diff --git a/modules/authentication_saml/routes.py b/modules/authentication_saml/routes.py
index 658fcdeeb8..bb84014dd7 100644
--- a/modules/authentication_saml/routes.py
+++ b/modules/authentication_saml/routes.py
@@ -156,6 +156,9 @@ def acs(request, pool, identity):
     with Transaction().set_user(user_id):
         session = Session.new()
 
+    allow_subscribe = config.getboolean(
+        'bus', 'allow_subscribe', default=False)
+    bus_url_host = config.get('bus', 'url_host', default=request.host_url)
     redirect_url = request.form.get('RelayState')
     if not redirect_url:
         redirect_url = http_host()
@@ -165,6 +168,7 @@ def acs(request, pool, identity):
     query.append(('login', login))
     query.append(('user_id', user_id))
     query.append(('session', session))
+    query.append(('bus_url_host', bus_url_host if allow_subscribe else ''))
     parts = list(parts)
     parts[3] = urllib.parse.urlencode(query)
     return redirect(urllib.parse.urlunsplit(parts))
diff --git a/sao/src/bus.js b/sao/src/bus.js
index 6ef8f2f980..6aae5ef78e 100644
--- a/sao/src/bus.js
+++ b/sao/src/bus.js
@@ -16,12 +16,13 @@
         wait = wait || 1;
         last_message = last_message || Sao.Bus.last_message;
         var session = Sao.Session.current_session;
-        if (!session) {
+        if (!session || !session.bus_url_host) {
             return;
         }
         Sao.Bus.listening = true;
 
         let channels = Object.keys(Sao.Bus.channel_actions);
+        let url = new URL(`${session.database}/bus`, session.bus_url_host);
         Sao.Bus.last_message = last_message;
         Sao.Bus.request = jQuery.ajax({
             headers: {
@@ -33,7 +34,7 @@
                 channels: channels,
             }),
             dataType: 'json',
-            url: '/' + session.database + '/bus',
+            url: url,
             type: 'POST',
             timeout: Sao.config.bus_timeout,
         });
diff --git a/sao/src/sao.js b/sao/src/sao.js
index 3b6c2cfee9..c5c2390e69 100644
--- a/sao/src/sao.js
+++ b/sao/src/sao.js
@@ -1135,6 +1135,7 @@ var Sao = {
                 login: url.searchParams.get('login'),
                 user_id: parseInt(url.searchParams.get('user_id'), 10),
                 session: url.searchParams.get('session'),
+                bus_url_host: url.searchParams.get('bus_url_host'),
             };
             if (url.searchParams.has('renew')) {
                 var renew_id = parseInt(url.searchParams.get('renew'), 10);
diff --git a/sao/src/session.js b/sao/src/session.js
index 5f5d49ff71..2d1519d16b 100644
--- a/sao/src/session.js
+++ b/sao/src/session.js
@@ -13,6 +13,7 @@
             this.login_service = null;
             this.user_id = null;
             this.session = null;
+            this.bus_url_host = null;
             this.cache = new Cache();
             this.prm = jQuery.when();  // renew promise
             this.database = database;
@@ -47,12 +48,14 @@
                 this.login = login;
                 this.user_id = result[0];
                 this.session = result[1];
+                this.bus_url_host = result[2];
                 this.store();
                 this.renew_device_cookie();
                 dfd.resolve();
             }, () => {
                 this.user_id = null;
                 this.session = null;
+                this.bus_url_host = null;
                 this.store();
                 dfd.reject();
             });
@@ -148,6 +151,7 @@
                         this.login = session_data.login;
                         this.user_id = session_data.user_id;
                         this.session = session_data.session;
+                        this.bus_url_host = session_data.bus_url_host;
                     }
                 }
             }
@@ -157,6 +161,7 @@
                 'login': this.login,
                 'user_id': this.user_id,
                 'session': this.session,
+                'bus_url_host': this.bus_url_host,
             };
             session = JSON.stringify(session);
             localStorage.setItem('sao_session_' + this.database, session);
diff --git a/tryton/tryton/bus.py b/tryton/tryton/bus.py
index b1944c4c00..20d457c376 100644
--- a/tryton/tryton/bus.py
+++ b/tryton/tryton/bus.py
@@ -9,6 +9,7 @@ import time
 import uuid
 from collections import defaultdict
 from urllib.error import HTTPError
+from urllib.parse import urljoin
 from urllib.request import Request, urlopen
 
 from gi.repository import GLib
@@ -25,20 +26,25 @@ class Bus:
     current_thread = None
     channel_actions = defaultdict(list)
     listening = False
+    connection = None
+    host = None
 
     @classmethod
-    def listen(cls, connection):
+    def listen(cls, connection, host):
         if not CONFIG['thread']:
             return
-        listener = threading.Thread(
-            target=cls._listen, args=(connection,), daemon=True)
+        cls.connection = connection
+        cls.host = host
+        if not host:
+            return
+        listener = threading.Thread(target=cls._listen, daemon=True)
         listener.start()
         cls.current_thread = listener.ident
 
     @classmethod
-    def _listen(cls, connection):
+    def _listen(cls):
         bus_timeout = CONFIG['client.bus_timeout']
-        session = connection.session
+        session = cls.connection.session
         authorization = base64.b64encode(session.encode('utf-8'))
         headers = {
             'Content-Type': 'application/json',
@@ -49,12 +55,12 @@ class Bus:
         wait = 1
         last_message = None
         url = None
-        while connection.session == session:
+        while cls.connection.session == session:
             if url is None:
-                if connection.url is None:
+                if cls.connection._database is None:
                     time.sleep(1)
                     continue
-                url = connection.url + '/bus'
+                url = urljoin(cls.host, f'{cls.connection._database}/bus')
             cls.listening = True
 
             channels = list(cls.channel_actions)
@@ -91,7 +97,7 @@ class Bus:
                 wait *= 2
                 continue
 
-            if connection.session != session:
+            if cls.connection.session != session:
                 break
             if thread_id != cls.current_thread:
                 break
@@ -109,14 +115,12 @@ class Bus:
 
     @classmethod
     def register(cls, channel, function):
-        from tryton import rpc
-
         restart = channel not in cls.channel_actions
         cls.channel_actions[channel].append(function)
         if restart:
             # We can not really abort a thread, so we will just start a new one
             # and ignore the result of the one already running
-            Bus.listen(rpc.CONNECTION)
+            Bus.listen(cls.connection, cls.host)
 
     @classmethod
     def unregister(cls, channel, function):
diff --git a/tryton/tryton/rpc.py b/tryton/tryton/rpc.py
index e941862dac..6559e0aa67 100644
--- a/tryton/tryton/rpc.py
+++ b/tryton/tryton/rpc.py
@@ -102,12 +102,13 @@ def set_service_session(parameters):
         if _USER != renew_id:
             raise ValueError
     _USER = user_id
+    bus_url_host = parameters.get('bus_url_host', [''])[0]
     session = ':'.join(map(str, [username, user_id, session]))
     if CONNECTION is not None:
         CONNECTION.close()
     CONNECTION = ServerPool(
         hostname, port, database, session=session, cache=not CONFIG['dev'])
-    Bus.listen(CONNECTION)
+    Bus.listen(CONNECTION, bus_url_host)
 
 
 def login(parameters):
@@ -126,13 +127,14 @@ def login(parameters):
     result = connection.common.db.login(username, parameters, language)
     logger.debug('%r', result)
     _USER = result[0]
-    session = ':'.join(map(str, [username] + result))
+    session = ':'.join(map(str, [username] + result[:2]))
+    bus_url_host = result[2]
     if CONNECTION is not None:
         CONNECTION.close()
     CONNECTION = ServerPool(
         hostname, port, database, session=session, cache=not CONFIG['dev'])
     device_cookie.renew()
-    Bus.listen(CONNECTION)
+    Bus.listen(CONNECTION, bus_url_host)
 
 
 def logout():
diff --git a/trytond/CHANGELOG b/trytond/CHANGELOG
index b139e02259..0058ea2397 100644
--- a/trytond/CHANGELOG
+++ b/trytond/CHANGELOG
@@ -1,3 +1,4 @@
+* Handle URL host of the bus on login
 * Restrict sessions to the client's IP address
 * Use ``tryton.cfg`` to register in the Pool
 * Use the FILTER syntax with SQL aggregate functions
diff --git a/trytond/trytond/bus.py b/trytond/trytond/bus.py
index 938a8d3804..360e2299d1 100644
--- a/trytond/trytond/bus.py
+++ b/trytond/trytond/bus.py
@@ -9,13 +9,11 @@ import selectors
 import threading
 import time
 import uuid
-from urllib.parse import urljoin
 
 from trytond import backend
 from trytond.config import config
 from trytond.protocols.jsonrpc import JSONDecoder, JSONEncoder
-from trytond.protocols.wrappers import (
-    HTTPStatus, Response, exceptions, redirect)
+from trytond.protocols.wrappers import HTTPStatus, Response, abort, exceptions
 from trytond.tools import resolve
 from trytond.transaction import Transaction
 from trytond.wsgi import app
@@ -231,12 +229,7 @@ def subscribe(request, database_name):
     if not _allow_subscribe:
         raise exceptions.NotImplemented
     if _url_host and _url_host != request.host_url:
-        response = redirect(
-            urljoin(_url_host, request.path), HTTPStatus.PERMANENT_REDIRECT)
-        # Allow to change the redirection after some time
-        response.headers['Cache-Control'] = (
-            'private, max-age=%s' % _web_cache_timeout)
-        return response
+        abort(HTTPStatus.UNAUTHORIZED)
     user = request.authorization.get('userid')
     channels = request.parsed_data.get('channels', [])
     if user is None:
diff --git a/trytond/trytond/protocols/dispatcher.py b/trytond/trytond/protocols/dispatcher.py
index e71374f4d2..4d97bf5897 100644
--- a/trytond/trytond/protocols/dispatcher.py
+++ b/trytond/trytond/protocols/dispatcher.py
@@ -62,7 +62,10 @@ def login(request, database_name, user, parameters, language=None):
         code = HTTPStatus.TOO_MANY_REQUESTS
     if not session:
         abort(code)
-    return session
+    allow_subscribe = config.getboolean(
+        'bus', 'allow_subscribe', default=False)
+    bus_url_host = config.get('bus', 'url_host', default=request.host_url)
+    return (*session, bus_url_host if allow_subscribe else None)
 
 
 @app.auth_required