diff --git a/apps/emqx_gateway/src/emqx_gateway_cm.erl b/apps/emqx_gateway/src/emqx_gateway_cm.erl
index 814e37163..4c07d3938 100644
--- a/apps/emqx_gateway/src/emqx_gateway_cm.erl
+++ b/apps/emqx_gateway/src/emqx_gateway_cm.erl
@@ -389,7 +389,7 @@ open_session(
                 end,
             case takeover_session(GwName, ClientId) of
                 {ok, ConnMod, ChanPid, Session} ->
-                    ok = emqx_session:resume(ClientInfo, Session),
+                    ok = SessionMod:resume(ClientInfo, Session),
                     case request_stepdown({takeover, 'end'}, ConnMod, ChanPid) of
                         {ok, Pendings} ->
                             register_channel(
diff --git a/apps/emqx_gateway_mqttsn/include/emqx_mqttsn.hrl b/apps/emqx_gateway_mqttsn/include/emqx_mqttsn.hrl
index 5ab2d4a05..2b63e8c12 100644
--- a/apps/emqx_gateway_mqttsn/include/emqx_mqttsn.hrl
+++ b/apps/emqx_gateway_mqttsn/include/emqx_mqttsn.hrl
@@ -14,6 +14,8 @@
 %% limitations under the License.
 %%--------------------------------------------------------------------
 
+-define(SN_MAX_PREDEF_TOPIC_ID, 1024).
+
 %%--------------------------------------------------------------------
 %% MQTT-SN Types
 %%--------------------------------------------------------------------
diff --git a/apps/emqx_gateway_mqttsn/src/emqx_gateway_mqttsn.erl b/apps/emqx_gateway_mqttsn/src/emqx_gateway_mqttsn.erl
index 167ee465c..23f32497b 100644
--- a/apps/emqx_gateway_mqttsn/src/emqx_gateway_mqttsn.erl
+++ b/apps/emqx_gateway_mqttsn/src/emqx_gateway_mqttsn.erl
@@ -56,8 +56,7 @@ on_gateway_load(
     },
     Ctx
 ) ->
-    %% We Also need to start `emqx_mqttsn_broadcast` &
-    %% `emqx_mqttsn_registry` process
+    %% We Also need to start `emqx_mqttsn_broadcast`
     case maps:get(broadcast, Config, false) of
         false ->
             ok;
@@ -70,12 +69,9 @@ on_gateway_load(
     end,
 
     PredefTopics = maps:get(predefined, Config, []),
-    {ok, RegistrySvr} = emqx_mqttsn_registry:start_link(GwName, PredefTopics),
+    ok = emqx_mqttsn_registry:persist_predefined_topics(PredefTopics),
 
-    NConfig = maps:without(
-        [broadcast, predefined],
-        Config#{registry => emqx_mqttsn_registry:lookup_name(RegistrySvr)}
-    ),
+    NConfig = maps:without([broadcast, predefined], Config),
 
     Listeners = emqx_gateway_utils:normalize_config(NConfig),
 
@@ -125,5 +121,7 @@ on_gateway_unload(
     },
     _GwState
 ) ->
+    PredefTopics = maps:get(predefined, Config, []),
+    ok = emqx_mqttsn_registry:clear_predefined_topics(PredefTopics),
     Listeners = normalize_config(Config),
     stop_listeners(GwName, Listeners).
diff --git a/apps/emqx_gateway_mqttsn/src/emqx_mqttsn_channel.erl b/apps/emqx_gateway_mqttsn/src/emqx_mqttsn_channel.erl
index b03d878b7..720c288d3 100644
--- a/apps/emqx_gateway_mqttsn/src/emqx_mqttsn_channel.erl
+++ b/apps/emqx_gateway_mqttsn/src/emqx_mqttsn_channel.erl
@@ -51,8 +51,6 @@
 -record(channel, {
     %% Context
     ctx :: emqx_gateway_ctx:context(),
-    %% Registry
-    registry :: emqx_mqttsn_registry:registry(),
     %% Gateway Id
     gateway_id :: integer(),
     %% Enable negative_qos
@@ -62,7 +60,7 @@
     %% MQTT-SN Client Info
     clientinfo :: emqx_types:clientinfo(),
     %% Session
-    session :: emqx_session:session() | undefined,
+    session :: emqx_mqttsn_session:session() | undefined,
     %% Keepalive
     keepalive :: emqx_keepalive:keepalive() | undefined,
     %% Will Msg
@@ -147,7 +145,6 @@ init(
 ) ->
     Peercert = maps:get(peercert, ConnInfo, undefined),
     Mountpoint = maps:get(mountpoint, Option, undefined),
-    Registry = maps:get(registry, Option),
     GwId = maps:get(gateway_id, Option),
     EnableNegQoS = maps:get(enable_qos3, Option, true),
     ListenerId =
@@ -180,7 +177,6 @@ init(
     ),
     #channel{
         ctx = Ctx,
-        registry = Registry,
         gateway_id = GwId,
         enable_negative_qos = EnableNegQoS,
         conninfo = ConnInfo,
@@ -217,7 +213,7 @@ info(conn_state, #channel{conn_state = ConnState}) ->
 info(clientinfo, #channel{clientinfo = ClientInfo}) ->
     ClientInfo;
 info(session, #channel{session = Session}) ->
-    emqx_utils:maybe_apply(fun emqx_session:info/1, Session);
+    emqx_utils:maybe_apply(fun emqx_mqttsn_session:info/1, Session);
 info(will_msg, #channel{will_msg = WillMsg}) ->
     WillMsg;
 info(clientid, #channel{clientinfo = #{clientid := ClientId}}) ->
@@ -229,7 +225,7 @@ info(ctx, #channel{ctx = Ctx}) ->
 stats(#channel{session = undefined}) ->
     [];
 stats(#channel{session = Session}) ->
-    emqx_session:stats(Session).
+    emqx_mqttsn_session:stats(Session).
 
 set_conn_state(ConnState, Channel) ->
     Channel#channel{conn_state = ConnState}.
@@ -388,19 +384,15 @@ process_connect(
         clientinfo = ClientInfo
     }
 ) ->
-    SessFun = fun(ClientInfoT, _) ->
-        Conf = emqx_cm:get_session_confs(
-            ClientInfoT, #{receive_maximum => 1, expiry_interval => 0}
-        ),
-        emqx_session:init(Conf)
-    end,
+    SessFun = fun(ClientInfoT, _) -> emqx_mqttsn_session:init(ClientInfoT) end,
     case
         emqx_gateway_ctx:open_session(
             Ctx,
             CleanStart,
             ClientInfo,
             ConnInfo,
-            SessFun
+            SessFun,
+            _SessMod = emqx_mqttsn_session
         )
     of
         {ok, #{
@@ -470,7 +462,7 @@ handle_in(
             MsgId,
             Data
         ),
-    Channel = #channel{conn_state = idle, registry = Registry}
+    Channel = #channel{conn_state = idle}
 ) ->
     case check_negative_qos_enable(Publish, Channel) of
         ok ->
@@ -479,11 +471,8 @@ handle_in(
                     ?SN_SHORT_TOPIC ->
                         TopicId;
                     ?SN_PREDEFINED_TOPIC ->
-                        emqx_mqttsn_registry:lookup_topic(
-                            Registry,
-                            ?NEG_QOS_CLIENT_ID,
-                            TopicId
-                        );
+                        Registry = emqx_mqttsn_registry:init(),
+                        emqx_mqttsn_registry:lookup_topic(TopicId, Registry);
                     _ ->
                         undefined
                 end,
@@ -631,20 +620,19 @@ handle_in(
     end;
 handle_in(
     ?SN_REGISTER_MSG(_TopicId, MsgId, TopicName),
-    Channel = #channel{
-        registry = Registry,
-        clientinfo = #{clientid := ClientId}
-    }
+    Channel = #channel{session = Session}
 ) ->
-    case emqx_mqttsn_registry:register_topic(Registry, ClientId, TopicName) of
-        TopicId when is_integer(TopicId) ->
+    Registry = emqx_mqttsn_session:registry(Session),
+    case emqx_mqttsn_registry:reg(TopicName, Registry) of
+        {ok, TopicId, NRegistry} ->
             ?SLOG(debug, #{
                 msg => "registered_topic_name",
                 topic_name => TopicName,
                 topic_id => TopicId
             }),
             AckPacket = ?SN_REGACK_MSG(TopicId, MsgId, ?SN_RC_ACCEPTED),
-            {ok, {outgoing, AckPacket}, Channel};
+            NSession = emqx_mqttsn_session:set_registry(NRegistry, Session),
+            {ok, {outgoing, AckPacket}, Channel#channel{session = NSession}};
         {error, too_large} ->
             ?SLOG(error, #{
                 msg => "register_topic_failed",
@@ -756,14 +744,14 @@ handle_in(
     ?SN_PUBACK_MSG(TopicId, MsgId, ReturnCode),
     Channel = #channel{
         ctx = Ctx,
-        registry = Registry,
         session = Session,
-        clientinfo = ClientInfo = #{clientid := ClientId}
+        clientinfo = ClientInfo
     }
 ) ->
+    Registry = emqx_mqttsn_session:registry(Session),
     case ReturnCode of
         ?SN_RC_ACCEPTED ->
-            case emqx_session:puback(ClientInfo, MsgId, Session) of
+            case emqx_mqttsn_session:puback(ClientInfo, MsgId, Session) of
                 {ok, Msg, NSession} ->
                     ok = after_message_acked(ClientInfo, Msg, Channel),
                     {Replies, NChannel} = goto_asleep_if_buffered_msgs_sent(
@@ -795,7 +783,7 @@ handle_in(
                     {ok, Channel}
             end;
         ?SN_RC_INVALID_TOPIC_ID ->
-            case emqx_mqttsn_registry:lookup_topic(Registry, ClientId, TopicId) of
+            case emqx_mqttsn_registry:lookup_topic(TopicId, Registry) of
                 undefined ->
                     {ok, Channel};
                 TopicName ->
@@ -820,7 +808,7 @@ handle_in(
         clientinfo = ClientInfo
     }
 ) ->
-    case emqx_session:pubrec(ClientInfo, MsgId, Session) of
+    case emqx_mqttsn_session:pubrec(ClientInfo, MsgId, Session) of
         {ok, Msg, NSession} ->
             ok = after_message_acked(ClientInfo, Msg, Channel),
             NChannel = Channel#channel{session = NSession},
@@ -846,7 +834,7 @@ handle_in(
     ?SN_PUBREC_MSG(?SN_PUBREL, MsgId),
     Channel = #channel{ctx = Ctx, session = Session, clientinfo = ClientInfo}
 ) ->
-    case emqx_session:pubrel(ClientInfo, MsgId, Session) of
+    case emqx_mqttsn_session:pubrel(ClientInfo, MsgId, Session) of
         {ok, NSession} ->
             NChannel = Channel#channel{session = NSession},
             handle_out(pubcomp, MsgId, NChannel);
@@ -863,7 +851,7 @@ handle_in(
     ?SN_PUBREC_MSG(?SN_PUBCOMP, MsgId),
     Channel = #channel{ctx = Ctx, session = Session, clientinfo = ClientInfo}
 ) ->
-    case emqx_session:pubcomp(ClientInfo, MsgId, Session) of
+    case emqx_mqttsn_session:pubcomp(ClientInfo, MsgId, Session) of
         {ok, NSession} ->
             {Replies, NChannel} = goto_asleep_if_buffered_msgs_sent(
                 Channel#channel{session = NSession}
@@ -1100,12 +1088,10 @@ convert_topic_id_to_name({{name, TopicName}, Flags, Data}, Channel) ->
     {ok, {TopicName, Flags, Data}, Channel};
 convert_topic_id_to_name(
     {{id, TopicId}, Flags, Data},
-    Channel = #channel{
-        registry = Registry,
-        clientinfo = #{clientid := ClientId}
-    }
+    Channel = #channel{session = Session}
 ) ->
-    case emqx_mqttsn_registry:lookup_topic(Registry, ClientId, TopicId) of
+    Registry = emqx_mqttsn_session:registry(Session),
+    case emqx_mqttsn_registry:lookup_topic(TopicId, Registry) of
         undefined ->
             {error, ?SN_RC_INVALID_TOPIC_ID};
         TopicName ->
@@ -1174,7 +1160,7 @@ do_publish(
     Msg = #message{qos = ?QOS_2},
     Channel = #channel{ctx = Ctx, session = Session, clientinfo = ClientInfo}
 ) ->
-    case emqx_session:publish(ClientInfo, MsgId, Msg, Session) of
+    case emqx_mqttsn_session:publish(ClientInfo, MsgId, Msg, Session) of
         {ok, _PubRes, NSession} ->
             NChannel1 = ensure_timer(
                 await_timer,
@@ -1207,15 +1193,13 @@ preproc_subs_type(
         TopicName,
         QoS
     ),
-    Channel = #channel{
-        registry = Registry,
-        clientinfo = #{clientid := ClientId}
-    }
+    Channel = #channel{session = Session}
 ) ->
+    Registry = emqx_mqttsn_session:registry(Session),
     %% If the gateway is able accept the subscription,
     %% it assigns a topic id to the received topic name
     %% and returns it within a SUBACK message
-    case emqx_mqttsn_registry:register_topic(Registry, ClientId, TopicName) of
+    case emqx_mqttsn_registry:reg(TopicName, Registry) of
         {error, too_large} ->
             {error, ?SN_RC2_EXCEED_LIMITATION};
         {error, wildcard_topic} ->
@@ -1226,8 +1210,9 @@ preproc_subs_type(
             %% value when it has the first PUBLISH message with a matching
             %% topic name to be sent to the client, see also Section 6.10.
             {ok, {?SN_INVALID_TOPIC_ID, TopicName, QoS}, Channel};
-        TopicId when is_integer(TopicId) ->
-            {ok, {TopicId, TopicName, QoS}, Channel}
+        {ok, TopicId, NRegistry} ->
+            NSession = emqx_mqttsn_session:set_registry(NRegistry, Session),
+            {ok, {TopicId, TopicName, QoS}, Channel#channel{session = NSession}}
     end;
 preproc_subs_type(
     ?SN_SUBSCRIBE_MSG_TYPE(
@@ -1235,18 +1220,10 @@ preproc_subs_type(
         TopicId,
         QoS
     ),
-    Channel = #channel{
-        registry = Registry,
-        clientinfo = #{clientid := ClientId}
-    }
+    Channel = #channel{session = Session}
 ) ->
-    case
-        emqx_mqttsn_registry:lookup_topic(
-            Registry,
-            ClientId,
-            TopicId
-        )
-    of
+    Registry = emqx_mqttsn_session:registry(Session),
+    case emqx_mqttsn_registry:lookup_topic(TopicId, Registry) of
         undefined ->
             {error, ?SN_RC_INVALID_TOPIC_ID};
         TopicName ->
@@ -1323,7 +1300,7 @@ do_subscribe(
 ) ->
     NTopicName = emqx_mountpoint:mount(Mountpoint, TopicName),
     NSubOpts = maps:merge(emqx_gateway_utils:default_subopts(), SubOpts),
-    case emqx_session:subscribe(ClientInfo, NTopicName, NSubOpts, Session) of
+    case emqx_mqttsn_session:subscribe(ClientInfo, NTopicName, NSubOpts, Session) of
         {ok, NSession} ->
             {ok, {TopicId, NTopicName, NSubOpts}, Channel#channel{session = NSession}};
         {error, ?RC_QUOTA_EXCEEDED} ->
@@ -1351,18 +1328,10 @@ preproc_unsub_type(
         ?SN_PREDEFINED_TOPIC,
         TopicId
     ),
-    Channel = #channel{
-        registry = Registry,
-        clientinfo = #{clientid := ClientId}
-    }
+    Channel = #channel{session = Session}
 ) ->
-    case
-        emqx_mqttsn_registry:lookup_topic(
-            Registry,
-            ClientId,
-            TopicId
-        )
-    of
+    Registry = emqx_mqttsn_session:registry(Session),
+    case emqx_mqttsn_registry:lookup_topic(TopicId, Registry) of
         undefined ->
             {error, not_found};
         TopicName ->
@@ -1422,7 +1391,7 @@ do_unsubscribe(
                     SubOpts
                 ),
                 case
-                    emqx_session:unsubscribe(
+                    emqx_mqttsn_session:unsubscribe(
                         ClientInfo,
                         NTopicName,
                         NSubOpts,
@@ -1467,9 +1436,9 @@ awake(
         clientid => ClientId,
         previous_state => ConnState
     }),
-    {ok, Publishes, Session1} = emqx_session:replay(ClientInfo, Session),
+    {ok, Publishes, Session1} = emqx_mqttsn_session:replay(ClientInfo, Session),
     {NPublishes, NSession} =
-        case emqx_session:deliver(ClientInfo, [], Session1) of
+        case emqx_mqttsn_session:deliver(ClientInfo, [], Session1) of
             {ok, Session2} ->
                 {Publishes, Session2};
             {ok, More, Session2} ->
@@ -1497,8 +1466,8 @@ goto_asleep_if_buffered_msgs_sent(
     }
 ) ->
     case
-        emqx_mqueue:is_empty(emqx_session:info(mqueue, Session)) andalso
-            emqx_inflight:is_empty(emqx_session:info(inflight, Session))
+        emqx_mqueue:is_empty(emqx_mqttsn_session:info(mqueue, Session)) andalso
+            emqx_inflight:is_empty(emqx_mqttsn_session:info(inflight, Session))
     of
         true ->
             ?SLOG(info, #{
@@ -1591,7 +1560,7 @@ handle_out(
         register_inflight = undefined
     }
 ) ->
-    {MsgId, NSession} = emqx_session:obtain_next_pkt_id(Session),
+    {MsgId, NSession} = emqx_mqttsn_session:obtain_next_pkt_id(Session),
     Outgoing = {outgoing, ?SN_REGISTER_MSG(TopicId, MsgId, TopicName)},
     NChannel = Channel#channel{
         session = NSession,
@@ -1667,7 +1636,7 @@ maybe_resume_session(
         resuming = true
     }
 ) ->
-    Subs = emqx_session:info(subscriptions, Session),
+    Subs = emqx_mqttsn_session:info(subscriptions, Session),
     case subs_resume() andalso map_size(Subs) =/= 0 of
         true ->
             TopicNames = lists:filter(fun(T) -> not emqx_topic:wildcard(T) end, maps:keys(Subs)),
@@ -1692,9 +1661,9 @@ resume_or_replay_messages(
             false ->
                 {[], Channel}
         end,
-    {ok, Publishes, Session1} = emqx_session:replay(ClientInfo, Session),
+    {ok, Publishes, Session1} = emqx_mqttsn_session:replay(ClientInfo, Session),
     {NPublishes, NSession} =
-        case emqx_session:deliver(ClientInfo, NPendings, Session1) of
+        case emqx_mqttsn_session:deliver(ClientInfo, NPendings, Session1) of
             {ok, Session2} ->
                 {Publishes, Session2};
             {ok, More, Session2} ->
@@ -1765,10 +1734,7 @@ outgoing_deliver_and_register({Packets, Channel}) ->
 message_to_packet(
     MsgId,
     Message,
-    #channel{
-        registry = Registry,
-        clientinfo = #{clientid := ClientId}
-    }
+    #channel{session = Session}
 ) ->
     QoS = emqx_message:qos(Message),
     Topic = emqx_message:topic(Message),
@@ -1778,7 +1744,8 @@ message_to_packet(
             ?QOS_0 -> 0;
             _ -> MsgId
         end,
-    case emqx_mqttsn_registry:lookup_topic_id(Registry, ClientId, Topic) of
+    Registry = emqx_mqttsn_session:registry(Session),
+    case emqx_mqttsn_registry:lookup_topic_id(Topic, Registry) of
         {predef, PredefTopicId} ->
             Flags = #mqtt_sn_flags{qos = QoS, topic_id_type = ?SN_PREDEFINED_TOPIC},
             ?SN_PUBLISH_MSG(Flags, PredefTopicId, NMsgId, Payload);
@@ -1813,7 +1780,7 @@ handle_call({unsubscribe, Topic}, _From, Channel) ->
     {ok, _, NChannel} = do_unsubscribe(TopicFilters, Channel),
     reply_and_update(ok, NChannel);
 handle_call(subscriptions, _From, Channel = #channel{session = Session}) ->
-    reply({ok, maps:to_list(emqx_session:info(subscriptions, Session))}, Channel);
+    reply({ok, maps:to_list(emqx_mqttsn_session:info(subscriptions, Session))}, Channel);
 handle_call(kick, _From, Channel) ->
     NChannel = ensure_disconnected(kicked, Channel),
     shutdown_and_reply(kicked, ok, NChannel);
@@ -1834,7 +1801,7 @@ handle_call(
         pendings = Pendings
     }
 ) ->
-    ok = emqx_session:takeover(Session),
+    ok = emqx_mqttsn_session:takeover(Session),
     %% TODO: Should not drain deliver here (side effect)
     Delivers = emqx_utils:drain_deliver(),
     AllPendings = lists:append(Delivers, Pendings),
@@ -1911,8 +1878,9 @@ handle_info(clean_authz_cache, Channel) ->
     {ok, Channel};
 handle_info({subscribe, _}, Channel) ->
     {ok, Channel};
-handle_info({register, TopicName}, Channel) ->
-    case ensure_registered_topic_name(TopicName, Channel) of
+handle_info({register, TopicName}, Channel = #channel{session = Session}) ->
+    Registry = emqx_mqttsn_session:registry(Session),
+    case emqx_mqttsn_registry:reg(TopicName, Registry) of
         {error, Reason} ->
             ?SLOG(error, #{
                 msg => "register_topic_failed",
@@ -1920,8 +1888,9 @@ handle_info({register, TopicName}, Channel) ->
                 reason => Reason
             }),
             {ok, Channel};
-        {ok, TopicId} ->
-            handle_out(register, {TopicId, TopicName}, Channel)
+        {ok, TopicId, NRegistry} ->
+            NSession = emqx_mqttsn_session:set_registry(NRegistry, Session),
+            handle_out(register, {TopicId, TopicName}, Channel#channel{session = NSession})
     end;
 handle_info(Info, Channel) ->
     ?SLOG(error, #{
@@ -1940,21 +1909,6 @@ maybe_shutdown(Reason, Channel = #channel{conninfo = ConnInfo}) ->
             shutdown(Reason, Channel)
     end.
 
-ensure_registered_topic_name(
-    TopicName,
-    Channel = #channel{registry = Registry}
-) ->
-    ClientId = clientid(Channel),
-    case emqx_mqttsn_registry:lookup_topic_id(Registry, ClientId, TopicName) of
-        undefined ->
-            case emqx_mqttsn_registry:register_topic(Registry, ClientId, TopicName) of
-                {error, Reason} -> {error, Reason};
-                TopicId -> {ok, TopicId}
-            end;
-        TopicId ->
-            {ok, TopicId}
-    end.
-
 %%--------------------------------------------------------------------
 %% Ensure disconnected
 
@@ -2003,7 +1957,7 @@ handle_deliver(
     ConnState =:= disconnected;
     ConnState =:= asleep
 ->
-    NSession = emqx_session:enqueue(
+    NSession = emqx_mqttsn_session:enqueue(
         ClientInfo,
         ignore_local(maybe_nack(Delivers), ClientId, Session, Ctx),
         Session
@@ -2039,7 +1993,7 @@ handle_deliver(
     }
 ) ->
     case
-        emqx_session:deliver(
+        emqx_mqttsn_session:deliver(
             ClientInfo,
             ignore_local(Delivers, ClientId, Session, Ctx),
             Session
@@ -2057,7 +2011,7 @@ handle_deliver(
     end.
 
 ignore_local(Delivers, Subscriber, Session, Ctx) ->
-    Subs = emqx_session:info(subscriptions, Session),
+    Subs = emqx_mqttsn_session:info(subscriptions, Session),
     lists:filter(
         fun({deliver, Topic, #message{from = Publisher}}) ->
             case maps:find(Topic, Subs) of
@@ -2132,7 +2086,7 @@ handle_timeout(
     retry_delivery,
     Channel = #channel{session = Session, clientinfo = ClientInfo}
 ) ->
-    case emqx_session:retry(ClientInfo, Session) of
+    case emqx_mqttsn_session:retry(ClientInfo, Session) of
         {ok, NSession} ->
             {ok, clean_timer(retry_timer, Channel#channel{session = NSession})};
         {ok, Publishes, Timeout, NSession} ->
@@ -2157,7 +2111,7 @@ handle_timeout(
     expire_awaiting_rel,
     Channel = #channel{session = Session, clientinfo = ClientInfo}
 ) ->
-    case emqx_session:expire(ClientInfo, awaiting_rel, Session) of
+    case emqx_mqttsn_session:expire(ClientInfo, awaiting_rel, Session) of
         {ok, NSession} ->
             {ok, clean_timer(await_timer, Channel#channel{session = NSession})};
         {ok, Timeout, NSession} ->
@@ -2301,17 +2255,14 @@ clean_timer(Name, Channel = #channel{timers = Timers}) ->
 interval(alive_timer, #channel{keepalive = KeepAlive}) ->
     emqx_keepalive:info(interval, KeepAlive);
 interval(retry_timer, #channel{session = Session}) ->
-    emqx_session:info(retry_interval, Session);
+    emqx_mqttsn_session:info(retry_interval, Session);
 interval(await_timer, #channel{session = Session}) ->
-    emqx_session:info(await_rel_timeout, Session).
+    emqx_mqttsn_session:info(await_rel_timeout, Session).
 
 %%--------------------------------------------------------------------
 %% Helper functions
 %%--------------------------------------------------------------------
 
-clientid(#channel{clientinfo = #{clientid := ClientId}}) ->
-    ClientId.
-
 run_hooks(Ctx, Name, Args) ->
     emqx_gateway_ctx:metrics_inc(Ctx, Name),
     emqx_hooks:run(Name, Args).
diff --git a/apps/emqx_gateway_mqttsn/src/emqx_mqttsn_registry.erl b/apps/emqx_gateway_mqttsn/src/emqx_mqttsn_registry.erl
index 9db355a9b..3113fc43d 100644
--- a/apps/emqx_gateway_mqttsn/src/emqx_mqttsn_registry.erl
+++ b/apps/emqx_gateway_mqttsn/src/emqx_mqttsn_registry.erl
@@ -17,64 +17,92 @@
 %% @doc The MQTT-SN Topic Registry
 -module(emqx_mqttsn_registry).
 
--behaviour(gen_server).
-
 -include("emqx_mqttsn.hrl").
--include_lib("emqx/include/logger.hrl").
-
--export([start_link/2]).
 
 -export([
-    register_topic/3,
-    unregister_topic/2
+    persist_predefined_topics/1,
+    clear_predefined_topics/1
 ]).
 
 -export([
-    lookup_topic/3,
-    lookup_topic_id/3
+    init/0,
+    reg/2,
+    unreg/2,
+    lookup_topic/2,
+    lookup_topic_id/2
 ]).
 
-%% gen_server callbacks
--export([
-    init/1,
-    handle_call/3,
-    handle_cast/2,
-    handle_info/2,
-    terminate/2,
-    code_change/3
-]).
+-define(PKEY(Id), {mqttsn, predef_topics, Id}).
 
-%% Internal exports (RPC)
--export([
-    do_register/4
-]).
+-type registry() :: #{
+    %% The last topic id aallocated
+    last_topic_id := pos_integer(),
+    %% The mapping from topic id to topic name
+    id_to_name := map(),
+    %% The mapping from topic name to topic id
+    name_to_id := map()
+}.
 
--export([lookup_name/1]).
-
--define(SN_SHARD, emqx_mqttsn_shard).
-
--record(state, {tabname, max_predef_topic_id = 0}).
-
--record(emqx_mqttsn_registry, {key, value}).
-
--type registry() :: {Tab :: atom(), RegistryPid :: pid()}.
+-type predef_topic() :: #{
+    id := 1..1024,
+    topic := iolist()
+}.
 
 %%-----------------------------------------------------------------------------
+%% APIs
 
--spec start_link(atom(), list()) ->
-    ignore
-    | {ok, pid()}
-    | {error, Reason :: term()}.
-start_link(InstaId, PredefTopics) ->
-    gen_server:start_link(?MODULE, [InstaId, PredefTopics], []).
+-spec persist_predefined_topics([predef_topic()]) -> ok.
+persist_predefined_topics(PredefTopics) when is_list(PredefTopics) ->
+    try
+        F = fun(#{id := TopicId, topic := TopicName0}) when TopicId =< 1024 ->
+            TopicName = iolist_to_binary(TopicName0),
+            persistent_term:put(?PKEY(TopicId), TopicName),
+            persistent_term:put(?PKEY(TopicName), TopicId)
+        end,
+        lists:foreach(F, PredefTopics)
+    catch
+        _:_ ->
+            clear_predefined_topics(PredefTopics),
+            error(badarg)
+    end.
 
--spec register_topic(registry(), emqx_types:clientid(), emqx_types:topic()) ->
-    integer()
+-spec clear_predefined_topics([predef_topic()]) -> ok.
+clear_predefined_topics(PredefTopics) ->
+    lists:foreach(
+        fun(#{id := TopicId, topic := TopicName0}) ->
+            TopicName = iolist_to_binary(TopicName0),
+            persistent_term:erase(?PKEY(TopicId)),
+            persistent_term:erase(?PKEY(TopicName))
+        end,
+        PredefTopics
+    ),
+    ok.
+
+-spec init() -> registry().
+init() ->
+    #{
+        last_topic_id => ?SN_MAX_PREDEF_TOPIC_ID,
+        id_to_name => #{},
+        name_to_id => #{}
+    }.
+
+-spec reg(emqx_types:topic(), registry()) ->
+    {ok, integer(), registry()}
     | {error, term()}.
-register_topic({_, Pid}, ClientId, TopicName) when is_binary(TopicName) ->
+reg(
+    TopicName,
+    Registry
+) when is_binary(TopicName) ->
     case emqx_topic:wildcard(TopicName) of
         false ->
-            gen_server:call(Pid, {register, ClientId, TopicName});
+            case lookup_topic_id(TopicName, Registry) of
+                {predef, TopicId} when is_integer(TopicId) ->
+                    {ok, TopicId, Registry};
+                TopicId when is_integer(TopicId) ->
+                    {ok, TopicId, Registry};
+                undefined ->
+                    do_reg(TopicName, Registry)
+            end;
         %% TopicId: in case of “accepted” the value that will be used as topic
         %% id by the gateway when sending PUBLISH messages to the client (not
         %% relevant in case of subscriptions to a short topic name or to a topic
@@ -83,182 +111,64 @@ register_topic({_, Pid}, ClientId, TopicName) when is_binary(TopicName) ->
             {error, wildcard_topic}
     end.
 
--spec lookup_topic(registry(), emqx_types:clientid(), pos_integer()) ->
+do_reg(
+    TopicName,
+    Registry = #{
+        last_topic_id := TopicId0,
+        id_to_name := IdMap,
+        name_to_id := NameMap
+    }
+) ->
+    case next_topic_id(TopicId0) of
+        {error, too_large} ->
+            {error, too_large};
+        NextTopicId ->
+            NRegistry = Registry#{
+                last_topic_id := NextTopicId,
+                id_to_name := maps:put(NextTopicId, TopicName, IdMap),
+                name_to_id := maps:put(TopicName, NextTopicId, NameMap)
+            },
+            {ok, NextTopicId, NRegistry}
+    end.
+
+next_topic_id(Id) when is_integer(Id) andalso (Id < 16#FFFF) ->
+    Id + 1;
+next_topic_id(Id) when is_integer(Id) ->
+    {error, too_large}.
+
+-spec lookup_topic(pos_integer(), registry()) ->
     undefined
     | binary().
-lookup_topic({Tab, _}, ClientId, TopicId) when is_integer(TopicId) ->
-    case lookup_element(Tab, {predef, TopicId}, 3) of
+lookup_topic(TopicId, _Registry = #{id_to_name := IdMap}) when is_integer(TopicId) ->
+    case persistent_term:get(?PKEY(TopicId), undefined) of
         undefined ->
-            lookup_element(Tab, {ClientId, TopicId}, 3);
+            maps:get(TopicId, IdMap, undefined);
         Topic ->
             Topic
     end.
 
--spec lookup_topic_id(registry(), emqx_types:clientid(), emqx_types:topic()) ->
+-spec lookup_topic_id(emqx_types:topic(), registry()) ->
     undefined
     | pos_integer()
     | {predef, integer()}.
-lookup_topic_id({Tab, _}, ClientId, TopicName) when is_binary(TopicName) ->
-    case lookup_element(Tab, {predef, TopicName}, 3) of
+lookup_topic_id(TopicName, _Registry = #{name_to_id := NameMap}) when is_binary(TopicName) ->
+    case persistent_term:get(?PKEY(TopicName), undefined) of
         undefined ->
-            lookup_element(Tab, {ClientId, TopicName}, 3);
+            maps:get(TopicName, NameMap, undefined);
         TopicId ->
             {predef, TopicId}
     end.
 
-%% @private
-lookup_element(Tab, Key, Pos) ->
-    try
-        ets:lookup_element(Tab, Key, Pos)
-    catch
-        error:badarg -> undefined
-    end.
-
--spec unregister_topic(registry(), emqx_types:clientid()) -> ok.
-unregister_topic({_, Pid}, ClientId) ->
-    gen_server:call(Pid, {unregister, ClientId}).
-
-lookup_name(Pid) ->
-    gen_server:call(Pid, name).
-
-%%-----------------------------------------------------------------------------
-
-name(InstaId) ->
-    list_to_atom(lists:concat([emqx_mqttsn_, InstaId, '_registry'])).
-
-init([InstaId, PredefTopics]) ->
-    %% {predef, TopicId}     -> TopicName
-    %% {predef, TopicName}   -> TopicId
-    %% {ClientId, TopicId}   -> TopicName
-    %% {ClientId, TopicName} -> TopicId
-    Tab = name(InstaId),
-    ok = mria:create_table(Tab, [
-        {storage, ram_copies},
-        {record_name, emqx_mqttsn_registry},
-        {attributes, record_info(fields, emqx_mqttsn_registry)},
-        {storage_properties, [{ets, [{read_concurrency, true}]}]},
-        {rlog_shard, ?SN_SHARD}
-    ]),
-    ok = mria:wait_for_tables([Tab]),
-    MaxPredefId = lists:foldl(
-        fun(#{id := TopicId, topic := TopicName0}, AccId) ->
-            TopicName = iolist_to_binary(TopicName0),
-            mria:dirty_write(Tab, #emqx_mqttsn_registry{
-                key = {predef, TopicId},
-                value = TopicName
-            }),
-            mria:dirty_write(Tab, #emqx_mqttsn_registry{
-                key = {predef, TopicName},
-                value = TopicId
-            }),
-            case TopicId > AccId of
-                true -> TopicId;
-                false -> AccId
-            end
-        end,
-        0,
-        PredefTopics
-    ),
-    {ok, #state{tabname = Tab, max_predef_topic_id = MaxPredefId}}.
-
-handle_call(
-    {register, ClientId, TopicName},
-    _From,
-    State = #state{tabname = Tab, max_predef_topic_id = PredefId}
-) ->
-    case lookup_topic_id({Tab, self()}, ClientId, TopicName) of
-        {predef, PredefTopicId} when is_integer(PredefTopicId) ->
-            {reply, PredefTopicId, State};
-        TopicId when is_integer(TopicId) ->
-            {reply, TopicId, State};
-        undefined ->
-            case next_topic_id(Tab, PredefId, ClientId) of
-                TopicId when TopicId >= 16#FFFF ->
-                    {reply, {error, too_large}, State};
-                TopicId ->
-                    case
-                        mria:transaction(?SN_SHARD, fun ?MODULE:do_register/4, [
-                            Tab, ClientId, TopicId, TopicName
-                        ])
-                    of
-                        {atomic, ok} ->
-                            {reply, TopicId, State};
-                        {aborted, Error} ->
-                            {reply, {error, Error}, State}
-                    end
-            end
-    end;
-handle_call({unregister, ClientId}, _From, State = #state{tabname = Tab}) ->
-    Registry = mnesia:dirty_match_object(
-        Tab,
-        {emqx_mqttsn_registry, {ClientId, '_'}, '_'}
-    ),
-    lists:foreach(
-        fun(R) ->
-            mria:dirty_delete_object(Tab, R)
-        end,
-        Registry
-    ),
-    {reply, ok, State};
-handle_call(name, _From, State = #state{tabname = Tab}) ->
-    {reply, {Tab, self()}, State};
-handle_call(Req, _From, State) ->
-    ?SLOG(error, #{
-        msg => "unexpected_call",
-        call => Req
-    }),
-    {reply, ignored, State}.
-
-handle_cast(Msg, State) ->
-    ?SLOG(error, #{
-        msg => "unexpected_cast",
-        cast => Msg
-    }),
-    {noreply, State}.
-
-handle_info(Info, State) ->
-    ?SLOG(error, #{
-        msg => "unexpected_info",
-        info => Info
-    }),
-    {noreply, State}.
-
-terminate(_Reason, _State) ->
-    ok.
-
-code_change(_OldVsn, State, _Extra) ->
-    {ok, State}.
-
-do_register(Tab, ClientId, TopicId, TopicName) ->
-    mnesia:write(
-        Tab,
-        #emqx_mqttsn_registry{
-            key = {ClientId, next_topic_id},
-            value = TopicId + 1
-        },
-        write
-    ),
-    mnesia:write(
-        Tab,
-        #emqx_mqttsn_registry{
-            key = {ClientId, TopicName},
-            value = TopicId
-        },
-        write
-    ),
-    mnesia:write(
-        Tab,
-        #emqx_mqttsn_registry{
-            key = {ClientId, TopicId},
-            value = TopicName
-        },
-        write
-    ).
-
-%%-----------------------------------------------------------------------------
-
-next_topic_id(Tab, PredefId, ClientId) ->
-    case mnesia:dirty_read(Tab, {ClientId, next_topic_id}) of
-        [#emqx_mqttsn_registry{value = Id}] -> Id;
-        [] -> PredefId + 1
+-spec unreg(emqx_types:topic(), registry()) -> registry().
+unreg(TopicName, Registry = #{name_to_id := NameMap, id_to_name := IdMap}) when
+    is_binary(TopicName)
+->
+    case maps:find(TopicName, NameMap) of
+        {ok, TopicId} ->
+            Registry#{
+                name_to_id := maps:remove(TopicName, NameMap),
+                id_to_name := maps:remove(TopicId, IdMap)
+            };
+        error ->
+            Registry
     end.
diff --git a/apps/emqx_gateway_mqttsn/src/emqx_mqttsn_schema.erl b/apps/emqx_gateway_mqttsn/src/emqx_mqttsn_schema.erl
index 8adf7a934..08fb854b4 100644
--- a/apps/emqx_gateway_mqttsn/src/emqx_mqttsn_schema.erl
+++ b/apps/emqx_gateway_mqttsn/src/emqx_mqttsn_schema.erl
@@ -16,6 +16,7 @@
 
 -module(emqx_mqttsn_schema).
 
+-include("emqx_mqttsn.hrl").
 -include_lib("hocon/include/hoconsc.hrl").
 -include_lib("typerefl/include/types.hrl").
 
@@ -72,7 +73,7 @@ fields(mqttsn) ->
 fields(mqttsn_predefined) ->
     [
         {id,
-            sc(integer(), #{
+            sc(range(1, ?SN_MAX_PREDEF_TOPIC_ID), #{
                 required => true,
                 desc => ?DESC(mqttsn_predefined_id)
             })},
diff --git a/apps/emqx_gateway_mqttsn/src/emqx_mqttsn_session.erl b/apps/emqx_gateway_mqttsn/src/emqx_mqttsn_session.erl
new file mode 100644
index 000000000..7c62800cc
--- /dev/null
+++ b/apps/emqx_gateway_mqttsn/src/emqx_mqttsn_session.erl
@@ -0,0 +1,144 @@
+%%--------------------------------------------------------------------
+%% Copyright (c) 2023 EMQ Technologies Co., Ltd. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%--------------------------------------------------------------------
+
+-module(emqx_mqttsn_session).
+
+-export([registry/1, set_registry/2]).
+
+-export([
+    init/1,
+    info/1,
+    info/2,
+    stats/1,
+    resume/2
+]).
+
+-export([
+    publish/4,
+    subscribe/4,
+    unsubscribe/4,
+    puback/3,
+    pubrec/3,
+    pubrel/3,
+    pubcomp/3
+]).
+
+-export([
+    replay/2,
+    deliver/3,
+    obtain_next_pkt_id/1,
+    takeover/1,
+    enqueue/3,
+    retry/2,
+    expire/3
+]).
+
+-type session() :: #{
+    registry := emqx_mqttsn_registry:registry(),
+    session := emqx_session:session()
+}.
+
+-export_type([session/0]).
+
+init(ClientInfo) ->
+    Conf = emqx_cm:get_session_confs(
+        ClientInfo, #{receive_maximum => 1, expiry_interval => 0}
+    ),
+    #{
+        registry => emqx_mqttsn_registry:init(),
+        session => emqx_session:init(Conf)
+    }.
+
+registry(#{registry := Registry}) ->
+    Registry.
+
+set_registry(Registry, Session) ->
+    Session#{registry := Registry}.
+
+info(#{session := Session}) ->
+    emqx_session:info(Session).
+
+info(Key, #{session := Session}) ->
+    emqx_session:info(Key, Session).
+
+stats(#{session := Session}) ->
+    emqx_session:stats(Session).
+
+puback(ClientInfo, MsgId, Session) ->
+    with_sess(?FUNCTION_NAME, [ClientInfo, MsgId], Session).
+
+pubrec(ClientInfo, MsgId, Session) ->
+    with_sess(?FUNCTION_NAME, [ClientInfo, MsgId], Session).
+
+pubrel(ClientInfo, MsgId, Session) ->
+    with_sess(?FUNCTION_NAME, [ClientInfo, MsgId], Session).
+
+pubcomp(ClientInfo, MsgId, Session) ->
+    with_sess(?FUNCTION_NAME, [ClientInfo, MsgId], Session).
+
+publish(ClientInfo, MsgId, Msg, Session) ->
+    with_sess(?FUNCTION_NAME, [ClientInfo, MsgId, Msg], Session).
+
+subscribe(ClientInfo, Topic, SubOpts, Session) ->
+    with_sess(?FUNCTION_NAME, [ClientInfo, Topic, SubOpts], Session).
+
+unsubscribe(ClientInfo, Topic, SubOpts, Session) ->
+    with_sess(?FUNCTION_NAME, [ClientInfo, Topic, SubOpts], Session).
+
+replay(ClientInfo, Session) ->
+    with_sess(?FUNCTION_NAME, [ClientInfo], Session).
+
+deliver(ClientInfo, Delivers, Session1) ->
+    with_sess(?FUNCTION_NAME, [ClientInfo, Delivers], Session1).
+
+obtain_next_pkt_id(Session = #{session := Sess}) ->
+    {Id, Sess1} = emqx_session:obtain_next_pkt_id(Sess),
+    {Id, Session#{session := Sess1}}.
+
+takeover(_Session = #{session := Sess}) ->
+    emqx_session:takeover(Sess).
+
+enqueue(ClientInfo, Delivers, Session = #{session := Sess}) ->
+    Sess1 = emqx_session:enqueue(ClientInfo, Delivers, Sess),
+    Session#{session := Sess1}.
+
+retry(ClientInfo, Session) ->
+    with_sess(?FUNCTION_NAME, [ClientInfo], Session).
+
+expire(ClientInfo, awaiting_rel, Session) ->
+    with_sess(?FUNCTION_NAME, [ClientInfo, awaiting_rel], Session).
+
+resume(ClientInfo, #{session := Sess}) ->
+    emqx_session:resume(ClientInfo, Sess).
+
+%%--------------------------------------------------------------------
+%% internal funcs
+
+with_sess(Fun, Args, Session = #{session := Sess}) ->
+    case apply(emqx_session, Fun, Args ++ [Sess]) of
+        %% for subscribe
+        {error, Reason} ->
+            {error, Reason};
+        %% for pubrel
+        {ok, Sess1} ->
+            {ok, Session#{session := Sess1}};
+        %% for publish and puback
+        {ok, Result, Sess1} ->
+            {ok, Result, Session#{session := Sess1}};
+        %% for puback
+        {ok, Msgs, Replies, Sess1} ->
+            {ok, Msgs, Replies, Session#{session := Sess1}}
+    end.
diff --git a/apps/emqx_gateway_mqttsn/test/emqx_sn_protocol_SUITE.erl b/apps/emqx_gateway_mqttsn/test/emqx_sn_protocol_SUITE.erl
index 73e8d5312..c3fa89c70 100644
--- a/apps/emqx_gateway_mqttsn/test/emqx_sn_protocol_SUITE.erl
+++ b/apps/emqx_gateway_mqttsn/test/emqx_sn_protocol_SUITE.erl
@@ -47,12 +47,15 @@
 
 -define(LOG(Format, Args), ct:log("TEST: " ++ Format, Args)).
 
--define(MAX_PRED_TOPIC_ID, 2).
+-define(MAX_PRED_TOPIC_ID, ?SN_MAX_PREDEF_TOPIC_ID).
 -define(PREDEF_TOPIC_ID1, 1).
 -define(PREDEF_TOPIC_ID2, 2).
 -define(PREDEF_TOPIC_NAME1, <<"/predefined/topic/name/hello">>).
 -define(PREDEF_TOPIC_NAME2, <<"/predefined/topic/name/nice">>).
--define(ENABLE_QOS3, true).
+-define(DEFAULT_PREDEFINED_TOPICS, [
+    #{<<"id">> => ?PREDEF_TOPIC_ID1, <<"topic">> => ?PREDEF_TOPIC_NAME1},
+    #{<<"id">> => ?PREDEF_TOPIC_ID2, <<"topic">> => ?PREDEF_TOPIC_NAME2}
+]).
 % FLAG NOT USED
 -define(FNU, 0).
 
@@ -143,6 +146,13 @@ restart_mqttsn_with_mountpoint(Mp) ->
         Conf#{<<"mountpoint">> => Mp}
     ).
 
+restart_mqttsn_with_predefined_topics(Topics) ->
+    Conf = emqx:get_raw_config([gateway, mqttsn]),
+    emqx_gateway_conf:update_gateway(
+        mqttsn,
+        Conf#{<<"predefined">> => Topics}
+    ).
+
 default_config() ->
     ?CONF_DEFAULT.
 
@@ -487,6 +497,35 @@ t_subscribe_case08(_) ->
     ?assertEqual(<<2, ?SN_DISCONNECT>>, receive_response(Socket)),
     gen_udp:close(Socket).
 
+t_subscribe_predefined_topic(_) ->
+    Dup = 0,
+    QoS = 0,
+    Retain = 0,
+    Will = 0,
+    CleanSession = 0,
+    MsgId = 1,
+    Socket = ensure_connected_client(?CLIENTID),
+    send_subscribe_msg_predefined_topic(Socket, 0, ?PREDEF_TOPIC_ID1, 1),
+    ?assertEqual(
+        <<8, ?SN_SUBACK, Dup:1, QoS:2, Retain:1, Will:1, CleanSession:1, ?SN_NORMAL_TOPIC:2,
+            ?PREDEF_TOPIC_ID1:16, MsgId:16, ?SN_RC_ACCEPTED>>,
+        receive_response(Socket)
+    ),
+    send_disconnect_msg(Socket, undefined),
+    gen_udp:close(Socket),
+
+    restart_mqttsn_with_predefined_topics([]),
+    Socket1 = ensure_connected_client(?CLIENTID),
+    send_subscribe_msg_predefined_topic(Socket1, 0, ?PREDEF_TOPIC_ID1, 1),
+    ?assertEqual(
+        <<8, ?SN_SUBACK, Dup:1, QoS:2, Retain:1, Will:1, CleanSession:1, ?SN_NORMAL_TOPIC:2, 0:16,
+            MsgId:16, ?SN_RC_INVALID_TOPIC_ID>>,
+        receive_response(Socket1)
+    ),
+    send_disconnect_msg(Socket1, undefined),
+    restart_mqttsn_with_predefined_topics(?DEFAULT_PREDEFINED_TOPICS),
+    gen_udp:close(Socket1).
+
 t_publish_negqos_enabled(_) ->
     Dup = 0,
     QoS = 0,
@@ -513,14 +552,11 @@ t_publish_negqos_enabled(_) ->
     Payload1 = <<20, 21, 22, 23>>,
     send_publish_msg_normal_topic(Socket, NegQoS, MsgId1, TopicId1, Payload1),
     timer:sleep(100),
-    case ?ENABLE_QOS3 of
-        true ->
-            Eexp =
-                <<11, ?SN_PUBLISH, Dup:1, QoS:2, Retain:1, Will:1, CleanSession:1,
-                    ?SN_NORMAL_TOPIC:2, TopicId1:16, (mid(0)):16, <<20, 21, 22, 23>>/binary>>,
-            What = receive_response(Socket),
-            ?assertEqual(Eexp, What)
-    end,
+    Eexp =
+        <<11, ?SN_PUBLISH, Dup:1, QoS:2, Retain:1, Will:1, CleanSession:1, ?SN_NORMAL_TOPIC:2,
+            TopicId1:16, (mid(0)):16, <<20, 21, 22, 23>>/binary>>,
+    What = receive_response(Socket),
+    ?assertEqual(Eexp, What),
 
     send_disconnect_msg(Socket, undefined),
     ?assertEqual(<<2, ?SN_DISCONNECT>>, receive_response(Socket)),
@@ -2777,3 +2813,9 @@ flush(Msgs) ->
         M -> flush([M | Msgs])
     after 0 -> lists:reverse(Msgs)
     end.
+
+ensure_connected_client(ClientId) ->
+    {ok, Socket} = gen_udp:open(0, [binary]),
+    send_connect_msg(Socket, ClientId),
+    ?assertEqual(<<3, ?SN_CONNACK, 0>>, receive_response(Socket)),
+    Socket.
diff --git a/apps/emqx_gateway_mqttsn/test/emqx_sn_registry_SUITE.erl b/apps/emqx_gateway_mqttsn/test/emqx_sn_registry_SUITE.erl
index 4d89a802d..8d60570a0 100644
--- a/apps/emqx_gateway_mqttsn/test/emqx_sn_registry_SUITE.erl
+++ b/apps/emqx_gateway_mqttsn/test/emqx_sn_registry_SUITE.erl
@@ -19,10 +19,11 @@
 -compile(export_all).
 -compile(nowarn_export_all).
 
+-include("emqx_mqttsn.hrl").
 -include_lib("eunit/include/eunit.hrl").
 
 -define(REGISTRY, emqx_mqttsn_registry).
--define(MAX_PREDEF_ID, 2).
+-define(MAX_PREDEF_ID, ?SN_MAX_PREDEF_TOPIC_ID).
 -define(PREDEF_TOPICS, [
     #{id => 1, topic => <<"/predefined/topic/name/hello">>},
     #{id => 2, topic => <<"/predefined/topic/name/nice">>}
@@ -36,96 +37,64 @@ all() ->
     emqx_common_test_helpers:all(?MODULE).
 
 init_per_suite(Config) ->
-    application:ensure_all_started(ekka),
-    mria:start(),
     Config.
 
 end_per_suite(_Config) ->
-    application:stop(ekka),
     ok.
 
 init_per_testcase(_TestCase, Config) ->
-    {ok, Pid} = ?REGISTRY:start_link('mqttsn', ?PREDEF_TOPICS),
-    {Tab, Pid} = ?REGISTRY:lookup_name(Pid),
-    [{reg, {Tab, Pid}} | Config].
+    emqx_mqttsn_registry:persist_predefined_topics(?PREDEF_TOPICS),
+    Config.
 
 end_per_testcase(_TestCase, Config) ->
-    {Tab, _Pid} = proplists:get_value(reg, Config),
-    mria:clear_table(Tab),
+    emqx_mqttsn_registry:clear_predefined_topics(?PREDEF_TOPICS),
     Config.
 
 %%--------------------------------------------------------------------
 %% Test cases
 %%--------------------------------------------------------------------
 
-t_register(Config) ->
-    Reg = proplists:get_value(reg, Config),
-    ?assertEqual(?MAX_PREDEF_ID + 1, ?REGISTRY:register_topic(Reg, <<"ClientId">>, <<"Topic1">>)),
-    ?assertEqual(?MAX_PREDEF_ID + 2, ?REGISTRY:register_topic(Reg, <<"ClientId">>, <<"Topic2">>)),
-    ?assertEqual(<<"Topic1">>, ?REGISTRY:lookup_topic(Reg, <<"ClientId">>, ?MAX_PREDEF_ID + 1)),
-    ?assertEqual(<<"Topic2">>, ?REGISTRY:lookup_topic(Reg, <<"ClientId">>, ?MAX_PREDEF_ID + 2)),
-    ?assertEqual(?MAX_PREDEF_ID + 1, ?REGISTRY:lookup_topic_id(Reg, <<"ClientId">>, <<"Topic1">>)),
-    ?assertEqual(?MAX_PREDEF_ID + 2, ?REGISTRY:lookup_topic_id(Reg, <<"ClientId">>, <<"Topic2">>)),
-    emqx_mqttsn_registry:unregister_topic(Reg, <<"ClientId">>),
-    ?assertEqual(undefined, ?REGISTRY:lookup_topic(Reg, <<"ClientId">>, ?MAX_PREDEF_ID + 1)),
-    ?assertEqual(undefined, ?REGISTRY:lookup_topic(Reg, <<"ClientId">>, ?MAX_PREDEF_ID + 2)),
-    ?assertEqual(undefined, ?REGISTRY:lookup_topic_id(Reg, <<"ClientId">>, <<"Topic1">>)),
-    ?assertEqual(undefined, ?REGISTRY:lookup_topic_id(Reg, <<"ClientId">>, <<"Topic2">>)).
+t_register(_) ->
+    Reg = ?REGISTRY:init(),
+    {ok, ?MAX_PREDEF_ID + 1, Reg1} = ?REGISTRY:reg(<<"Topic1">>, Reg),
+    {ok, ?MAX_PREDEF_ID + 2, Reg2} = ?REGISTRY:reg(<<"Topic2">>, Reg1),
+    ?assertMatch({ok, ?MAX_PREDEF_ID + 1, Reg2}, ?REGISTRY:reg(<<"Topic1">>, Reg2)),
+    ?assertEqual(<<"Topic1">>, ?REGISTRY:lookup_topic(?MAX_PREDEF_ID + 1, Reg2)),
+    ?assertEqual(<<"Topic2">>, ?REGISTRY:lookup_topic(?MAX_PREDEF_ID + 2, Reg2)),
+    ?assertEqual(?MAX_PREDEF_ID + 1, ?REGISTRY:lookup_topic_id(<<"Topic1">>, Reg2)),
+    ?assertEqual(?MAX_PREDEF_ID + 2, ?REGISTRY:lookup_topic_id(<<"Topic2">>, Reg2)),
 
-t_register_case2(Config) ->
-    Reg = proplists:get_value(reg, Config),
-    ?assertEqual(?MAX_PREDEF_ID + 1, ?REGISTRY:register_topic(Reg, <<"ClientId">>, <<"Topic1">>)),
-    ?assertEqual(?MAX_PREDEF_ID + 2, ?REGISTRY:register_topic(Reg, <<"ClientId">>, <<"Topic2">>)),
-    ?assertEqual(?MAX_PREDEF_ID + 1, ?REGISTRY:register_topic(Reg, <<"ClientId">>, <<"Topic1">>)),
-    ?assertEqual(<<"Topic1">>, ?REGISTRY:lookup_topic(Reg, <<"ClientId">>, ?MAX_PREDEF_ID + 1)),
-    ?assertEqual(<<"Topic2">>, ?REGISTRY:lookup_topic(Reg, <<"ClientId">>, ?MAX_PREDEF_ID + 2)),
-    ?assertEqual(?MAX_PREDEF_ID + 1, ?REGISTRY:lookup_topic_id(Reg, <<"ClientId">>, <<"Topic1">>)),
-    ?assertEqual(?MAX_PREDEF_ID + 2, ?REGISTRY:lookup_topic_id(Reg, <<"ClientId">>, <<"Topic2">>)),
-    ?assertEqual(undefined, ?REGISTRY:lookup_topic_id(Reg, <<"ClientId">>, <<"Topic3">>)),
-    ?REGISTRY:unregister_topic(Reg, <<"ClientId">>),
-    ?assertEqual(undefined, ?REGISTRY:lookup_topic(Reg, <<"ClientId">>, ?MAX_PREDEF_ID + 1)),
-    ?assertEqual(undefined, ?REGISTRY:lookup_topic(Reg, <<"ClientId">>, ?MAX_PREDEF_ID + 2)),
-    ?assertEqual(undefined, ?REGISTRY:lookup_topic_id(Reg, <<"ClientId">>, <<"Topic1">>)),
-    ?assertEqual(undefined, ?REGISTRY:lookup_topic_id(Reg, <<"ClientId">>, <<"Topic2">>)).
+    Reg3 = emqx_mqttsn_registry:unreg(<<"Topic1">>, Reg2),
+    ?assertEqual(undefined, ?REGISTRY:lookup_topic(?MAX_PREDEF_ID + 1, Reg3)),
+    ?assertEqual(undefined, ?REGISTRY:lookup_topic_id(<<"Topic1">>, Reg3)),
+    ?assertEqual(<<"Topic2">>, ?REGISTRY:lookup_topic(?MAX_PREDEF_ID + 2, Reg3)),
+    ?assertEqual(?MAX_PREDEF_ID + 2, ?REGISTRY:lookup_topic_id(<<"Topic2">>, Reg3)),
 
-t_reach_maximum(Config) ->
-    Reg = proplists:get_value(reg, Config),
-    register_a_lot(?MAX_PREDEF_ID + 1, 16#ffff, Reg),
-    ?assertEqual({error, too_large}, ?REGISTRY:register_topic(Reg, <<"ClientId">>, <<"TopicABC">>)),
-    Topic1 = iolist_to_binary(io_lib:format("Topic~p", [?MAX_PREDEF_ID + 1])),
-    Topic2 = iolist_to_binary(io_lib:format("Topic~p", [?MAX_PREDEF_ID + 2])),
-    ?assertEqual(?MAX_PREDEF_ID + 1, ?REGISTRY:lookup_topic_id(Reg, <<"ClientId">>, Topic1)),
-    ?assertEqual(?MAX_PREDEF_ID + 2, ?REGISTRY:lookup_topic_id(Reg, <<"ClientId">>, Topic2)),
-    ?REGISTRY:unregister_topic(Reg, <<"ClientId">>),
-    ?assertEqual(undefined, ?REGISTRY:lookup_topic(Reg, <<"ClientId">>, ?MAX_PREDEF_ID + 1)),
-    ?assertEqual(undefined, ?REGISTRY:lookup_topic(Reg, <<"ClientId">>, ?MAX_PREDEF_ID + 2)),
-    ?assertEqual(undefined, ?REGISTRY:lookup_topic_id(Reg, <<"ClientId">>, Topic1)),
-    ?assertEqual(undefined, ?REGISTRY:lookup_topic_id(Reg, <<"ClientId">>, Topic2)).
+    ?assertMatch({ok, ?MAX_PREDEF_ID + 3, _Reg4}, ?REGISTRY:reg(<<"Topic3">>, Reg3)).
 
-t_register_case4(Config) ->
-    Reg = proplists:get_value(reg, Config),
-    ?assertEqual(?MAX_PREDEF_ID + 1, ?REGISTRY:register_topic(Reg, <<"ClientId">>, <<"TopicA">>)),
-    ?assertEqual(?MAX_PREDEF_ID + 2, ?REGISTRY:register_topic(Reg, <<"ClientId">>, <<"TopicB">>)),
-    ?assertEqual(?MAX_PREDEF_ID + 3, ?REGISTRY:register_topic(Reg, <<"ClientId">>, <<"TopicC">>)),
-    ?REGISTRY:unregister_topic(Reg, <<"ClientId">>),
-    ?assertEqual(?MAX_PREDEF_ID + 1, ?REGISTRY:register_topic(Reg, <<"ClientId">>, <<"TopicD">>)).
+t_reach_maximum(_) ->
+    Reg0 = ?REGISTRY:init(),
+    Reg = register_a_lot(?MAX_PREDEF_ID + 1, 16#ffff, Reg0),
+    ?assertEqual({error, too_large}, ?REGISTRY:reg(<<"TopicABC">>, Reg)),
+    ?assertEqual(?MAX_PREDEF_ID + 1, ?REGISTRY:lookup_topic_id(<<"Topic1025">>, Reg)),
+    ?assertEqual(?MAX_PREDEF_ID + 2, ?REGISTRY:lookup_topic_id(<<"Topic1026">>, Reg)).
 
-t_deny_wildcard_topic(Config) ->
-    Reg = proplists:get_value(reg, Config),
-    ?assertEqual(
-        {error, wildcard_topic}, ?REGISTRY:register_topic(Reg, <<"ClientId">>, <<"/TopicA/#">>)
-    ),
-    ?assertEqual(
-        {error, wildcard_topic}, ?REGISTRY:register_topic(Reg, <<"ClientId">>, <<"/+/TopicB">>)
-    ).
+t_deny_wildcard_topic(_) ->
+    Reg = ?REGISTRY:init(),
+    ?assertEqual({error, wildcard_topic}, ?REGISTRY:reg(<<"/TopicA/#">>, Reg)),
+    ?assertEqual({error, wildcard_topic}, ?REGISTRY:reg(<<"/+/TopicB">>, Reg)).
 
 %%--------------------------------------------------------------------
 %% Helper funcs
 %%--------------------------------------------------------------------
 
-register_a_lot(Max, Max, _Reg) ->
-    ok;
-register_a_lot(N, Max, Reg) when N < Max ->
+register_a_lot(N, Max, Reg) when N =< Max ->
     Topic = iolist_to_binary(["Topic", integer_to_list(N)]),
-    ?assertEqual(N, ?REGISTRY:register_topic(Reg, <<"ClientId">>, Topic)),
-    register_a_lot(N + 1, Max, Reg).
+    {ok, ReturnedId, Reg1} = ?REGISTRY:reg(Topic, Reg),
+    ?assertEqual(N, ReturnedId),
+    case N == Max of
+        true ->
+            Reg1;
+        _ ->
+            register_a_lot(N + 1, Max, Reg1)
+    end.
diff --git a/changes/ce/fix-10955.en.md b/changes/ce/fix-10955.en.md
new file mode 100644
index 000000000..a08b80560
--- /dev/null
+++ b/changes/ce/fix-10955.en.md
@@ -0,0 +1 @@
+Fix the issue in MQTT-SN gateway where deleting Predefined Topics configuration does not work.