diff --git a/openbsc/include/Makefile.am b/openbsc/include/Makefile.am
index a95129f..56b2a33 100644
--- a/openbsc/include/Makefile.am
+++ b/openbsc/include/Makefile.am
@@ -1,3 +1,3 @@
-SUBDIRS = openbsc vty
+SUBDIRS = openbsc vty sccp
 
 noinst_HEADERS = mISDNif.h compat_af_isdn.h
diff --git a/openbsc/include/sccp/Makefile.am b/openbsc/include/sccp/Makefile.am
new file mode 100644
index 0000000..42fd310
--- /dev/null
+++ b/openbsc/include/sccp/Makefile.am
@@ -0,0 +1 @@
+noinst_HEADERS = sccp_types.h sccp.h
diff --git a/openbsc/include/sccp/sccp.h b/openbsc/include/sccp/sccp.h
new file mode 100644
index 0000000..8ee4b68
--- /dev/null
+++ b/openbsc/include/sccp/sccp.h
@@ -0,0 +1,145 @@
+/*
+ * SCCP management code
+ *
+ * (C) 2009 by Holger Hans Peter Freyther <zecke@selfish.org>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#ifndef SCCP_H
+#define SCCP_H
+
+#include <stdlib.h>
+
+#include <sys/socket.h>
+
+#include <openbsc/msgb.h>
+
+#include "sccp_types.h"
+
+struct sccp_system;
+
+enum {
+	SCCP_CONNECTION_STATE_NONE,
+	SCCP_CONNECTION_STATE_REQUEST,
+	SCCP_CONNECTION_STATE_CONFIRM,
+	SCCP_CONNECTION_STATE_ESTABLISHED,
+	SCCP_CONNECTION_STATE_RELEASE,
+	SCCP_CONNECTION_STATE_RELEASE_COMPLETE,
+	SCCP_CONNECTION_STATE_REFUSED,
+	SCCP_CONNECTION_STATE_SETUP_ERROR,
+};
+
+struct sockaddr_sccp {
+	sa_family_t	sccp_family;		/* AF_SCCP in the future??? */
+	u_int8_t	sccp_ssn;		/* subssystem number for routing */
+
+	/* TODO fill in address indicator... if that is ever needed */
+
+	/* not sure about these */
+	/* u_int8_t    sccp_class; */
+};
+
+/*
+ * parsed structure of an address
+ */
+struct sccp_address {
+	struct sccp_called_party_address    address;
+	u_int8_t			    ssn;
+	u_int8_t			    poi[2];
+};
+
+struct sccp_optional_data {
+	u_int8_t			    data_len;
+	u_int8_t			    data_start;
+};
+
+struct sccp_connection {
+	/* public */
+	void *data_ctx;
+	void (*data_cb)(struct sccp_connection *conn, struct msgb *msg, unsigned int len);
+
+	void *state_ctx;
+	void (*state_cb)(struct sccp_connection *, int old_state);
+
+	struct sccp_source_reference source_local_reference;
+	struct sccp_source_reference destination_local_reference;
+
+	int connection_state;
+
+	/* private */
+	/* list of active connections */
+	struct llist_head list;
+	struct sccp_system *system;
+	int incoming;
+};
+
+/**
+ * system functionality to implement on top of any other transport layer:
+ *   call sccp_system_incoming for incoming data (from the network)
+ *   sccp will call outgoing whenever outgoing data exists
+ */
+int sccp_system_init(int (*outgoing)(struct msgb *data, void *ctx), void *context);
+int sccp_system_incoming(struct msgb *data);
+
+/**
+ * Send data on an existing connection
+ */
+int sccp_connection_write(struct sccp_connection *connection, struct msgb *data);
+int sccp_connection_close(struct sccp_connection *connection, int cause);
+int sccp_connection_free(struct sccp_connection *connection);
+
+/**
+ * Create a new socket. Set your callbacks and then call bind to open
+ * the connection.
+ */
+struct sccp_connection *sccp_connection_socket(void);
+
+/**
+ * Open the connection and send additional data
+ */
+int sccp_connection_connect(struct sccp_connection *conn,
+			    const struct sockaddr_sccp *sccp_called,
+			    struct msgb *data);
+
+/**
+ * mostly for testing purposes only. Set the accept callback.
+ * TODO: add true routing information... in analogy to socket, bind, accept
+ */
+int sccp_connection_set_incoming(const struct sockaddr_sccp *sock,
+				 int (*accept_cb)(struct sccp_connection *connection, void *data),
+				 void *user_data);
+
+/**
+ * Send data in terms of unit data. A fixed address indicator will be used.
+ */
+int sccp_write(struct msgb *data,
+	       const struct sockaddr_sccp *sock_sender,
+	       const struct sockaddr_sccp *sock_target, int class);
+int sccp_set_read(const struct sockaddr_sccp *sock,
+		  int (*read_cb)(struct msgb *msgb, unsigned int, void *user_data),
+		  void *user_data);
+
+/* generic sock addresses */
+extern const struct sockaddr_sccp sccp_ssn_bssap;
+
+/* helpers */
+u_int32_t sccp_src_ref_to_int(struct sccp_source_reference *ref);
+struct sccp_source_reference sccp_src_ref_from_int(u_int32_t);
+
+#endif
diff --git a/openbsc/include/sccp/sccp_types.h b/openbsc/include/sccp/sccp_types.h
new file mode 100644
index 0000000..c6b1182
--- /dev/null
+++ b/openbsc/include/sccp/sccp_types.h
@@ -0,0 +1,383 @@
+/*
+ * ITU Q.713 defined types for SCCP
+ *
+ * (C) 2009 by Holger Hans Peter Freyther <zecke@selfish.org>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#ifndef SCCP_TYPES_H
+#define SCCP_TYPES_H
+
+/* Table 1/Q.713 - SCCP message types */
+enum sccp_message_types {
+	SCCP_MSG_TYPE_CR	= 1,
+	SCCP_MSG_TYPE_CC	= 2,
+	SCCP_MSG_TYPE_CREF	= 3,
+	SCCP_MSG_TYPE_RLSD	= 4,
+	SCCP_MSG_TYPE_RLC	= 5,
+	SCCP_MSG_TYPE_DT1	= 6,
+	SCCP_MSG_TYPE_DT2	= 7,
+	SCCP_MSG_TYPE_AK	= 8,
+	SCCP_MSG_TYPE_UDT	= 9,
+	SCCP_MSG_TYPE_UDTS	= 10,
+	SCCP_MSG_TYPE_ED	= 11,
+	SCCP_MSG_TYPE_EA	= 12,
+	SCCP_MSG_TYPE_RSR	= 13,
+	SCCP_MSG_TYPE_RSC	= 14,
+	SCCP_MSG_TYPE_ERR	= 15,
+	SCCP_MSG_TYPE_IT	= 16,
+	SCCP_MSG_TYPE_XUDT	= 17,
+	SCCP_MSG_TYPE_XUDTS	= 18,
+	SCCP_MSG_TYPE_LUDT	= 19,
+	SCCP_MSG_TYPE_LUDTS	= 20
+};
+
+/* Table 2/Q.713 - SCCP parameter name codes */
+enum sccp_parameter_name_codes {
+	SCCP_PNC_END_OF_OPTIONAL		= 0,
+	SCCP_PNC_DESTINATION_LOCAL_REFERENCE	= 1,
+	SCCP_PNC_SOURCE_LOCAL_REFERENCE		= 2,
+	SCCP_PNC_CALLED_PARTY_ADDRESS		= 3,
+	SCCP_PNC_CALLING_PARTY_ADDRESS		= 4,
+	SCCP_PNC_PROTOCOL_CLASS			= 5,
+	SCCP_PNC_SEGMENTING			= 6,
+	SCCP_PNC_RECEIVE_SEQ_NUMBER		= 7,
+	SCCP_PNC_SEQUENCING			= 8,
+	SCCP_PNC_CREDIT				= 9,
+	SCCP_PNC_RELEASE_CAUSE			= 10,
+	SCCP_PNC_RETURN_CAUSE			= 11,
+	SCCP_PNC_RESET_CAUSE			= 12,
+	SCCP_PNC_ERROR_CAUSE			= 13,
+	SCCP_PNC_REFUSAL_CAUSE			= 14,
+	SCCP_PNC_DATA				= 15,
+	SCCP_PNC_SEGMENTATION			= 16,
+	SCCP_PNC_HOP_COUNTER			= 17,
+	SCCP_PNC_IMPORTANCE			= 18,
+	SCCP_PNC_LONG_DATA			= 19,
+};
+
+/* Figure 3/Q.713 Called/calling party address */
+enum {
+	SCCP_TITLE_IND_NONE			= 0,
+	SCCP_TITLE_IND_NATURE_ONLY		= 1,
+	SCCP_TITLE_IND_TRANSLATION_ONLY		= 2,
+	SCCP_TITLE_IND_TRANS_NUM_ENC		= 3,
+	SCCP_TITLE_IND_TRANS_NUM_ENC_NATURE	= 4,
+};
+
+enum {
+	SCCP_CALL_ROUTE_ON_SSN			= 1,
+	SCCP_CALL_ROUTE_ON_GT			= 0,
+};
+
+struct sccp_called_party_address {
+	u_int8_t	point_code_indicator : 1,
+			ssn_indicator	     : 1,
+			global_title_indicator : 4,
+			routing_indicator    : 1,
+			reserved	     : 1;
+	u_int8_t	data[0];
+} __attribute__((packed));
+
+/* indicator indicates presence in the above order */
+
+/* Figure 6/Q.713 */
+struct sccp_signalling_point_code {
+	u_int8_t	lsb;
+	u_int8_t	msb : 6,
+			reserved : 2;
+} __attribute__((packed));
+
+/* SSN == subsystem number */
+enum sccp_subsystem_number {
+	SCCP_SSN_NOT_KNOWN_OR_USED	    = 0,
+	SCCP_SSN_MANAGEMENT		    = 1,
+	SCCP_SSN_RESERVED_ITU		    = 2,
+	SCCP_SSN_ISDN_USER_PART		    = 3,
+	SCCP_SSN_OMAP			    = 4, /* operation, maint and administration part */
+	SCCP_SSN_MAP			    = 5, /* mobile application part */
+	SCCP_SSN_HLR			    = 6,
+	SCCP_SSN_VLR			    = 7,
+	SCCP_SSN_MSC			    = 8,
+	SCCP_SSN_EIC			    = 9, /* equipent identifier centre */
+	SCCP_SSN_AUC			    = 10, /* authentication centre */
+	SCCP_SSN_ISDN_SUPPL_SERVICES	    = 11,
+	SCCP_SSN_RESERVED_INTL		    = 12,
+	SCCP_SSN_ISDN_EDGE_TO_EDGE	    = 13,
+	SCCP_SSN_TC_TEST_RESPONDER	    = 14,
+
+	/* From GSM 03.03 8.2 */
+	SCCP_SSN_BSSAP			    = 254,
+	SCCP_SSN_BSSOM			    = 253,
+};
+
+/* Q.713, 3.4.2.3 */
+enum {
+	SCCP_NAI_UNKNOWN		    = 0,
+	SCCP_NAI_SUBSCRIBER_NUMBER	    = 1,
+	SCCP_NAI_RESERVED_NATIONAL	    = 2,
+	SCCP_NAI_NATIONAL_SIGNIFICANT	    = 3,
+	SCCP_NAI_INTERNATIONAL		    = 4,
+};
+
+struct sccp_global_title {
+	u_int8_t	nature_of_addr_ind : 7,
+			odd_even : 1;
+	u_int8_t	data[0];
+} __attribute__((packed));
+
+/* Q.713, 3.3 */
+struct sccp_source_reference {
+	u_int8_t    octet1;
+	u_int8_t    octet2;
+	u_int8_t    octet3;
+} __attribute__((packed));
+
+/* Q.714, 3.6 */
+enum sccp_protocol_class {
+	SCCP_PROTOCOL_CLASS_0		    = 0,
+	SCCP_PROTOCOL_CLASS_1		    = 1,
+	SCCP_PROTOCOL_CLASS_2		    = 2,
+	SCCP_PROTOCOL_CLASS_3		    = 3,
+};
+
+/* bits 5-8 when class0, class1 is used */
+enum sccp_protocol_options {
+	SCCP_PROTOCOL_NO_SPECIAL	    = 0,
+	SCCP_PROTOCOL_RETURN_MESSAGE	    = 8,
+};
+
+enum sccp_release_cause {
+	SCCP_RELEASE_CAUSE_END_USER_ORIGINATED	    = 0,
+	SCCP_RELEASE_CAUSE_END_USER_CONGESTION	    = 1,
+	SCCP_RELEASE_CAUSE_END_USER_FAILURE	    = 2,
+	SCCP_RELEASE_CAUSE_SCCP_USER_ORIGINATED	    = 3,
+	SCCP_RELEASE_CAUSE_REMOTE_PROCEDURE_ERROR   = 4,
+	SCCP_RELEASE_CAUSE_INCONSISTENT_CONN_DATA   = 5,
+	SCCP_RELEASE_CAUSE_ACCESS_FAILURE	    = 6,
+	SCCP_RELEASE_CAUSE_ACCESS_CONGESTION	    = 7,
+	SCCP_RELEASE_CAUSE_SUBSYSTEM_FAILURE	    = 8,
+	SCCP_RELEASE_CAUSE_SUBSYSTEM_CONGESTION	    = 9,
+	SCCP_RELEASE_CAUSE_MTP_FAILURE		    = 10,
+	SCCP_RELEASE_CAUSE_NETWORK_CONGESTION	    = 11,
+	SCCP_RELEASE_CAUSE_EXPIRATION_RESET	    = 12,
+	SCCP_RELEASE_CAUSE_EXPIRATION_INACTIVE	    = 13,
+	SCCP_RELEASE_CAUSE_RESERVED		    = 14,
+	SCCP_RELEASE_CAUSE_UNQUALIFIED		    = 15,
+	SCCP_RELEASE_CAUSE_SCCP_FAILURE		    = 16,
+};
+
+enum sccp_return_cause {
+	SCCP_RETURN_CAUSE_NO_TRANSLATION_NATURE	    = 0,
+	SCCP_RETURN_CAUSE_NO_TRANSLATION	    = 1,
+	SCCP_RETURN_CAUSE_SUBSYSTEM_CONGESTION	    = 2,
+	SCCP_RETURN_CAUSE_SUBSYSTEM_FAILURE	    = 3,
+	SCCP_RETURN_CAUSE_UNEQUIPPED_USER	    = 4,
+	SCCP_RETURN_CAUSE_MTP_FAILURE		    = 5,
+	SCCP_RETURN_CAUSE_NETWORK_CONGESTION	    = 6,
+	SCCP_RETURN_CAUSE_UNQUALIFIED		    = 7,
+	SCCP_RETURN_CAUSE_ERROR_IN_MSG_TRANSPORT    = 8,
+	SCCP_RETURN_CAUSE_ERROR_IN_LOCAL_PROCESSING = 9,
+	SCCP_RETURN_CAUSE_DEST_CANNOT_PERFORM_REASSEMBLY = 10,
+	SCCP_RETURN_CAUSE_SCCP_FAILURE		    = 11,
+	SCCP_RETURN_CAUSE_HOP_COUNTER_VIOLATION	    = 12,
+	SCCP_RETURN_CAUSE_SEGMENTATION_NOT_SUPPORTED= 13,
+	SCCP_RETURN_CAUSE_SEGMENTATION_FAOLURE	    = 14
+};
+
+enum sccp_reset_cause {
+	SCCP_RESET_CAUSE_END_USER_ORIGINATED	    = 0,
+	SCCP_RESET_CAUSE_SCCP_USER_ORIGINATED	    = 1,
+	SCCP_RESET_CAUSE_MSG_OUT_OF_ORDER_PS	    = 2,
+	SCCP_RESET_CAUSE_MSG_OUT_OF_ORDER_PR	    = 3,
+	SCCP_RESET_CAUSE_RPC_OUT_OF_WINDOW	    = 4,
+	SCCP_RESET_CAUSE_RPC_INCORRECT_PS	    = 5,
+	SCCP_RESET_CAUSE_RPC_GENERAL		    = 6,
+	SCCP_RESET_CAUSE_REMOTE_END_USER_OPERATIONAL= 7,
+	SCCP_RESET_CAUSE_NETWORK_OPERATIONAL	    = 8,
+	SCCP_RESET_CAUSE_ACCESS_OPERATIONAL	    = 9,
+	SCCP_RESET_CAUSE_NETWORK_CONGESTION	    = 10,
+	SCCP_RESET_CAUSE_RESERVED		    = 11,
+};
+
+enum sccp_error_cause {
+	SCCP_ERROR_LRN_MISMATCH_UNASSIGNED	    = 0, /* local reference number */
+	SCCP_ERROR_LRN_MISMATCH_INCONSISTENT	    = 1,
+	SCCP_ERROR_POINT_CODE_MISMATCH		    = 2,
+	SCCP_ERROR_SERVICE_CLASS_MISMATCH	    = 3,
+	SCCP_ERROR_UNQUALIFIED			    = 4,
+};
+
+enum sccp_refusal_cause {
+	SCCP_REFUSAL_END_USER_ORIGINATED	    = 0,
+	SCCP_REFUSAL_END_USER_CONGESTION	    = 1,
+	SCCP_REFUSAL_END_USER_FAILURE		    = 2,
+	SCCP_REFUSAL_SCCP_USER_ORIGINATED	    = 3,
+	SCCP_REFUSAL_DESTINATION_ADDRESS_UKNOWN	    = 4,
+	SCCP_REFUSAL_DESTINATION_INACCESSIBLE	    = 5,
+	SCCP_REFUSAL_NET_QOS_NON_TRANSIENT	    = 6,
+	SCCP_REFUSAL_NET_QOS_TRANSIENT		    = 7,
+	SCCP_REFUSAL_ACCESS_FAILURE		    = 8,
+	SCCP_REFUSAL_ACCESS_CONGESTION		    = 9,
+	SCCP_REFUSAL_SUBSYSTEM_FAILURE		    = 10,
+	SCCP_REFUSAL_SUBSYTEM_CONGESTION	    = 11,
+	SCCP_REFUSAL_EXPIRATION			    = 12,
+	SCCP_REFUSAL_INCOMPATIBLE_USER_DATA	    = 13,
+	SCCP_REFUSAL_RESERVED			    = 14,
+	SCCP_REFUSAL_UNQUALIFIED		    = 15,
+	SCCP_REFUSAL_HOP_COUNTER_VIOLATION	    = 16,
+	SCCP_REFUSAL_SCCP_FAILURE		    = 17,
+	SCCP_REFUSAL_UNEQUIPPED_USER		    = 18,
+};
+
+/*
+ * messages... as of Q.713 Chapter 4
+ */
+struct sccp_connection_request {
+	/* mandantory */
+	u_int8_t			type;
+	struct sccp_source_reference	source_local_reference;
+	u_int8_t			proto_class;
+
+
+	/* variable */
+	u_int8_t			variable_called;
+#if VARIABLE
+	called_party_address
+#endif
+
+	/* optional */
+	u_int8_t			optional_start;
+
+#if OPTIONAL
+	credit 3
+	callingparty var 4-n
+	data            3-130
+	hop_counter     3
+	importance      3
+	end_of_optional 1
+#endif
+
+	u_int8_t			data[0];
+} __attribute__((packed));
+
+struct sccp_connection_confirm {
+	/* mandantory */
+	u_int8_t			type;
+	struct sccp_source_reference	destination_local_reference;
+	struct sccp_source_reference	source_local_reference;
+	u_int8_t			proto_class;
+
+	/* optional */
+	u_int8_t			optional_start;
+
+	/* optional */
+#if OPTIONAL
+	credit 3
+	called party 4
+	data            3-130
+	importance      3
+	end_of_optional 1
+#endif
+
+	u_int8_t			data[0];
+} __attribute__((packed));
+
+struct sccp_connection_refused {
+	/* mandantory */
+	u_int8_t			type;
+	struct sccp_source_reference	destination_local_reference;
+	u_int8_t			cause;
+
+	/* optional */
+	u_int8_t			optional_start;
+
+	/* optional */
+#if OPTIONAL
+	called party 4
+	data            3-130
+	importance      3
+	end_of_optional 1
+#endif
+
+	u_int8_t			data[0];
+} __attribute__((packed));
+
+struct sccp_connection_released {
+	/* mandantory */
+	u_int8_t			type;
+	struct sccp_source_reference	destination_local_reference;
+	struct sccp_source_reference	source_local_reference;
+	u_int8_t			release_cause;
+
+
+	/* optional */
+	u_int8_t			optional_start;
+
+#if OPTIONAL
+	data            3-130
+	importance      3
+	end_of_optional 1
+#endif
+	u_int8_t			data[0];
+} __attribute__((packed));
+
+struct sccp_connection_release_complete {
+	u_int8_t			type;
+	struct sccp_source_reference	destination_local_reference;
+	struct sccp_source_reference	source_local_reference;
+} __attribute__((packed));
+
+struct sccp_data_form1 {
+	/* mandantory */
+	u_int8_t			type;
+	struct sccp_source_reference	destination_local_reference;
+	u_int8_t			segmenting;
+
+	/* variable */
+	u_int8_t			variable_start;
+
+#if VARIABLE
+	data 2-256;
+#endif
+
+	u_int8_t			data[0];
+} __attribute__((packed));
+
+
+struct sccp_data_unitdata {
+	/* mandantory */
+	u_int8_t			type;
+	u_int8_t			proto_class;
+
+
+	/* variable */
+	u_int8_t			variable_called;
+	u_int8_t			variable_calling;
+	u_int8_t			variable_data;
+
+#if VARIABLE
+	called party address
+	calling party address
+#endif
+
+	u_int8_t			data[0];
+} __attribute__((packed));
+
+#endif