diff --git a/src/tests/ranap_common_cn.c b/src/tests/ranap_common_cn.c
new file mode 100644
index 0000000..a26df03
--- /dev/null
+++ b/src/tests/ranap_common_cn.c
@@ -0,0 +1,303 @@
+/* RANAP interface for a core-network node */
+
+/* (C) 2015 by Harald Welte <laforge@gnumonks.org>
+ * 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 <unistd.h>
+#include <errno.h>
+#include <string.h>
+
+#include <osmocom/core/utils.h>
+#include <osmocom/core/logging.h>
+
+#include "ranap_common.h"
+#include "ranap_ies_defs.h"
+
+#include "cn_ranap_common.h"
+
+static int cn_ranap_rx_initiating_msg_co(void *ctx, RANAP_InitiatingMessage_t *imsg,
+					 ranap_message *message)
+{
+	int rc = 0;
+
+	message->procedureCode = imsg->procedureCode;
+	message->criticality = imsg->criticality;
+
+	DEBUGP(DRANAP, "Rx CO IM (%s)\n",
+		get_value_string(ranap_procedure_code_vals, imsg->procedureCode));
+
+	switch (imsg->procedureCode) {
+	case RANAP_ProcedureCode_id_InitialUE_Message:
+		rc = ranap_decode_initialue_messageies(&message->msg.initialUE_MessageIEs, &imsg->value);
+		break;
+	case RANAP_ProcedureCode_id_DirectTransfer:
+		rc = ranap_decode_directtransferies(&message->msg.directTransferIEs, &imsg->value);
+		break;
+	case RANAP_ProcedureCode_id_RAB_ReleaseRequest:
+		/* RNC requests the release of RAB */
+		rc = ranap_decode_rab_releaserequesties(&message->msg.raB_ReleaseRequestIEs, &imsg->value);
+		break;
+	case RANAP_ProcedureCode_id_Iu_ReleaseRequest:
+		/* RNC requests the release of Iu */
+		rc = ranap_decode_iu_releaserequesties(&message->msg.iu_ReleaseRequestIEs, &imsg->value);
+		break;
+	case RANAP_ProcedureCode_id_ErrorIndication:
+		rc = ranap_decode_errorindicationies(&message->msg.errorIndicationIEs, &imsg->value);
+		break;
+	case RANAP_ProcedureCode_id_RAB_ModifyRequest:
+		rc = ranap_decode_rab_modifyrequesties(&message->msg.raB_ModifyRequestIEs, &imsg->value);
+		break;
+	default:
+		LOGP(DRANAP, LOGL_NOTICE, "Received suspicious RANAP "
+		     "Procedure %s (CO, IM) from RNC, ignoring\n",
+		     get_value_string(ranap_procedure_code_vals, imsg->procedureCode));
+		rc = -1;
+		break;
+	}
+
+	return rc;
+}
+
+static int cn_ranap_rx_successful_msg_co(void *ctx, RANAP_SuccessfulOutcome_t *imsg,
+					 ranap_message *message)
+{
+	int rc = 0;
+
+	message->procedureCode = imsg->procedureCode;
+	message->criticality = imsg->criticality;
+
+	DEBUGP(DRANAP, "Rx CL SO (%s)\n",
+		get_value_string(ranap_procedure_code_vals, imsg->procedureCode));
+
+	switch (imsg->procedureCode) {
+	case RANAP_ProcedureCode_id_RAB_Assignment:
+		/* RAB assignment response */
+		rc = ranap_decode_rab_assignmentresponseies(&message->msg.raB_AssignmentResponseIEs, &imsg->value);
+		break;
+	case RANAP_ProcedureCode_id_SecurityModeControl:
+		/* Security Mode Complete */
+		rc = ranap_decode_securitymodecompleteies(&message->msg.securityModeCompleteIEs, &imsg->value);
+		break;
+	case RANAP_ProcedureCode_id_Iu_Release:
+		/* Iu release Complete; confirmation of CN-initiated release */
+		rc = ranap_decode_iu_releasecompleteies(&message->msg.iu_ReleaseCompleteIEs, &imsg->value);
+		break;
+	default:
+		LOGP(DRANAP, LOGL_NOTICE, "Received suspicious RANAP "
+		     "Procedure %s (SO) from RNC, ignoring\n",
+		     get_value_string(ranap_procedure_code_vals, imsg->procedureCode));
+		rc = -1;
+		break;
+	}
+
+	return rc;
+}
+
+static int _cn_ranap_rx_co(void *ctx, RANAP_RANAP_PDU_t *pdu, ranap_message *message)
+{
+	int rc = 0;
+
+	switch (pdu->present) {
+	case RANAP_RANAP_PDU_PR_initiatingMessage:
+		rc = cn_ranap_rx_initiating_msg_co(ctx, &pdu->choice.initiatingMessage, message);
+		break;
+	case RANAP_RANAP_PDU_PR_successfulOutcome:
+		rc = cn_ranap_rx_successful_msg_co(ctx, &pdu->choice.successfulOutcome, message);
+		break;
+	case RANAP_RANAP_PDU_PR_unsuccessfulOutcome:
+		LOGP(DRANAP, LOGL_NOTICE, "Received unsupported RANAP "
+		     "unsuccessful outcome procedure %s (CO) from RNC, ignoring\n",
+		     get_value_string(ranap_procedure_code_vals,
+			     	      pdu->choice.unsuccessfulOutcome.procedureCode));
+		rc = -1;
+		break;
+	default:
+		LOGP(DRANAP, LOGL_NOTICE, "Received suspicious RANAP "
+		     "presence %s (CO) from RNC, ignoring\n",
+		     get_value_string(ranap_presence_vals, pdu->present));
+		rc = -1;
+		break;
+	}
+
+	return rc;
+}
+
+/* receive a connection-oriented RANAP message and call
+ * cn_ranap_handle_co() with the resulting ranap_message struct */
+int cn_ranap_rx_co(void *ctx, uint8_t *data, size_t len)
+{
+	RANAP_RANAP_PDU_t *pdu = NULL;
+	ranap_message message;
+	asn_dec_rval_t dec_ret;
+	int rc;
+
+	memset(&message, 0, sizeof(message));
+
+	memset(pdu, 0, sizeof(*pdu));
+	dec_ret = aper_decode(NULL,&asn_DEF_RANAP_RANAP_PDU, (void **) &pdu,
+			      data, len, 0, 0);
+	if (dec_ret.code != RC_OK) {
+		LOGP(DRANAP, LOGL_ERROR, "Error in RANAP ASN.1 decode\n");
+		return rc;
+	}
+
+	message.direction = pdu->present;
+
+	rc = _cn_ranap_rx_co(ctx, pdu, &message);
+
+	if (rc == 0)
+		cn_ranap_handle_co(ctx, &message);
+
+	ASN_STRUCT_FREE(asn_DEF_RANAP_RANAP_PDU, pdu);
+
+	return rc;
+}
+
+static int cn_ranap_rx_initiating_msg_cl(void *ctx, RANAP_InitiatingMessage_t *imsg,
+					 ranap_message *message)
+{
+	int rc;
+
+	message->procedureCode = imsg->procedureCode;
+	message->criticality = imsg->criticality;
+
+	DEBUGP(DRANAP, "Rx CL IM (%s)\n",
+		get_value_string(ranap_procedure_code_vals, imsg->procedureCode));
+
+	switch (imsg->procedureCode) {
+	case RANAP_ProcedureCode_id_Reset:
+		/* Reset request */
+		rc = ranap_decode_reseties(&message->msg.resetIEs, &imsg->value);
+		break;
+	case RANAP_ProcedureCode_id_OverloadControl: /* Overload ind */
+		rc = ranap_decode_overloadies(&message->msg.overloadIEs, &imsg->value);
+		break;
+	case RANAP_ProcedureCode_id_ErrorIndication: /* Error ind */
+		rc = ranap_decode_errorindicationies(&message->msg.errorIndicationIEs, &imsg->value);
+		break;
+	case RANAP_ProcedureCode_id_ResetResource: /* request */
+		rc = ranap_decode_resetresourceies(&message->msg.resetResourceIEs, &imsg->value);
+		break;
+	case RANAP_ProcedureCode_id_InformationTransfer:
+		rc = ranap_decode_informationtransferindicationies(&message->msg.informationTransferIndicationIEs, &imsg->value);
+		break;
+	case RANAP_ProcedureCode_id_DirectInformationTransfer:
+		rc = ranap_decode_directinformationtransferies(&message->msg.directInformationTransferIEs, &imsg->value);
+		break;
+	case RANAP_ProcedureCode_id_UplinkInformationExchange:
+		rc = ranap_decode_uplinkinformationexchangerequesties(&message->msg.uplinkInformationExchangeRequestIEs, &imsg->value);
+		break;
+	default:
+		LOGP(DRANAP, LOGL_NOTICE, "Received suspicious RANAP "
+		     "Procedure %s (CL, IM) from RNC, ignoring\n",
+		     get_value_string(ranap_procedure_code_vals, imsg->procedureCode));
+		break;
+	}
+}
+
+static int cn_ranap_rx_successful_msg_cl(void *ctx, RANAP_SuccessfulOutcome_t *imsg,
+					 ranap_message *message)
+{
+	int rc;
+
+	message->procedureCode = imsg->procedureCode;
+	message->criticality = imsg->criticality;
+
+	DEBUGP(DRANAP, "Rx CL SO (%s)\n",
+		get_value_string(ranap_procedure_code_vals, imsg->procedureCode));
+
+	switch (imsg->procedureCode) {
+	case RANAP_ProcedureCode_id_Reset: /* Reset acknowledge */
+		rc = ranap_decode_resetacknowledgeies(&message->msg.resetAcknowledgeIEs, &imsg->value);
+		break;
+	case RANAP_ProcedureCode_id_ResetResource: /* response */
+		rc = ranap_decode_resetresourceacknowledgeies(&message->msg.resetResourceAcknowledgeIEs, &imsg->value);
+	case RANAP_ProcedureCode_id_InformationTransfer:
+		rc = ranap_decode_resetresourceacknowledgeies(&message->msg.resetResourceAcknowledgeIEs, &imsg->value);
+		break;
+	case RANAP_ProcedureCode_id_DirectInformationTransfer:
+		rc = ranap_decode_informationtransferconfirmationies(&message->msg.informationTransferConfirmationIEs, &imsg->value);
+		break;
+	case RANAP_ProcedureCode_id_UplinkInformationExchange:
+		rc = ranap_decode_uplinkinformationexchangeresponseies(&message->msg.uplinkInformationExchangeResponseIEs, &imsg->value);
+		break;
+	default:
+		LOGP(DRANAP, LOGL_NOTICE, "Received suspicious RANAP "
+		     "Procedure %s (CL, SO) from RNC, ignoring\n",
+		     get_value_string(ranap_procedure_code_vals, imsg->procedureCode));
+		break;
+	}
+}
+
+static int _cn_ranap_rx_cl(void *ctx, RANAP_RANAP_PDU_t *pdu, ranap_message *message)
+{
+	int rc;
+
+	switch (pdu->present) {
+	case RANAP_RANAP_PDU_PR_initiatingMessage:
+		rc = cn_ranap_rx_initiating_msg_cl(ctx, &pdu->choice.initiatingMessage,
+						   message);
+		break;
+	case RANAP_RANAP_PDU_PR_successfulOutcome:
+		rc = cn_ranap_rx_successful_msg_cl(ctx, &pdu->choice.successfulOutcome,
+						   message);
+		break;
+	case RANAP_RANAP_PDU_PR_unsuccessfulOutcome:
+		LOGP(DRANAP, LOGL_NOTICE, "Received unsupported RANAP "
+		     "unsuccessful outcome procedure %s (CL) from RNC, ignoring\n",
+		     get_value_string(ranap_procedure_code_vals,
+			     	      pdu->choice.unsuccessfulOutcome.procedureCode));
+		break;
+	default:
+		LOGP(DRANAP, LOGL_NOTICE, "Received suspicious RANAP "
+		     "presence %s (CL) from RNC, ignoring\n",
+		     get_value_string(ranap_presence_vals, pdu->present));
+		break;
+	}
+}
+
+/* receive a connection-oriented RANAP message and call
+ * cn_ranap_handle_co() with the resulting ranap_message struct */
+int cn_ranap_rx_cl(void *ctx, uint8_t *data, size_t len)
+{
+	RANAP_RANAP_PDU_t *pdu = NULL;
+	ranap_message message;
+	asn_dec_rval_t dec_ret;
+	int rc;
+
+	memset(&message, 0, sizeof(message));
+
+	memset(pdu, 0, sizeof(*pdu));
+	dec_ret = aper_decode(NULL,&asn_DEF_RANAP_RANAP_PDU, (void **) &pdu,
+			      data, len, 0, 0);
+	if (dec_ret.code != RC_OK) {
+		LOGP(DRANAP, LOGL_ERROR, "Error in RANAP ASN.1 decode\n");
+		return rc;
+	}
+
+	message.direction = pdu->present;
+
+	rc = _cn_ranap_rx_cl(ctx, pdu, &message);
+
+	if (rc == 0)
+		cn_ranap_handle_cl(ctx, &message);
+
+	ASN_STRUCT_FREE(asn_DEF_RANAP_RANAP_PDU, pdu);
+
+	return rc;
+}