diff --git a/asterisk/Asterisk_Tests.ttcn b/asterisk/Asterisk_Tests.ttcn
index c4cad38..75c51e1 100644
--- a/asterisk/Asterisk_Tests.ttcn
+++ b/asterisk/Asterisk_Tests.ttcn
@@ -225,11 +225,13 @@
 		return;
 	}
 
-	as_SIP_mt_call_accept();
+	as_SIP_mt_call_accept(exp_update_to_direct_rtp := g_pars.cp.exp_update_to_direct_rtp);
 	COORD.send(COORD_CMD_CALL_ESTABLISHED);
 
-	/* Once MO hangs up, Asterisk updates us to point RTP to it: */
-	as_SIP_exp_call_update(g_pars.cp.sip_seq_nr + 1);
+	if (g_pars.cp.exp_update_to_direct_rtp) {
+		/* Once MO hangs up, Asterisk updates us to point RTP to it: */
+		as_SIP_exp_call_update(g_pars.cp.sip_seq_nr + 1);
+	}
 	as_SIP_exp_call_hangup(g_pars.cp.sip_seq_nr + 1);
 
 	setverdict(pass);
@@ -491,6 +493,74 @@
 	f_shutdown();
 }
 
+/* Test SIP registration of local clients */
+private function f_TC_ims_call_mt(charstring id) runs on IMS_ConnHdlr {
+	f_create_sip_expect(valueof(ts_SipUrl_from_Addr_Union(g_pars.subscr.registrar_sip_record.addr)));
+	as_IMS_register();
+	COORD.send(IMS_COORD_CMD_REGISTERED);
+	setverdict(pass);
+
+	COORD.receive(IMS_COORD_CMD_START);
+	f_IMS_mt_call_setup();
+	setverdict(pass);
+	COORD.send(IMS_COORD_CMD_CALL_ESTABLISHED);
+
+	COORD.receive(IMS_COORD_CMD_HANGUP);
+	f_IMS_do_call_hangup();
+	setverdict(pass);
+
+	as_IMS_unregister();
+}
+testcase TC_ims_call_mt() runs on test_CT {
+	var SIPConnHdlrPars sip_pars;
+	var IMS_ConnHdlrPars ims_pars;
+	var SIPConnHdlr vc_conn_sip;
+	var IMS_ConnHdlr vc_conn_ims;
+	const charstring c_ext_msisdn := "90829";
+
+	f_init();
+
+	sip_pars := f_init_ConnHdlrPars(idx := 1);
+	ims_pars := f_init_IMS_ConnHdlrPars();
+
+	sip_pars.cp.exp_update_to_direct_rtp := false;
+	sip_pars.cp.calling := valueof(ts_SipAddr(ts_HostPort(sip_pars.remote_sip_host),
+						 ts_UserInfo(c_ext_msisdn)));
+	sip_pars.cp.called := sip_pars.local_sip_record;
+	ims_pars.subscr.cp.calling := valueof(ts_SipAddr(ts_HostPort(ims_pars.realm),
+							ts_UserInfo(c_ext_msisdn)));
+	ims_pars.subscr.cp.called := valueof(ts_SipAddr(ts_HostPort(ims_pars.realm),
+							 ts_UserInfo(ims_pars.subscr.msisdn)));
+
+	vc_conn_ims := f_start_handler_IMS(refers(f_TC_ims_call_mt), ims_pars);
+	vc_conn_sip := f_start_handler(refers(f_TC_internal_call_mt), sip_pars);
+
+	COORD.receive(COORD_CMD_REGISTERED) from vc_conn_sip;
+
+	f_AMI_IMS_register(ims_pars);
+	IMS_COORD.receive(IMS_COORD_CMD_REGISTERED) from vc_conn_ims;
+
+	IMS_COORD.send(IMS_COORD_CMD_START) to vc_conn_ims;
+	IMS_COORD.receive(IMS_COORD_CMD_CALL_ESTABLISHED) from vc_conn_ims;
+	COORD.receive(COORD_CMD_CALL_ESTABLISHED) from vc_conn_sip;
+
+	/* TODO: "Action: DedicatedBearerStatus" */
+
+	/* Call on-going */
+	f_sleep(1.0);
+
+	IMS_COORD.send(IMS_COORD_CMD_HANGUP) to vc_conn_ims;
+
+	/* Trigger unregistration: */
+	f_sleep(1.0);
+	AMI_CLIENT.clear;
+	f_AMI_IMS_unregister(ims_pars);
+
+	vc_conn_sip.done;
+	vc_conn_ims.done;
+	f_shutdown();
+}
+
 control {
 	execute( TC_internal_registration() );
 	execute( TC_internal_call_momt() );
@@ -499,6 +569,7 @@
 	execute( TC_internal_call_all_4registered() );
 	execute( TC_ims_registration() );
 	execute( TC_ims_call_mo() );
+	execute( TC_ims_call_mt() );
 }
 
 }
diff --git a/asterisk/IMS_ConnectionHandler.ttcn b/asterisk/IMS_ConnectionHandler.ttcn
index c7eb84c..3c3a51b 100644
--- a/asterisk/IMS_ConnectionHandler.ttcn
+++ b/asterisk/IMS_ConnectionHandler.ttcn
@@ -43,7 +43,10 @@
 	inout charstring;
 } with { extension "internal" };
 
-const charstring IMS_COORD_CMD_REGISTERED := "COORD_CMD_REGISTERED";
+const charstring IMS_COORD_CMD_REGISTERED := "IMS_COORD_CMD_REGISTERED";
+const charstring IMS_COORD_CMD_START := "IMS_COORD_CMD_START";
+const charstring IMS_COORD_CMD_CALL_ESTABLISHED := "IMS_COORD_CMD_CALL_ESTABLISHED";
+const charstring IMS_COORD_CMD_HANGUP := "IMS_COORD_CMD_HANGUP";
 
 type component IMS_ConnHdlr extends SIP_ConnHdlr {
 	var charstring g_name;
@@ -87,7 +90,7 @@
 	integer registrar_sip_seq_nr,
 	SipUrl local_sip_url_ext,
 	SipAddr local_sip_record,
-	Contact local_contact,
+	Contact registered_contact optional,
 	P_Associated_Uri p_associated_uri,
 	IMS_CallPars cp optional
 }
@@ -190,14 +193,7 @@
 				       ts_UserInfo(imsi)),
 	local_sip_record := ts_SipAddr(ts_HostPort(domain),
 				       ts_UserInfo(imsi)),
-	local_contact := valueof(ts_Contact({
-					ts_ContactAddress(
-						ts_Addr_Union_SipUrl(ts_SipUrl(ts_HostPort(
-										 domain,
-										 local_sip_port),
-								     ts_UserInfo(imsi))),
-						omit)
-				})),
+	registered_contact := omit,
 	p_associated_uri := ts_P_Associated_Uri({}),
 	cp := cp
 }
@@ -253,6 +249,22 @@
 	}
 }
 
+altstep as_SIP_expect_resp(template (present) PDU_SIP_Response sip_expect, boolean fail_others := true) runs on IMS_ConnHdlr
+{
+	var charstring sip_expect_str := log2str(sip_expect);
+	[] SIP.receive(sip_expect) -> value g_rx_sip_resp;
+	[fail_others] as_SIP_fail_resp(sip_expect_str);
+	[fail_others] as_SIP_fail_req(sip_expect_str);
+}
+
+altstep as_SIP_ignore_resp(template PDU_SIP_Response sip_expect := ?) runs on IMS_ConnHdlr
+{
+	[] SIP.receive(sip_expect) -> value g_rx_sip_resp {
+		log("Ignoring ", g_rx_sip_resp);
+		repeat;
+	}
+}
+
 private function f_nonce_from_rand_autn(octetstring rand, octetstring autn) return charstring {
 	var octetstring concat := rand & autn;
 	var charstring nonce := enc_MIME_Base64(concat);
@@ -510,6 +522,7 @@
 
 		contact := g_rx_sip_req.msgHeader.contact;
 		f_ims_validate_register_contact(contact);
+		g_pars.subscr.registered_contact := contact;
 
 		/* Validate P-Access-Network-Info: rfc7315 6.4:
 		 * "3GPP will use the P-Access-Network-Info header field to
@@ -722,6 +735,7 @@
 		for (var integer i := 0; i < lengthof(contact.contactBody.contactAddresses); i := i + 1) {
 			contact.contactBody.contactAddresses[i].contactParams := valueof({ ts_Param("expires", "0") });
 		}
+		g_pars.subscr.registered_contact := omit;
 		/* Tx 200 OK */
 		to_addr.toParams := f_sip_param_set(to_addr.toParams, "tag", f_sip_rand_tag());
 		tx_resp := ts_SIP_Response(sip_call_id,
@@ -743,6 +757,130 @@
 	[fail_others] as_SIP_fail_req(sip_expect_str);
 }
 
+function f_IMS_mt_call_setup() runs on IMS_ConnHdlr
+{
+	var template (value) PDU_SIP_Request req;
+	var template (present) PDU_SIP_Response exp;
+	var template (present) From from_addr_exp;
+	var template (present) To to_addr_exp;
+	var Via via;
+	var charstring tx_sdp := f_gen_sdp();
+	var default d_trying, d_ringing;
+	var charstring branch_value;
+	var Contact calling_contact;
+
+	/* RFC 3261 8.1.1.3 From */
+	g_pars.subscr.cp.from_addr := valueof(ts_From(g_pars.subscr.cp.calling.addr, g_pars.subscr.cp.calling.params));
+	g_pars.subscr.cp.from_addr.fromParams := f_sip_param_set(g_pars.subscr.cp.from_addr.fromParams, "tag", f_sip_rand_tag());
+	g_pars.subscr.cp.to_addr := valueof(ts_To(g_pars.subscr.cp.called.addr, g_pars.subscr.cp.called.params));
+	from_addr_exp := tr_From(tr_Addr_Union_from_val(g_pars.subscr.cp.from_addr.addressField), *);
+	to_addr_exp := tr_To(tr_Addr_Union_from_val(g_pars.subscr.cp.to_addr.addressField), *);
+	branch_value := f_sip_gen_branch(f_sip_Addr_Union_to_str(g_pars.subscr.cp.from_addr.addressField),
+					 f_sip_Addr_Union_to_str(valueof(g_pars.subscr.cp.to_addr.addressField)),
+					 g_pars.subscr.cp.sip_call_id,
+					 g_pars.subscr.cp.sip_seq_nr);
+	via := g_pars.local_via;
+	via.viaBody[0].viaParams := f_sip_param_set(via.viaBody[0].viaParams, "branch", branch_value);
+
+	calling_contact := valueof(ts_Contact({
+					ts_ContactAddress(g_pars.subscr.cp.calling.addr, omit)
+				}));
+
+	req := ts_SIP_INVITE(g_pars.subscr.cp.sip_call_id,
+			     g_pars.subscr.cp.from_addr,
+			     g_pars.subscr.cp.to_addr,
+			     via,
+			     calling_contact,
+			     g_pars.subscr.cp.sip_seq_nr,
+			     body := tx_sdp);
+
+	SIP.send(req);
+
+	/* Conditionally match and accept 100 Trying. */
+	exp := tr_SIP_Response_Trying(g_pars.subscr.cp.sip_call_id,
+			from_addr_exp,
+			to_addr_exp,
+			f_tr_Via_response(via),
+			g_pars.subscr.cp.sip_seq_nr, "INVITE");
+	d_trying := activate(as_SIP_ignore_resp(exp));
+
+	/* Conditionally match and accept 180 Ringing */
+	exp := tr_SIP_Response_Ringing(g_pars.subscr.cp.sip_call_id,
+			from_addr_exp,
+			to_addr_exp,
+			f_tr_Via_response(via),
+			g_pars.subscr.cp.sip_seq_nr, "INVITE");
+	d_ringing := activate(as_SIP_ignore_resp(exp));
+
+	/* Wait for OK answer */
+	exp := tr_SIP_Response(
+			g_pars.subscr.cp.sip_call_id,
+			from_addr_exp,
+			to_addr_exp,
+			f_tr_Via_response(via),
+			*,
+			"INVITE", 200,
+			g_pars.subscr.cp.sip_seq_nr, "OK",
+			body := ?);
+	as_SIP_expect_resp(exp, fail_others := false);
+
+	deactivate(d_trying);
+	deactivate(d_ringing);
+
+	/* Update To with the tags received from peer: */
+	g_pars.subscr.cp.to_addr := g_rx_sip_resp.msgHeader.toField;
+
+	/* Transmit ACK */
+	g_pars.subscr.cp.sip_seq_nr := g_pars.subscr.cp.sip_seq_nr + 1;
+	req := ts_SIP_ACK(g_pars.subscr.cp.sip_call_id,
+			  g_pars.subscr.cp.from_addr,
+			  g_pars.subscr.cp.to_addr,
+			  via,
+			  g_pars.subscr.cp.sip_seq_nr,
+			  omit);
+	SIP.send(req);
+	g_pars.subscr.cp.sip_seq_nr := g_pars.subscr.cp.sip_seq_nr + 1;
+}
+
+/* Tx BYE: */
+function f_IMS_do_call_hangup() runs on IMS_ConnHdlr
+{
+	var template (value) PDU_SIP_Request req;
+	var template (present) PDU_SIP_Response exp_resp;
+	var Via via;
+	var charstring branch_value;
+
+	branch_value := f_sip_gen_branch(f_sip_Addr_Union_to_str(g_pars.subscr.cp.from_addr.addressField),
+					 f_sip_Addr_Union_to_str(valueof(g_pars.subscr.cp.to_addr.addressField)),
+					 g_pars.subscr.cp.sip_call_id,
+					 g_pars.subscr.cp.sip_seq_nr);
+
+	via := g_pars.local_via;
+	via.viaBody[0].viaParams := f_sip_param_set(via.viaBody[0].viaParams, "branch", branch_value);
+
+	/* Transmit ACK */
+	req := ts_SIP_BYE(g_pars.subscr.cp.sip_call_id,
+			  g_pars.subscr.cp.from_addr,
+			  g_pars.subscr.cp.to_addr,
+			  via,
+			  g_pars.subscr.cp.sip_seq_nr,
+			  omit);
+	SIP.send(req);
+
+	/* Wait for OK answer */
+	exp_resp := tr_SIP_Response(
+			g_pars.subscr.cp.sip_call_id,
+			g_pars.subscr.cp.from_addr,
+			tr_To(tr_Addr_Union_from_val(g_pars.subscr.cp.to_addr.addressField), *),
+			f_tr_Via_response(via),
+			*,
+			"BYE", 200,
+			g_pars.subscr.cp.sip_seq_nr, "OK");
+	as_SIP_expect_resp(exp_resp);
+
+	g_pars.subscr.cp.sip_seq_nr := g_pars.subscr.cp.sip_seq_nr + 1;
+}
+
 private function f_ConnHdlr_parse_initial_SIP_INVITE(PDU_SIP_Request rx_sip_req) runs on IMS_ConnHdlr
 {
 	f_SDP_decodeMessage(rx_sip_req.messageBody, g_pars.subscr.cp.peer_sdp);
diff --git a/asterisk/SIP_ConnectionHandler.ttcn b/asterisk/SIP_ConnectionHandler.ttcn
index cd50be6..05f872f 100644
--- a/asterisk/SIP_ConnectionHandler.ttcn
+++ b/asterisk/SIP_ConnectionHandler.ttcn
@@ -90,6 +90,8 @@
 	charstring local_rtp_addr,
 	uint16_t local_rtp_port,
 
+	/* Whether to expect Asterisk to re-INVITE to make RTP flow directly to peer. */
+	boolean exp_update_to_direct_rtp,
 	SDP_Message peer_sdp optional,
 	CallParsMT mt
 }
@@ -107,6 +109,7 @@
 	sip_body := omit,
 	local_rtp_addr := local_rtp_addr,
 	local_rtp_port := local_rtp_port,
+	exp_update_to_direct_rtp := true,
 	peer_sdp := omit,
 	mt := t_CallParsMT
 }
diff --git a/asterisk/expected-results.xml b/asterisk/expected-results.xml
index 78c5ee4..44d6c01 100644
--- a/asterisk/expected-results.xml
+++ b/asterisk/expected-results.xml
@@ -7,4 +7,5 @@
     <testcase classname='Asterisk_Tests' name='TC_internal_call_all_4registered' time='MASKED'/>
     <testcase classname='Asterisk_Tests' name='TC_ims_registration' time='MASKED'/>
     <testcase classname='Asterisk_Tests' name='TC_ims_call_mo' time='MASKED'/>
+    <testcase classname='Asterisk_Tests' name='TC_ims_call_mt' time='MASKED'/>
 </testsuite>