diff --git a/src/emqx_channel.erl b/src/emqx_channel.erl
index 6fbd7d217..59ff7c1ef 100644
--- a/src/emqx_channel.erl
+++ b/src/emqx_channel.erl
@@ -321,9 +321,13 @@ handle_in(?AUTH_PACKET(), Channel) ->
 handle_in({frame_error, Reason}, Channel = #channel{conn_state = idle}) ->
     shutdown(Reason, Channel);
 
+handle_in({frame_error, frame_too_large}, Channel = #channel{conn_state = connecting}) ->
+    shutdown(frame_too_large, ?CONNACK_PACKET(?RC_PACKET_TOO_LARGE), Channel);
 handle_in({frame_error, Reason}, Channel = #channel{conn_state = connecting}) ->
     shutdown(Reason, ?CONNACK_PACKET(?RC_MALFORMED_PACKET), Channel);
 
+handle_in({frame_error, frame_too_large}, Channel = #channel{conn_state = connected}) ->
+    handle_out(disconnect, {?RC_PACKET_TOO_LARGE, frame_too_large}, Channel);
 handle_in({frame_error, Reason}, Channel = #channel{conn_state = connected}) ->
     handle_out(disconnect, {?RC_MALFORMED_PACKET, Reason}, Channel);
 
diff --git a/test/emqx_channel_SUITE.erl b/test/emqx_channel_SUITE.erl
index 161f7d8e5..1f9f81bc5 100644
--- a/test/emqx_channel_SUITE.erl
+++ b/test/emqx_channel_SUITE.erl
@@ -267,7 +267,7 @@ t_handle_in_frame_error(_) ->
     ConnackPacket = ?CONNACK_PACKET(?RC_MALFORMED_PACKET),
     {shutdown, frame_too_large, ConnackPacket, _} =
         emqx_channel:handle_in({frame_error, frame_too_large}, ConnectingChan),
-    DisconnectPacket = ?DISCONNECT_PACKET(?RC_MALFORMED_PACKET),
+    DisconnectPacket = ?DISCONNECT_PACKET(?RC_PACKET_TOO_LARGE),
     ConnectedChan = channel(#{conn_state => connected}),
     {ok, [{outgoing, DisconnectPacket}, {close, frame_too_large}], _} =
         emqx_channel:handle_in({frame_error, frame_too_large}, ConnectedChan),
diff --git a/test/emqx_cm_SUITE.erl b/test/emqx_cm_SUITE.erl
index c148b14e0..985d91684 100644
--- a/test/emqx_cm_SUITE.erl
+++ b/test/emqx_cm_SUITE.erl
@@ -22,6 +22,8 @@
 -include("emqx.hrl").
 -include_lib("eunit/include/eunit.hrl").
 
+-define(CM, emqx_cm).
+
 %%--------------------------------------------------------------------
 %% CT callbacks
 %%--------------------------------------------------------------------
@@ -81,10 +83,55 @@ t_open_session(_) ->
     ?assertEqual(100, emqx_session:info(inflight_max, Session2)).
 
 t_discard_session(_) ->
-    ok = emqx_cm:discard_session(<<"clientid">>).
+    ok = meck:new(emqx_connection, [passthrough, no_history]),
+    ok = meck:expect(emqx_connection, call, fun(_, _) -> ok end),
+    ok = emqx_cm:discard_session(<<"clientid">>),
+    ok = emqx_cm:register_channel(<<"clientid">>),
+    ok = emqx_cm:discard_session(<<"clientid">>),
+    ok = emqx_cm:unregister_channel(<<"clientid">>),
+    ok = emqx_cm:register_channel(<<"clientid">>, #{conninfo => #{conn_mod => emqx_connection}}, []),
+    ok = emqx_cm:discard_session(<<"clientid">>),
+    ok = meck:expect(emqx_connection, call, fun(_, _) -> error(testing) end),
+    ok = emqx_cm:discard_session(<<"clientid">>),
+    ok = emqx_cm:unregister_channel(<<"clientid">>),
+    ok = meck:unload(emqx_connection).
 
 t_takeover_session(_) ->
-    {error, not_found} = emqx_cm:takeover_session(<<"clientid">>).
+    ok = meck:new(emqx_connection, [passthrough, no_history]),
+    ok = meck:expect(emqx_connection, call, fun(_, _) -> test end),
+    {error, not_found} = emqx_cm:takeover_session(<<"clientid">>),
+    ok = emqx_cm:register_channel(<<"clientid">>),
+    {error, not_found} = emqx_cm:takeover_session(<<"clientid">>),
+    ok = emqx_cm:unregister_channel(<<"clientid">>),
+    ok = emqx_cm:register_channel(<<"clientid">>, #{conninfo => #{conn_mod => emqx_connection}}, []),
+    Pid = self(),
+    {ok, emqx_connection, Pid, test} = emqx_cm:takeover_session(<<"clientid">>),
+    erlang:spawn(fun() ->
+                     ok = emqx_cm:register_channel(<<"clientid">>, #{conninfo => #{conn_mod => emqx_connection}}, []),
+                     timer:sleep(1000)
+                 end),
+    ct:sleep(100),
+    {ok, emqx_connection, _, test} = emqx_cm:takeover_session(<<"clientid">>),
+    ok = emqx_cm:unregister_channel(<<"clientid">>),
+    ok = meck:unload(emqx_connection).
+
+t_kick_session(_) ->
+    ok = meck:new(emqx_connection, [passthrough, no_history]),
+    ok = meck:expect(emqx_connection, call, fun(_, _) -> test end),
+    {error, not_found} = emqx_cm:kick_session(<<"clientid">>),
+    ok = emqx_cm:register_channel(<<"clientid">>),
+    {error, not_found} = emqx_cm:kick_session(<<"clientid">>),
+    ok = emqx_cm:unregister_channel(<<"clientid">>),
+    ok = emqx_cm:register_channel(<<"clientid">>, #{conninfo => #{conn_mod => emqx_connection}}, []),
+    test = emqx_cm:kick_session(<<"clientid">>),
+    erlang:spawn(fun() ->
+                     ok = emqx_cm:register_channel(<<"clientid">>, #{conninfo => #{conn_mod => emqx_connection}}, []),
+                     timer:sleep(1000)
+                 end),
+    ct:sleep(100),
+    test = emqx_cm:kick_session(<<"clientid">>),
+    ok = emqx_cm:unregister_channel(<<"clientid">>),
+    ok = meck:unload(emqx_connection).
 
 t_lock_clientid(_) ->
     {true, _Nodes} = emqx_cm_locker:lock(<<"clientid">>),
@@ -92,27 +139,7 @@ t_lock_clientid(_) ->
     {true, _Nodes} = emqx_cm_locker:unlock(<<"clientid">>),
     {true, _Nodes} = emqx_cm_locker:unlock(<<"clientid">>).
 
-
-% t_unregister_channel(_) ->
-%     error('TODO').
-
-% t_get_chan_attrs(_) ->
-%     error('TODO').
-
-% t_get_chan_stats(_) ->
-%     error('TODO').
-
-% t_lookup_channels(_) ->
-%     error('TODO').
-
-% t_set_chan_stats(_) ->
-%     error('TODO').
-
-% t_set_chan_attrs(_) ->
-%     error('TODO').
-
-% t_register_channel(_) ->
-%     error('TODO').
-
-% t_stats_fun(_) ->
-%     error('TODO').
+t_message(_) ->
+    ?CM ! testing,
+    gen_server:cast(?CM, testing),
+    gen_server:call(?CM, testing).
diff --git a/test/emqx_router_helper_SUITE.erl b/test/emqx_router_helper_SUITE.erl
index 55bb6c5d7..f7ce4b11d 100644
--- a/test/emqx_router_helper_SUITE.erl
+++ b/test/emqx_router_helper_SUITE.erl
@@ -21,20 +21,30 @@
 
 -include_lib("eunit/include/eunit.hrl").
 
+-define(ROUTER_HELPER, emqx_router_helper).
+
 all() -> emqx_ct:all(?MODULE).
 
 init_per_testcase(_TestCase, Config) ->
+    emqx_ct_helpers:start_apps([emqx]),
     Config.
 
 end_per_testcase(_TestCase, Config) ->
     Config.
 
-% t_mnesia(_) ->
-%     error('TODO').
+t_monitor(_) ->
+    ok = emqx_router_helper:monitor({undefined, node()}),
+    emqx_router_helper:monitor(undefined).
 
-% t_monitor(_) ->
-%     error('TODO').
-
-% t_stats_fun(_) ->
-%     error('TODO').
+t_mnesia(_) ->
+    ?ROUTER_HELPER ! {mnesia_table_event, {delete, {emqx_routing_node, node()}, undefined}},
+    ?ROUTER_HELPER ! {mnesia_table_event, testing},
+    ?ROUTER_HELPER ! {mnesia_table_event, {write, {emqx_routing_node, node()}, undefined}},
+    ?ROUTER_HELPER ! {membership, testing},
+    ?ROUTER_HELPER ! {membership, {mnesia, down, node()}},
+    ct:sleep(200).
 
+t_message(_) ->
+    ?ROUTER_HELPER ! testing,
+    gen_server:cast(?ROUTER_HELPER, testing),
+    gen_server:call(?ROUTER_HELPER, testing).