diff --git a/src/sg_as_sup.erl b/src/sg_as_sup.erl
new file mode 100644
index 0000000..96ab1b7
--- /dev/null
+++ b/src/sg_as_sup.erl
@@ -0,0 +1,52 @@
+% SIGTRAN SGW AS supervisor
+
+% (C) 2012 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 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/>.
+%
+% Additional Permission under GNU AGPL version 3 section 7:
+%
+% If you modify this Program, or any covered work, by linking or
+% combining it with runtime libraries of Erlang/OTP as released by
+% Ericsson on http://www.erlang.org (or a modified version of these
+% libraries), containing parts covered by the terms of the Erlang Public
+% License (http://www.erlang.org/EPLICENSE), the licensors of this
+% Program grant you additional permission to convey the resulting work
+% without the need to license the runtime libraries of Erlang/OTP under
+% the GNU Affero General Public License. Corresponding Source for a
+% non-source form of such a combination shall include the source code
+% for the parts of the runtime libraries of Erlang/OTP used as well as
+% that of the covered work.
+
+-module(sg_as_sup).
+-author('Harald Welte <laforge@gnumonks.org>').
+-behaviour(supervisor).
+
+-export([init/1, start_link/2]).
+
+init([Name, Options]) ->
+	AsName = list_to_atom("sg_as_" ++ Name ++ "_fsm"),
+	StartArgs = [{local, AsName}, xua_as_fsm, [], Options],
+	StartFunc = {gen_fsm, start_link, StartArgs},
+	ChildSpec = {as_fsm, StartFunc, permanent, 4000, worker, [xua_as_fsm]},
+
+	AspsName = list_to_atom("sg_asp_" ++ Name ++ "_sup"),
+	StartFuncASPS = {supervisor, start_link, [{local, AspsName}, sg_asp_sup, [Name, self()]]},
+	ChildSpecASPS = {asp_sup, StartFuncASPS, permanent, 4000, worker, [asp_sup]},
+	{ok, {{one_for_all, 1, 1}, [ChildSpec, ChildSpecASPS]}}.
+
+start_link(Name, Options) ->
+	supervisor:start_link(?MODULE, [Name, Options]).
diff --git a/src/sg_asp_sup.erl b/src/sg_asp_sup.erl
new file mode 100644
index 0000000..3c9e5ac
--- /dev/null
+++ b/src/sg_asp_sup.erl
@@ -0,0 +1,48 @@
+% SIGTRAN SGW ASP supervisor
+
+% (C) 2012 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 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/>.
+%
+% Additional Permission under GNU AGPL version 3 section 7:
+%
+% If you modify this Program, or any covered work, by linking or
+% combining it with runtime libraries of Erlang/OTP as released by
+% Ericsson on http://www.erlang.org (or a modified version of these
+% libraries), containing parts covered by the terms of the Erlang Public
+% License (http://www.erlang.org/EPLICENSE), the licensors of this
+% Program grant you additional permission to convey the resulting work
+% without the need to license the runtime libraries of Erlang/OTP under
+% the GNU Affero General Public License. Corresponding Source for a
+% non-source form of such a combination shall include the source code
+% for the parts of the runtime libraries of Erlang/OTP used as well as
+% that of the covered work.
+
+-module(sg_asp_sup).
+-author('Harald Welte <laforge@gnumonks.org>').
+-behaviour(supervisor).
+
+-export([init/1, start_link/2]).
+
+init([Name, AsSupPid]) ->
+	%AsName = list_to_atom("sg_as_" ++ Name ++ "_fsm"),
+	StartFunc = {xua_asp_fsm, start_link, []},
+	ChildSpec = {xua_asp_fsm, StartFunc, permanent, infinity, worker, [xua_asp_fsm]},
+	% simple_one_for_one will not start any children!
+	{ok, {{simple_one_for_one, 10, 60}, [ChildSpec]}}.
+
+start_link(Name, Options) ->
+	supervisor:start_link(?MODULE, [Name, Options]).
diff --git a/src/xua_as_fsm.erl b/src/xua_as_fsm.erl
new file mode 100644
index 0000000..386c51a
--- /dev/null
+++ b/src/xua_as_fsm.erl
@@ -0,0 +1,214 @@
+% M2UA / M3UA / SUA AS gsn_fsm according to RFC3868 4.3.1
+
+% (C) 2011-2012 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 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/>.
+%
+% Additional Permission under GNU AGPL version 3 section 7:
+%
+% If you modify this Program, or any covered work, by linking or
+% combining it with runtime libraries of Erlang/OTP as released by
+% Ericsson on http://www.erlang.org (or a modified version of these
+% libraries), containing parts covered by the terms of the Erlang Public
+% License (http://www.erlang.org/EPLICENSE), the licensors of this
+% Program grant you additional permission to convey the resulting work
+% without the need to license the runtime libraries of Erlang/OTP under
+% the GNU Affero General Public License. Corresponding Source for a
+% non-source form of such a combination shall include the source code
+% for the parts of the runtime libraries of Erlang/OTP used as well as
+% that of the covered work.
+
+-module(xua_as_fsm).
+-author('Harald Welte <laforge@gnumonks.org>').
+-behaviour(gen_fsm).
+
+-include("osmo_util.hrl").
+-include("m3ua.hrl").
+
+% gen_fsm exports
+-export([init/1, terminate/3, code_change/4, handle_event/3, handle_info/3]).
+
+% states in this FSM
+-export([as_down/2, as_inactive/2, as_active/2, as_pending/2]).
+
+% Timeouts in milliseconds
+-define(T_R_TIMEOUT, 2*60*100).
+
+-record(as_state, {
+		role,
+		t_r,
+		asp_list
+	}).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% gen_fsm callbacks
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+init([]) ->
+	AsState = #as_state{asp_list = [],
+			    role = sg},
+	{ok, as_down, AsState}.
+
+terminate(Reason, State, _LoopDat) ->
+	io:format("Terminating ~p in State ~p (Reason: ~p)~n",
+		  [?MODULE, State, Reason]),
+	ok.
+
+code_change(_OldVsn, StateName, LoopDat, _Extra) ->
+	{ok, StateName, LoopDat}.
+
+handle_event(Event, State, LoopDat) ->
+	io:format("Unknown Event ~p in state ~p~n", [Event, State]),
+	{next_state, State, LoopDat}.
+
+handle_info({'EXIT', Pid, Reason}, State, LoopDat) ->
+	io:format("EXIT from Process ~p (~p), cleaning up ASP list~n",
+		  [Pid, Reason]),
+	% FIXME: send fake ASP-DOWN event about ASP to self
+	{next_state, State, LoopDat};
+
+handle_info(Info, State, LoopDat) ->
+	io:format("Unknown Info ~p in state ~p~n", [Info, State]),
+	{next_state, State, LoopDat}.
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% STATE "as_down"
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+as_down(#primitive{subsystem = 'ASPAS', gen_name = 'ASP_INACTIVE',
+		   spec_name = indication, parameters = _Params}, LoopDat) ->
+	% One ASP transitions into ASP-INACTIVE
+	next_state(as_inactive, LoopDat);
+
+as_down(#primitive{subsystem = 'ASPAS', gen_name = 'ASP_DOWN',
+		   spec_name = indication, parameters = _Params}, LoopDat) ->
+	% ignore
+	next_state(as_down, LoopDat).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% STATE "as_inactive"
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+as_inactive(#primitive{subsystem = 'ASPAS', gen_name = 'ASP_DOWN',
+			spec_name = indication, parameters = AsPid}, LoopDat) ->
+	% One ASP transitions into ASP-DOWN
+	% FIXME: check if there are any other ASP != DOWN, if yes -> as_inactive
+	case check_any_other_asp_not_down(LoopDat, AsPid) of
+		true ->
+			next_state(as_inactive, LoopDat);
+		false ->
+			next_state(as_down, LoopDat)
+	end;
+
+as_inactive(#primitive{subsystem = 'ASPAS', gen_name = 'ASP_ACTIVE',
+			spec_name = indication, parameters = Params}, LoopDat) ->
+	% One ASP transitions to ASP-ACTIVE
+	next_state(as_active, LoopDat);
+
+as_inactive(#primitive{subsystem = 'ASPAS', gen_name = 'ASP_INACTIVE',
+		       spec_name = indication, parameters = _Params}, LoopDat) ->
+	% ignore
+	next_state(as_inactive, LoopDat).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% STATE "as_active"
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+as_active(#primitive{subsystem = 'ASPAS', gen_name = InactDown,
+		     spec_name = indication, parameters = AspPid}, LoopDat) when
+		InactDown == 'ASP_DOWN'; InactDown == 'ASP_INACTIVE' ->
+	% One ASP transitions to ASP-INACTIVE
+	% check if there are other ASP in active, if yes -> as_active
+	case check_any_other_asp_in_active(LoopDat, AspPid) of
+		true ->
+			next_state(as_active, LoopDat);
+		false ->
+			{ok, Tr} = timer:apply_after(?T_R_TIMEOUT, gen_fsm, send_event,
+						 [self(), {timer_expired, t_r}]),
+			next_state(as_pending, LoopDat#as_state{t_r = Tr})
+	end;
+
+as_active(#primitive{subsystem = 'ASPAS', gen_name = 'ASP_ACTIVE',
+		     spec_name = indication, parameters = _Params}, LoopDat) ->
+	% ignore
+	next_state(as_active, LoopDat).
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% STATE "as_pending"
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+as_pending(#primitive{subsystem = 'ASPAS', gen_name = 'ASP_ACTIVE',
+		      spec_name = indication}, LoopDat) ->
+	% One ASP transitions into ASP-ACTIVE
+	timer:cancel(LoopDat#as_state.t_r),
+	next_state(as_active, LoopDat);
+
+as_pending(#primitive{subsystem = 'ASPAS', gen_name = 'ASP_INACTIVE',
+		      spec_name = indication, parameters = _Params}, LoopDat) ->
+	% ignore
+	next_state(as_pending, LoopDat);
+
+% FIXME: do we need to re-check as_pending state if we get ASP_DOWN of the last
+% inactive ASP ?
+
+as_pending({timer_expired, t_r}, LoopDat) ->
+	% check if there is at least one ASP in ASP-INACTIVE -> AS-INACTIVE
+	case check_any_other_asp_in_inactive(LoopDat, undefined) of
+		true ->
+			next_state(as_inactive, LoopDat);
+		false ->
+			next_state(as_down, LoopDat)
+	end.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% helper functions
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+next_state(NewState, LoopDat) ->
+	%FIXME Module:as_state_change(NewState, LoopDat#as_state.ext_state),
+	{next_state, NewState, LoopDat}.
+
+%create_asp(LoopDatIn = #as_state{asp_module = {AspModule, AspModuleArgs},
+%				 asp_list = AspListIn}) ->
+%	Args = [AspModule, AspModuleArgs, UserFun, UserFunArgs, SctpPid],
+%	{ok, AspPid} = gen_fsm:start_link(xua_asp_fsm, Args, [{debug, [trace]}]),
+%	{AspPid, LoopDatIn#{asp_list = [AspPid|AspListIn]}}.
+
+
+
+check_any_other_asp_in_inactive(LoopDat, AspPid) ->
+	check_any_other_asp_in_state('ASP_INACTIVE', LoopDat, AspPid).
+
+check_any_other_asp_in_active(LoopDat, AspPid) ->
+	check_any_other_asp_in_state('ASP_ACTIVE', LoopDat, AspPid).
+
+check_any_other_asp_not_down(LoopDat, AspPid) ->
+	ListWithoutMe = lists:delete(AspPid, LoopDat#as_state.asp_list),
+	StateList = build_asp_state_list(ListWithoutMe),
+	not lists:all('ASP_DOWN', StateList).
+
+check_any_other_asp_in_state(State, LoopDat, AspPid) ->
+	ListWithoutMe = lists:delete(AspPid, LoopDat#as_state.asp_list),
+	StateList = build_asp_state_list(ListWithoutMe),
+	lists:member(State, StateList).
+
+build_asp_state_list(ListOfPids) ->
+	% FIXME
+	[].