Add M2PA codec, MTP2 IAC and LSC gen_fsm implementations

4 files changed, 845 insertions, 0 deletions

diff --git a/include/m2pa.hrl b/include/m2pa.hrl
new file mode 100644
index 0000000..959133d
--- /dev/null
+++ b/include/m2pa.hrl
@@ -0,0 +1,51 @@
+% RFC 4165 MTP2 P2P Adaption Layer coding / decoding
+
+% (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/>.
+
+-define(M2PA_PPID,		5).
+
+% Section 2.1.3
+-define(M2PA_CLASS_M2PA,	11).
+
+% Section 2.1.4
+-define(M2PA_TYPE_USER,		1).
+-define(M2PA_TYPE_LINK,		2).
+
+% Section 2.3.2
+-define(M2PA_LS_ALIGNMENT,	1).
+-define(M2PA_LS_PROVING_NORMAL,	2).
+-define(M2PA_LS_PROVING_EMERG,	3).
+-define(M2PA_LS_READY,		4).
+-define(M2PA_LS_PROC_OUTAGE,	5).
+-define(M2PA_LS_PROC_RECOVERED,	6).
+-define(M2PA_LS_BUSY,		7).
+-define(M2PA_LS_BUSY_ENDED,	8).
+-define(M2PA_LS_OOS,		9).
+
+% SCTP stream IDs
+-define(M2PA_STREAM_STATUS,	0).
+-define(M2PA_STREAM_USER,	1).
+
+-record(m2pa_msg, {
+		msg_class,
+		msg_type,
+		fwd_seq_nr,
+		back_seq_nr,
+		mtp3,
+		parameters
+	}).
diff --git a/src/m2pa_codec.erl b/src/m2pa_codec.erl
new file mode 100644
index 0000000..585b9c9
--- /dev/null
+++ b/src/m2pa_codec.erl
@@ -0,0 +1,66 @@
+% RFC 4165 MTP2 P2P Adaption Layer coding / decoding
+
+% (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/>.
+
+-module(m2pa_codec).
+-author('Harald Welte <laforge@gnumonks.org>').
+-include("m2pa.hrl").
+-include("mtp3.hrl").
+
+-export([parse_msg/1, encode_msg/1]).
+
+-compile({parse_transform, exprecs}).
+-export_records([m2pa_msg]).
+
+parse_m2pa_msgt(?M2PA_CLASS_M2PA, ?M2PA_TYPE_LINK, Len, Remain) ->
+	<<State:32/big, Filler/binary>> = Remain,
+	Ret = [{link_state, State}],
+	if
+		byte_size(Filler) > 0 ->
+			{undefined, [{filler, Filler}|Ret]};
+		true ->
+			{undefined, Ret}
+	end;
+parse_m2pa_msgt(?M2PA_CLASS_M2PA, ?M2PA_TYPE_USER, Len, RemainIn) ->
+	<<Pri:1, _:7, SIO:8, SIF/binary>> = RemainIn,
+	Mtp3 = #mtp3_msg{service_ind = SIO, m3ua_mp = Pri, payload = SIF},
+	{Mtp3, []}.
+
+parse_msg(DataBin) when is_binary(DataBin) ->
+	<<1:8, 0:8, MsgClass:8, MsgType:8, MsgLen:32/big, AllRemain/binary>> = DataBin,
+	<<_:8, BSN:24/big, _:8, FSN:24/big, Remain/binary>> = AllRemain,
+	{Mtp3, Params} = parse_m2pa_msgt(MsgClass, MsgType, MsgLen, Remain),
+	{ok, #m2pa_msg{msg_class = MsgClass, msg_type = MsgType,
+			fwd_seq_nr = FSN, back_seq_nr = BSN,
+			mtp3 = Mtp3, parameters = Params}}.
+
+encode_m2pa_msgt(?M2PA_CLASS_M2PA, ?M2PA_TYPE_USER, Mtp3, _Params) ->
+	<<Mtp3/binary>>;
+encode_m2pa_msgt(?M2PA_CLASS_M2PA, ?M2PA_TYPE_LINK, _, Params) ->
+	State = proplists:get_value(link_state, Params),
+	% FIXME: filler
+	Filler = <<>>,
+	<<State:32/big, Filler/binary>>.
+
+
+encode_msg(Msg) when is_record(Msg, m2pa_msg) ->
+	#m2pa_msg{msg_class = MsgClass, msg_type = MsgType, fwd_seq_nr = FSN,
+			back_seq_nr = BSN, mtp3 = Mtp3, parameters = Params} = Msg,
+	Payload = encode_m2pa_msgt(MsgClass, MsgType, Mtp3, Params),
+	MsgLen = byte_size(Payload) + 16,
+	<<1:8, 0:8, MsgClass:8, MsgType:8, MsgLen:32/big, 0:8, BSN:24/big, 0:8, FSN:24/big, Payload/binary>>.
diff --git a/src/mtp2_iac.erl b/src/mtp2_iac.erl
new file mode 100644
index 0000000..d23aaf0
--- /dev/null
+++ b/src/mtp2_iac.erl
@@ -0,0 +1,324 @@
+% MTP2 Initial Alignment Control according to Q.703 Figure 4 / Figure 9
+
+% (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_iac).
+-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]).
+
+% states in this FSM
+-export([idle/2, not_aligned/2, aligned/2, proving/2]).
+
+% Timeouts in milliseconds According to Q.703 / Section 12.3
+-define(M2PA_T1_DEF,	 50000).
+-define(M2PA_T2_DEF,	150000).
+-define(M2PA_T3_DEF,	  2000).
+-define(M2PA_T4N_DEF,	  8200).
+-define(M2PA_T4E_DEF,	   500).
+
+-record(iac_state, {
+		t2_timeout,
+		t3_timeout,
+		t4_timeout,
+		t4_timeout_pn,
+		t4_timeout_pe,
+		t2, t3, t4,
+		emergency,
+		cp,
+		further_prov,
+		lsc_pid,
+		aerm_pid,
+		txc_pid
+	}).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% gen_fsm callbacks
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+init([Lsc, Aerm, Txc]) ->
+	IacState = #iac_state{t2_timeout = ?M2PA_T2_DEF,
+			      t3_timeout = ?M2PA_T3_DEF,
+			      t4_timeout_pn = ?M2PA_T4N_DEF,
+			      t4_timeout_pe = ?M2PA_T4E_DEF,
+			      emergency = 0,
+			      cp = 0,
+			      further_prov = 1,
+			      lsc_pid = Lsc,
+			      aerm_pid = Aerm,
+			      txc_pid = Txc},
+	{ok, idle, IacState}.
+
+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 "idle"
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+idle(start, LoopDat) ->
+	% send sio
+	send_to_txc(si_o, LoopDat),
+	% start timer
+	T2tout = LoopDat#iac_state.t2_timeout,
+	{ok, T2} = timer:apply_after(T2tout, gen_fsm, send_event,
+			  	     [self(), {timer_expired, t2}]),
+	{next_state, not_aligned, LoopDat#iac_state{t2 = T2}};
+idle(emergency, LoopDat) ->
+	% mark emergency
+	{next_state, idle, LoopDat#iac_state{emergency = 1}}.
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% STATE "not aligned"
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+not_aligned(stop, LoopDat) ->
+	% stop T2
+	timer:cancel(LoopDat#iac_state.t2),
+	% cancel emergency
+	{next_state, idle, LoopDat#iac_state{emergency=0}};
+not_aligned(si_e, LoopDat) ->
+	% stop T2
+	timer:cancel(LoopDat#iac_state.t2),
+	T4tout = LoopDat#iac_state.t4_timeout_pe,
+	% send SIE or SIN
+	case LoopDat#iac_state.emergency of
+		0 ->
+			Send = si_n;
+		_ ->
+			Send = si_e
+	end,
+	send_to_txc(Send, LoopDat),
+	% start T3
+	T3tout = LoopDat#iac_state.t3_timeout,
+	{ok, T3} = timer:apply_after(T3tout, gen_fsm, send_event,
+				     [self(), {timer_expired, t3}]),
+	{next_state, aligned, LoopDat#iac_state{t3 = T3, t2 = undefined, t4_timeout = T4tout}};
+not_aligned(What, LoopDat) when What == si_o; What == si_n ->
+	% stop T2
+	timer:cancel(LoopDat#iac_state.t2),
+	% send SIE or SIN
+	case LoopDat#iac_state.emergency of
+		0 ->
+			T4tout = LoopDat#iac_state.t4_timeout_pn,
+			Send = si_n;
+		_ ->
+			T4tout = LoopDat#iac_state.t4_timeout_pe,
+			Send = si_e
+	end,
+	send_to_txc(Send, LoopDat),
+	T3tout = LoopDat#iac_state.t3_timeout,
+	{ok, T3} = timer:apply_after(T3tout, gen_fsm, send_event,
+				     [self(), {timer_expired, t3}]),
+	{next_state, aligned, LoopDat#iac_state{t3 = T3, t2 = undefined, t4_timeout = T4tout}};
+not_aligned(emergency, LoopDat) ->
+	% mark emergency
+	{next_state, not_aligned, LoopDat#iac_state{emergency=1}};
+not_aligned({timer_expired, t2}, LoopDat) ->
+	% send 'alignment not possible' to LSC
+	send_to_lsc(alignment_not_possible, LoopDat),
+	% stop emergency
+	{next_state, idle, LoopDat#iac_state{emergency=0}}.
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% STATE "aligned"
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+aligned(What, LoopDat) when What == si_n; What == si_e ->
+	case What of
+		si_e ->
+			% set T4 to Pe
+			T4tout = LoopDat#iac_state.t4_timeout_pe;
+		_ ->
+			T4tout = LoopDat#iac_state.t4_timeout_pn
+	end,
+	% stop T3
+	timer:cancel(LoopDat#iac_state.t3),
+	ToutPE = LoopDat#iac_state.t4_timeout_pe,
+	case T4tout of
+		ToutPE ->
+			% set i to ie IAC->AERM
+			send_to_aerm(set_i_to_ie, LoopDat);
+		_ ->
+			ok
+	end,
+	% send Start to AERM
+	send_to_aerm(start, LoopDat),
+	% start T4
+	io:format("trying to start T4, T4tout=~p~n", [T4tout]),
+	{ok, T4} = timer:apply_after(T4tout, gen_fsm, send_event,
+				     [self(), {timer_expired, t4}]),
+	% Cp := 0
+	% cancel further proving?
+	LoopDat2 = LoopDat#iac_state{t4 = T4, t4_timeout = T4tout,
+				     cp = 0, further_prov = 0},
+	{next_state, proving, LoopDat2};
+aligned(emergency, LoopDat) ->
+	% Send SIE
+	send_to_txc(si_e, LoopDat),
+	T4tout = LoopDat#iac_state.t4_timeout_pe,
+	{next_State, aligned, LoopDat#iac_state{t4_timeout = T4tout}};
+aligned(si_os, LoopDat) ->
+	% Send alignment not possible
+	send_to_lsc(alignment_not_possible, LoopDat),
+	% stop T3
+	timer:cancel(LoopDat#iac_state.t3),
+	{next_state, idle, LoopDat#iac_state{emergency=0, t3=undefined}};
+aligned(stop, LoopDat) ->
+	% Stop T3
+	timer:cancel(LoopDat#iac_state.t3),
+	% cancel Emergency
+	{next_state, idle, LoopDat#iac_state{emergency=0, t3=undefined}};
+aligned({timer_expired, t3}, LoopDat) ->
+	% Send alignment not possible
+	send_to_lsc(alignment_not_possible, LoopDat),
+	% cancel emergency
+	{next_state, idle, LoopDat#iac_state{emergency=0}}.
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% STATE "proving"
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+fig9_4(LoopDat) ->
+	% send Stop to AERM
+	send_to_aerm(stop, LoopDat),
+	% cancel emergency
+	{next_state, idle, LoopDat#iac_state{emergency=0}}.
+
+fig9_5(LoopDat) ->
+	% send Start to AERM
+	send_to_aerm(start, LoopDat),
+	% cancel further proving
+	% start T4
+	T4tout = LoopDat#iac_state.t4_timeout,
+	{ok, T4} = timer:apply_after(T4tout, gen_fsm, send_event,
+				     [self(), {timer_expired, t4}]),
+	{next_state, proving, LoopDat#iac_state{t4=T4, further_prov=0}}.
+
+prov_emerg_or_sie(LoopDat) ->
+	% stop T4
+	timer:cancel(LoopDat#iac_state.t4),
+	% Set T4 to Pe
+	T4tout = LoopDat#iac_state.t4_timeout_pe,
+	% Send stop to AERM
+	send_to_aerm(stop, LoopDat),
+	% Send 'set ti to tie' to AERM
+	send_to_aerm(set_ti_to_tie, LoopDat),
+	fig9_5(LoopDat#iac_state{t4_timeout=T4tout, t4=undefined}).
+
+
+proving(expires, LoopDat) ->
+	% alignment complete
+	{next_state, idle, LoopDat};
+proving(si_e, LoopDat) ->
+	ToutPE = LoopDat#iac_state.t4_timeout_pe,
+	case LoopDat#iac_state.t4_timeout of
+		ToutPE ->
+			{next_state, proving, LoopDat};
+		_ ->
+			prov_emerg_or_sie(LoopDat)
+	end;
+proving(emergency, LoopDat) ->
+	prov_emerg_or_sie(LoopDat);
+proving(stop, LoopDat) ->
+	% stop T4
+	timer:cancel(LoopDat#iac_state.t4),
+	fig9_4(LoopDat);
+proving(si_os, LoopDat) ->
+	% stop T4
+	timer:cancel(LoopDat#iac_state.t4),
+	% Send alignment not possible to LSC
+	send_to_lsc(alignment_not_possible, LoopDat),
+	fig9_4(LoopDat);
+proving(high_err_rate, LoopDat) ->
+	% alignment not possible
+	{next_state, idle, LoopDat};
+proving(sio, LoopDat) ->
+	% stop T4
+	timer:cancel(LoopDat#iac_state.t4),
+	% send Stop to AERM
+	send_to_aerm(stop, LoopDat),
+	% start T3
+	T3tout = LoopDat#iac_state.t3_timeout,
+	{ok, T3} = timer:apply_after(T3tout, gen_fsm, send_event,
+				     [self(), {timer_expired, t3}]),
+	{next_state, aligned, LoopDat#iac_state{t3=T3, t4=undefined}};
+proving(What, LoopDat) when What == correct_su; What == si_n ->
+	case LoopDat#iac_state.further_prov of
+		1 ->
+			% stop T4
+			timer:cancel(LoopDat#iac_state.t4),
+			fig9_5(LoopDat);
+		_ ->
+			{next_state, proving, LoopDat}
+	end;
+proving({timer_expired, t4}, LoopDat) ->
+	% check if we are further proving, if yes, call fig9_5
+	case LoopDat#iac_state.further_prov of
+		1 ->
+			fig9_5(LoopDat);
+		_ ->
+			% send 'aligment complete' to LSC
+			send_to_lsc(alignment_complete, LoopDat),
+			fig9_4(LoopDat)
+	end;
+proving(abort_proving, LoopDat) ->
+	% Cp := Cp + 1
+	Cp = LoopDat#iac_state.cp,
+	LoopDat2 = LoopDat#iac_state{cp = Cp + 1},
+	case Cp + 1 of
+		5 ->
+			% send 'alignment not possible' to LSC
+			send_to_lsc(alignment_not_possible, LoopDat),
+			% stop T4
+			timer:cancel(LoopDat#iac_state.t4),
+			fig9_4(LoopDat2);
+		_ ->
+			% mark further proving
+			{next_state, proving, LoopDat2#iac_state{further_prov=1}}
+	end.
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% helper functions
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+send_to_lsc(What, #iac_state{lsc_pid = Lsc}) ->
+	gen_fsm:send_event(Lsc, What).
+
+send_to_aerm(What, #iac_state{aerm_pid = Aerm}) ->
+	Aerm ! {iac_aerm, What}.
+
+send_to_txc(What, #iac_state{txc_pid = Txc}) ->
+	Txc ! {iac_txc, What}.
diff --git a/src/mtp2_lsc.erl b/src/mtp2_lsc.erl
new file mode 100644
index 0000000..459d77b
--- /dev/null
+++ 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]).
+