diff --git a/src_erl/NerlnetApp/src/Init/jsonHandler.erl b/src_erl/NerlnetApp/src/Init/jsonHandler.erl
index b870c346..b58d3137 100644
--- a/src_erl/NerlnetApp/src/Init/jsonHandler.erl
+++ b/src_erl/NerlnetApp/src/Init/jsonHandler.erl
@@ -19,6 +19,7 @@
 
 %%%%%% Getting files in multipart format.
 init(Req0, [ApplicationPid]) ->
+  io:format("@JsonHAndler: Got ~p~n" , [cowboy_req:parse_header(<<"content-type">>, Req0)]),
   case cowboy_req:parse_header(<<"content-type">>, Req0) of
     {<<"multipart">>, <<"form-data">>, _} ->
         nerl_tools:deleteOldJson(?JSON_ADDR++?LOCAL_DC_FILE_NAME),
@@ -26,6 +27,7 @@ init(Req0, [ApplicationPid]) ->
         %% get files from Req
         % io:format("parsing json of req with body: ~p~n",[cowboy_req:read_body(Req0)]),
         {_Req, Data} = nerl_tools:multipart(Req0, []), % multipart also save data to file      %% Data = [FileName1, FileName2]
+        io:format("@JsonHandler: got here~n"),
         ApplicationPid ! {jsonAddress,{lists:nth(1, Data),lists:nth(2, Data)}};
     _Other -> 
         {ok,Body,_} = cowboy_req:read_body(Req0),           %% shouldn't be here, files expected
diff --git a/src_erl/NerlnetApp/src/MainServer/ackHandler.erl b/src_erl/NerlnetApp/src/MainServer/ackHandler.erl
index ef842fa2..13e36f6a 100644
--- a/src_erl/NerlnetApp/src/MainServer/ackHandler.erl
+++ b/src_erl/NerlnetApp/src/MainServer/ackHandler.erl
@@ -20,7 +20,8 @@ init(Req0, [Who,Main_genserver_Pid]) ->
   case Who of
     dataReady -> gen_server:cast(Main_genserver_Pid, {sourceAckDataReady,Body});      %% when source data is ready
     sourceDone -> gen_server:cast(Main_genserver_Pid, {sourceDone,Body}); %% when source finished casting
-    clientAck -> gen_server:cast(Main_genserver_Pid, {clientAck,Body})       %% when client received message (new state)
+    clientAck -> gen_server:cast(Main_genserver_Pid, {clientAck,Body});       %% when client received message (new state)
+    jsonReceived -> gen_server:cast(Main_genserver_Pid, {jsonReceived,Body}) %% when other devices got the json and ready to start
   end,
   Reply = io_lib:format("Body Received: ~p ~n ", [Body]),
   Req = cowboy_req:reply(200,
diff --git a/src_erl/NerlnetApp/src/MainServer/mainGenserver.erl b/src_erl/NerlnetApp/src/MainServer/mainGenserver.erl
index c688ac0b..49815f8d 100644
--- a/src_erl/NerlnetApp/src/MainServer/mainGenserver.erl
+++ b/src_erl/NerlnetApp/src/MainServer/mainGenserver.erl
@@ -50,7 +50,7 @@ handle_call(_Call, _From, State) ->
 {ok, State :: #main_genserver_state{}} | {ok, State :: #main_genserver_state{}, timeout() | hibernate} |
 {stop, Reason :: term()} | ignore).
 
-init({MyName,ClientsNames,BatchSize,WorkersMap,NerlnetGraph}) ->
+init({MyName,ClientsNames,BatchSize,WorkersMap,NerlnetGraph , DeviceName}) ->
   nerl_tools:setup_logger(?MODULE),
   inets:start(),
   MyNameStr = atom_to_list(MyName),
@@ -61,6 +61,7 @@ init({MyName,ClientsNames,BatchSize,WorkersMap,NerlnetGraph}) ->
   MainServerEts = ets:new(main_server_ets , [set]),
   put(main_server_ets, MainServerEts),
   put(nerlnet_graph, NerlnetGraph),
+  put(device_name, DeviceName),
   EtsStats = ets:new(stats , [set]),
   put(etsStats, EtsStats), %% All entities including mainServer ets tables statistics
   Entities = [digraph:vertex(NerlnetGraph,Vertex) || Vertex <- digraph:vertices(NerlnetGraph)--[?API_SERVER_ATOM]],
@@ -71,6 +72,7 @@ init({MyName,ClientsNames,BatchSize,WorkersMap,NerlnetGraph}) ->
   ets:insert(MainServerEts , {workers_map , WorkersMap}),
   ets:insert(MainServerEts , {clients_names_list , ClientsNames}),
   ets:insert(MainServerEts , {counter_received_stats, 0}),
+  ets:insert(MainServerEts , {json_received_counter, 0}),
   % Getting the router that main server is connected with
   {MyRouterHost,MyRouterPort} = nerl_tools:getShortPath(MyName,hd(ClientsNames),get(nerlnet_graph)),
   ets:insert(MainServerEts, {my_router,{MyRouterHost,MyRouterPort}}),
@@ -88,6 +90,29 @@ handle_cast({initCSV, _SourceName ,_SourceData}, State) ->
   ?LOG_ERROR("initCSV is only applicalble when main server is in idle state!"),
   {noreply, State#main_genserver_state{}};
 
+handle_cast({jsonReceived,Body}, State = #main_genserver_state{}) ->
+  StatsEts = get_entity_stats_ets(?MAIN_SERVER_ATOM),
+  stats:increment_messages_received(StatsEts),
+  {DeviceName , TotalNumberOfDevices} = binary_to_term(Body),
+  case TotalNumberOfDevices of 
+    0 -> ack(atom_to_list(received_jsons_done)); %% if the exeperiment runs on a single device
+    _ -> ok
+  end,
+  MainServerDeviceName = get(device_name),
+  case DeviceName of
+    MainServerDeviceName -> ?LOG_NOTICE("Device ~p received the json files and is ready to start", [DeviceName]);
+    _OtherDevice ->
+      ?LOG_NOTICE("Device ~p received the json files and is ready to start", [DeviceName]),
+      ets:update_counter(get(main_server_ets), json_received_counter, 1),
+      NumOfDevicesReady = ets:lookup_element(get(main_server_ets), json_received_counter, ?DATA_IDX),
+      if NumOfDevicesReady == TotalNumberOfDevices -> 
+        ack(atom_to_list(received_jsons_done));
+        true -> ok
+      end
+  end,
+  stats:increment_messages_sent(StatsEts),
+  {noreply, State#main_genserver_state{}};
+
 handle_cast({clientsPhaseUpdate , Phase}, State = #main_genserver_state{myName = MyName}) ->
   ?LOG_INFO("Received clientsPhaseUpdate message with phase ~p",[binary_to_list(Phase)]),
   StatsEts = get_entity_stats_ets(?MAIN_SERVER_ATOM),
diff --git a/src_erl/NerlnetApp/src/nerlnetApp_app.erl b/src_erl/NerlnetApp/src/nerlnetApp_app.erl
index 4251aa4f..5a8da4fc 100644
--- a/src_erl/NerlnetApp/src/nerlnetApp_app.erl
+++ b/src_erl/NerlnetApp/src/nerlnetApp_app.erl
@@ -107,7 +107,7 @@ start(_StartType, _StartArgs) ->
 
 waitForInit() ->
     receive 
-        {jsonAddress, MSG} -> {_ArchitectureAdderess,_CommunicationMapAdderess} = MSG; % TODO GUY this is the case for main server which spread the message using http direct requests to devices
+        {jsonAddress, MSG} -> io:format("@NERLNET_APP got here~n"),{_ArchitectureAdderess,_CommunicationMapAdderess} = MSG; % TODO GUY this is the case for main server which spread the message using http direct requests to devices
         Other -> ?LOG_WARNING(?LOG_HEADER++"Got bad message: ~p,~ncontinue listening for init Json~n",[Other]), waitForInit()
         after ?PYTHON_SERVER_WAITING_TIMEOUT_MS -> waitForInit()
     end.
@@ -167,15 +167,27 @@ parseJsonAndStartNerlnet(ThisDeviceIP) ->
     createSources(BatchSize, DefaultFrequency, ThisDeviceIP), % TODO extract all of this args from ETS
 
     HostOfMainServer = ets:member(nerlnet_data, mainServer),
-    DevicesListWithoutMainServerDevice = [], % TODO extract this devices list
-    createMainServer(HostOfMainServer,BatchSize,ThisDeviceIP),
+    ThisDeviceName = maps:get(ThisDeviceIP , ets:lookup_element(nerlnet_data , ipv4_to_devices , ?DATA_IDX)),
+    DevicesMap = ets:lookup_element(nerlnet_data, devices_map , ?DATA_IDX), % format of key value pairs: DeviceName => {Host,Port}
+    DevicesListWithoutMainServerDevice = maps:to_list(maps:remove(ThisDeviceName, DevicesMap)), %% Form: [{device_atom , {IP,Port}} , ..]
+    createMainServer(HostOfMainServer,BatchSize,ThisDeviceIP , ThisDeviceName),
     if 
-        HostOfMainServer -> send_jsons_to_other_devices(DCJsonFileBytes, CommunicationMapFileBytes, DevicesListWithoutMainServerDevice);
-        true -> skip % rest of devices should send ready to main server
-    end.
+        HostOfMainServer -> 
+            send_jsons_to_other_devices(DCJsonFileBytes, CommunicationMapFileBytes, DevicesListWithoutMainServerDevice);
+        true -> ok % Other devices get here and notify the main server they're ready
+    end,
+    NerlnetGraph = ets:lookup_element(nerlnet_data, communicationGraph, ?DATA_IDX),
+    {?MAIN_SERVER_ATOM , {MainServerIP , MainServerPort , _MainServerDeviceName}} = digraph:vertex(NerlnetGraph, ?MAIN_SERVER_ATOM),
+    URL = "http://" ++ MainServerIP ++ ":" ++ integer_to_list(MainServerPort) ++ "/jsonReceived",
+    httpc:request(post , {URL , [] , "application/x-www-form-urlencoded" , term_to_binary({ThisDeviceName , length(DevicesListWithoutMainServerDevice)})}, [], []).
 
+send_jsons_to_other_devices(_DCJsonFileBytes, _CommunicationMapFileBytes, []) -> ?LOG_INFO("This experiment is running on a single device!",[]);
 send_jsons_to_other_devices(DCJsonFileBytes, CommunicationMapFileBytes, DevicesList) -> 
-    send_with_direct_http_cowboy_request_to_all_devices.
+    Fun = fun({DeviceName, {Host, Port}}) -> 
+        ?LOG_INFO("Sending jsons to ~p",[DeviceName]),
+        {ok, _} = httpc:request(post, {Host ++ ":" ++ integer_to_list(Port) ++ "/sendJsons", [], "application/json", term_to_binary({DCJsonFileBytes , CommunicationMapFileBytes})}, [], [])
+    end,
+    lists:foreach(Fun, DevicesList).
 
 %% internal functions
 port_validator(Port, EntityName) ->
@@ -279,8 +291,8 @@ createRouters(MapOfRouters, HostName) ->
     end,
     maps:foreach(Func, MapOfRouters). % iterates as key/values
 
-createMainServer(false,_BatchSize,_HostName) -> none;
-createMainServer(true,BatchSize,HostName) ->
+createMainServer(false,_BatchSize,_HostName,_DeviceName) -> none;
+createMainServer(true,BatchSize,HostName,DeviceName) ->
     Name = mainServer,
     {Port, _Args} = ets:lookup_element(nerlnet_data, mainServer, ?DATA_IDX),
     port_validator(Port, Name),
@@ -291,12 +303,13 @@ createMainServer(true,BatchSize,HostName) ->
     NerlnetGraph = ets:lookup_element(nerlnet_data, communicationGraph, ?DATA_IDX),
     %%Create a gen_Server for maintaining Database for Main Server.
     %% all http requests will be handled by Cowboy which updates main_genserver if necessary.
-    MainGenServer_Args= {Name,ClientsNames,BatchSize,WorkersMap,NerlnetGraph},        %%TODO change from mainserverport to routerport . also make this a list of client
+    MainGenServer_Args= {Name,ClientsNames,BatchSize,WorkersMap,NerlnetGraph,DeviceName},        %%TODO change from mainserverport to routerport . also make this a list of client
     MainGenServerPid = mainGenserver:start_link(MainGenServer_Args),
     
     MainServerDispatcher = cowboy_router:compile([
     {'_', [
         %Nerlnet actions
+        {"/jsonReceived",[],ackHandler,[jsonReceived,MainGenServerPid]},
         {"/updateCSV",[],initHandler,[MainGenServerPid]},
         {"/lossFunction",[],actionHandler,[lossFunction,MainGenServerPid]},
         {"/predictRes",[],actionHandler,[predictRes,MainGenServerPid]},