diff --git a/src/tests/Makefile.am b/src/tests/Makefile.am
index 3970f60..18490be 100644
--- a/src/tests/Makefile.am
+++ b/src/tests/Makefile.am
@@ -1,8 +1,8 @@
-AM_CFLAGS = $(OSMOVTY_CFLAGS) $(OSMOCORE_CFLAGS) $(OSMOGSM_CFLAGS) $(OSMONETIF_CFLAGS) $(ASN1C_CFLAGS) -g -I$(top_builddir)/src -I$(top_builddir)/src/hnbap/
+AM_CFLAGS = $(OSMOVTY_CFLAGS) $(OSMOCORE_CFLAGS) $(OSMOGSM_CFLAGS) $(OSMONETIF_CFLAGS) $(ASN1C_CFLAGS) $(OSMOSIGTRAN_CFLAGS) -g -I$(top_builddir)/src -I$(top_builddir)/src/hnbap/
 
-COMMON_LIBS = $(OSMOVTY_LIBS) $(OSMOCORE_LIBS) $(OSMOGSM_LIBS) $(ASN1C_LIBS) -lsctp
+COMMON_LIBS = $(OSMOVTY_LIBS) $(OSMOCORE_LIBS) $(OSMOGSM_LIBS) $(ASN1C_LIBS) $(OSMOSIGTRAN_LIBS) -lsctp
 
-check_PROGRAMS = test-ranap test-helpers test-hnbap hnb-test
+check_PROGRAMS = test-ranap test-helpers test-hnbap hnb-test dummy-cn
 
 HNBAP_FILES = $(top_builddir)/src/hnbap_common.c $(top_builddir)/src/hnbap_decoder.c $(top_builddir)/src/hnbap_encoder.c
 RUA_FILES = $(top_builddir)/src/rua_common.c $(top_builddir)/src/rua_decoder.c $(top_builddir)/src/rua_encoder.c
@@ -24,6 +24,9 @@
 test_ranap_SOURCES = $(HELPER_FILES) $(RANAP_FILES) test-ranap.c test_common.c
 test_ranap_LDADD = $(COMMON_LIBS) $(top_builddir)/src/ranap/libosmo-asn1-ranap.a
 
+dummy_cn_SOURCES = $(HELPER_FILES) $(RANAP_FILES) test_common.c dummy_cn_sua.c ranap_common_cn.c
+dummy_cn_LDADD = $(COMMON_LIBS) $(top_builddir)/src/ranap/libosmo-asn1-ranap.a
+
 # The `:;' works around a Bash 3.2 bug when the output is not writeable.
 $(srcdir)/package.m4: $(top_srcdir)/configure.ac
 	:;{ \
diff --git a/src/tests/dummy_cn_sua.c b/src/tests/dummy_cn_sua.c
new file mode 100644
index 0000000..6d8098a
--- /dev/null
+++ b/src/tests/dummy_cn_sua.c
@@ -0,0 +1,264 @@
+#include <stdint.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <osmocom/core/select.h>
+#include <osmocom/core/prim.h>
+#include <osmocom/core/talloc.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/application.h>
+#include <osmocom/vty/logging.h>
+
+#include <osmocom/sigtran/sua.h>
+#include <osmocom/sigtran/sccp_sap.h>
+
+#include "test_common.h"
+#include "ranap_common_cn.h"
+#include "hnbgw.h"
+
+int asn1_xer_print = 1;
+
+/***********************************************************************
+ * RANAP handling
+ ***********************************************************************/
+
+static int ranap_handle_co_initial_ue(void *ctx, RANAP_InitialUE_MEssageIEs_t *ies)
+{
+	struct gprs_ra_id ra_id;
+	uint16_t sai;
+	struct msgb *msg = msgb_alloc(256, "RANAP->NAS");
+	uint8_t *cur;
+
+	ranap_parse_lai(&ra_id, &ies.lai);
+	sai = asn1str_to_u16(&ies.sai.sAC);
+	cur = msgb_put(msg, ies.nas_pdu.size);
+	memcpy(msg, ies.nas_pdu.buf, ies.nas_pdu.size);
+	/* FIXME: set msgb_gmmh() */
+
+	/* FIXME: Feed into the MM layer */
+	rc = gsm0408_gprs_rcvmsg_iu(msg, ra_id, sai, conn_id);
+
+	return 0;
+}
+
+static int ranap_handle_co_dt(void *ctx, RANAP_DirectTransferIEs_t *ies)
+{
+	struct gprs_ra_id _ra_id, *ra_id = NULL;
+	uint16_t _sai, *sai = NULL;
+	struct msgb *msg = msgb_alloc(256, "RANAP->NAS");
+	uint8_t *cur;
+
+	if (ies.presenceMask & DIRECTTRANSFERIES_RANAP_LAI_PRESENT) {
+		ranap_parse_lai(&_ra_id, &ies.lai);
+		ra_id = &_ra_id;
+		if (ies.presenceMask & DIRECTTRANSFERIES_RANAP_RAC_PRESENT) {
+			_ra_id.rac = asn1str_to_u16(&ies.rac);
+		}
+		if (ies.presenceMask & DIRECTTRANSFERIES_RANAP_SAI_PRESENT) {
+			_sai = asn1str_to_u16(&ies.sai.sAC);
+			sai = &_sai;
+		}
+	}
+
+	cur = msgb_put(msg, ies.nas_pdu.size);
+	memcpy(msg, ies.nas_pdu.buf, ies.nas_pdu.size);
+	/* FIXME: set msgb_gmmh() */
+
+	/* FIXME: Feed into the MM/CC/SMS-CP layer */
+	rc = gsm0408_gprs_rcvmsg_iu(msg, ra_id, sai, conn_id);
+
+	return 0;
+}
+
+static int ranap_handle_co_err_ind(void *ctx, RANAP_ErrorIndicationIEs_t *ies)
+{
+	if (ies->presenceMask & ERRORINDICATIONIES_RANAP_CAUSE_PRESENT)
+		LOGP(DRANAP, LOGL_ERROR, "Rx Error Indication (%s)\n",
+			ranap_cause_str(&ies->cause));
+	else
+		LOGP(DRANAP, LOGL_ERROR, "Rx Error Indication\n");
+
+	return 0;
+}
+
+/* Entry point for connection-oriented ANAP message */
+int cn_ranap_handle_co(void *ctx, ranap_message *message)
+{
+	int rc = 0;
+
+	switch (message->direction) {
+	case RANAP_RANAP_PDU_PR_initiatingMessage:
+		switch (message->procedureCode) {
+		case RANAP_ProcedureCode_id_InitialUE_Message:
+			rc = ranap_handle_co_initial_ue(ctx, &message->msg.initialUE_MessageIEs);
+			break;
+		case RANAP_ProcedureCode_id_DirectTransfer:
+			rc = ranap_handle_co_dt(ctx, &message->msg.directTransferIEs);
+			break;
+		case RANAP_ProcedureCode_id_ErrorIndication:
+			rc = ranap_handle_co_err_ind(ctx, &message->msg.errorIndicationIEs);
+			break;
+		}
+		break;
+	case RANAP_RANAP_PDU_PR_successfulOutcome:
+		switch (message->procedureCode) {
+		case RANAP_ProcedureCode_id_RAB_Assignment:
+			/* RAB Assignment Response */
+			break;
+		case RANAP_ProcedureCode_id_SecurityModeControl:
+			/* Security Mode Complete */
+			break;
+		case RANAP_ProcedureCode_id_Iu_Release:
+			/* Iu Release Complete */
+			break;
+		}
+	case RANAP_RANAP_PDU_PR_unsuccessfulOutcome:
+	case RANAP_RANAP_PDU_PR_outcome:
+	default:
+		rc = -1;
+		break;
+	}
+
+	return rc;
+}
+
+static int ranap_handle_cl_reset_req(void *ctx, RANAP_ResetIEs_t *ies)
+{
+	/* FIXME: send reset response */
+}
+
+static int ranap_handle_cl_err_ind(void *ctx, RANAP_ErrorIndicationIEs_t *ies)
+{
+	if (ies->presenceMask & ERRORINDICATIONIES_RANAP_CAUSE_PRESENT)
+		LOGP(DRANAP, LOGL_ERROR, "Rx Error Indication (%s)\n",
+			ranap_cause_str(&ies->cause));
+	else
+		LOGP(DRANAP, LOGL_ERROR, "Rx Error Indication\n");
+
+	return 0;
+}
+
+/* Entry point for connection-less RANAP message */
+int cn_ranap_handle_cl(void *ctx, ranap_message *message)
+{
+	int rc = 0;
+
+	switch (message->direction) {
+	case RANAP_RANAP_PDU_PR_initiatingMessage:
+		switch (message->procedureCode) {
+		case RANAP_ProcedureCode_id_Reset:
+			/* received reset.req, send reset.resp */
+			rc = ranap_handle_cl_reset_req(ctx, &message->msg.resetIEs);
+			break;
+		case RANAP_ProcedureCode_id_ErrorIndication:
+			rc = ranap_handle_cl_err_ind(ctx, &message->msg.errorIndicationIEs);
+			break;
+		}
+		break;
+	case RANAP_RANAP_PDU_PR_successfulOutcome:
+	case RANAP_RANAP_PDU_PR_unsuccessfulOutcome:
+	case RANAP_RANAP_PDU_PR_outcome:
+	default:
+		rc = -1;
+		break;
+	}
+}
+
+/***********************************************************************
+ *
+ ***********************************************************************/
+
+int tx_unitdata(struct osmo_sua_link *link);
+int tx_conn_req(struct osmo_sua_link *link, uint32_t conn_id);
+
+struct osmo_prim_hdr *make_conn_req(uint32_t conn_id);
+struct osmo_prim_hdr *make_dt1_req(uint32_t conn_id, const uint8_t *data, unsigned int len);
+
+struct osmo_prim_hdr *make_conn_resp(struct osmo_scu_connect_param *param)
+{
+	struct msgb *msg = msgb_alloc(1024, "conn_resp");
+	struct osmo_scu_prim *prim;
+
+	prim = (struct osmo_scu_prim *) msgb_put(msg, sizeof(*prim));
+	osmo_prim_init(&prim->oph, SCCP_SAP_USER,
+			OSMO_SCU_PRIM_N_CONNECT,
+			PRIM_OP_RESPONSE, msg);
+	memcpy(&prim->u.connect, param, sizeof(prim->u.connect));
+	return &prim->oph;
+}
+
+static int sccp_sap_up(struct osmo_prim_hdr *oph, void *link)
+{
+	struct osmo_scu_prim *prim = (struct osmo_scu_prim *) oph;
+	struct osmo_prim_hdr *resp = NULL;
+	const uint8_t payload[] = { 0xb1, 0xb2, 0xb3 };
+	int rc;
+	void *ue;
+
+	printf("sccp_sap_up(%s)\n", osmo_scu_prim_name(oph));
+
+	switch (OSMO_PRIM_HDR(oph)) {
+	case OSMO_PRIM(OSMO_SCU_PRIM_N_CONNECT, PRIM_OP_CONFIRM):
+		/* confirmation of outbound connection */
+		break;
+	case OSMO_PRIM(OSMO_SCU_PRIM_N_CONNECT, PRIM_OP_INDICATION):
+		/* indication of new inbound connection request*/
+		printf("N-CONNECT.ind(X->%u)\n", prim->u.connect.conn_id);
+		if (/*  prim->u.connect.called_addr.ssn != OSMO_SCCP_SSN_RANAP || */
+		    !msgb_l2(oph->msg) || msgb_l2len(oph->msg) == 0) {
+			LOGP(DMAIN, LOGL_NOTICE, "Received invalid N-CONNECT.ind\n");
+			return 0;
+		}
+		/* FIXME: allocate UE context */
+		/* first ensure the local SUA/SCCP socket is ACTIVE */
+		resp = make_conn_resp(&prim->u.connect);
+		osmo_sua_user_link_down(link, resp);
+		/* then handle the RANAP payload */
+		rc = cn_ranap_rx_co(ue, msgb_l2(oph->msg), msgb_l2len(oph->msg));
+		break;
+	case OSMO_PRIM(OSMO_SCU_PRIM_N_DISCONNECT, PRIM_OP_INDICATION):
+		/* indication of disconnect */
+		printf("N-DISCONNECT.ind(%u)\n", prim->u.disconnect.conn_id);
+		break;
+	case OSMO_PRIM(OSMO_SCU_PRIM_N_DATA, PRIM_OP_INDICATION):
+		/* connection-oriented data received */
+		printf("N-DATA.ind(%u, %s)\n", prim->u.data.conn_id,
+			osmo_hexdump(msgb_l2(oph->msg), msgb_l2len(oph->msg)));
+		/* FIXME: resolve UE context */
+		rc = cn_ranap_rx_co(ue, msgb_l2(oph->msg), msgb_l2len(oph->msg));
+		break;
+	case OSMO_PRIM(OSMO_SCU_PRIM_N_UNITDATA, PRIM_OP_INDICATION):
+		/* connection-oriented data received */
+		printf("N-UNITDATA.ind(%s)\n", 
+			osmo_hexdump(msgb_l2(oph->msg), msgb_l2len(oph->msg)));
+		rc = cn_ranap_rx_cl(link, msgb_l2(oph->msg), msgb_l2len(oph->msg));
+		break;
+	}
+
+	msgb_free(oph->msg);
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	struct osmo_sua_user *user;
+	void *ctx = talloc_named_const(NULL, 1, "root");
+	int rc;
+
+	osmo_sua_set_log_area(DSUA);
+
+	test_common_init();
+
+	user = osmo_sua_user_create(ctx, sccp_sap_up);
+
+	rc = osmo_sua_server_listen(user, "127.0.0.1", 14001);
+	if (rc < 0) {
+		exit(1);
+	}
+
+	while (1) {
+		osmo_select_main(0);
+	}
+}