();

	/* puzzle together the ASSIGNMENT REQ for given codec[s] */
	if (mp_bssap_cfg[0].transport == BSSAP_TRANSPORT_AoIP) {
		ass_cmd.pdu.bssmap.assignmentRequest.codecList := g_pars.ass_codec_list;
		exp_compl.pdu.bssmap.assignmentComplete.speechCodec.codecElements[0] :=
								g_pars.ass_codec_list.codecElements[0];
		if (isvalue(g_pars.expect_mr_s0_s7)) {
			exp_compl.pdu.bssmap.assignmentComplete.speechCodec.codecElements[0].s0_7 :=
								g_pars.expect_mr_s0_s7;
		}
	}
	ass_cmd.pdu.bssmap.assignmentRequest.channelType :=
				f_BSSMAP_chtype_from_codec(g_pars.ass_codec_list.codecElements[0]);
	log("expecting ASS COMPL like this: ", exp_compl);

	f_establish_fully(ass_cmd, exp_compl);

	var integer current_subslot := f_rsl_chan_nr_to_subslot(g_chan_nr);

	f_sleep(1.0);

	activate(as_Media_mgw());

	f_rslem_register(0, new_chan_nr, RSL_PROC);
	log("f_rslem_register(0, new_chan_nr = ", new_chan_nr, ")");

	f_vty_transceive(BSCVTY, "bts 0 trx 0 timeslot " & int2str(g_chan_nr.tn) & " sub-slot " & int2str(current_subslot)
			 & " reassign-to trx 0 timeslot " & int2str(new_chan_nr.tn) & " vamos-sub-slot " & int2str(new_subslot) & " tsc 4 2");
	/* RSL CHAN ACT is ACKed by RSL emulation */

	var RSL_Message rsl;
	var RSL_IE_Body ie;
	var boolean b_unused;
	interleave {
	[] RSL.receive(tr_RSL_DATA_REQ(g_chan_nr)) -> value rsl {
		var PDU_ML3_NW_MS l3 := dec_PDU_ML3_NW_MS(rsl.ies[2].body.l3_info.payload);
		var template PDU_ML3_NW_MS expect_rr_assignment := tr_RR_AssignmentCommand(
			desc := tr_ChannelDescription2_V(timeslotNumber := int2bit(new_chan_nr.tn, 3),
							 channelTypeandTDMAOffset := new_rr_cbits),
			mode := tr_ChannelMode_TV(mode := 'C1'O
						  /* 1 1 0 0 0 0 0 1 speech full rate or half rate version 1 in VAMOS mode (3GPP TS 44.018) */),
			extendedTSCSet := tr_ExtendedTSCSet_TV(cSDomainTSCSet := '11'B
							       /* 3 means TSC Set 4 (range 1-4 in spec tables and naming, 0-3 on the wire) */));
		if (not match(l3, expect_rr_assignment)) {
			log("expected: ", expect_rr_assignment);
			log("got: ", l3);
			setverdict(fail, "RR assignmentCommand message is not as expected");
			mtc.stop;
		}

		var PDU_ML3_MS_NW l3_tx := valueof(ts_RRM_AssignmentComplete('00'O));
		RSL.send(ts_RSL_EST_IND(new_chan_nr, valueof(ts_RslLinkID_DCCH(0)),
					enc_PDU_ML3_MS_NW(l3_tx)));

		}
	[] RSL.receive(tr_RSL_IPA_CRCX(new_chan_nr)) -> value rsl {
		var uint7_t rtp_pt := 0;
		if (f_rsl_find_ie(rsl, RSL_IE_IPAC_RTP_PAYLOAD, ie)) {
			rtp_pt := ie.ipa_rtp_pt;
		}
		RSL.send(ts_RSL_IPA_CRCX_ACK(new_chan_nr, 123,
						f_inet_addr("1.2.3.4"),
						4321,
						rtp_pt));
		}
	[] RSL.receive(tr_RSL_IPA_MDCX(new_chan_nr, ?)) -> value rsl{
		/* Extract conn_id, ip, port, rtp_pt2 from request + use in response */
		b_unused := f_rsl_find_ie(rsl, RSL_IE_IPAC_CONN_ID, ie);
		var uint16_t conn_id := ie.ipa_conn_id;
		/* mandatory */
		b_unused := f_rsl_find_ie(rsl, RSL_IE_IPAC_REMOTE_IP, ie);
		var HostPort peer;
		peer.host := f_inet_ntoa(ie.ipa_remote_ip);
		b_unused := f_rsl_find_ie(rsl, RSL_IE_IPAC_REMOTE_PORT, ie);
		peer.port_nr := ie.ipa_remote_port;
		var uint7_t rtp_pt := 0;
		/* optional */
		if (f_rsl_find_ie(rsl, RSL_IE_IPAC_RTP_PAYLOAD, ie)) {
			rtp_pt := ie.ipa_rtp_pt;
		}
		RSL.send(ts_RSL_IPA_MDCX_ACK(new_chan_nr, conn_id,
						f_inet_addr(peer.host),
						peer.port_nr,
						rtp_pt));
		}
	[] RSL.receive(tr_RSL_DEACT_SACCH(g_chan_nr)) {}
	[] RSL.receive(tr_RSL_RF_CHAN_REL(g_chan_nr)) {
		RSL.send(ts_ASP_RSL_UD(ts_RSL_RF_CHAN_REL_ACK(g_chan_nr),
				       IPAC_PROTO_RSL_TRX0));
		f_rslem_unregister(0, g_chan_nr, RSL_PROC);
		g_chan_nr := new_chan_nr;
		}
	/* (There must be no RSL_MT_REL_REQ on the old lchan.) */
	}

	setverdict(pass);

	f_sleep(1.0);
	f_vty_transceive(BSCVTY, "show lchan summary");

	f_verify_dtap();
}

/* Establish a primary lchan, and then do a re-assignment to a VAMOS shadow lchan.
 * Also re-assign back to a primary lchan. */
private function f_TC_assign_to_secondary_lchan_fr(charstring id) runs on MSC_ConnHdlr {
	f_est_and_reassign_to_secondary_lchan(valueof(t_RslChanNr_Osmo_VAMOS_Bm(2)));
	f_reassign_secondary_to_primary_lchan(valueof(t_RslChanNr_Bm(3)));
	f_perform_clear(RSL);
	f_sleep(1.0);
}

/* Establish a primary lchan, and then do a re-assignment to a VAMOS shadow lchan. */
testcase TC_assign_to_secondary_lchan_fr() runs on test_CT {
	var TestHdlrParams pars := f_gen_test_hdlr_pars();
	var MSC_ConnHdlr vc_conn;

	f_init(1, true);
	f_sleep(1.0);

	pars.ass_codec_list := valueof(ts_BSSMAP_IE_CodecList({ts_CodecFR}));
	vc_conn := f_start_handler(refers(f_TC_assign_to_secondary_lchan_fr), pars);
	vc_conn.done;
	f_shutdown_helper();
}

/* Establish a primary lchan, and then do a re-assignment to a VAMOS shadow lchan.
 * Also re-assign back to a primary lchan. */
private function f_TC_assign_to_secondary_lchan_hr(charstring id) runs on MSC_ConnHdlr {
	f_est_and_reassign_to_secondary_lchan(valueof(t_RslChanNr_Osmo_VAMOS_Lm(6, 0)));
	f_reassign_secondary_to_primary_lchan(valueof(t_RslChanNr_Lm(6, 1)));
	f_perform_clear(RSL);
	f_sleep(1.0);
}

/* Establish a primary lchan, and then do a re-assignment to a VAMOS shadow lchan. */
testcase TC_assign_to_secondary_lchan_hr() runs on test_CT {
	var TestHdlrParams pars := f_gen_test_hdlr_pars();
	var MSC_ConnHdlr vc_conn;

	f_init(1, true);
	f_sleep(1.0);

	pars.ass_codec_list := valueof(ts_BSSMAP_IE_CodecList({ts_CodecHR}));
	vc_conn := f_start_handler(refers(f_TC_assign_to_secondary_lchan_hr), pars);
	vc_conn.done;
	f_shutdown_helper();
}

/* First, primary lchan of TC_vamos_multiplex_tch_f_tch_f() */
private function f_TC_vamos_multiplex_tch_f_tch_f1(charstring id) runs on MSC_ConnHdlr {
	f_est_lchan_and_mode_modify_to_vamos();
	f_logp(BSCVTY, "f_est_lchan_and_mode_modify_to_vamos done");
}

/* Second, VAMOS shadow lchan of TC_vamos_multiplex_tch_f_tch_f() */
private function f_TC_vamos_multiplex_tch_f_tch_f2(charstring id) runs on MSC_ConnHdlr {
	f_est_and_reassign_to_secondary_lchan(valueof(t_RslChanNr_Osmo_VAMOS_Bm(1)));
}

/* Establish a primary lchan and modify it to VAMOS speech mode. Then establish
 * another primary lchan, and re-assign it to the VAMOS secondary lchan of the
 * first primary lchan. */
testcase TC_vamos_multiplex_tch_f_tch_f() runs on test_CT {
	var TestHdlrParams pars1 := f_gen_test_hdlr_pars();
	var MSC_ConnHdlr vc_conn1;

	var TestHdlrParams pars2 := f_gen_test_hdlr_pars();
	var MSC_ConnHdlr vc_conn2;
	pars2.imsi := '001014234234234'H;
	pars2.media_nr := 2;

	f_init(1, true);
	f_sleep(1.0);

	pars1.ass_codec_list := valueof(ts_BSSMAP_IE_CodecList({ts_CodecFR}));
	pars2.ass_codec_list := valueof(ts_BSSMAP_IE_CodecList({ts_CodecFR}));
	vc_conn1 := f_start_handler(refers(f_TC_vamos_multiplex_tch_f_tch_f1), pars1);
	vc_conn1.done;

	vc_conn2 := f_start_handler(refers(f_TC_vamos_multiplex_tch_f_tch_f2), pars2);
	vc_conn2.done;
	f_shutdown_helper();
}

/* First, primary lchan of TC_vamos_multiplex_tch_h_tch_h_tch_h_tch_h() */
private function f_TC_vamos_multiplex_tch_h_tch_h1(charstring id) runs on MSC_ConnHdlr {
	f_est_lchan_and_mode_modify_to_vamos();
	f_logp(BSCVTY, "f_est_lchan_and_mode_modify_to_vamos done");
}

/* Second, VAMOS shadow lchan of TC_vamos_multiplex_tch_h_tch_h_tch_h_tch_h() */
private function f_TC_vamos_multiplex_tch_h_tch_h2(charstring id) runs on MSC_ConnHdlr {
	f_est_and_reassign_to_secondary_lchan(valueof(t_RslChanNr_Osmo_VAMOS_Lm(5, 0)));
}

private function f_TC_vamos_multiplex_tch_h_tch_h4(charstring id) runs on MSC_ConnHdlr {
	f_est_and_reassign_to_secondary_lchan(valueof(t_RslChanNr_Osmo_VAMOS_Lm(5, 1)));
}

/* Establish a primary lchan and modify it to VAMOS speech mode. Then establish
 * another primary lchan, and re-assign it to the VAMOS secondary lchan of the
 * first primary lchan. */
testcase TC_vamos_multiplex_tch_h_tch_h_tch_h_tch_h() runs on test_CT {
	var TestHdlrParams pars1 := f_gen_test_hdlr_pars();
	var MSC_ConnHdlr vc_conn1;
	pars1.imsi := '001011111111111'H;
	pars1.media_nr := 1;

	var TestHdlrParams pars2 := f_gen_test_hdlr_pars();
	var MSC_ConnHdlr vc_conn2;
	pars2.imsi := '001012222222222'H;
	pars2.media_nr := 2;

	var TestHdlrParams pars3 := f_gen_test_hdlr_pars();
	var MSC_ConnHdlr vc_conn3;
	pars3.imsi := '001013333333333'H;
	pars3.media_nr := 3;

	var TestHdlrParams pars4 := f_gen_test_hdlr_pars();
	var MSC_ConnHdlr vc_conn4;
	pars4.imsi := '001014444444444'H;
	pars4.media_nr := 4;

	f_init(1, true);
	f_sleep(1.0);

	pars1.ass_codec_list := valueof(ts_BSSMAP_IE_CodecList({ts_CodecHR}));
	pars2.ass_codec_list := valueof(ts_BSSMAP_IE_CodecList({ts_CodecHR}));
	pars3.ass_codec_list := valueof(ts_BSSMAP_IE_CodecList({ts_CodecHR}));
	pars4.ass_codec_list := valueof(ts_BSSMAP_IE_CodecList({ts_CodecHR}));

	vc_conn1 := f_start_handler(refers(f_TC_vamos_multiplex_tch_h_tch_h1), pars1);
	vc_conn1.done;

	vc_conn2 := f_start_handler(refers(f_TC_vamos_multiplex_tch_h_tch_h2), pars2);
	vc_conn2.done;

	/* Also fill up the second subslot of the TCH/H timeslot */
	vc_conn3 := f_start_handler(refers(f_TC_vamos_multiplex_tch_h_tch_h1), pars3);
	vc_conn3.done;

	vc_conn4 := f_start_handler(refers(f_TC_vamos_multiplex_tch_h_tch_h4), pars4);
	vc_conn4.done;
	f_shutdown_helper();
}

control {
	execute( TC_chan_act_to_vamos() );
	execute( TC_mode_modify_to_vamos_fr() );
	execute( TC_mode_modify_to_vamos_hr() );
	execute( TC_assign_to_secondary_lchan_fr() );
	execute( TC_assign_to_secondary_lchan_hr() );
	execute( TC_vamos_multiplex_tch_f_tch_f() );
	execute( TC_vamos_multiplex_tch_h_tch_h_tch_h_tch_h() );
}

}