diff --git a/src/osmo_sccp_tcap.erl b/src/osmo_sccp_tcap.erl
new file mode 100644
index 0000000..8b9201d
--- /dev/null
+++ b/src/osmo_sccp_tcap.erl
@@ -0,0 +1,127 @@
+% wrapper code between signerl/TCAP and osmo_ss7/SCCP
+
+-module(osmo_sccp_tcap).
+
+-copyright('Copyright (C) 2011 by Harald Welte <laforge@gnumonks.org>').
+-author('Harald Welte <laforge@gnumonks.org>').
+
+-behaviour(tcap_tco_server).
+
+-include_lib("osmo_ss7/include/osmo_util.hrl").
+-include_lib("osmo_ss7/include/sccp.hrl").
+-include_lib("TCAP/include/sccp.hrl").
+
+%% callbacks needed for gen_server behaviour
+-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
+	 terminate/2, code_change/3]).
+
+%% callbacks needed for tcap_tco_server
+-export([send_primitive/2, start_user/3]).
+
+%% our published API functions
+-export([start_link/1, stop/1]).
+
+start_link(SSN) ->
+	Ourname = list_to_atom("sccp_ssn" ++ integer_to_list(SSN)),
+	gen_server:start_link({local, Ourname}, ?MODULE, [SSN],[]).
+
+init([SupRef, SSN]) ->
+	ok = sccp_user:bind_ssn(SSN, undefined),
+	State = 1,
+	{ok, State}.
+
+handle_call(stop, _From, State) ->
+	{stop, shutdown, State}.
+
+handle_cast(Request, State) ->
+	error_logger:error_report(["unknown handle_cast",
+				   {request, Request}, {state, State}]),
+	{noreply, State}.
+
+osmo_prim2signerl(#primitive{subsystem='N', gen_name='UNITDATA',
+			     spec_name=Spec, parameters=Msg}) ->
+	Params = Msg#sccp_msg.parameters,
+	CalledAddr = proplists:get_value(called_party_addr, Params),
+	CallingAddr = proplists:get_value(calling_party_addr, Params),
+	UserData = proplists:get_value(user_data, Params),
+	{PC, Opt} = proplists:get_value(protocol_class, Params),
+	Rec = #'N-UNITDATA'{calledAddress = CalledAddr,
+			    callingAddress = CallingAddr,
+			    sequenceControl = undefined,
+			    returnOption = undefined,
+			    importance = undefined,
+		    	    userData = UserData},
+	{'N','UNITDATA', Spec, Rec}.
+
+% incoming message from
+handle_info({sccp, P= #primitive{subsystem='N',
+				 gen_name='UNITDATA',
+				 spec_name=indication}}, State) ->
+	% this is really ugly, we need to make TCO understand #primitives
+	gen_server:cast(self(), osmo_prim2signerl(P)),
+	{noreply, State};
+handle_info(Info, State) ->
+	error_logger:error_report(["unknown handle_info",
+				   {info, Info}, {state, State}]),
+	{noreply, State}.
+
+terminate(Reason, State) ->
+	io:format("terminating with Reason ~w", [Reason]),
+	ok.
+
+%% @spec (NSAP) -> ok
+%% 	NSAP = pid()
+%%
+%% @doc Stop an sccp server.
+%% 	<p>Closes an SCCP service access point (SAP).</p>
+%% 	<p><tt>NSAP</tt> is a pid returned from a previous call to
+%% 	<tt>start_link/2,3,7</tt>.</p>
+%%
+stop(NSAP) ->
+	gen_server:call(NSAP, stop).
+
+% UNITDATA.req
+
+% message coming down from TCO to SCCP, to be transmitted
+send_primitive({'N', 'UNITDATA', request, #'N-UNITDATA'{calledAddress = Called,
+						     callingAddress = Calling,
+						     sequenceControl = Seq,
+						     returnOption = RetOpt,
+						     importance = Imp,
+						     userData = UserData}=Par}, State) ->
+	io:format("N-UNITDATA.req (~w,~w)~n", [Par, State]),
+	ClassOut = protocol_class(tcap_to_osmo, {Seq, RetOpt}),
+	UserDataOut = iolist_to_binary(UserData),
+	% Build an osmo_ss7 primitive
+	Prim = osmo_util:make_prim('N', 'UNITDATA', request,
+				       [{called_party_addr, Called},
+					{calling_party_addr, Calling},
+					{protocol_class, ClassOut},
+					{user_data, UserDataOut}]),
+	% send primitive to SCCP code
+	gen_fsm:send_event(sccp_scrc, Prim).
+
+
+% TCAP has received the start of a new dialogue, return pid() of new user
+start_user({DhaPid, CcoPid}, DialogueID, State) ->
+	tcap_test_user:start_link({DhaPid,CcoPid}, DialogueID).
+
+
+% convert signerl format to osmo format
+protocol_class(tcap_to_osmo, {SeqIn, ReturnIn}) ->
+	case SeqIn of
+	    true ->
+		Class = 1;
+	    _ ->
+		Class = 0
+	end,
+	case ReturnIn of
+	    true ->
+		{Class, 8};
+	    _ ->
+		{Class, 0}
+	end.
+
+
+code_change(_OldVsn, State, _Extra) ->
+	{ok, State}.