diff --git a/TCAP/src/ITU/tcap_cco_server.erl b/TCAP/src/ITU/tcap_cco_server.erl
index 539f33a..2eabbfc 100644
--- a/TCAP/src/ITU/tcap_cco_server.erl
+++ b/TCAP/src/ITU/tcap_cco_server.erl
@@ -236,7 +236,7 @@ process_request_components([Head|Tail], State, AsnComps, ISMs) when
 	    		 invokeID = InvId} ->
 		% if INVOKE component
 		% start ISM and store ISM
-		{ok, ISM} = tcap_ism_fsm:start_link(Usap, DialogueId,
+		{ok, ISM} = tcap_invocation_sup:start_ism(Usap, DialogueId,
 						    InvId, Class, Tout),
 		% signal 'operation-sent' to ISM
 		gen_fsm:sent_event(ISM, 'operation-sent'),
diff --git a/TCAP/src/tcap_components_sup.erl b/TCAP/src/tcap_components_sup.erl
index ebecb14..75d84ac 100644
--- a/TCAP/src/tcap_components_sup.erl
+++ b/TCAP/src/tcap_components_sup.erl
@@ -46,10 +46,20 @@
 %% call backs needed for supervisor behaviour
 -export([init/1]).
 
-init([USAP, ID]) ->
+gen_cco_child(USAP, ID) ->
 	Name = list_to_atom("tcap_cco_" ++ integer_to_list(ID)),
 	StartArgs = [{local, Name}, tcap_cco_server, [self(), USAP, ID], [{debug, [trace]}]],
 	StartFunc = {gen_server, start_link, StartArgs},
-	ChildSpec = {cco, StartFunc, temporary, 4000, worker, [tcap_cco_server]},
-	{ok,{{one_for_all, 0, 1}, [ChildSpec]}}.
+	{cco, StartFunc, permanent, 4000, worker, [tcap_cco_server]}.
+
+gen_inv_sup_child(ID) ->
+	StartFunc = {tcap_invocation_sup, start_link, [ID]},
+	{invocation_sup, StartFunc, permanent, 4000, supervisor, [tcap_invocation_sup]}.
+
+init([USAP, ID]) ->
+	% start the CCO server as well as a (childless) invocation supervisor
+	InvSup = gen_inv_sup_child(ID),
+	Cco = gen_cco_child(USAP, ID),
+	io:format("~p~n", [InvSup]),
+	{ok,{{one_for_all, 0, 1}, [InvSup, Cco]}}.
 
diff --git a/TCAP/src/tcap_invocation_sup.erl b/TCAP/src/tcap_invocation_sup.erl
index cbd145f..ecf7434 100644
--- a/TCAP/src/tcap_invocation_sup.erl
+++ b/TCAP/src/tcap_invocation_sup.erl
@@ -46,10 +46,20 @@
 %% call backs needed for supervisor behaviour
 -export([init/1]).
 
-init([USAP, DlgId, InvokeID, OpClass, Timeout]) ->
+%% API to other modules
+-export([start_ism/1, start_link/1]).
+
+init([]) ->
+	{ok,{{one_for_all, 0, 1}, []}}.
+
+start_ism([USAP, DlgId, InvokeID, OpClass, Timeout]) ->
+	SupRef = list_to_atom("tcap_invocation_sup_" ++ integer_to_list(DlgId)),
 	StartArgs = [USAP, DlgId, InvokeID, OpClass, Timeout],
 	StartFunc = {tcap_ism_fsm, start_link, StartArgs},
 	ChildSpec = {ism, StartFunc, temporary, 4000, worker,
 			[tcap_ism_sup]},
-	{ok,{{one_for_all, 0, 1}, [ChildSpec]}}.
+	supervisor:start_child(SupRef, ChildSpec).
 
+start_link(ID) ->
+	Name = list_to_atom("tcap_invocation_sup_" ++ integer_to_list(ID)),
+	supervisor:start_link({local, Name}, ?MODULE, []).