diff --git a/src/osmo-bsc/Makefile.am b/src/osmo-bsc/Makefile.am
index ae9410c..5642fb2 100644
--- a/src/osmo-bsc/Makefile.am
+++ b/src/osmo-bsc/Makefile.am
@@ -14,6 +14,7 @@
 	$(LIBOSMOSCCP_CFLAGS) \
 	$(COVERAGE_CFLAGS) \
 	$(LIBOSMOABIS_CFLAGS) \
+	$(LIBOSMOSIGTRAN_CFLAGS) \
 	$(NULL)
 
 AM_LDFLAGS = \
@@ -30,7 +31,7 @@
 	osmo_bsc_api.c \
 	osmo_bsc_grace.c \
 	osmo_bsc_msc.c \
-	osmo_bsc_sccp.c \
+	osmo_bsc_sigtran.c \
 	osmo_bsc_filter.c \
 	osmo_bsc_bssap.c \
 	osmo_bsc_audio.c \
@@ -52,4 +53,5 @@
 	$(LIBOSMOCTRL_LIBS) \
 	$(COVERAGE_LDFLAGS) \
 	$(LIBOSMOABIS_LIBS) \
+	$(LIBOSMOSIGTRAN_LIBS) \
 	$(NULL)
diff --git a/src/osmo-bsc/osmo_bsc_api.c b/src/osmo-bsc/osmo_bsc_api.c
index 8c33e2b..f7343f7 100644
--- a/src/osmo-bsc/osmo_bsc_api.c
+++ b/src/osmo-bsc/osmo_bsc_api.c
@@ -27,6 +27,7 @@
 #include <osmocom/gsm/gsm0808.h>
 
 #include <osmocom/sccp/sccp.h>
+#include <openbsc/osmo_bsc_sigtran.h>
 
 #define return_when_not_connected(conn) \
 	if (!conn->sccp_con) {\
@@ -45,7 +46,7 @@
 		LOGP(DMSC, LOGL_ERROR, "Failed to allocate response.\n"); \
 		return; \
 	} \
-	bsc_queue_for_msc(conn->sccp_con, resp);
+	osmo_bsc_sigtran_send(conn->sccp_con, resp);
 
 static int bsc_clear_request(struct gsm_subscriber_connection *conn, uint32_t cause);
 static int complete_layer3(struct gsm_subscriber_connection *conn,
@@ -263,7 +264,8 @@
 	}
 
 	/* allocate resource for a new connection */
-	ret = bsc_create_new_connection(conn, msc, send_ping);
+	//ret = bsc_create_new_connection(conn, msc, send_ping);
+	ret = osmo_bsc_sigtran_new_conn(conn, msc);
 
 	if (ret != BSC_CON_SUCCESS) {
 		/* allocation has failed */
@@ -292,13 +294,13 @@
 	if (!resp) {
 		LOGP(DMSC, LOGL_DEBUG, "Failed to create layer3 message.\n");
 		sccp_connection_free(conn->sccp_con->sccp);
-		bsc_delete_connection(conn->sccp_con);
+		osmo_bsc_sigtran_del_conn(conn->sccp_con);
 		return BSC_API_CONN_POL_REJECT;
 	}
 
-	if (bsc_open_connection(conn->sccp_con, resp) != 0) {
+	if (osmo_bsc_sigtran_open_conn(conn->sccp_con, resp) != 0) {
 		sccp_connection_free(conn->sccp_con->sccp);
-		bsc_delete_connection(conn->sccp_con);
+		osmo_bsc_sigtran_del_conn(conn->sccp_con);
 		msgb_free(resp);
 		return BSC_API_CONN_POL_REJECT;
 	}
@@ -433,11 +435,28 @@
 	struct msgb *resp;
 	return_when_not_connected(conn);
 
-	LOGP(DMSC, LOGL_INFO, "Tx MSC ASSIGN COMPL\n");
+	if (is_ipaccess_bts(conn->bts) && conn->sccp_con->rtp_ip) {
+		/* NOTE: In a network that makes use of an IPA base station
+		 * and AoIP, we have to wait until the BTS reports its RTP
+		 * IP/Port combination back to BSC via RSL. Unfortunately, the
+		 * IPA protocol sends its Abis assignment complete message
+		 * before it sends its RTP IP/Port via IPACC. So we will now
+		 * postpone the AoIP assignment completed message until we
+		 * know the RTP IP/Port combination. */
+		LOGP(DMSC, LOGL_INFO, "POSTPONE MSC ASSIGN COMPL\n");
+		conn->lchan->abis_ip.ass_compl.rr_cause = rr_cause;
+		conn->lchan->abis_ip.ass_compl.chosen_channel = chosen_channel;
+		conn->lchan->abis_ip.ass_compl.encr_alg_id = encr_alg_id;
+		conn->lchan->abis_ip.ass_compl.speech_mode = speech_model;
+		conn->lchan->abis_ip.ass_compl.valid = true;
 
-	resp = gsm0808_create_assignment_completed(rr_cause, chosen_channel,
-						   encr_alg_id, speech_model);
-	queue_msg_or_return(resp);
+	} else {
+		/* NOTE: Send the A assignment complete message immediately. */
+		LOGP(DMSC, LOGL_INFO, "Tx MSC ASSIGN COMPL\n");
+		resp = gsm0808_create_assignment_completed(rr_cause, chosen_channel,
+							   encr_alg_id, speech_model);
+		queue_msg_or_return(resp);
+	}
 }
 
 static void bsc_assign_fail(struct gsm_subscriber_connection *conn,
@@ -474,7 +493,7 @@
 		return 1;
 	}
 
-	bsc_queue_for_msc(sccp, resp);
+	osmo_bsc_sigtran_send(sccp, resp);
 	return 1;
 }
 
diff --git a/src/osmo-bsc/osmo_bsc_audio.c b/src/osmo-bsc/osmo_bsc_audio.c
index 1160209..b4ffa88 100644
--- a/src/osmo-bsc/osmo_bsc_audio.c
+++ b/src/osmo-bsc/osmo_bsc_audio.c
@@ -26,15 +26,57 @@
 #include <openbsc/gsm_data.h>
 #include <openbsc/debug.h>
 #include <openbsc/signal.h>
+#include <osmocom/gsm/gsm0808.h>
+#include <osmocom/gsm/gsm0808_utils.h>
+#include <openbsc/osmo_bsc_sigtran.h>
 
 #include <arpa/inet.h>
 
+/* Generate and send assignment complete message */
+static int send_aoip_ass_compl(struct gsm_subscriber_connection *conn, struct gsm_lchan *lchan)
+{
+	struct msgb *resp;
+	struct sockaddr_storage rtp_addr;
+	struct sockaddr_in rtp_addr_in;
+	struct gsm0808_speech_codec sc;
+
+	OSMO_ASSERT(lchan->abis_ip.ass_compl.valid == true);
+
+	/* Package RTP-Address data */
+	memset(&rtp_addr_in, 0, sizeof(rtp_addr_in));
+	rtp_addr_in.sin_family = AF_INET;
+	rtp_addr_in.sin_port = htons(lchan->abis_ip.bound_port);
+	rtp_addr_in.sin_addr.s_addr = htonl(lchan->abis_ip.bound_ip);
+	memset(&rtp_addr, 0, sizeof(rtp_addr));
+	memcpy(&rtp_addr, &rtp_addr_in, sizeof(rtp_addr_in));
+
+	/* Extrapolate speech codec from speech mode */
+	gsm0808_speech_codec_from_chan_type(&sc, lchan->abis_ip.ass_compl.speech_mode);
+
+	/* Generate message */
+	resp = gsm0808_create_ass_compl(lchan->abis_ip.ass_compl.rr_cause,
+					lchan->abis_ip.ass_compl.chosen_channel,
+					lchan->abis_ip.ass_compl.encr_alg_id,
+					lchan->abis_ip.ass_compl.speech_mode,
+					&rtp_addr,
+					&sc,
+					NULL);
+
+	if (!resp) {
+		LOGP(DMSC, LOGL_ERROR, "Failed to generate assignment completed message!\n"); \
+		return -EINVAL;
+	}
+
+	return osmo_bsc_sigtran_send(conn->sccp_con, resp);
+}
+
 static int handle_abisip_signal(unsigned int subsys, unsigned int signal,
 				 void *handler_data, void *signal_data)
 {
 	struct gsm_subscriber_connection *con;
 	struct gsm_lchan *lchan = signal_data;
 	int rc;
+	uint32_t rtp_ip;
 
 	if (subsys != SS_ABISIP)
 		return 0;
@@ -49,11 +91,19 @@
 		 * TODO: handle handover here... then the audio should go to
 		 * the old mgcp port..
 		 */
+
 		/* we can ask it to connect now */
 		LOGP(DMSC, LOGL_DEBUG, "Connecting BTS to port: %d conn: %d\n",
 		     con->sccp_con->rtp_port, lchan->abis_ip.conn_id);
 
-		rc = rsl_ipacc_mdcx(lchan, ntohl(INADDR_ANY),
+		/* If AoIP is in use, the rtp_ip, which has been communicated
+		 * via the A interface as connect_ip */
+		if(con->sccp_con->rtp_ip)
+			rtp_ip = con->sccp_con->rtp_ip;
+		else
+			rtp_ip = ntohl(INADDR_ANY);
+
+		rc = rsl_ipacc_mdcx(lchan, rtp_ip,
 				    con->sccp_con->rtp_port,
 				    lchan->abis_ip.rtp_payload2);
 		if (rc < 0) {
@@ -61,6 +111,24 @@
 			return rc;
 		}
 		break;
+
+	case S_ABISIP_MDCX_ACK:
+		if (con->ho_lchan) {
+			/* NOTE: When an ho_lchan exists, the MDCX is part of an
+			 * handover operation (intra-bsc). This means we will not
+			 * inform the MSC about the event, which means that no
+			 * assignment complete message is transmitted */
+			LOGP(DMSC, LOGL_INFO," RTP connection handover complete\n");
+		} else if (is_ipaccess_bts(con->bts) && con->sccp_con->rtp_ip) {
+			/* NOTE: This is only relevant on AoIP networks with
+			 * IPA based base stations. See also osmo_bsc_api.c,
+			 * function bsc_assign_compl() */
+			LOGP(DMSC, LOGL_INFO, "Tx MSC ASSIGN COMPL (POSTPONED)\n");
+			if (send_aoip_ass_compl(con, lchan) != 0)
+				return -EINVAL;
+		}
+		break;
+	break;
 	}
 
 	return 0;
diff --git a/src/osmo-bsc/osmo_bsc_bssap.c b/src/osmo-bsc/osmo_bsc_bssap.c
index 100f664..4353b9a 100644
--- a/src/osmo-bsc/osmo_bsc_bssap.c
+++ b/src/osmo-bsc/osmo_bsc_bssap.c
@@ -29,11 +29,21 @@
 
 #include <osmocom/gsm/protocol/gsm_08_08.h>
 #include <osmocom/gsm/gsm0808.h>
+#include <osmocom/gsm/gsm0808_utils.h>
+#include <openbsc/osmo_bsc_sigtran.h>
+#include <openbsc/a_reset.h>
+#include <osmocom/core/byteswap.h>
+
+#define IP_V4_ADDR_LEN 4
 
 /*
  * helpers for the assignment command
  */
-enum gsm0808_permitted_speech audio_support_to_gsm88(struct gsm_audio_support *audio)
+
+/* Helper function for match_codec_pref(), looks up a matching permitted speech
+ * value for a given msc audio codec pref */
+enum gsm0808_permitted_speech audio_support_to_gsm88(struct gsm_audio_support
+						     *audio)
 {
 	if (audio->hr) {
 		switch (audio->ver) {
@@ -47,8 +57,9 @@
 			return GSM0808_PERM_HR3;
 			break;
 		default:
-			    LOGP(DMSC, LOGL_ERROR, "Wrong speech mode: %d\n", audio->ver);
-			    return GSM0808_PERM_FR1;
+			LOGP(DMSC, LOGL_ERROR, "Wrong speech mode: %d\n",
+			     audio->ver);
+			return GSM0808_PERM_FR1;
 		}
 	} else {
 		switch (audio->ver) {
@@ -62,12 +73,15 @@
 			return GSM0808_PERM_FR3;
 			break;
 		default:
-			LOGP(DMSC, LOGL_ERROR, "Wrong speech mode: %d\n", audio->ver);
+			LOGP(DMSC, LOGL_ERROR, "Wrong speech mode: %d\n",
+			     audio->ver);
 			return GSM0808_PERM_HR1;
 		}
 	}
 }
 
+/* Helper function for match_codec_pref(), looks up a matching chan mode for
+ * a given permitted speech value */
 enum gsm48_chan_mode gsm88_to_chan_mode(enum gsm0808_permitted_speech speech)
 {
 	switch (speech) {
@@ -83,16 +97,130 @@
 	case GSM0808_PERM_FR3:
 		return GSM48_CMODE_SPEECH_AMR;
 		break;
+	default:
+		LOGP(DMSC, LOGL_FATAL,
+		     "Unsupported permitted speech selected, assuming AMR as channel mode...\n");
+		return GSM48_CMODE_SPEECH_AMR;
+	}
+}
+
+/* Helper function for match_codec_pref(), tests if a given audio support
+ * matches one of the permitted speech settings of the channel type element.
+ * The matched permitted speech value is then also compared against the
+ * speech codec list. (optional, only relevant for AoIP) */
+static bool test_codec_pref(const struct gsm0808_channel_type *ct,
+			    const struct gsm0808_speech_codec_list *scl,
+			    uint8_t perm_spch)
+{
+	unsigned int i;
+	bool match = false;
+	struct gsm0808_speech_codec sc;
+	int rc;
+
+	/* Try to finde the given permitted speech value in the
+	 * codec list of the channel type element */
+	for (i = 0; i < ct->perm_spch_len; i++) {
+		if (ct->perm_spch[i] == perm_spch) {
+			match = true;
+			break;
+		}
 	}
 
-	LOGP(DMSC, LOGL_FATAL, "Should not be reached.\n");
-	return GSM48_CMODE_SPEECH_AMR;
+	/* If we do not have a speech codec list to test against,
+	 * we just exit early (will be always the case in non-AoIP networks) */
+	if (!scl)
+		return match;
+
+	/* If we failed to match until here, there is no
+	 * point in testing further */
+	if (match == false)
+		return false;
+
+	/* Extrapolate speech codec data */
+	rc = gsm0808_speech_codec_from_chan_type(&sc, perm_spch);
+	if (rc < 0)
+		return false;
+
+	/* Try to find extrapolated speech codec data in
+	 * the speech codec list */
+	for (i = 0; i < scl->len; i++) {
+		if (memcmp(&sc, &scl->codec[i], sizeof(sc)) == 0)
+			return true;
+	}
+
+	return false;
+}
+
+/* Helper function for bssmap_handle_assignm_req(), matches the codec
+ * preferences from the MSC with the codec preferences */
+static int match_codec_pref(int *full_rate, enum gsm48_chan_mode *chan_mode,
+			    const struct gsm0808_channel_type *ct,
+			    const struct gsm0808_speech_codec_list *scl,
+			    const struct bsc_msc_data *msc)
+{
+	unsigned int i;
+	uint8_t perm_spch;
+	bool match = false;
+
+	for (i = 0; i < msc->audio_length; i++) {
+		perm_spch = audio_support_to_gsm88(msc->audio_support[i]);
+		if (test_codec_pref(ct, scl, perm_spch)) {
+			match = true;
+			break;
+		}
+	}
+
+	/* Exit without result, in case no match can be deteched */
+	if (!match) {
+		*full_rate = -1;
+		*chan_mode = GSM48_CMODE_SIGN;
+		return -1;
+	}
+
+	/* Check if the result is a half or full rate codec */
+	if (perm_spch == GSM0808_PERM_HR1 || perm_spch == GSM0808_PERM_HR2
+	    || perm_spch == GSM0808_PERM_HR3 || perm_spch == GSM0808_PERM_HR4
+	    || perm_spch == GSM0808_PERM_HR6)
+		*full_rate = 0;
+	else
+		*full_rate = 1;
+
+	/* Lookup a channel mode for the selected codec */
+	*chan_mode = gsm88_to_chan_mode(perm_spch);
+
+	return 0;
 }
 
 static int bssmap_handle_reset_ack(struct bsc_msc_data *msc,
 				   struct msgb *msg, unsigned int length)
 {
-	LOGP(DMSC, LOGL_NOTICE, "Reset ACK from MSC\n");
+	LOGP(DMSC, LOGL_NOTICE, "RESET ACK from MSC: %s\n",
+	     osmo_sccp_addr_name(osmo_ss7_instance_find(msc->a.cs7_instance),
+				 &msc->a.msc_addr));
+
+	/* Inform the FSM that controls the RESET/RESET-ACK procedure
+	 * that we have successfully received the reset-ack message */
+	a_reset_ack_confirm(msc->a.reset);
+
+	return 0;
+}
+
+/* Handle MSC sided reset */
+static int bssmap_handle_reset(struct bsc_msc_data *msc,
+			       struct msgb *msg, unsigned int length)
+{
+	LOGP(DMSC, LOGL_NOTICE, "RESET from MSC: %s\n",
+	     osmo_sccp_addr_name(osmo_ss7_instance_find(msc->a.cs7_instance),
+				 &msc->a.msc_addr));
+
+	/* Instruct the bsc to close all open sigtran connections and to
+	 * close all active channels on the BTS side as well */
+	osmo_bsc_sigtran_reset(msc);
+
+	/* Inform the MSC that we have received the reset request and
+	 * that we acted accordingly */
+	osmo_bsc_sigtran_tx_reset_ack(msc);
+
 	return 0;
 }
 
@@ -199,7 +327,7 @@
 		return -1;
 	}
 
-	bsc_queue_for_msc(conn, resp);
+	osmo_bsc_sigtran_send(conn, resp);
 	return 0;
 }
 
@@ -276,7 +404,7 @@
 		return -1;
 	}
 
-	bsc_queue_for_msc(conn, resp);
+	osmo_bsc_sigtran_send(conn, resp);
 	return -1;
 }
 
@@ -291,99 +419,141 @@
 	struct msgb *resp;
 	struct bsc_msc_data *msc;
 	struct tlv_parsed tp;
-	uint8_t *data;
-	uint8_t timeslot;
-	uint8_t multiplex;
+	uint8_t timeslot = 0;
+	uint8_t multiplex = 0;
 	enum gsm48_chan_mode chan_mode = GSM48_CMODE_SIGN;
-	int i, supported, port, full_rate = -1;
+	int port, full_rate = -1;
+	bool aoip = false;
+	struct sockaddr_storage rtp_addr;
+	struct sockaddr_in *rtp_addr_in;
+	struct gsm0808_channel_type ct;
+	struct gsm0808_speech_codec_list scl;
+	struct gsm0808_speech_codec_list *scl_ptr = NULL;
+	int rc;
+	const uint8_t *data;
+	char len;
 
 	if (!conn->conn) {
-		LOGP(DMSC, LOGL_ERROR, "No lchan/msc_data in cipher mode command.\n");
+		LOGP(DMSC, LOGL_ERROR,
+		     "No lchan/msc_data in cipher mode command.\n");
 		return -1;
 	}
 
+	msc = conn->msc;
+
 	tlv_parse(&tp, gsm0808_att_tlvdef(), msg->l4h + 1, length - 1, 0, 0);
 
+	/* Check for channel type element, if its missing, immediately reject */
 	if (!TLVP_PRESENT(&tp, GSM0808_IE_CHANNEL_TYPE)) {
 		LOGP(DMSC, LOGL_ERROR, "Mandatory channel type not present.\n");
 		goto reject;
 	}
 
-	if (!TLVP_PRESENT(&tp, GSM0808_IE_CIRCUIT_IDENTITY_CODE)) {
-		LOGP(DMSC, LOGL_ERROR, "Identity code missing. Audio routing will not work.\n");
-		goto reject;
-	}
-
-	conn->cic = osmo_load16be(TLVP_VAL(&tp, GSM0808_IE_CIRCUIT_IDENTITY_CODE));
-	timeslot = conn->cic & 0x1f;
-	multiplex = (conn->cic & ~0x1f) >> 5;
-
-	/*
-	 * Currently we only support a limited subset of all
-	 * possible channel types. The limitation ends by not using
-	 * multi-slot, limiting the channel coding, speech...
-	 */
-	if (TLVP_LEN(&tp, GSM0808_IE_CHANNEL_TYPE) < 3) {
-		LOGP(DMSC, LOGL_ERROR, "ChannelType len !=3 not supported: %d\n",
-			TLVP_LEN(&tp, GSM0808_IE_CHANNEL_TYPE));
-		goto reject;
-	}
-
-	/*
-	 * Try to figure out if we support the proposed speech codecs. For
-	 * now we will always pick the full rate codecs.
-	 */
-
-	data = (uint8_t *) TLVP_VAL(&tp, GSM0808_IE_CHANNEL_TYPE);
-	if ((data[0] & 0xf) != 0x1) {
-		LOGP(DMSC, LOGL_ERROR, "ChannelType != speech: %d\n", data[0]);
-		goto reject;
-	}
-
-	/*
-	 * go through the list of preferred codecs of our gsm network
-	 * and try to find it among the permitted codecs. If we found
-	 * it we will send chan_mode to the right mode and break the
-	 * inner loop. The outer loop will exit due chan_mode having
-	 * the correct value.
-	 */
-	full_rate = 0;
-	msc = conn->msc;
-	for (supported = 0;
-		chan_mode == GSM48_CMODE_SIGN && supported < msc->audio_length;
-		++supported) {
-
-		int perm_val = audio_support_to_gsm88(msc->audio_support[supported]);
-		for (i = 2; i < TLVP_LEN(&tp, GSM0808_IE_CHANNEL_TYPE); ++i) {
-			if ((data[i] & 0x7f) == perm_val) {
-				chan_mode = gsm88_to_chan_mode(perm_val);
-				full_rate = (data[i] & 0x4) == 0;
-				break;
-			} else if ((data[i] & 0x80) == 0x00) {
-				break;
-			}
+	/* Detect if a CIC code is present, if so, we use the classic ip.access
+	 * method to calculate the RTP port */
+	if (TLVP_PRESENT(&tp, GSM0808_IE_CIRCUIT_IDENTITY_CODE)) {
+		conn->cic =
+		    osmo_load16be(TLVP_VAL
+				  (&tp, GSM0808_IE_CIRCUIT_IDENTITY_CODE));
+		timeslot = conn->cic & 0x1f;
+		multiplex = (conn->cic & ~0x1f) >> 5;
+	} else if (TLVP_PRESENT(&tp, GSM0808_IE_AOIP_TRASP_ADDR)) {
+		/* Decode AoIP transport address element */
+		data = TLVP_VAL(&tp, GSM0808_IE_AOIP_TRASP_ADDR);
+		len = TLVP_LEN(&tp, GSM0808_IE_AOIP_TRASP_ADDR);
+		rc = gsm0808_dec_aoip_trasp_addr(&rtp_addr, data, len);
+		if (rc < 0) {
+			LOGP(DMSC, LOGL_ERROR,
+			     "Unable to decode aoip transport address.\n");
+			goto reject;
 		}
+		aoip = true;
+	} else {
+		LOGP(DMSC, LOGL_ERROR,
+		     "transport address missing. Audio routing will not work.\n");
+		goto reject;
 	}
 
-	if (chan_mode == GSM48_CMODE_SIGN) {
+	/* Decode speech codec list (AoIP) */
+	if (aoip) {
+		/* Check for speech codec list element */
+		if (!TLVP_PRESENT(&tp, GSM0808_IE_SPEECH_CODEC_LIST)) {
+			LOGP(DMSC, LOGL_ERROR,
+			     "Mandatory speech codec list not present.\n");
+			goto reject;
+		}
+
+		/* Decode Speech Codec list */
+		data = TLVP_VAL(&tp, GSM0808_IE_SPEECH_CODEC_LIST);
+		len = TLVP_LEN(&tp, GSM0808_IE_SPEECH_CODEC_LIST);
+		rc = gsm0808_dec_speech_codec_list(&scl, data, len);
+		if (rc < 0) {
+			LOGP(DMSC, LOGL_ERROR,
+			     "Unable to decode speech codec list\n");
+			goto reject;
+		}
+		scl_ptr = &scl;
+	}
+
+	/* Decode Channel Type element */
+	data = TLVP_VAL(&tp, GSM0808_IE_CHANNEL_TYPE);
+	len = TLVP_LEN(&tp, GSM0808_IE_CHANNEL_TYPE);
+	rc = gsm0808_dec_channel_type(&ct, data, len);
+	if (rc < 0) {
+		LOGP(DMSC, LOGL_ERROR, "unable to decode channel type.\n");
+		goto reject;
+	}
+
+	/* Currently we only support a limited subset of all
+	 * possible channel types. The limitation ends by not using
+	 * multi-slot, limiting the channel coding to speech */
+	if (ct.ch_indctr != GSM0808_CHAN_SPEECH) {
+		LOGP(DMSC, LOGL_ERROR,
+		     "Unsupported channel type, currently only speech is supported!\n");
+		goto reject;
+	}
+
+	/* Match codec information from the assignment command against the
+	 * local preferences of the BSC */
+	rc = match_codec_pref(&full_rate, &chan_mode, &ct, scl_ptr, msc);
+	if (rc < 0) {
 		LOGP(DMSC, LOGL_ERROR, "No supported audio type found.\n");
 		goto reject;
 	}
 
-	/* map it to a MGCP Endpoint and a RTP port */
-	port = mgcp_timeslot_to_endpoint(multiplex, timeslot);
-	conn->rtp_port = rtp_calculate_port(port, msc->rtp_base);
+	if (aoip == false) {
+		/* map it to a MGCP Endpoint and a RTP port */
+		port = mgcp_timeslot_to_endpoint(multiplex, timeslot);
+		conn->rtp_port = rtp_calculate_port(port, msc->rtp_base);
+		conn->rtp_ip = 0;
+	} else {
+		/* use address / port supplied with the AoIP
+		 * transport address element */
+		if (rtp_addr.ss_family == AF_INET) {
+			rtp_addr_in = (struct sockaddr_in *)&rtp_addr;
+			conn->rtp_port = osmo_ntohs(rtp_addr_in->sin_port);
+			memcpy(&conn->rtp_ip, &rtp_addr_in->sin_addr.s_addr,
+			       IP_V4_ADDR_LEN);
+			conn->rtp_ip = osmo_ntohl(conn->rtp_ip);
+		} else {
+			LOGP(DMSC, LOGL_ERROR,
+			     "Unsopported addressing scheme. (supports only IPV4)\n");
+			goto reject;
+		}
+	}
 
 	return gsm0808_assign_req(conn->conn, chan_mode, full_rate);
 
 reject:
-	resp = gsm0808_create_assignment_failure(GSM0808_CAUSE_NO_RADIO_RESOURCE_AVAILABLE, NULL);
+	resp =
+	    gsm0808_create_assignment_failure
+	    (GSM0808_CAUSE_NO_RADIO_RESOURCE_AVAILABLE, NULL);
 	if (!resp) {
 		LOGP(DMSC, LOGL_ERROR, "Channel allocation failure.\n");
 		return -1;
 	}
 
-	bsc_queue_for_msc(conn, resp);
+	osmo_bsc_sigtran_send(conn, resp);
 	return -1;
 }
 
@@ -404,6 +574,9 @@
 	case BSS_MAP_MSG_RESET_ACKNOWLEDGE:
 		ret = bssmap_handle_reset_ack(msc, msg, length);
 		break;
+	case BSS_MAP_MSG_RESET:
+		ret = bssmap_handle_reset(msc, msg, length);
+		break;
 	case BSS_MAP_MSG_PAGING:
 		ret = bssmap_handle_paging(msc, msg, length);
 		break;
@@ -524,8 +697,8 @@
 	return 0;
 }
 
-int bsc_handle_dt1(struct osmo_bsc_sccp_con *conn,
-		   struct msgb *msg, unsigned int len)
+int bsc_handle_dt(struct osmo_bsc_sccp_con *conn,
+		  struct msgb *msg, unsigned int len)
 {
 	if (len < sizeof(struct bssmap_header)) {
 		LOGP(DMSC, LOGL_ERROR, "The header is too short.\n");
diff --git a/src/osmo-bsc/osmo_bsc_main.c b/src/osmo-bsc/osmo_bsc_main.c
index 90651b9..cf188a9 100644
--- a/src/osmo-bsc/osmo_bsc_main.c
+++ b/src/osmo-bsc/osmo_bsc_main.c
@@ -28,6 +28,7 @@
 #include <openbsc/vty.h>
 #include <openbsc/ipaccess.h>
 #include <openbsc/ctrl.h>
+#include <openbsc/osmo_bsc_sigtran.h>
 
 #include <osmocom/ctrl/control_cmd.h>
 #include <osmocom/ctrl/control_if.h>
@@ -217,6 +218,10 @@
 	bsc_msg_lst_vty_init(tall_bsc_ctx, &access_lists, BSC_NODE);
 	ctrl_vty_init(tall_bsc_ctx);
 
+	/* Initalize SS7 */
+	osmo_ss7_init();
+	osmo_ss7_vty_init_asp(tall_bsc_ctx);
+
 	INIT_LLIST_HEAD(&access_lists);
 
 	/* parse options */
@@ -269,9 +274,8 @@
 		}
 	}
 
-
-	if (osmo_bsc_sccp_init(bsc_gsmnet) != 0) {
-		LOGP(DNM, LOGL_ERROR, "Failed to register SCCP.\n");
+	if (osmo_bsc_sigtran_init(&bsc_gsmnet->bsc_data->mscs) != 0) {
+		LOGP(DNM, LOGL_ERROR, "Failed to initalize sigtran backhaul.\n");
 		exit(1);
 	}
 
diff --git a/src/osmo-bsc/osmo_bsc_msc.c b/src/osmo-bsc/osmo_bsc_msc.c
index 8d02624..351fd2c 100644
--- a/src/osmo-bsc/osmo_bsc_msc.c
+++ b/src/osmo-bsc/osmo_bsc_msc.c
@@ -42,7 +42,7 @@
 #include <netinet/tcp.h>
 #include <unistd.h>
 
-
+#if 0
 static void initialize_if_needed(struct bsc_msc_connection *conn);
 static void send_lacs(struct gsm_network *net, struct bsc_msc_connection *conn);
 static void send_id_get_response(struct bsc_msc_data *data, int fd, struct msgb *inp);
@@ -52,6 +52,8 @@
 /*
  * MGCP forwarding code
  */
+
+#endif
 static int mgcp_do_read(struct osmo_fd *fd)
 {
 	struct bsc_msc_data *data = (struct bsc_msc_data *) fd->data;
@@ -93,6 +95,7 @@
 	return ret;
 }
 
+#if 0
 static void mgcp_forward(struct bsc_msc_data *data, struct msgb *msg)
 {
 	struct msgb *mgcp;
@@ -115,6 +118,7 @@
 		msgb_free(mgcp);
 	}
 }
+#endif
 
 static int mgcp_create_port(struct bsc_msc_data *data)
 {
@@ -168,6 +172,7 @@
 	return 0;
 }
 
+
 /*
  * Send data to the network
  */
@@ -183,6 +188,7 @@
 	return 0;
 }
 
+#if 0
 int msc_queue_write_with_ping(struct bsc_msc_connection *conn,
 			struct msgb *msg, int proto)
 {
@@ -356,10 +362,10 @@
 
 static void msc_pong_timeout_cb(void *_data)
 {
-	struct bsc_msc_data *data = (struct bsc_msc_data *) _data;
+//	struct bsc_msc_data *data = (struct bsc_msc_data *) _data;
 
 	LOGP(DMSC, LOGL_ERROR, "MSC didn't answer PING. Closing connection.\n");
-	bsc_msc_lost(data->msc_con);
+//	bsc_msc_lost(data->msc_con);
 }
 
 static void msc_connection_connected(struct bsc_msc_connection *con)
@@ -368,12 +374,12 @@
 	struct bsc_msc_data *data;
 	int ret, on;
 	on = 1;
-	ret = setsockopt(con->write_queue.bfd.fd, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on));
-	if (ret != 0)
-                LOGP(DMSC, LOGL_ERROR, "Failed to set TCP_NODELAY: %s\n", strerror(errno));
+//	ret = setsockopt(con->write_queue.bfd.fd, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on));
+//	if (ret != 0)
+//                LOGP(DMSC, LOGL_ERROR, "Failed to set TCP_NODELAY: %s\n", strerror(errno));
 
-	data = (struct bsc_msc_data *) con->write_queue.bfd.data;
-	msc_ping_timeout_cb(data);
+//	data = (struct bsc_msc_data *) con->write_queue.bfd.data;
+//	msc_ping_timeout_cb(data);
 
 	sig.data = data;
 	osmo_signal_dispatch(SS_MSC, S_MSC_CONNECTED, &sig);
@@ -385,20 +391,20 @@
  */
 static void msc_connection_was_lost(struct bsc_msc_connection *msc)
 {
-	struct msc_signal_data sig;
-	struct bsc_msc_data *data;
+//	struct msc_signal_data sig;
+//	struct bsc_msc_data *data;
 
 	LOGP(DMSC, LOGL_ERROR, "Lost MSC connection. Freing stuff.\n");
 
-	data = (struct bsc_msc_data *) msc->write_queue.bfd.data;
-	osmo_timer_del(&data->ping_timer);
-	osmo_timer_del(&data->pong_timer);
-
-	sig.data = data;
-	osmo_signal_dispatch(SS_MSC, S_MSC_LOST, &sig);
+//	data = (struct bsc_msc_data *) msc->write_queue.bfd.data;
+//	osmo_timer_del(&data->ping_timer);
+//	osmo_timer_del(&data->pong_timer);
+//
+//	sig.data = data;
+//	osmo_signal_dispatch(SS_MSC, S_MSC_LOST, &sig);
 
 	msc->is_authenticated = 0;
-	bsc_msc_schedule_connect(msc);
+//	bsc_msc_schedule_connect(msc);
 }
 
 static void send_lacs(struct gsm_network *net, struct bsc_msc_connection *conn)
@@ -515,6 +521,8 @@
 	osmo_signal_dispatch(SS_MSC, S_MSC_AUTHENTICATED, &sig);
 }
 
+#endif 
+
 int osmo_bsc_msc_init(struct bsc_msc_data *data)
 {
 	if (mgcp_create_port(data) != 0)
@@ -526,19 +534,24 @@
 		return -1;
 	}
 
-	osmo_timer_setup(&data->ping_timer, msc_ping_timeout_cb, data);
-	osmo_timer_setup(&data->pong_timer, msc_pong_timeout_cb, data);
+//	osmo_timer_setup(&data->ping_timer, msc_ping_timeout_cb, data);
+//	osmo_timer_setup(&data->pong_timer, msc_pong_timeout_cb, data);
 
 	data->msc_con->write_queue.bfd.data = data;
-	data->msc_con->connection_loss = msc_connection_was_lost;
-	data->msc_con->connected = msc_connection_connected;
-	data->msc_con->write_queue.read_cb = ipaccess_a_fd_cb;
-	data->msc_con->write_queue.write_cb = msc_alink_do_write;
-	bsc_msc_connect(data->msc_con);
+//	data->msc_con->connection_loss = msc_connection_was_lost;
+//	data->msc_con->connected = msc_connection_connected;
+//	data->msc_con->write_queue.read_cb = ipaccess_a_fd_cb;
+//	data->msc_con->write_queue.write_cb = msc_alink_do_write;
+//	bsc_msc_connect(data->msc_con);
+
+	data->msc_con->is_connected = 1;
+	data->msc_con->is_authenticated = 1;
+
 
 	return 0;
 }
 
+
 struct bsc_msc_data *osmo_msc_data_find(struct gsm_network *net, int nr)
 {
 	struct bsc_msc_data *msc_data;
@@ -584,3 +597,4 @@
 
 	return msc_data;
 }
+
diff --git a/src/osmo-bsc/osmo_bsc_reset.c b/src/osmo-bsc/osmo_bsc_reset.c
new file mode 100644
index 0000000..0baf080
--- /dev/null
+++ b/src/osmo-bsc/osmo_bsc_reset.c
@@ -0,0 +1,190 @@
+/* (C) 2017 by sysmocom s.f.m.c. GmbH
+ * 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/>.
+ *
+ */
+
+#include <osmocom/core/logging.h>
+#include <osmocom/core/utils.h>
+#include <osmocom/core/timer.h>
+#include <osmocom/core/fsm.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <openbsc/debug.h>
+#include <openbsc/bsc_msc_data.h>
+#include <openbsc/osmo_bsc_sigtran.h>
+
+#define RESET_RESEND_INTERVAL 2	/* sec */
+#define RESET_RESEND_TIMER_NO 1234	/* FIXME: dig out the real timer number */
+#define BAD_CONNECTION_THRESOLD 3	/* connection failures */
+
+enum fsm_states {
+	ST_DISC,		/* Disconnected from MSC */
+	ST_CONN,		/* We have a confirmed connection to the MSC */
+};
+
+static const struct value_string fsm_state_names[] = {
+	{ST_DISC, "ST_DISC (disconnected)"},
+	{ST_CONN, "ST_CONN (connected)"},
+	{0, NULL},
+};
+
+enum fsm_evt {
+	EV_RESET_ACK,		/* got reset acknowlegement from the MSC */
+	EV_N_DISCONNECT,	/* lost a connection */
+	EV_N_CONNECT,		/* made a successful connection */
+};
+
+static const struct value_string fsm_evt_names[] = {
+	{EV_RESET_ACK, "EV_RESET_ACK"},
+	{EV_N_DISCONNECT, "EV_N_DISCONNECT"},
+	{EV_N_CONNECT, "EV_N_CONNECT"},
+	{0, NULL},
+};
+
+/* Disconnected state */
+static void fsm_disc_cb(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+	struct bsc_msc_data *msc = (struct bsc_msc_data *)data;
+
+	LOGP(DMSC, LOGL_NOTICE, "fsm-state (msc-reset): %s, fsm-event: %s, MSC No.: %i\n",
+	     get_value_string(fsm_state_names, ST_DISC), get_value_string(fsm_evt_names, event), msc->nr);
+	msc->msc_con->msc_conn_loss_count = 0;
+	osmo_fsm_inst_state_chg(fi, ST_CONN, 0, 0);
+}
+
+/* Connected state */
+static void fsm_conn_cb(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+	struct bsc_msc_data *msc = (struct bsc_msc_data *)data;
+
+	LOGP(DMSC, LOGL_NOTICE, "fsm-state (msc-reset): %s, fsm-event: %s, MSC No.: %i\n",
+	     get_value_string(fsm_state_names, ST_CONN), get_value_string(fsm_evt_names, event), msc->nr);
+
+	OSMO_ASSERT(msc);
+
+	switch (event) {
+	case EV_N_DISCONNECT:
+		if (msc->msc_con->msc_conn_loss_count >= BAD_CONNECTION_THRESOLD) {
+			LOGP(DMSC, LOGL_NOTICE, "SIGTRAN connection to MSC No.: %i down, reconnecting...\n", msc->nr);
+			osmo_fsm_inst_state_chg(fi, ST_DISC, RESET_RESEND_INTERVAL, RESET_RESEND_TIMER_NO);
+		} else
+			msc->msc_con->msc_conn_loss_count++;
+		break;
+	case EV_N_CONNECT:
+		msc->msc_con->msc_conn_loss_count = 0;
+		break;
+	}
+}
+
+/* Timer callback to retransmit the reset signal */
+static int fsm_reset_ack_timeout_cb(struct osmo_fsm_inst *fi)
+{
+	struct bsc_msc_data *msc = (struct bsc_msc_data *)fi->priv;
+
+	LOGP(DMSC, LOGL_NOTICE, "reset-ack timeout (T%i) in state %s, MSC No.: %i, resending...\n", fi->T,
+	     get_value_string(fsm_state_names, fi->state), msc->nr);
+
+	osmo_bsc_sigtran_reset(msc);
+	osmo_bsc_sigtran_tx_reset(msc);
+
+	osmo_fsm_inst_state_chg(fi, ST_DISC, RESET_RESEND_INTERVAL, RESET_RESEND_TIMER_NO);
+	return 0;
+}
+
+static struct osmo_fsm_state fsm_states[] = {
+	[ST_DISC] = {
+		     .in_event_mask = (1 << EV_RESET_ACK),
+		     .out_state_mask = (1 << ST_DISC) | (1 << ST_CONN),
+		     .name = "DISC",
+		     .action = fsm_disc_cb,
+		     },
+	[ST_CONN] = {
+		     .in_event_mask = (1 << EV_N_DISCONNECT) | (1 << EV_N_CONNECT),
+		     .out_state_mask = (1 << ST_DISC) | (1 << ST_CONN),
+		     .name = "CONN",
+		     .action = fsm_conn_cb,
+		     },
+};
+
+/* State machine definition */
+static struct osmo_fsm fsm = {
+	.name = "FSM RESET",
+	.states = fsm_states,
+	.num_states = ARRAY_SIZE(fsm_states),
+	.log_subsys = DMSC,
+	.timer_cb = fsm_reset_ack_timeout_cb,
+};
+
+/* Create and start state machine which handles the reset/reset-ack procedure */
+void start_reset_fsm(struct bsc_msc_data *msc)
+{
+	OSMO_ASSERT(msc);
+	OSMO_ASSERT(msc->msc_con);
+
+	osmo_fsm_register(&fsm);
+	msc->msc_con->fsm_reset = osmo_fsm_inst_alloc(&fsm, NULL, NULL, LOGL_DEBUG, "FSM RESET INST");
+	OSMO_ASSERT(msc->msc_con->fsm_reset);
+
+	msc->msc_con->fsm_reset->priv = msc;
+
+	/* kick off reset-ack sending mechanism */
+	osmo_fsm_inst_state_chg(msc->msc_con->fsm_reset, ST_DISC, RESET_RESEND_INTERVAL, RESET_RESEND_TIMER_NO);
+}
+
+/* Confirm that we sucessfully received a reset acknowlege message */
+void reset_ack_confirm(struct bsc_msc_data *msc)
+{
+	OSMO_ASSERT(msc);
+	OSMO_ASSERT(msc->msc_con);
+	OSMO_ASSERT(msc->msc_con->fsm_reset);
+
+	osmo_fsm_inst_dispatch(msc->msc_con->fsm_reset, EV_RESET_ACK, msc);
+}
+
+/* Report a failed connection */
+void report_conn_fail(struct bsc_msc_data *msc)
+{
+	OSMO_ASSERT(msc);
+	OSMO_ASSERT(msc->msc_con);
+	OSMO_ASSERT(msc->msc_con->fsm_reset);
+
+	osmo_fsm_inst_dispatch(msc->msc_con->fsm_reset, EV_N_DISCONNECT, msc);
+}
+
+/* Report a successful connection */
+void report_conn_success(struct bsc_msc_data *msc)
+{
+	OSMO_ASSERT(msc);
+	OSMO_ASSERT(msc->msc_con);
+	OSMO_ASSERT(msc->msc_con->fsm_reset);
+
+	osmo_fsm_inst_dispatch(msc->msc_con->fsm_reset, EV_N_CONNECT, msc);
+}
+
+/* Check if we have a connection to a specified msc */
+bool sccp_conn_ready(struct bsc_msc_data *msc)
+{
+	OSMO_ASSERT(msc);
+	OSMO_ASSERT(msc->msc_con);
+	OSMO_ASSERT(msc->msc_con->fsm_reset);
+	if (msc->msc_con->fsm_reset->state == ST_CONN)
+		return true;
+
+	return false;
+}
diff --git a/src/osmo-bsc/osmo_bsc_sccp.c b/src/osmo-bsc/osmo_bsc_sccp.c
deleted file mode 100644
index e242390..0000000
--- a/src/osmo-bsc/osmo_bsc_sccp.c
+++ /dev/null
@@ -1,328 +0,0 @@
-/* Interaction with the SCCP subsystem */
-/*
- * (C) 2009-2014 by Holger Hans Peter Freyther <zecke@selfish.org>
- * (C) 2009-2014 by On-Waves
- * All Rights Reserved
- *
- * 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/>.
- *
- */
-
-#include <openbsc/gsm_data.h>
-#include <openbsc/osmo_bsc.h>
-#include <openbsc/osmo_bsc_grace.h>
-#include <openbsc/bsc_msc_data.h>
-#include <openbsc/gsm_04_80.h>
-#include <openbsc/debug.h>
-#include <openbsc/ipaccess.h>
-#include <openbsc/signal.h>
-
-#include <osmocom/core/talloc.h>
-#include <osmocom/gsm/gsm0808.h>
-#include <osmocom/gsm/protocol/gsm_08_08.h>
-
-#include <osmocom/sccp/sccp.h>
-
-/* SCCP helper */
-#define SCCP_IT_TIMER 60
-
-static LLIST_HEAD(active_connections);
-
-static void free_queued(struct osmo_bsc_sccp_con *conn)
-{
-	struct msgb *msg;
-
-	while (!llist_empty(&conn->sccp_queue)) {
-		/* this is not allowed to fail */
-		msg = msgb_dequeue(&conn->sccp_queue);
-		msgb_free(msg);
-	}
-
-	conn->sccp_queue_size = 0;
-}
-
-static void send_queued(struct osmo_bsc_sccp_con *conn)
-{
-	struct msgb *msg;
-
-	while (!llist_empty(&conn->sccp_queue)) {
-		/* this is not allowed to fail */
-		msg = msgb_dequeue(&conn->sccp_queue);
-		sccp_connection_write(conn->sccp, msg);
-		msgb_free(msg);
-		conn->sccp_queue_size -= 1;
-	}
-}
-
-static void msc_outgoing_sccp_data(struct sccp_connection *conn,
-				   struct msgb *msg, unsigned int len)
-{
-	struct osmo_bsc_sccp_con *bsc_con =
-			(struct osmo_bsc_sccp_con *) conn->data_ctx;
-
-	bsc_handle_dt1(bsc_con, msg, len);
-}
-
-static void msc_outgoing_sccp_state(struct sccp_connection *conn, int old_state)
-{
-	struct osmo_bsc_sccp_con *con_data;
-
-	if (conn->connection_state >= SCCP_CONNECTION_STATE_RELEASE_COMPLETE) {
-		con_data = (struct osmo_bsc_sccp_con *) conn->data_ctx;
-		if (con_data->conn) {
-			LOGP(DMSC, LOGL_ERROR,
-				"ERROR: The lchan is still associated.\n");
-			gsm0808_clear(con_data->conn);
-			bsc_subscr_con_free(con_data->conn);
-			con_data->conn = NULL;
-		}
-
-		con_data->sccp = NULL;
-		free_queued(con_data);
-		sccp_connection_free(conn);
-		bsc_delete_connection(con_data);
-	} else if (conn->connection_state == SCCP_CONNECTION_STATE_ESTABLISHED) {
-		LOGP(DMSC, LOGL_DEBUG, "Connection established: %p\n", conn);
-		con_data = (struct osmo_bsc_sccp_con *) conn->data_ctx;
-
-		osmo_timer_del(&con_data->sccp_cc_timeout);
-		osmo_timer_schedule(&con_data->sccp_it_timeout, SCCP_IT_TIMER, 0);
-
-		send_queued(con_data);
-	}
-}
-
-static void bsc_sccp_force_free(struct osmo_bsc_sccp_con *data)
-{
-	if (data->conn) {
-		gsm0808_clear(data->conn);
-		bsc_subscr_con_free(data->conn);
-		data->conn = NULL;
-	}
-
-	free_queued(data);
-	sccp_connection_force_free(data->sccp);
-	data->sccp = NULL;
-	bsc_delete_connection(data);
-}
-
-static void sccp_it_timeout(void *_data)
-{
-	struct osmo_bsc_sccp_con *data =
-		(struct osmo_bsc_sccp_con *) _data;
-
-	sccp_connection_send_it(data->sccp);
-	osmo_timer_schedule(&data->sccp_it_timeout, SCCP_IT_TIMER, 0);
-}
-
-static void sccp_cc_timeout(void *_data)
-{
-	struct osmo_bsc_sccp_con *data =
-		(struct osmo_bsc_sccp_con *) _data;
-
-	if (data->sccp->connection_state >= SCCP_CONNECTION_STATE_ESTABLISHED)
-		return;
-
-	LOGP(DMSC, LOGL_ERROR, "The connection was never established.\n");
-	bsc_sccp_force_free(data);
-}
-
-static void msc_sccp_write_ipa(struct sccp_connection *conn, struct msgb *msg,
-			      void *global_ctx, void *ctx)
-{
-	struct bsc_msc_connection *msc_con;
-
-	if (conn) {
-		struct osmo_bsc_sccp_con *bsc_con = conn->data_ctx;
-		msc_con = bsc_con->msc->msc_con;
-		if (bsc_con->send_ping) {
-			bsc_con->send_ping = 0;
-			msc_queue_write_with_ping(msc_con, msg, IPAC_PROTO_SCCP);
-			return;
-		}
-	} else {
-		msc_con = ctx;
-	}
-
-	msc_queue_write(msc_con, msg, IPAC_PROTO_SCCP);
-}
-
-static int msc_sccp_accept(struct sccp_connection *connection, void *data)
-{
-	LOGP(DMSC, LOGL_DEBUG, "Rejecting incoming SCCP connection.\n");
-	return -1;
-}
-
-static int msc_sccp_read(struct msgb *msgb, unsigned int length, void *data)
-{
-	struct bsc_msc_data *msc = (struct bsc_msc_data *) msgb->cb[0];
-	return bsc_handle_udt(msc, msgb, length);
-}
-
-int bsc_queue_for_msc(struct osmo_bsc_sccp_con *conn, struct msgb *msg)
-{
-	struct sccp_connection *sccp = conn->sccp;
-
-	if (sccp->connection_state > SCCP_CONNECTION_STATE_ESTABLISHED) {
-		LOGP(DMSC, LOGL_ERROR, "Connection closing, dropping packet on: %p\n", sccp);
-		msgb_free(msg);
-	} else if (sccp->connection_state == SCCP_CONNECTION_STATE_ESTABLISHED
-		   && conn->sccp_queue_size == 0) {
-		sccp_connection_write(sccp, msg);
-		msgb_free(msg);
-	} else if (conn->sccp_queue_size > 10) {
-		LOGP(DMSC, LOGL_ERROR, "Connection closing, dropping packet on: %p\n", sccp);
-		msgb_free(msg);
-	} else {
-		LOGP(DMSC, LOGL_DEBUG, "Queueing packet on %p. Queue size: %d\n", sccp, conn->sccp_queue_size);
-		conn->sccp_queue_size += 1;
-		msgb_enqueue(&conn->sccp_queue, msg);
-	}
-
-	return 0;
-}
-
-enum bsc_con bsc_create_new_connection(struct gsm_subscriber_connection *conn,
-			      struct bsc_msc_data *msc, int send_ping)
-{
-	struct osmo_bsc_sccp_con *bsc_con;
-	struct sccp_connection *sccp;
-
-	/* This should not trigger */
-	if (!msc || !msc->msc_con->is_authenticated) {
-		LOGP(DMSC, LOGL_ERROR,
-		     "How did this happen? MSC is not connected. Dropping.\n");
-		return BSC_CON_REJECT_NO_LINK;
-	}
-
-	if (!bsc_grace_allow_new_connection(conn->bts->network, conn->bts)) {
-		LOGP(DMSC, LOGL_NOTICE, "BSC in grace period. No new connections.\n");
-		return BSC_CON_REJECT_RF_GRACE;
-	}
-
-	sccp = sccp_connection_socket();
-	if (!sccp) {
-		LOGP(DMSC, LOGL_ERROR, "Failed to allocate memory.\n");
-		return BSC_CON_NO_MEM;
-	}
-
-	bsc_con = talloc_zero(conn->bts, struct osmo_bsc_sccp_con);
-	if (!bsc_con) {
-		LOGP(DMSC, LOGL_ERROR, "Failed to allocate.\n");
-		sccp_connection_free(sccp);
-		return BSC_CON_NO_MEM;
-	}
-
-	/* callbacks */
-	sccp->state_cb = msc_outgoing_sccp_state;
-	sccp->data_cb = msc_outgoing_sccp_data;
-	sccp->data_ctx = bsc_con;
-
-	bsc_con->send_ping = send_ping;
-
-	/* prepare the timers */
-	osmo_timer_setup(&bsc_con->sccp_it_timeout, sccp_it_timeout, bsc_con);
-	osmo_timer_setup(&bsc_con->sccp_cc_timeout, sccp_cc_timeout, bsc_con);
-
-	INIT_LLIST_HEAD(&bsc_con->sccp_queue);
-
-	bsc_con->sccp = sccp;
-	bsc_con->msc = msc;
-	bsc_con->conn = conn;
-	llist_add_tail(&bsc_con->entry, &active_connections);
-	conn->sccp_con = bsc_con;
-	return BSC_CON_SUCCESS;
-}
-
-int bsc_open_connection(struct osmo_bsc_sccp_con *conn, struct msgb *msg)
-{
-	osmo_timer_schedule(&conn->sccp_cc_timeout, 10, 0);
-	sccp_connection_connect(conn->sccp, &sccp_ssn_bssap, msg);
-	msgb_free(msg);
-	return 0;
-}
-
-int bsc_delete_connection(struct osmo_bsc_sccp_con *sccp)
-{
-	if (!sccp)
-		return 0;
-
-	if (sccp->conn)
-		LOGP(DMSC, LOGL_ERROR, "Should have been cleared.\n");
-
-	llist_del(&sccp->entry);
-	osmo_timer_del(&sccp->sccp_it_timeout);
-	osmo_timer_del(&sccp->sccp_cc_timeout);
-	talloc_free(sccp);
-	return 0;
-}
-
-static void bsc_notify_msc_lost(struct osmo_bsc_sccp_con *con)
-{
-	struct gsm_subscriber_connection *conn = con->conn;
-
-	/* send USSD notification if string configured and con->data is set */
-	if (!conn)
-		return;
-
-	/* check for config string */
-	if (!con->msc->ussd_msc_lost_txt)
-		return;
-	if (con->msc->ussd_msc_lost_txt[0] == '\0')
-		return;
-
-	/* send USSD notification */
-	bsc_send_ussd_notify(conn, 1, conn->sccp_con->msc->ussd_msc_lost_txt);
-	bsc_send_ussd_release_complete(conn);
-}
-
-static void bsc_notify_and_close_conns(struct bsc_msc_connection *msc_con)
-{
-	struct osmo_bsc_sccp_con *con, *tmp;
-
-	llist_for_each_entry_safe(con, tmp, &active_connections, entry) {
-		if (con->msc->msc_con != msc_con)
-			continue;
-
-		bsc_notify_msc_lost(con);
-		bsc_sccp_force_free(con);
-	}
-}
-
-static int handle_msc_signal(unsigned int subsys, unsigned int signal,
-			     void *handler_data, void *signal_data)
-{
-	struct msc_signal_data *msc;
-
-	if (subsys != SS_MSC)
-		return 0;
-
-	msc = signal_data;
-	if (signal == S_MSC_LOST)
-		bsc_notify_and_close_conns(msc->data->msc_con);
-
-	return 0;
-}
-
-int osmo_bsc_sccp_init(struct gsm_network *gsmnet)
-{
-	sccp_set_log_area(DSCCP);
-	sccp_system_init(msc_sccp_write_ipa, gsmnet);
-	sccp_connection_set_incoming(&sccp_ssn_bssap, msc_sccp_accept, NULL);
-	sccp_set_read(&sccp_ssn_bssap, msc_sccp_read, gsmnet);
-
-	osmo_signal_register_handler(SS_MSC, handle_msc_signal, gsmnet);
-
-	return 0;
-}
diff --git a/src/osmo-bsc/osmo_bsc_sigtran.c b/src/osmo-bsc/osmo_bsc_sigtran.c
new file mode 100644
index 0000000..0f6ca33
--- /dev/null
+++ b/src/osmo-bsc/osmo_bsc_sigtran.c
@@ -0,0 +1,561 @@
+/* (C) 2017 by sysmocom s.f.m.c. GmbH
+ * 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/>.
+ *
+ */
+
+#include <osmocom/core/utils.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/sigtran/osmo_ss7.h>
+#include <osmocom/sigtran/sccp_sap.h>
+#include <osmocom/sccp/sccp_types.h>
+#include <osmocom/core/linuxlist.h>
+#include <osmocom/gsm/gsm0808.h>
+#include <osmocom/core/msgb.h>
+#include <openbsc/bsc_msc_data.h>
+#include <openbsc/debug.h>
+#include <openbsc/osmo_bsc.h>
+#include <openbsc/osmo_bsc_grace.h>
+#include <openbsc/osmo_bsc_sigtran.h>
+#include <openbsc/a_reset.h>
+#include <openbsc/gsm_04_80.h>
+
+/* A pointer to a list with all involved MSCs
+ * (a copy of the pointer location submitted with osmo_bsc_sigtran_init() */
+static struct llist_head *msc_list;
+
+#define RESET_INTERVAL 1	/* sek */
+#define SCCP_MSG_MAXSIZE 1024
+#define CS7_POINTCODE_DEFAULT_OFFSET 2
+
+/* Internal list with connections we currently maintain. This
+ * list is of type struct osmo_bsc_sccp_con */
+static LLIST_HEAD(active_connections);
+
+/* The SCCP stack will not assign connection IDs to us automatically, we
+ * will do this ourselves using a counter variable, that counts one up
+ * for every new connection */
+static uint32_t conn_id_counter;
+
+/* Helper function to Check if the given connection id is already assigned */
+static struct osmo_bsc_sccp_con *get_bsc_conn_by_conn_id(int conn_id)
+{
+	conn_id &= 0xFFFFFF;
+	struct osmo_bsc_sccp_con *bsc_con;
+
+	llist_for_each_entry(bsc_con, &active_connections, entry) {
+		if (bsc_con->conn_id == conn_id)
+			return bsc_con;
+	}
+
+	return NULL;
+}
+
+/* Pick a free connection id */
+static int pick_free_conn_id(const struct bsc_msc_data *msc)
+{
+	int conn_id = conn_id_counter;
+	int i;
+
+	for (i = 0; i < 0xFFFFFF; i++) {
+		conn_id++;
+		conn_id &= 0xFFFFFF;
+		if (get_bsc_conn_by_conn_id(conn_id) == false) {
+			conn_id_counter = conn_id;
+			return conn_id;
+		}
+	}
+
+	return -1;
+}
+
+/* Send reset to MSC */
+static void osmo_bsc_sigtran_tx_reset(const struct bsc_msc_data *msc)
+{
+	struct osmo_ss7_instance *ss7;
+	struct msgb *msg;
+
+	ss7 = osmo_ss7_instance_find(msc->a.cs7_instance);
+	OSMO_ASSERT(ss7);
+	LOGP(DMSC, LOGL_NOTICE, "Sending RESET to MSC: %s\n", osmo_sccp_addr_name(ss7, &msc->a.msc_addr));
+	msg = gsm0808_create_reset();
+	osmo_sccp_tx_unitdata_msg(msc->a.sccp_user, &msc->a.bsc_addr,
+				  &msc->a.msc_addr, msg);
+}
+
+/* Send reset-ack to MSC */
+void osmo_bsc_sigtran_tx_reset_ack(const struct bsc_msc_data *msc)
+{
+	struct osmo_ss7_instance *ss7;
+	struct msgb *msg;
+	OSMO_ASSERT(msc);
+
+	ss7 = osmo_ss7_instance_find(msc->a.cs7_instance);
+	OSMO_ASSERT(ss7);
+	LOGP(DMSC, LOGL_NOTICE, "Sending RESET ACK to MSC: %s\n", osmo_sccp_addr_name(ss7, &msc->a.msc_addr));
+	msg = gsm0808_create_reset_ack();
+	osmo_sccp_tx_unitdata_msg(msc->a.sccp_user, &msc->a.bsc_addr,
+				  &msc->a.msc_addr, msg);
+}
+
+/* Find an MSC by its sigtran point code */
+static struct bsc_msc_data *get_msc_by_addr(const struct osmo_sccp_addr *msc_addr)
+{
+	struct osmo_ss7_instance *ss7;
+	struct bsc_msc_data *msc;
+	llist_for_each_entry(msc, msc_list, entry) {
+		if (memcmp(msc_addr, &msc->a.msc_addr, sizeof(*msc_addr)) == 0)
+			return msc;
+	}
+
+	ss7 = osmo_ss7_instance_find(msc->a.cs7_instance);
+	OSMO_ASSERT(ss7);
+	LOGP(DMSC, LOGL_ERROR, "Unable to find MSC data under address: %s\n", osmo_sccp_addr_name(ss7, msc_addr));
+	return NULL;
+}
+
+/* Send data to MSC, use the connection id which MSC it is */
+static int handle_data_from_msc(int conn_id, struct msgb *msg)
+{
+	struct osmo_bsc_sccp_con *bsc_con = get_bsc_conn_by_conn_id(conn_id);
+	int rc = -EINVAL;
+
+	if (bsc_con) {
+		msg->l3h = msgb_l2(msg);
+		rc = bsc_handle_dt(bsc_con, msg, msgb_l2len(msg));
+	} else
+		LOGP(DMSC, LOGL_NOTICE, "incoming data from unknown connection id: %i\n", conn_id);
+
+	return rc;
+}
+
+/* Sent unitdata to MSC, use the point code to determine which MSC it is */
+static int handle_unitdata_from_msc(const struct osmo_sccp_addr *msc_addr, struct msgb *msg,
+				    const struct osmo_sccp_user *scu)
+{
+	struct osmo_ss7_instance *ss7;
+	struct bsc_msc_data *msc = get_msc_by_addr(msc_addr);
+	int rc = -EINVAL;
+
+	if (msc) {
+		msg->l3h = msgb_l2(msg);
+		rc = bsc_handle_udt(msc, msg, msgb_l2len(msg));
+	} else {
+		ss7 = osmo_sccp_get_ss7(osmo_sccp_get_sccp(scu));
+		OSMO_ASSERT(ss7);
+		LOGP(DMSC, LOGL_NOTICE, "incoming unitdata data from unknown remote address: %s\n",
+		     osmo_sccp_addr_name(ss7, msc_addr));
+	}
+	return rc;
+}
+
+/* Callback function, called by the SSCP stack when data arrives */
+static int sccp_sap_up(struct osmo_prim_hdr *oph, void *_scu)
+{
+	struct osmo_scu_prim *scu_prim = (struct osmo_scu_prim *)oph;
+	struct osmo_sccp_user *scu = _scu;
+	struct osmo_bsc_sccp_con *bsc_con;
+	int rc = 0;
+
+	switch (OSMO_PRIM_HDR(&scu_prim->oph)) {
+	case OSMO_PRIM(OSMO_SCU_PRIM_N_UNITDATA, PRIM_OP_INDICATION):
+		/* Handle inbound UNITDATA */
+		DEBUGP(DMSC, "N-UNITDATA.ind(%s)\n", osmo_hexdump(msgb_l2(oph->msg), msgb_l2len(oph->msg)));
+		rc = handle_unitdata_from_msc(&scu_prim->u.unitdata.calling_addr, oph->msg, scu);
+		break;
+
+	case OSMO_PRIM(OSMO_SCU_PRIM_N_CONNECT, PRIM_OP_INDICATION):
+		/* Handle (Reject) inbound connections */
+		DEBUGP(DMSC, "N-CONNECT.ind(X->%u)\n", scu_prim->u.connect.conn_id);
+		LOGP(DMSC, LOGL_DEBUG, "Rejecting inbound SCCP connection...\n");
+		rc = osmo_sccp_tx_disconn(scu, scu_prim->u.connect.conn_id, &scu_prim->u.connect.called_addr, 0);
+		break;
+
+	case OSMO_PRIM(OSMO_SCU_PRIM_N_CONNECT, PRIM_OP_CONFIRM):
+		/* Handle outbound connection confirmation */
+		if (msgb_l2len(oph->msg) > 0) {
+			DEBUGP(DMSC, "N-CONNECT.cnf(%u, %s)\n", scu_prim->u.connect.conn_id,
+			       osmo_hexdump(msgb_l2(oph->msg), msgb_l2len(oph->msg)));
+			rc = handle_data_from_msc(scu_prim->u.connect.conn_id, oph->msg);
+		} else
+			DEBUGP(DRANAP, "N-CONNECT.cnf(%u)\n", scu_prim->u.connect.conn_id);
+		break;
+
+	case OSMO_PRIM(OSMO_SCU_PRIM_N_DATA, PRIM_OP_INDICATION):
+		/* Handle incoming connection oriented data */
+		DEBUGP(DMSC, "N-DATA.ind(%u, %s)\n", scu_prim->u.data.conn_id,
+		       osmo_hexdump(msgb_l2(oph->msg), msgb_l2len(oph->msg)));
+
+		/* Incoming data is a sign of a vital connection */
+		bsc_con = get_bsc_conn_by_conn_id(scu_prim->u.disconnect.conn_id);
+		if (bsc_con)
+			a_reset_conn_success(bsc_con->msc->a.reset);
+
+		rc = handle_data_from_msc(scu_prim->u.data.conn_id, oph->msg);
+		break;
+
+	case OSMO_PRIM(OSMO_SCU_PRIM_N_DISCONNECT, PRIM_OP_INDICATION):
+		/* indication of disconnect */
+		if (msgb_l2len(oph->msg) > 0) {
+			DEBUGP(DMSC, "N-DISCONNECT.ind(%u, %s, cause=%i)\n", scu_prim->u.disconnect.conn_id,
+			       osmo_hexdump(msgb_l2(oph->msg), msgb_l2len(oph->msg)), scu_prim->u.disconnect.cause);
+			handle_data_from_msc(scu_prim->u.disconnect.conn_id, oph->msg);
+		} else
+			DEBUGP(DRANAP, "N-DISCONNECT.ind(%u, cause=%i)\n", scu_prim->u.disconnect.conn_id,
+			       scu_prim->u.disconnect.cause);
+
+		bsc_con = get_bsc_conn_by_conn_id(scu_prim->u.disconnect.conn_id);
+		if (bsc_con) {
+			/* We might have a connectivity problem. Maybe we need to go
+			 * through the reset procedure again? */
+			if (scu_prim->u.disconnect.cause == 0)
+				a_reset_conn_fail(bsc_con->msc->a.reset);
+
+			rc = osmo_bsc_sigtran_del_conn(bsc_con);
+		}
+		break;
+
+	default:
+		LOGP(DMSC, LOGL_ERROR, "Unhandled SIGTRAN primitive: %u:%u\n", oph->primitive, oph->operation);
+		break;
+	}
+
+	msgb_free(oph->msg);
+	return rc;
+}
+
+/* Allocate resources to make a new connection oriented sigtran connection
+ * (not the connection ittself!) */
+enum bsc_con osmo_bsc_sigtran_new_conn(struct gsm_subscriber_connection *conn, struct bsc_msc_data *msc)
+{
+	struct osmo_ss7_instance *ss7;
+	struct osmo_bsc_sccp_con *bsc_con;
+	int conn_id;
+
+	OSMO_ASSERT(conn);
+	OSMO_ASSERT(msc);
+
+	ss7 = osmo_ss7_instance_find(msc->a.cs7_instance);
+	OSMO_ASSERT(ss7);
+	LOGP(DMSC, LOGL_NOTICE, "Initializing resources for new SIGTRAN connection to MSC: %s...\n",
+	     osmo_sccp_addr_name(ss7, &msc->a.msc_addr));
+
+	if (a_reset_conn_ready(msc->a.reset) == false) {
+		LOGP(DMSC, LOGL_ERROR, "MSC is not connected. Dropping.\n");
+		return BSC_CON_REJECT_NO_LINK;
+	}
+
+	if (!bsc_grace_allow_new_connection(conn->bts->network, conn->bts)) {
+		LOGP(DMSC, LOGL_NOTICE, "BSC in grace period. No new connections.\n");
+		return BSC_CON_REJECT_RF_GRACE;
+	}
+
+	bsc_con = talloc_zero(conn->bts, struct osmo_bsc_sccp_con);
+	if (!bsc_con) {
+		LOGP(DMSC, LOGL_ERROR, "Failed to allocate new SIGTRAN connection.\n");
+		return BSC_CON_NO_MEM;
+	}
+
+	bsc_con->msc = msc;
+	bsc_con->conn = conn;
+	llist_add_tail(&bsc_con->entry, &active_connections);
+	conn->sccp_con = bsc_con;
+
+	/* Pick a free connection id */
+	conn_id = pick_free_conn_id(msc);
+	if (conn_id < 0)
+		return BSC_CON_REJECT_NO_LINK;
+	bsc_con->conn_id = conn_id;
+
+	LOGP(DMSC, LOGL_NOTICE, "Allocated new connection id: %i\n", conn_id);
+
+	return BSC_CON_SUCCESS;
+}
+
+/* Open a new connection oriented sigtran connection */
+int osmo_bsc_sigtran_open_conn(const struct osmo_bsc_sccp_con *conn, struct msgb *msg)
+{
+	struct osmo_ss7_instance *ss7;
+	struct bsc_msc_data *msc;
+	int conn_id;
+	int rc;
+
+	OSMO_ASSERT(conn);
+	OSMO_ASSERT(msg);
+	OSMO_ASSERT(conn->msc);
+
+	msc = conn->msc;
+
+	if (a_reset_conn_ready(msc->a.reset) == false) {
+		LOGP(DMSC, LOGL_ERROR, "MSC is not connected. Dropping.\n");
+		return -EINVAL;
+	}
+
+	conn_id = conn->conn_id;
+	ss7 = osmo_ss7_instance_find(msc->a.cs7_instance);
+	OSMO_ASSERT(ss7);
+	LOGP(DMSC, LOGL_NOTICE, "Opening new SIGTRAN connection (id=%i) to MSC: %s\n", conn_id,
+	     osmo_sccp_addr_name(ss7, &msc->a.msc_addr));
+
+	rc = osmo_sccp_tx_conn_req_msg(msc->a.sccp_user, conn_id, &msc->a.bsc_addr,
+				       &msc->a.msc_addr, msg);
+
+	return rc;
+}
+
+/* Send data to MSC */
+int osmo_bsc_sigtran_send(const struct osmo_bsc_sccp_con *conn, struct msgb *msg)
+{
+	struct osmo_ss7_instance *ss7;
+	int conn_id;
+	int rc;
+	struct bsc_msc_data *msc;
+
+	OSMO_ASSERT(conn);
+	OSMO_ASSERT(msg);
+	OSMO_ASSERT(conn->msc);
+
+	msc = conn->msc;
+
+	if (a_reset_conn_ready(msc->a.reset) == false) {
+		LOGP(DMSC, LOGL_ERROR, "MSC is not connected. Dropping.\n");
+		return -EINVAL;
+	}
+
+	conn_id = conn->conn_id;
+
+	ss7 = osmo_ss7_instance_find(msc->a.cs7_instance);
+	OSMO_ASSERT(ss7);
+	LOGP(DMSC, LOGL_DEBUG, "Sending connection (id=%i) oriented data to MSC: %si\n",
+	     conn_id, osmo_sccp_addr_name(ss7, &msc->a.msc_addr));
+
+	rc = osmo_sccp_tx_data_msg(msc->a.sccp_user, conn_id, msg);
+
+	return rc;
+}
+
+/* Delete a connection from the list with open connections
+ * (called by osmo_bsc_api.c on failing open connections and
+ * locally, when a connection is closed by the MSC */
+int osmo_bsc_sigtran_del_conn(struct osmo_bsc_sccp_con *conn)
+{
+	if (!conn)
+		return 0;
+
+	if (conn->conn) {
+		LOGP(DMSC, LOGL_ERROR,
+		     "sccp connection (id=%i) not cleared (gsm subscriber connection still active) -- forcefully clearing it now!\n",
+		     conn->conn_id);
+		bsc_subscr_con_free(conn->conn);
+		conn->conn = NULL;
+
+		/* This bahaviour might be caused by a bad connection. Maybe we
+		 * will have to go through the reset procedure again */
+		a_reset_conn_fail(conn->msc->a.reset);
+	}
+
+	llist_del(&conn->entry);
+	talloc_free(conn);
+
+	return 0;
+}
+
+/* Send an USSD notification in case we loose the connection to the MSC */
+static void bsc_notify_msc_lost(const struct osmo_bsc_sccp_con *conn)
+{
+	struct gsm_subscriber_connection *subscr_conn;
+
+	/* Check if sccp conn is still present */
+	if (!conn)
+		return;
+	subscr_conn = conn->conn;
+
+	/* send USSD notification if string configured and conn->data is set */
+	if (!subscr_conn)
+		return;
+
+	/* check for config string */
+	if (!conn->msc->ussd_msc_lost_txt)
+		return;
+	if (conn->msc->ussd_msc_lost_txt[0] == '\0')
+		return;
+
+	/* send USSD notification */
+	bsc_send_ussd_notify(subscr_conn, 1, subscr_conn->sccp_con->msc->ussd_msc_lost_txt);
+	bsc_send_ussd_release_complete(subscr_conn);
+}
+
+/* Close all open sigtran connections and channels */
+void osmo_bsc_sigtran_reset(const struct bsc_msc_data *msc)
+{
+	struct osmo_bsc_sccp_con *conn;
+	struct osmo_bsc_sccp_con *conn_temp;
+	OSMO_ASSERT(msc);
+
+	/* Close all open connections */
+	llist_for_each_entry_safe(conn, conn_temp, &active_connections, entry) {
+
+		/* We only may close connections which actually belong to this
+		 * MSC. All other open connections are left untouched */
+		if (conn->msc == msc) {
+			/* Notify active connection users via USSD that the MSC is down */
+			bsc_notify_msc_lost(conn);
+
+			/* Take down all occopied RF channels */
+			if (conn->conn)
+				gsm0808_clear(conn->conn);
+
+			/* Disconnect all Sigtran connections */
+			osmo_sccp_tx_disconn(msc->a.sccp_user, conn->conn_id, &msc->a.bsc_addr, 0);
+
+			/* Delete subscriber connection */
+			osmo_bsc_sigtran_del_conn(conn);
+		}
+	}
+}
+
+/* Callback function: Close all open connections */
+static void osmo_bsc_sigtran_reset_cb(const void *priv)
+{
+	struct bsc_msc_data *msc = (struct bsc_msc_data*) priv;
+
+	/* Shut down all ongoing traffic */
+	osmo_bsc_sigtran_reset(msc);
+
+	/* Send reset to MSC */
+	osmo_bsc_sigtran_tx_reset(msc);
+}
+
+/* Default point-code to be used as local address (BSC) */
+#define BSC_DEFAULT_PC "0.23.3"
+
+/* Default point-code to be used as remote address (MSC) */
+#define MSC_DEFAULT_PC "0.23.1"
+
+/* Initalize osmo sigtran backhaul */
+int osmo_bsc_sigtran_init(struct llist_head *mscs)
+{
+	bool free_attempt_used = false;
+	bool fail_on_next_invalid_cfg = false;
+
+	struct bsc_msc_data *msc;
+	char msc_name[32];
+	uint32_t default_pc;
+
+	OSMO_ASSERT(mscs);
+	msc_list = mscs;
+
+	llist_for_each_entry(msc, msc_list, entry) {
+		snprintf(msc_name, sizeof(msc_name), "msc-%u", msc->nr);
+		LOGP(DMSC, LOGL_NOTICE, "Initializing SCCP connection to MSC %s\n", msc_name);
+
+		/* Check if the VTY could determine a valid CS7 instance,
+		 * use safe default in case none is set */
+		if (msc->a.cs7_instance_valid == false) {
+			msc->a.cs7_instance = 0;
+			if (fail_on_next_invalid_cfg)
+				goto fail_auto_cofiguration;
+			free_attempt_used = true;
+		}
+		LOGP(DMSC, LOGL_NOTICE, "CS7 Instance identifier, A-Interface: %u\n", msc->a.cs7_instance);
+
+		/* Pre-Check if there is an ss7 instance present */
+		if (osmo_ss7_instance_find(msc->a.cs7_instance) == NULL) {
+			if (fail_on_next_invalid_cfg)
+				goto fail_auto_cofiguration;
+			free_attempt_used = true;
+		}
+
+		/* SS7 Protocol stack */
+		default_pc = osmo_ss7_pointcode_parse(NULL, BSC_DEFAULT_PC);
+		msc->a.sccp =
+		    osmo_sccp_simple_client_on_ss7_id(msc, msc->a.cs7_instance, msc_name, default_pc,
+						      OSMO_SS7_ASP_PROT_M3UA, 0, NULL, 0, NULL);
+		if (!msc->a.sccp)
+			return -EINVAL;
+
+		/* Check if the sccp-address fullfills minimum requirements (SSN+PC is present,
+		 * automatically recover addresses if the addresses are not set up properly) */
+		if (!osmo_sccp_check_addr(&msc->a.bsc_addr, OSMO_SCCP_ADDR_T_SSN | OSMO_SCCP_ADDR_T_PC)) {
+			if (fail_on_next_invalid_cfg)
+				goto fail_auto_cofiguration;
+			free_attempt_used = true;
+
+			LOGP(DMSC, LOGL_NOTICE,
+			     "A-interface: invalid or missing local (BSC) SCCP address (a.bsc_addr=%s)\n",
+			     osmo_sccp_addr_name(osmo_ss7_instance_find(msc->a.cs7_instance), &msc->a.bsc_addr));
+			osmo_sccp_local_addr_by_instance(&msc->a.bsc_addr, msc->a.sccp, SCCP_SSN_BSSAP);
+			LOGP(DMSC, LOGL_NOTICE,
+			     "A-interface: using automatically generated local (BSC) SCCP address (a.bsc_addr=%s)\n",
+			     osmo_sccp_addr_name(osmo_ss7_instance_find(msc->a.cs7_instance), &msc->a.bsc_addr));
+		} else {
+			LOGP(DMSC, LOGL_NOTICE,
+			     "A-interface: using local (BSC) automatically SCCP address (a.msc_addr=%s)\n",
+			     osmo_sccp_addr_name(osmo_ss7_instance_find(msc->a.cs7_instance), &msc->a.bsc_addr));
+		}
+
+		if (!osmo_sccp_check_addr(&msc->a.msc_addr, OSMO_SCCP_ADDR_T_SSN | OSMO_SCCP_ADDR_T_PC)) {
+			if (fail_on_next_invalid_cfg)
+				goto fail_auto_cofiguration;
+			free_attempt_used = true;
+
+			LOGP(DMSC, LOGL_NOTICE,
+			     "A-interface: invalid or missing remote (MSC) SCCP address for the MSC (a.msc_addr=%s)\n",
+			     osmo_sccp_addr_name(osmo_ss7_instance_find(msc->a.cs7_instance), &msc->a.msc_addr));
+			osmo_sccp_local_addr_by_instance(&msc->a.msc_addr, msc->a.sccp, SCCP_SSN_BSSAP);
+			msc->a.msc_addr.pc = osmo_ss7_pointcode_parse(NULL, MSC_DEFAULT_PC);
+			LOGP(DMSC, LOGL_NOTICE,
+			     "A-interface: using automatically generated remote (MSC) SCCP address (a.msc_addr=%s)\n",
+			     osmo_sccp_addr_name(osmo_ss7_instance_find(msc->a.cs7_instance), &msc->a.msc_addr));
+			free_attempt_used = true;
+		} else {
+			LOGP(DMSC, LOGL_NOTICE,
+			     "A-interface: using remote (MSC) automatically SCCP address (a.msc_addr=%s)\n",
+			     osmo_sccp_addr_name(osmo_ss7_instance_find(msc->a.cs7_instance), &msc->a.msc_addr));
+		}
+
+		/* Bind SCCP user */
+		msc->a.sccp_user = osmo_sccp_user_bind(msc->a.sccp, msc_name, sccp_sap_up, msc->a.bsc_addr.ssn);
+		if (!msc->a.sccp_user)
+			return -EINVAL;
+
+		/* Start MSC-Reset procedure */
+		msc->a.reset = a_reset_alloc(msc, msc_name, osmo_bsc_sigtran_reset_cb, msc);
+		if (!msc->a.reset)
+			return -EINVAL;
+
+		/* If we have detected that the SS7 configuration of the MSC we have just initalized
+		 * was incomplete or completely missing, we can not tolerate another incomplete
+		 * configuration. The reson for this is that we do only specify exactly one default
+		 * pointcode pair. We also specify localhost as default IP-Address. If we have wanted
+		 * to support multiple MSCs with automatic configuration we would be forced to invent
+		 * a complex ruleset how to allocate the pointcodes and respective IP-Addresses.
+		 * Furthermore, the situation where a single BSC is connected to multiple MSCs
+		 * is a very rare situation anyway. In this case we expect the user to experienced
+		 * enough to create a valid SS7/CS7 VTY configuration that does not lack any
+		 * components */
+		if (free_attempt_used)
+			fail_on_next_invalid_cfg = true;
+	}
+
+	return 0;
+
+fail_auto_cofiguration:
+	LOGP(DMSC, LOGL_ERROR,
+	     "A-interface: More than one invalid/inclomplete configuration detected, unable to revover - check config file!\n");
+	return -EINVAL;
+}
diff --git a/src/osmo-bsc/osmo_bsc_vty.c b/src/osmo-bsc/osmo_bsc_vty.c
index 2e2e99b..8edcbf3 100644
--- a/src/osmo-bsc/osmo_bsc_vty.c
+++ b/src/osmo-bsc/osmo_bsc_vty.c
@@ -28,6 +28,7 @@
 
 #include <osmocom/core/talloc.h>
 #include <osmocom/vty/logging.h>
+#include <osmocom/sccp/sccp_types.h>
 
 #include <time.h>
 
@@ -184,6 +185,16 @@
 
 	/* write amr options */
 	write_msc_amr_options(vty, msc);
+
+	/* write sccp connection configuration */
+	if (msc->a.bsc_addr_name) {
+		vty_out(vty, " bsc-addr %s%s",
+			msc->a.bsc_addr_name, VTY_NEWLINE);
+	}
+	if (msc->a.msc_addr_name) {
+		vty_out(vty, " msc-addr %s%s",
+			msc->a.msc_addr_name, VTY_NEWLINE);
+	}
 }
 
 static int config_write_msc(struct vty *vty)
@@ -685,6 +696,87 @@
 	return CMD_SUCCESS;
 }
 
+/* Make sure only standard SSN numbers are used. If no ssn number is
+ * configured, silently apply the default SSN */
+static void enforce_standard_ssn(struct vty *vty, struct osmo_sccp_addr *addr)
+{
+	if (addr->presence & OSMO_SCCP_ADDR_T_SSN) {
+		if (addr->ssn != SCCP_SSN_BSSAP)
+			vty_out(vty,
+				"setting an SSN (%u) different from the standard (%u) is not allowd, will use standard SSN for address: %s%s",
+				addr->ssn, SCCP_SSN_BSSAP, osmo_sccp_addr_dump(addr), VTY_NEWLINE);
+	}
+
+	addr->presence |= OSMO_SCCP_ADDR_T_SSN;
+	addr->ssn = SCCP_SSN_BSSAP;
+}
+
+DEFUN(cfg_msc_cs7_bsc_addr,
+      cfg_msc_cs7_bsc_addr_cmd,
+      "bsc-addr NAME",
+      "Calling Address (local address of this BSC)\n" "SCCP address name\n")
+{
+	struct bsc_msc_data *msc = bsc_msc_data(vty);
+	const char *bsc_addr_name = argv[0];
+	struct osmo_ss7_instance *ss7;
+
+	ss7 = osmo_sccp_addr_by_name(&msc->a.bsc_addr, bsc_addr_name);
+	if (!ss7) {
+		vty_out(vty, "No sccp address %s found%s", bsc_addr_name,
+			VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	/* Prevent mixing addresses from different CS7/SS7 instances */
+	if (msc->a.cs7_instance_valid) {
+		if (msc->a.cs7_instance != ss7->cfg.id) {
+			vty_out(vty,
+				"SCCP address %s from different CS7 instance%s",
+				bsc_addr_name, VTY_NEWLINE);
+			return CMD_WARNING;
+		}
+	}
+
+	msc->a.cs7_instance = ss7->cfg.id;
+	msc->a.cs7_instance_valid = true;
+	enforce_standard_ssn(vty, &msc->a.bsc_addr);
+	msc->a.bsc_addr_name = talloc_strdup(msc, bsc_addr_name);
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_msc_cs7_msc_addr,
+      cfg_msc_cs7_msc_addr_cmd,
+      "msc-addr NAME",
+      "Called Address (remote address of the MSC)\n" "SCCP address name\n")
+{
+	struct bsc_msc_data *msc = bsc_msc_data(vty);
+	const char *msc_addr_name = argv[0];
+	struct osmo_ss7_instance *ss7;
+
+	ss7 = osmo_sccp_addr_by_name(&msc->a.msc_addr, msc_addr_name);
+	if (!ss7) {
+		vty_out(vty, "No sccp address %s found%s", msc_addr_name,
+			VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	/* Prevent mixing addresses from different CS7/SS7 instances */
+	if (msc->a.cs7_instance_valid) {
+		if (msc->a.cs7_instance != ss7->cfg.id) {
+			vty_out(vty,
+				"SCCP address %s from different CS7 instance%s",
+				msc_addr_name, VTY_NEWLINE);
+			return CMD_WARNING;
+		}
+	}
+
+	msc->a.cs7_instance = ss7->cfg.id;
+	msc->a.cs7_instance_valid = true;
+	enforce_standard_ssn(vty, &msc->a.msc_addr);
+	msc->a.msc_addr_name = talloc_strdup(msc, msc_addr_name);
+	return CMD_SUCCESS;
+}
+
 DEFUN(cfg_net_bsc_mid_call_text,
       cfg_net_bsc_mid_call_text_cmd,
       "mid-call-text .TEXT",
@@ -931,6 +1023,8 @@
 	install_element(MSC_NODE, &cfg_net_msc_amr_4_75_cmd);
 	install_element(MSC_NODE, &cfg_msc_acc_lst_name_cmd);
 	install_element(MSC_NODE, &cfg_msc_no_acc_lst_name_cmd);
+	install_element(MSC_NODE, &cfg_msc_cs7_bsc_addr_cmd);
+	install_element(MSC_NODE, &cfg_msc_cs7_msc_addr_cmd);
 
 	install_element_ve(&show_statistics_cmd);
 	install_element_ve(&show_mscs_cmd);