move invert_rout_lbl to mtp3_codec and export it there
diff --git a/src/mtp3_codec.erl b/src/mtp3_codec.erl
index 9dc50c2..3c34a6e 100644
--- a/src/mtp3_codec.erl
+++ b/src/mtp3_codec.erl
@@ -21,7 +21,7 @@
 -author('Harald Welte <laforge@gnumonks.org>').
 -include("mtp3.hrl").
 
--export([parse_mtp3_msg/1, encode_mtp3_msg/1]).
+-export([parse_mtp3_msg/1, encode_mtp3_msg/1, invert_rout_lbl/1]).
 
 -compile({parse_transform, exprecs}).
 -export_records([mtp3_routing_label, mtp3_msg]).
@@ -74,3 +74,6 @@
 payload_to_binary(_, Whatever) ->
 	Whatever.
 
+
+invert_rout_lbl(L = #mtp3_routing_label{origin_pc = Opc, dest_pc = Dpc}) ->
+	L#mtp3_routing_label{origin_pc = Dpc, dest_pc = Opc}.
diff --git a/src/mtp3_sltc.erl b/src/mtp3_sltc.erl
index d440be0..cdca675 100644
--- a/src/mtp3_sltc.erl
+++ b/src/mtp3_sltc.erl
@@ -170,7 +170,7 @@
 			     payload = #mtp3mg_msg{h0 = ?MTP3MG_H0_TEST,
 						   h1 = ?MTP3MG_H1_SLTM,
 					   	   payload = TP}}) ->
-	InvRoutLbl = invert_rout_lbl(RoutLbl),
+	InvRoutLbl = mtp3_codec:invert_rout_lbl(RoutLbl),
 	M#mtp3_msg{routing_label = InvRoutLbl,
 		   payload = #mtp3mg_msg{h0 = ?MTP3MG_H0_TEST,
 			   		 h1 = ?MTP3MG_H1_SLTA,
@@ -204,8 +204,3 @@
 	    _ ->
 		false
 	end.
-
-
-
-invert_rout_lbl(L = #mtp3_routing_label{origin_pc = Opc, dest_pc = Dpc}) ->
-	L#mtp3_routing_label{origin_pc = Dpc, dest_pc = Opc}.