diff --git a/include/osmocom/msc/Makefile.am b/include/osmocom/msc/Makefile.am
index 88305db..d31883a 100644
--- a/include/osmocom/msc/Makefile.am
+++ b/include/osmocom/msc/Makefile.am
@@ -20,6 +20,7 @@
 	mncc.h \
 	mncc_int.h \
 	msc_ifaces.h \
+	msc_mgcp.h \
 	oap_client.h \
 	openbscdefines.h \
 	a_reset.h \
diff --git a/include/osmocom/msc/gsm_data.h b/include/osmocom/msc/gsm_data.h
index 2cddd25..3f322b3 100644
--- a/include/osmocom/msc/gsm_data.h
+++ b/include/osmocom/msc/gsm_data.h
@@ -188,9 +188,17 @@
 	uint8_t n_sd_next[4];
 
 	struct {
+		struct mgcp_ctx *mgcp_ctx;
 		unsigned int mgcp_rtp_endpoint;
-		uint16_t port_subscr;
-		uint16_t port_cn;
+
+		uint16_t local_port_ran;
+		char local_addr_ran[INET_ADDRSTRLEN];
+		uint16_t remote_port_ran;
+		char remote_addr_ran[INET_ADDRSTRLEN];
+		uint16_t local_port_cn;
+		char local_addr_cn[INET_ADDRSTRLEN];
+		uint16_t remote_port_cn;
+		char remote_addr_cn[INET_ADDRSTRLEN];
 	} rtp;
 
 	/* which Iu-CS connection, if any. */
diff --git a/include/osmocom/msc/iucs.h b/include/osmocom/msc/iucs.h
index b7d6064..a48a316 100644
--- a/include/osmocom/msc/iucs.h
+++ b/include/osmocom/msc/iucs.h
@@ -1,7 +1,10 @@
 #pragma once
 
+#include <osmocom/msc/transaction.h>
+
 int gsm0408_rcvmsg_iucs(struct gsm_network *network, struct msgb *msg,
 			uint16_t *lac);
 
 struct gsm_subscriber_connection *subscr_conn_lookup_iu(struct gsm_network *network,
 							struct ranap_ue_conn_ctx *ue);
+int iu_rab_act_cs(struct gsm_trans *trans);
diff --git a/include/osmocom/msc/msc_ifaces.h b/include/osmocom/msc/msc_ifaces.h
index 0592c07..ca25e9d 100644
--- a/include/osmocom/msc/msc_ifaces.h
+++ b/include/osmocom/msc/msc_ifaces.h
@@ -37,7 +37,3 @@
 			     enum gsm48_reject_value value);
 
 int msc_tx_common_id(struct gsm_subscriber_connection *conn);
-int msc_call_assignment(struct gsm_trans *trans);
-int msc_call_bridge(struct gsm_trans *trans1, struct gsm_trans *trans2);
-void msc_call_release(struct gsm_trans *trans);
-int msc_call_connect(struct gsm_trans *trans, uint16_t port, uint32_t ip);
diff --git a/include/osmocom/msc/msc_mgcp.h b/include/osmocom/msc/msc_mgcp.h
new file mode 100644
index 0000000..ac3283c
--- /dev/null
+++ b/include/osmocom/msc/msc_mgcp.h
@@ -0,0 +1,56 @@
+/* (C) 2017 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
+ * All Rights Reserved
+ *
+ * Author: Philipp Maier
+ *
+ * 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/mgcp_client/mgcp_client.h>
+#include <osmocom/msc/gsm_data.h>
+
+/* MGCP state handler context. This context information stores all information
+ * to handle the direction of the RTP streams via MGCP. There is one instance
+ * of this context struct per subscriber connection.
+ * (see also struct gsm_subscriber_connection) */
+struct mgcp_ctx {
+	/* FSM instance, which handles the connection switching procedure */
+	struct osmo_fsm_inst *fsm;
+
+	/* RTP endpoint number. This number identifies the endpoint
+	 * on the MGW on which the RAN and CN connection is created. This
+	 * endpoint number is assigned and released automatically. */
+	uint16_t rtp_endpoint;
+
+	/* Set to true, when the context information is no longer needed */
+	bool free_ctx;
+
+	/* RTP connection identifiers */
+	char conn_id_ran[MGCP_CONN_ID_LENGTH];
+	char conn_id_cn[MGCP_CONN_ID_LENGTH];
+
+	/* Copy of the pointer and the data with context information
+	 * needed to process the AoIP and MGCP requests (system data) */
+	struct mgcp_client *mgcp;
+	struct gsm_trans *trans;
+	mgcp_trans_id_t mgw_pending_trans;
+};
+
+int msc_mgcp_call_assignment(struct gsm_trans *trans);
+int msc_mgcp_ass_complete(struct gsm_subscriber_connection *conn, uint16_t port, char *addr);
+int msc_mgcp_call_complete(struct gsm_trans *trans, uint16_t port, char *addr);
+int msc_mgcp_call_release(struct gsm_trans *trans);