diff --git a/src/mtp2_lsc.erl b/src/mtp2_lsc.erl
new file mode 100644
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+++ b/src/mtp2_lsc.erl
@@ -0,0 +1,404 @@
+% MTP2 Link State Control according to Q.703 Figure 3 / Figure 8
+
+% (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/>.
+
+-module(mtp2_lsc).
+-author('Harald Welte <laforge@gnumonks.org>').
+-behaviour(gen_fsm).
+
+% gen_fsm exports 
+-export([init/1, terminate/3, code_change/4, handle_event/3, handle_info/3]).
+
+% individual FSM states
+-export([power_off/2, out_of_service/2, initial_alignment/2,
+	 aligned_not_ready/2, aligned_ready/2, in_service/2,
+	 processor_outage/2]).
+
+% sync event handlers
+-export([power_off/3]).
+
+-record(lsc_state, {
+		t1_timeout,
+		t1,
+		iac_pid,
+		aerm_pid,
+		l3_pid,
+		poc_pid,
+		txc_pid,
+		local_proc_out,
+		proc_out,
+		emergency
+	}).
+
+-define(M2PA_T1_DEF,	300000).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% gen_fsm callbacks
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+init([Aerm, Txc, L3, Poc]) ->
+	{ok, Iac} = gen_fsm:start_link(mtp2_iac, [self(), Aerm, Txc], [{debug, [trace]}]),
+	LscState = #lsc_state{t1_timeout = ?M2PA_T1_DEF,
+			      iac_pid = Iac,
+			      aerm_pid = Aerm,
+			      l3_pid = L3,
+			      poc_pid = L3,
+			      txc_pid = Txc,
+		      	      local_proc_out = 0,
+		      	      proc_out = 0,
+		      	      emergency = 0},
+	{ok, power_off, LscState}.
+
+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(Info, State, LoopDat) ->
+	io:format("Unknown Info ~p in state ~p~n", [Info, State]),
+	{next_state, State, LoopDat}.
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% STATE: power_off
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+power_off(power_on, LoopDat) ->
+	% Power On from MGMT
+	send_to(txc, start, LoopDat),
+	send_to(txc, si_os, LoopDat),
+	send_to(aerm, set_ti_to_tin, LoopDat),
+	% Cancel local processor outage, cancel emergency
+	{next_state, out_of_service, LoopDat#lsc_state{local_proc_out=0, emergency=0}}.
+
+power_off(get_iac_pid, From, LoopDat) ->
+	Iac = LoopDat#lsc_state.iac_pid,
+	{reply, {ok, Iac}, power_off, LoopDat}.
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% STATE: out_of_service
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+out_of_service(start, LoopDat) ->
+	% Start from L3
+	send_to(rc, start, LoopDat),
+	send_to(txc, start, LoopDat),
+	case LoopDat#lsc_state.emergency of
+		1 ->
+			send_to(iac, emergency, LoopDat);
+		_ ->
+			ok
+	end,
+	send_to(iac, start, LoopDat),
+	{next_state, initial_alignment, LoopDat};
+
+out_of_service(retrieve_bsnt, LoopDat) ->
+	send_to(rc, retrieve_bsnt, LoopDat),
+	{next_state, out_of_service, LoopDat};
+
+out_of_service(retrieval_request_and_fsnc, LoopDat) ->
+	send_to(txc, retrieval_request_and_fsnc, LoopDat),
+	{next_state, out_of_service, LoopDat};
+
+out_of_service(emergency, LoopDat) ->
+	{next_state, out_of_service, LoopDat#lsc_state{emergency=1}};
+
+out_of_service(emergency_ceases, LoopDat) ->
+	{next_state, out_of_service, LoopDat#lsc_state{emergency=0}};
+
+out_of_service(What, LoopDat) when	What == local_processor_outage;
+					What == level3_failure ->
+	{next_state, out_of_service, LoopDat#lsc_state{local_proc_out=1}};
+
+out_of_service(local_processor_recovered, LoopDat) ->
+	{next_state, out_of_service, LoopDat#lsc_state{local_proc_out=0}}.
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% STATE: initial_alignment
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+initial_alignment(What, LoopDat) when	What == local_processor_outage;
+					What == level3_failure ->
+	{next_state, initial_alignment, LoopDat#lsc_state{local_proc_out=1}};
+
+initial_alignment(local_processor_recovered, LoopDat) ->
+	{next_state, initial_alignment, LoopDat#lsc_state{local_proc_out=0}};
+
+initial_alignment(emergency, LoopDat) ->
+	send_to(iac, emergency, LoopDat),
+	{next_state, initial_alignment, LoopDat#lsc_state{emergency=1}};
+
+initial_alignment(alignment_complete, LoopDat) ->
+	send_to(suerm, start, LoopDat),
+	{ok, T1} = timer:apply_after(LoopDat#lsc_state.t1_timeout,
+				     gen_fsm, send_event,
+				     [self(), {timer_expired, t1}]),
+	case LoopDat#lsc_state.local_proc_out of
+		1 ->
+			send_to(poc, local_processor_outage, LoopDat),
+			send_to(txc, si_po, LoopDat),
+			send_to(rc, reject_msu_fiso, LoopDat),
+			NextState = aligned_not_ready;
+		_ ->
+			send_to(txc, fisu, LoopDat),
+			send_to(rc, accept_msu_fiso, LoopDat),
+			NextState = aligned_ready
+	end,
+	{next_state, NextState, LoopDat#lsc_state{t1=T1}};
+
+initial_alignment(stop, LoopDat) ->
+	send_to(iac, stop, LoopDat),
+	send_to(rc, stop, LoopDat),
+	send_to(txc, si_os, LoopDat),
+	{next_state, out_of_service, LoopDat#lsc_state{local_proc_out=0, emergency=0}};
+
+initial_alignment(link_failure, LoopDat) ->
+	send_to(l3, out_of_service, LoopDat),
+	send_to(iac, stop, LoopDat),
+	send_to(rc, stop, LoopDat),
+	send_to(txc, si_os, LoopDat),
+	{next_state, out_of_service, LoopDat#lsc_state{local_proc_out=0, emergency=0}};
+
+initial_alignment(alignment_not_possible, LoopDat) ->
+	send_to(rc, stop, LoopDat),
+	send_to(txc, si_os, LoopDat),
+	{next_state, out_of_service, LoopDat#lsc_state{local_proc_out=0, emergency=0}};
+
+% ignore
+initial_alignment(What, LoopDat) when
+		What == si_n; What == si_e; What == si_o; What == si_os ->
+	{next_state, initial_alignment, LoopDat}.
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% STATE: aligned_ready
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+aligned_ready(SioOrSios, LoopDat) when SioOrSios == si_o;
+					SioOrSios == si_os;
+			       		SioOrSios == link_failure ->
+	timer:cancel(LoopDat#lsc_state.t1),
+	send_to(l3, out_of_service, LoopDat),
+	send_to(rc, stop, LoopDat),
+	send_to(suerm, stop, LoopDat),
+	send_to(txc, si_os, LoopDat),
+	{next_state, out_of_service, LoopDat};
+
+aligned_ready(stop, LoopDat) ->
+	timer:cancel(LoopDat#lsc_state.t1),
+	send_to(rc, stop, LoopDat),
+	send_to(suerm, stop, LoopDat),
+	send_to(txc, si_os, LoopDat),
+	{next_state, out_of_service, LoopDat};
+
+aligned_ready({timer_expired, t1}, LoopDat) ->
+	send_to(l3, out_of_service, LoopDat),
+	send_to(rc, stop, LoopDat),
+	send_to(suerm, stop, LoopDat),
+	send_to(txc, si_os, LoopDat),
+	{next_state, out_of_service, LoopDat};
+
+aligned_ready(si_po, LoopDat) ->
+	timer:cancel(LoopDat#lsc_state.t1),
+	send_to(l3, remote_processor_outage, LoopDat),
+	send_to(poc, remote_processor_outage, LoopDat),
+	{next_state, processor_outage, LoopDat};
+
+aligned_ready(fisu_msu_received, LoopDat) ->
+	send_to(l3, in_service, LoopDat),
+	timer:cancel(LoopDat#lsc_state.t1),
+	send_to(txc, msu, LoopDat),
+	{next_state, in_service, LoopDat};
+aligned_ready(What, LoopDat) when	What == local_processor_outage;
+					What == level3_failure ->
+	send_to(poc, local_processor_outage, LoopDat),
+	send_to(txc, si_po, LoopDat),
+	send_to(rc, reject_msu_fiso, LoopDat),
+	{next_state, aligned_not_ready, LoopDat}.
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% STATE: aligned_not_ready
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+aligned_not_ready(Err, LoopDat) when 	Err == link_failure;
+					Err == si_o;
+					Err == si_os ->
+	timer:cancel(LoopDat#lsc_state.t1),
+	send_to(l3, out_of_service, LoopDat),
+	send_to(l3, stop, LoopDat),
+	send_to(suerm, stop, LoopDat),
+	send_to(txc, si_os, LoopDat),
+	send_to(poc, stop, LoopDat),
+	{next_state, out_of_service, LoopDat#lsc_state{local_proc_out=0, emergency=0}};
+
+aligned_not_ready(stop, LoopDat) ->
+	timer:cancel(LoopDat#lsc_state.t1),
+	send_to(l3, stop, LoopDat),
+	send_to(suerm, stop, LoopDat),
+	send_to(txc, si_os, LoopDat),
+	send_to(poc, stop, LoopDat),
+	{next_state, out_of_service, LoopDat#lsc_state{local_proc_out=0, emergency=0}};
+
+aligned_not_ready({timer_expired, t1}, LoopDat) ->
+	send_to(l3, stop, LoopDat),
+	send_to(suerm, stop, LoopDat),
+	send_to(txc, si_os, LoopDat),
+	send_to(poc, stop, LoopDat),
+	{next_state, out_of_service, LoopDat#lsc_state{local_proc_out=0, emergency=0}};
+
+aligned_not_ready(local_processor_recovered, LoopDat) ->
+	send_to(poc, local_processor_recovered, LoopDat),
+	send_to(txc, fisu, LoopDat),
+	send_to(rc, accept_msu_fisu, LoopDat),
+	{next_state, aligned_ready, LoopDat#lsc_state{local_proc_out=0}};
+
+aligned_not_ready(fisu_msu_received, LoopDat) ->
+	send_to(l3, in_service, LoopDat),
+	timer:cancel(LoopDat#lsc_state.t1),
+	{next_state, processor_outage, LoopDat};
+
+aligned_not_ready(si_po, LoopDat) ->
+	send_to(l3, remote_processor_outage, LoopDat),
+	send_to(poc, remote_processor_outage, LoopDat),
+	timer:cancel(LoopDat#lsc_state.t1),
+	{next_state, processor_outage, LoopDat}.
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% STATE: in_service
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+in_service(What, LoopDat) when	What == link_failure;
+				What == si_o;
+				What == si_n;
+				What == si_e;
+				What == si_os ->
+	send_to(l3, out_of_service, LoopDat),
+	send_to(suerm, stop, LoopDat),
+	send_to(rc, stop, LoopDat),
+	send_to(txc, si_os, LoopDat),
+	{next_state, out_of_service, LoopDat#lsc_state{emergency=0}};
+
+in_service(stop, LoopDat) ->
+	send_to(suerm, stop, LoopDat),
+	send_to(rc, stop, LoopDat),
+	send_to(txc, si_os, LoopDat),
+	{next_state, out_of_service, LoopDat#lsc_state{emergency=0}};
+
+in_service(What, LoopDat) when	What == local_processor_outage;
+				What == level3_failure ->
+	send_to(poc, local_processor_outage, LoopDat),
+	send_to(txc, si_po, LoopDat),
+	send_to(rc, reject_msu_fisu, LoopDat),
+	{next_state, aligned_not_ready, LoopDat#lsc_state{local_proc_out=1}};
+
+in_service(si_po, LoopDat) ->
+	send_to(txc, fisu, LoopDat),
+	send_to(l3, remote_processor_outage, LoopDat),
+	send_to(poc, remote_processor_outage, LoopDat),
+	{next_state, processor_outage, LoopDat#lsc_state{proc_out=1}}.
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% STATE: processor_outage
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+processor_outage(retrieval_request_and_fsnc, LoopDat) ->
+	send_to(txc, retrieval_request_and_fsnc, LoopDat),
+	{next_state, processor_outage, LoopDat};
+
+processor_outage(fisu_msu_received, LoopDat) ->
+	send_to(poc, remote_processor_recovered, LoopDat),
+	send_to(l3, remote_processor_recovered, LoopDat),
+	{next_state, processor_outage, LoopDat};
+
+processor_outage(retrieve_bsnt, LoopDat) ->
+	send_to(rc, retrieve_bsnt, LoopDat),
+	{next_state, processor_outage, LoopDat};
+
+processor_outage(What, LoopDat) when	What == local_processor_outage;
+					What == level3_failure ->
+	send_to(poc, local_processor_outage, LoopDat),
+	send_to(txc, si_po, LoopDat),
+	{next_state, processor_outage, LoopDat#lsc_state{local_proc_out=1}};
+
+processor_outage(si_po, LoopDat) ->
+	send_to(l3, remote_processor_outage, LoopDat),
+	send_to(poc, remote_processor_outage, LoopDat),
+	{next_state, processor_outage, LoopDat#lsc_state{proc_out=1}};
+
+processor_outage(local_processor_recovered, LoopDat) ->
+	send_to(poc, local_processor_recovered, LoopDat),
+	send_to(rc, retrieve_fsnx, LoopDat),
+	send_to(txc, fisu, LoopDat),
+	{next_state, processor_outage, LoopDat};
+
+processor_outage(flush_buffers, LoopDat) ->
+	send_to(txc, flush_buffers, LoopDat),
+	% FIXME: mark L3 ind recv
+	{next_state, processor_outage, LoopDat};
+
+processor_outage(no_processor_outage, LoopDat) ->
+	% FIXME: check L3 ind
+	send_to(txc, msu, LoopDat),
+	send_to(rc, accept_msu_fisu, LoopDat),
+	{next_state, in_service, LoopDat#lsc_state{local_proc_out=0, proc_out=0}};
+
+processor_outage(What, LoopDat) when	What == link_failure;
+					What == si_o;
+					What == si_n;
+					What == si_e;
+					What == si_os ->
+	send_to(l3, out_of_service, LoopDat),
+	send_to(suerm, stop, LoopDat),
+	send_to(rc, stop, LoopDat),
+	send_to(poc, stop, LoopDat),
+	send_to(txc, si_os, LoopDat),
+	{next_state, out_of_service, LoopDat#lsc_state{emergency=0, local_proc_out=0}};
+
+processor_outage(stop, LoopDat) ->
+	send_to(suerm, stop, LoopDat),
+	send_to(rc, stop, LoopDat),
+	send_to(poc, stop, LoopDat),
+	send_to(txc, si_os, LoopDat),
+	{next_state, out_of_service, LoopDat#lsc_state{emergency=0, local_proc_out=0}}.
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% helper functions
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+send_to(txc, What, #lsc_state{txc_pid = Txc}) ->
+	Txc ! {lsc_txc, What};
+send_to(iac, What, #lsc_state{iac_pid = Iac}) ->
+	gen_fsm:send_event(Iac, What);
+send_to(Who, What, _LoopDat) ->
+	io:format("Not sending LSC -> ~p: ~p~n", [Who, What]).
+