diff --git a/gajim/chat_control.py b/gajim/chat_control.py
index f3c7975e2..6fdfcad0e 100644
--- a/gajim/chat_control.py
+++ b/gajim/chat_control.py
@@ -1482,12 +1482,12 @@ class ChatControl(ChatControlBase):
         self._add_info_bar_message(markup, [b], file_props, Gtk.MessageType.ERROR)
 
     def _on_accept_gc_invitation(self, widget, event):
-        if event.is_continued:
-            app.interface.join_gc_room(self.account, event.room_jid,
+        if event.continued:
+            app.interface.join_gc_room(self.account, str(event.muc),
                 app.nicks[self.account], event.password,
                 is_continued=True)
         else:
-            app.interface.join_gc_minimal(self.account, event.room_jid)
+            app.interface.join_gc_minimal(self.account, str(event.muc))
 
         app.events.remove_events(self.account, self.contact.jid, event=event)
 
@@ -1495,14 +1495,14 @@ class ChatControl(ChatControlBase):
         app.events.remove_events(self.account, self.contact.jid, event=event)
 
     def _get_gc_invitation(self, event):
-        markup = '<b>%s:</b> %s' % (_('Groupchat Invitation'), event.room_jid)
+        markup = '<b>%s:</b> %s' % (_('Groupchat Invitation'), event.muc)
         if event.reason:
             markup += ' (%s)' % event.reason
         b1 = Gtk.Button.new_with_mnemonic(_('_Join'))
         b1.connect('clicked', self._on_accept_gc_invitation, event)
         b2 = Gtk.Button(stock=Gtk.STOCK_CANCEL)
         b2.connect('clicked', self._on_cancel_gc_invitation, event)
-        self._add_info_bar_message(markup, [b1, b2], (event.room_jid,
+        self._add_info_bar_message(markup, [b1, b2], (event.muc,
             event.reason), Gtk.MessageType.QUESTION)
 
     def on_event_added(self, event):
@@ -1546,7 +1546,7 @@ class ChatControl(ChatControlBase):
             removed = False
             for ib_msg in self.info_bar_queue:
                 if ev.type_ == 'gc-invitation':
-                    if ev.room_jid == ib_msg[2][0]:
+                    if ev.muc == ib_msg[2][0]:
                         self.info_bar_queue.remove(ib_msg)
                         removed = True
                 else: # file-*
diff --git a/gajim/common/app.py b/gajim/common/app.py
index d849b7e9b..d693d4d55 100644
--- a/gajim/common/app.py
+++ b/gajim/common/app.py
@@ -480,6 +480,7 @@ def zeroconf_is_connected():
             config.get_per('accounts', ZEROCONF_ACC_NAME, 'is_zeroconf')
 
 def in_groupchat(account, room_jid):
+    room_jid = str(room_jid)
     if room_jid not in gc_connected[account]:
         return False
     return gc_connected[account][room_jid]
diff --git a/gajim/common/contacts.py b/gajim/common/contacts.py
index 63b2d3363..da084ae32 100644
--- a/gajim/common/contacts.py
+++ b/gajim/common/contacts.py
@@ -307,12 +307,12 @@ class LegacyContactsAPI:
         return self_contact
 
     def create_not_in_roster_contact(self, jid, account, resource='', name='',
-    keyID=''):
+                                     keyID='', groupchat=False):
         # Use Account object if available
         account = self._accounts.get(account, account)
         return self.create_contact(jid=jid, account=account, resource=resource,
             name=name, groups=[_('Not in Roster')], show='not in roster',
-            status='', sub='none', keyID=keyID)
+            status='', sub='none', keyID=keyID, groupchat=groupchat)
 
     def copy_contact(self, contact):
         return self.create_contact(contact.jid, contact.account,
diff --git a/gajim/common/events.py b/gajim/common/events.py
index 372c092ab..a33da82bc 100644
--- a/gajim/common/events.py
+++ b/gajim/common/events.py
@@ -130,15 +130,10 @@ class UnsubscribedEvent(Event):
 
 class GcInvitationtEvent(Event):
     type_ = 'gc-invitation'
-    def __init__(self, room_jid, reason, password, is_continued, jid_from,
-    time_=None, show_in_roster=False, show_in_systray=True):
-        Event.__init__(self, time_, show_in_roster=show_in_roster,
-            show_in_systray=show_in_systray)
-        self.room_jid = room_jid
-        self.reason = reason
-        self.password = password
-        self.is_continued = is_continued
-        self.jid_from = jid_from
+    def __init__(self, event):
+        Event.__init__(self, None, show_in_roster=False, show_in_systray=True)
+        for key, value in vars(event).items():
+            setattr(self, key, value)
 
 class FileRequestEvent(Event):
     type_ = 'file-request'
diff --git a/gajim/common/helpers.py b/gajim/common/helpers.py
index 269332921..7ededa758 100644
--- a/gajim/common/helpers.py
+++ b/gajim/common/helpers.py
@@ -1462,6 +1462,15 @@ def load_json(path, key=None, default=None):
         return json_dict
     return json_dict.get(key, default)
 
+def ignore_contact(account, jid):
+    jid = str(jid)
+    known_contact = app.contacts.get_contacts(account, jid)
+    ignore = app.config.get_per('accounts', account, 'ignore_unknown_contacts')
+    if ignore and not known_contact:
+        log.info('Ignore unknown contact %s', jid)
+        return True
+    return False
+
 class AdditionalDataDict(collections.UserDict):
     def __init__(self, initialdata=None):
         collections.UserDict.__init__(self, initialdata)
diff --git a/gajim/common/modules/bits_of_binary.py b/gajim/common/modules/bits_of_binary.py
index 2bae0eb39..37745ac1e 100644
--- a/gajim/common/modules/bits_of_binary.py
+++ b/gajim/common/modules/bits_of_binary.py
@@ -170,5 +170,29 @@ def parse_bob_data(stanza):
     return filepath
 
 
+def store_bob_data(bob_data):
+    if bob_data is None:
+        return
+
+    algo_hash = '%s+%s' % (bob_data.algo, bob_data.hash_)
+
+    filepath = Path(configpaths.get('BOB')) / algo_hash
+    if algo_hash in app.bob_cache or filepath.exists():
+        log.info('BoB data already cached')
+        return
+
+    if bob_data.max_age == 0:
+        app.bob_cache[algo_hash] = bob_data.data
+    else:
+        try:
+            with open(str(filepath), 'w+b') as file:
+                file.write(bob_data.data)
+        except Exception:
+            log.exception('Unable to save data')
+            return
+    log.info('BoB data stored: %s', algo_hash)
+    return filepath
+
+
 def get_instance(*args, **kwargs):
     return BitsOfBinary(*args, **kwargs), 'BitsOfBinary'
diff --git a/gajim/common/modules/message.py b/gajim/common/modules/message.py
index 3f3e601b5..c301cd213 100644
--- a/gajim/common/modules/message.py
+++ b/gajim/common/modules/message.py
@@ -212,31 +212,14 @@ class Message:
         subject = event.stanza.getSubject()
         groupchat = event.mtype == 'groupchat'
 
-        # XEP-0045: only a message that contains a <subject/> but no <body/>
-        # element shall be considered a subject change for MUC purposes.
-        muc_subject = subject and groupchat and not event.msgtxt
-
         # Determine timestamps
-        if groupchat:
-            delay_entity_jid = event.jid
-        else:
-            delay_entity_jid = self._con.get_own_jid().getDomain()
-
-        if muc_subject:
-            # MUC Subjects can have a delay timestamp
-            # to indicate when the user has set the subject,
-            # the 'from' attr on these delays is the MUC server
-            # but we treat it as user timestamp
+        delay_jid = self._con.get_own_jid().getDomain()
+        timestamp = parse_delay(event.stanza, from_=delay_jid)
+        if timestamp is None:
             timestamp = time.time()
-            user_timestamp = parse_delay(event.stanza, from_=delay_entity_jid)
 
-        else:
-            timestamp = parse_delay(event.stanza, from_=delay_entity_jid)
-            if timestamp is None:
-                timestamp = time.time()
-
-            user_timestamp = parse_delay(event.stanza,
-                                         not_from=[delay_entity_jid])
+        user_timestamp = parse_delay(event.stanza,
+                                     not_from=[delay_jid])
 
         if user_timestamp is not None:
             event.additional_data.set_value(
@@ -271,11 +254,6 @@ class Message:
                     event.session, event.fjid, timestamp)
             return
 
-        if muc_subject:
-            app.nec.push_incoming_event(NetworkEvent('gc-subject-received',
-                                                     **vars(event)))
-            return
-
         if groupchat:
             if not event.msgtxt:
                 return
diff --git a/gajim/common/modules/muc.py b/gajim/common/modules/muc.py
index 08182fc12..58f14c849 100644
--- a/gajim/common/modules/muc.py
+++ b/gajim/common/modules/muc.py
@@ -17,18 +17,17 @@
 
 import time
 import logging
-import weakref
 
 import nbxmpp
+from nbxmpp.const import InviteType
+from nbxmpp.structs import StanzaHandler
 
 from gajim.common import i18n
 from gajim.common import app
 from gajim.common import helpers
 from gajim.common.caps_cache import muc_caps_cache
 from gajim.common.nec import NetworkEvent
-from gajim.common.nec import NetworkIncomingEvent
-from gajim.common.modules import dataforms
-from gajim.common.modules.bits_of_binary import parse_bob_data
+from gajim.common.modules.bits_of_binary import store_bob_data
 
 log = logging.getLogger('gajim.c.m.muc')
 
@@ -39,13 +38,55 @@ class MUC:
         self._account = con.name
 
         self.handlers = [
-            ('message', self._on_config_change, '', nbxmpp.NS_MUC_USER),
-            ('message', self._mediated_invite, 'normal', nbxmpp.NS_MUC_USER),
-            ('message', self._direct_invite, '', nbxmpp.NS_CONFERENCE),
-            ('message', self._on_captcha_challenge, '', nbxmpp.NS_CAPTCHA),
-            ('message', self._on_voice_request, '', nbxmpp.NS_DATA, 45),
+            StanzaHandler(name='message',
+                          callback=self._on_subject_change,
+                          typ='groupchat',
+                          priority=49),
+            StanzaHandler(name='message',
+                          callback=self._on_config_change,
+                          ns=nbxmpp.NS_MUC_USER,
+                          priority=49),
+            StanzaHandler(name='message',
+                          callback=self._on_invite_or_decline,
+                          typ='normal',
+                          ns=nbxmpp.NS_MUC_USER,
+                          priority=49),
+            StanzaHandler(name='message',
+                          callback=self._on_invite_or_decline,
+                          ns=nbxmpp.NS_CONFERENCE,
+                          priority=49),
+            StanzaHandler(name='message',
+                          callback=self._on_captcha_challenge,
+                          ns=nbxmpp.NS_CAPTCHA,
+                          priority=49),
+            StanzaHandler(name='message',
+                          callback=self._on_voice_request,
+                          ns=nbxmpp.NS_DATA,
+                          priority=49)
         ]
 
+        self._nbmxpp_methods = [
+            'get_affiliation',
+            'set_role',
+            'set_affiliation',
+            'set_config',
+            'set_subject',
+            'cancel_config',
+            'send_captcha',
+            'decline',
+            'request_voice'
+            'destroy',
+        ]
+
+    def __getattr__(self, key):
+        if key in self._nbmxpp_methods:
+            if not app.account_is_connected(self._account):
+                log.warning('Account %s not connected, cant use %s',
+                            self._account, key)
+                return
+            module = self._con.connection.get_module('MUC')
+            return getattr(module, key)
+
     def pass_disco(self, from_, identities, features, _data, _node):
         for identity in identities:
             if identity.get('category') != 'conference':
@@ -108,438 +149,136 @@ class MUC:
             if tags:
                 muc_x.setTag('history', tags)
 
-    def set_subject(self, room_jid, subject):
-        if not app.account_is_connected(self._account):
-            return
-        message = nbxmpp.Message(room_jid, typ='groupchat', subject=subject)
-        log.info('Set subject for %s', room_jid)
-        self._con.connection.send(message)
-
-    def _on_voice_request(self, _con, stanza):
-        data_form = stanza.getTag('x', namespace=nbxmpp.NS_DATA)
-        if data_form is None:
+    def _on_subject_change(self, _con, _stanza, properties):
+        if not properties.is_muc_subject:
             return
 
-        if stanza.getBody():
-            return
-
-        room_jid = str(stanza.getFrom())
-        contact = app.contacts.get_groupchat_contact(self._account, room_jid)
+        jid = properties.jid.getBare()
+        contact = app.contacts.get_groupchat_contact(self._account, jid)
         if contact is None:
             return
 
-        data_form = dataforms.extend_form(data_form)
-        try:
-            if data_form['FORM_TYPE'].value != nbxmpp.NS_MUC_REQUEST:
-                return
-        except KeyError:
+        contact.status = properties.subject
+
+        app.nec.push_incoming_event(
+            NetworkEvent('gc-subject-received',
+                         account=self._account,
+                         jid=jid,
+                         subject=properties.subject,
+                         nickname=properties.muc_nickname,
+                         user_timestamp=properties.user_timestamp))
+        raise nbxmpp.NodeProcessed
+
+    def _on_voice_request(self, _con, _stanza, properties):
+        if not properties.is_voice_request:
+            return
+
+        jid = str(properties.jid)
+        contact = app.contacts.get_groupchat_contact(self._account, jid)
+        if contact is None:
             return
 
         app.nec.push_incoming_event(
             NetworkEvent('voice-approval',
                          account=self._account,
-                         room_jid=room_jid,
-                         form=data_form))
+                         jid=jid,
+                         form=properties.voice_request.form))
         raise nbxmpp.NodeProcessed
 
-    def _on_captcha_challenge(self, _con, stanza):
-        captcha = stanza.getTag('captcha', namespace=nbxmpp.NS_CAPTCHA)
-        if captcha is None:
+    def _on_captcha_challenge(self, _con, _stanza, properties):
+        if not properties.is_captcha_challenge:
             return
 
-        parse_bob_data(stanza)
-        room_jid = str(stanza.getFrom())
-        contact = app.contacts.get_groupchat_contact(self._account, room_jid)
+        contact = app.contacts.get_groupchat_contact(self._account,
+                                                     str(properties.jid))
         if contact is None:
             return
 
-        log.info('Captcha challenge received from %s', room_jid)
-        data_form = captcha.getTag('x', namespace=nbxmpp.NS_DATA)
-        data_form = dataforms.extend_form(node=data_form)
+        log.info('Captcha challenge received from %s', properties.jid)
+        store_bob_data(properties.captcha.bob_data)
+
         app.nec.push_incoming_event(
             NetworkEvent('captcha-challenge',
                          account=self._account,
-                         room_jid=room_jid,
-                         form=data_form))
+                         jid=properties.jid,
+                         form=properties.captcha.form))
         raise nbxmpp.NodeProcessed
 
-    def send_captcha(self, room_jid, form_node):
-        if not app.account_is_connected(self._account):
-            return
-        iq = nbxmpp.Iq(typ='set', to=room_jid)
-        captcha = iq.addChild(name='captcha', namespace=nbxmpp.NS_CAPTCHA)
-        captcha.addChild(node=form_node)
-        self._con.connection.send(iq)
-
-    def request_config(self, room_jid):
-        if not app.account_is_connected(self._account):
-            return
-        iq = nbxmpp.Iq(typ='get',
-                       queryNS=nbxmpp.NS_MUC_OWNER,
-                       to=room_jid)
-        iq.setAttr('xml:lang', i18n.LANG)
-        log.info('Request config for %s', room_jid)
-        self._con.connection.SendAndCallForResponse(
-            iq, self._config_received)
-
-    def _config_received(self, stanza):
-        if not nbxmpp.isResultNode(stanza):
-            log.info('Error: %s', stanza.getError())
+    def _on_config_change(self, _con, _stanza, properties):
+        if not properties.is_muc_config_change:
             return
 
-        room_jid = stanza.getFrom().getStripped()
-        payload = stanza.getQueryPayload()
-
-        for form in payload:
-            if form.getNamespace() == nbxmpp.NS_DATA:
-                dataform = dataforms.extend_form(node=form)
-                log.info('Config form received for %s', room_jid)
-                app.nec.push_incoming_event(MucOwnerReceivedEvent(
-                    None,
-                    conn=self._con,
-                    form_node=form,
-                    dataform=dataform,
-                    jid=room_jid))
-                break
-
-    def cancel_config(self, room_jid):
-        if not app.account_is_connected(self._account):
-            return
-        cancel = nbxmpp.Node(tag='x', attrs={'xmlns': nbxmpp.NS_DATA,
-                                             'type': 'cancel'})
-        iq = nbxmpp.Iq(typ='set',
-                       queryNS=nbxmpp.NS_MUC_OWNER,
-                       payload=cancel,
-                       to=room_jid)
-        log.info('Cancel config for %s', room_jid)
-        self._con.connection.SendAndCallForResponse(
-            iq, self._default_response, {})
-
-    def _on_config_change(self, _con, stanza):
-        muc_user = stanza.getTag('x', namespace=nbxmpp.NS_MUC_USER)
-        if muc_user is None:
-            return
-
-        if stanza.getBody():
-            return
-
-        room_list = app.contacts.get_gc_list(self._account)
-        room_jid = str(stanza.getFrom())
-        if room_jid not in room_list:
-            # Message not from a group chat
-            return
-
-        # https://xmpp.org/extensions/xep-0045.html#registrar-statuscodes
-        change_codes = ['100', '102', '103', '104',
-                        '170', '171', '172', '173', '174']
-
-        codes = set()
-        for status in muc_user.getTags('status'):
-            code = status.getAttr('code')
-            if code in change_codes:
-                codes.add(code)
-
-        if not codes:
-            return
-
-        log.info('Received config change: %s', codes)
+        log.info('Received config change: %s %s',
+                 properties.jid, properties.muc_status_codes)
         app.nec.push_incoming_event(
             NetworkEvent('gc-config-changed-received',
                          account=self._account,
-                         room_jid=room_jid,
-                         status_codes=codes))
+                         jid=properties.jid,
+                         status_codes=properties.muc_status_codes))
         raise nbxmpp.NodeProcessed
 
-    def destroy(self, room_jid, reason='', jid=''):
-        if not app.account_is_connected(self._account):
-            return
-        iq = nbxmpp.Iq(typ='set',
-                       queryNS=nbxmpp.NS_MUC_OWNER,
-                       to=room_jid)
-        destroy = iq.setQuery().setTag('destroy')
-        if reason:
-            destroy.setTagData('reason', reason)
-        if jid:
-            destroy.setAttr('jid', jid)
-        log.info('Destroy room: %s, reason: %s, alternate: %s',
-                 room_jid, reason, jid)
-        self._con.connection.SendAndCallForResponse(
-            iq, self._default_response, {})
+    def _on_invite_or_decline(self, _con, _stanza, properties):
+        if properties.muc_decline is not None:
+            data = properties.muc_decline
+            if helpers.ignore_contact(self._account, data.from_):
+                raise nbxmpp.NodeProcessed
 
-    def set_config(self, room_jid, form):
-        if not app.account_is_connected(self._account):
-            return
-        iq = nbxmpp.Iq(typ='set', to=room_jid, queryNS=nbxmpp.NS_MUC_OWNER)
-        query = iq.setQuery()
-        form.setAttr('type', 'submit')
-        query.addChild(node=form)
-        log.info('Set config for %s', room_jid)
-        self._con.connection.SendAndCallForResponse(
-            iq, self._default_response, {})
+            log.info('Invite declined from: %s, reason: %s',
+                     data.from_, data.reason)
 
-    def set_affiliation(self, room_jid, users_dict):
-        if not app.account_is_connected(self._account):
-            return
-        iq = nbxmpp.Iq(typ='set', to=room_jid, queryNS=nbxmpp.NS_MUC_ADMIN)
-        item = iq.setQuery()
-        for jid in users_dict:
-            affiliation = users_dict[jid].get('affiliation')
-            reason = users_dict[jid].get('reason')
-            nick = users_dict[jid].get('nick')
-            item_tag = item.addChild('item', {'jid': jid,
-                                              'affiliation': affiliation})
-            if reason is not None:
-                item_tag.setTagData('reason', reason)
-
-            if nick is not None:
-                item_tag.setAttr('nick', nick)
-        log.info('Set affiliation for %s: %s', room_jid, users_dict)
-        self._con.connection.SendAndCallForResponse(
-            iq, self._default_response, {})
-
-    def get_affiliation(self, room_jid, affiliation, success_cb, error_cb):
-        if not app.account_is_connected(self._account):
-            return
-        iq = nbxmpp.Iq(typ='get', to=room_jid, queryNS=nbxmpp.NS_MUC_ADMIN)
-        item = iq.setQuery().setTag('item')
-        item.setAttr('affiliation', affiliation)
-        log.info('Get affiliation %s for %s', affiliation, room_jid)
-
-        weak_success_cb = weakref.WeakMethod(success_cb)
-        weak_error_cb = weakref.WeakMethod(error_cb)
-
-        self._con.connection.SendAndCallForResponse(
-            iq, self._affiliation_received, {'affiliation': affiliation,
-                                             'success_cb': weak_success_cb,
-                                             'error_cb': weak_error_cb})
-
-    def _affiliation_received(self, _con, stanza, affiliation,
-                              success_cb, error_cb):
-        if not nbxmpp.isResultNode(stanza):
-            if error_cb() is not None:
-                error_cb()(affiliation, stanza.getError())
-            return
-
-        room_jid = stanza.getFrom().getStripped()
-        query = stanza.getTag('query', namespace=nbxmpp.NS_MUC_ADMIN)
-        items = query.getTags('item')
-        users_dict = {}
-        for item in items:
-            try:
-                jid = helpers.parse_jid(item.getAttr('jid'))
-            except helpers.InvalidFormat:
-                log.warning('Invalid JID: %s, ignoring it',
-                            item.getAttr('jid'))
-                continue
-
-            users_dict[jid] = {}
-            if item.has_attr('nick'):
-                users_dict[jid]['nick'] = item.getAttr('nick')
-            if item.has_attr('role'):
-                users_dict[jid]['role'] = item.getAttr('role')
-            reason = item.getTagData('reason')
-            if reason:
-                users_dict[jid]['reason'] = reason
-
-        log.info('%s affiliations received from %s: %s',
-                 affiliation, room_jid, users_dict)
-
-        if success_cb() is not None:
-            success_cb()(self._account, room_jid, affiliation, users_dict)
-
-    def set_role(self, room_jid, nick, role, reason=''):
-        if not app.account_is_connected(self._account):
-            return
-        iq = nbxmpp.Iq(typ='set', to=room_jid, queryNS=nbxmpp.NS_MUC_ADMIN)
-        item = iq.setQuery().setTag('item')
-        item.setAttr('nick', nick)
-        item.setAttr('role', role)
-        if reason:
-            item.addChild(name='reason', payload=reason)
-        log.info('Set role for %s: %s %s %s', room_jid, nick, role, reason)
-        self._con.connection.SendAndCallForResponse(
-            iq, self._default_response, {})
-
-    def _mediated_invite(self, _con, stanza):
-        muc_user = stanza.getTag('x', namespace=nbxmpp.NS_MUC_USER)
-        if muc_user is None:
-            return
-
-        if stanza.getType() == 'error':
-            return
-
-        if stanza.getBody():
-            return
-
-        decline = muc_user.getTag('decline')
-        if decline is not None:
-
-            room_jid = stanza.getFrom().getStripped()
-            from_ = self._get_from(room_jid, decline)
-
-            reason = decline.getTagData('reason')
-            log.info('Invite declined: %s, %s', reason, from_)
             app.nec.push_incoming_event(
-                GcDeclineReceived(None,
-                                  account=self._account,
-                                  from_=from_,
-                                  room_jid=room_jid,
-                                  reason=reason))
+                NetworkEvent('gc-decline-received',
+                             account=self._account,
+                             **data._asdict()))
             raise nbxmpp.NodeProcessed
 
-        invite = muc_user.getTag('invite')
-        if invite is not None:
+        if properties.muc_invite is not None:
+            data = properties.muc_invite
+            if helpers.ignore_contact(self._account, data.from_):
+                raise nbxmpp.NodeProcessed
 
-            room_jid = stanza.getFrom().getStripped()
-            from_ = self._get_from(room_jid, invite)
+            log.info('Invite from: %s, to: %s', data.from_, data.muc)
 
-            reason = invite.getTagData('reason')
-            password = muc_user.getTagData('password')
-            is_continued = invite.getTag('continue') is not None
-            log.info('Mediated invite: continued: %s, reason: %s, from: %s',
-                     is_continued, reason, from_)
-            if room_jid in app.gc_connected[self._account] and \
-                    app.gc_connected[self._account][room_jid]:
+            if app.in_groupchat(self._account, data.muc):
                 # We are already in groupchat. Ignore invitation
                 log.info('We are already in this room')
                 raise nbxmpp.NodeProcessed
 
             app.nec.push_incoming_event(
-                GcInvitationReceived(None,
-                                     account=self._account,
-                                     from_=from_,
-                                     room_jid=room_jid,
-                                     reason=reason,
-                                     password=password,
-                                     is_continued=is_continued))
+                NetworkEvent('gc-invitation-received',
+                             account=self._account,
+                             **data._asdict()))
             raise nbxmpp.NodeProcessed
 
-    def _get_from(self, room_jid, stanza):
-        try:
-            from_ = nbxmpp.JID(helpers.parse_jid(stanza.getAttr('from')))
-        except helpers.InvalidFormat:
-            log.warning('Invalid JID on invite: %s, ignoring it',
-                        stanza.getAttr('from'))
-            raise nbxmpp.NodeProcessed
-
-        known_contact = app.contacts.get_contacts(self._account, room_jid)
-        ignore = app.config.get_per(
-            'accounts', self._account, 'ignore_unknown_contacts')
-        if ignore and not known_contact:
-            log.info('Ignore invite from unknown contact %s', from_)
-            raise nbxmpp.NodeProcessed
-
-        return from_
-
-    def _direct_invite(self, _con, stanza):
-        direct = stanza.getTag('x', namespace=nbxmpp.NS_CONFERENCE)
-        if direct is None:
-            return
-
-        from_ = stanza.getFrom()
-
-        try:
-            room_jid = helpers.parse_jid(direct.getAttr('jid'))
-        except helpers.InvalidFormat:
-            log.warning('Invalid JID on invite: %s, ignoring it',
-                        direct.getAttr('jid'))
-            raise nbxmpp.NodeProcessed
-
-        reason = direct.getAttr('reason')
-        password = direct.getAttr('password')
-        is_continued = direct.getAttr('continue') == 'true'
-
-        log.info('Direct invite: continued: %s, reason: %s, from: %s',
-                 is_continued, reason, from_)
-
-        app.nec.push_incoming_event(
-            GcInvitationReceived(None,
-                                 account=self._account,
-                                 from_=from_,
-                                 room_jid=room_jid,
-                                 reason=reason,
-                                 password=password,
-                                 is_continued=is_continued))
-        raise nbxmpp.NodeProcessed
-
     def invite(self, room, to, reason=None, continue_=False):
         if not app.account_is_connected(self._account):
             return
+
+        type_ = InviteType.MEDIATED
         contact = app.contacts.get_contact_from_full_jid(self._account, to)
         if contact and contact.supports(nbxmpp.NS_CONFERENCE):
-            invite = self._build_direct_invite(room, to, reason, continue_)
-        else:
-            invite = self._build_mediated_invite(room, to, reason, continue_)
-        self._con.connection.send(invite)
+            type_ = InviteType.DIRECT
 
-    @staticmethod
-    def _build_direct_invite(room, to, reason, continue_):
-        message = nbxmpp.Message(to=to)
-        attrs = {'jid': room}
-        if reason:
-            attrs['reason'] = reason
-        if continue_:
-            attrs['continue'] = 'true'
         password = app.gc_passwords.get(room, None)
-        if password:
-            attrs['password'] = password
-        message.addChild(name='x', attrs=attrs,
-                         namespace=nbxmpp.NS_CONFERENCE)
-        return message
+        self._con.connection.get_module('MUC').invite(
+            room, to, reason, password, continue_, type_)
 
-    @staticmethod
-    def _build_mediated_invite(room, to, reason, continue_):
-        message = nbxmpp.Message(to=room)
-        muc_user = message.addChild('x', namespace=nbxmpp.NS_MUC_USER)
-        invite = muc_user.addChild('invite', attrs={'to': to})
-        if continue_:
-            invite.addChild(name='continue')
-        if reason:
-            invite.setTagData('reason', reason)
-        password = app.gc_passwords.get(room, None)
-        if password:
-            muc_user.setTagData('password', password)
-        return message
-
-    def decline(self, room, to, reason=None):
+    def request_config(self, room_jid):
         if not app.account_is_connected(self._account):
             return
-        message = nbxmpp.Message(to=room)
-        muc_user = message.addChild('x', namespace=nbxmpp.NS_MUC_USER)
-        decline = muc_user.addChild('decline', attrs={'to': to})
-        if reason:
-            decline.setTagData('reason', reason)
-        self._con.connection.send(message)
 
-    def request_voice(self, room):
-        if not app.account_is_connected(self._account):
+        self._con.connection.get_module('MUC').request_config(
+            room_jid, i18n.LANG, callback=self._config_received)
+
+    def _config_received(self, result):
+        if result.is_error:
             return
-        message = nbxmpp.Message(to=room)
-        xdata = nbxmpp.DataForm(typ='submit')
-        xdata.addChild(node=nbxmpp.DataField(name='FORM_TYPE',
-                                             value=nbxmpp.NS_MUC + '#request'))
-        xdata.addChild(node=nbxmpp.DataField(name='muc#role',
-                                             value='participant',
-                                             typ='text-single'))
-        message.addChild(node=xdata)
-        self._con.connection.send(message)
 
-    @staticmethod
-    def _default_response(_con, stanza, **kwargs):
-        if not nbxmpp.isResultNode(stanza):
-            log.info('Error: %s', stanza.getError())
-
-
-class GcInvitationReceived(NetworkIncomingEvent):
-    name = 'gc-invitation-received'
-
-
-class GcDeclineReceived(NetworkIncomingEvent):
-    name = 'gc-decline-received'
-
-
-class MucOwnerReceivedEvent(NetworkIncomingEvent):
-    name = 'muc-owner-received'
+        app.nec.push_incoming_event(NetworkEvent(
+            'muc-owner-received',
+            conn=self._con,
+            dataform=result.form,
+            jid=result.jid))
 
 
 def get_instance(*args, **kwargs):
diff --git a/gajim/dialogs.py b/gajim/dialogs.py
index f0fe8bdb5..e76640677 100644
--- a/gajim/dialogs.py
+++ b/gajim/dialogs.py
@@ -1291,51 +1291,60 @@ class RosterItemExchangeWindow:
 
 
 class InvitationReceivedDialog:
-    def __init__(self, account, room_jid, contact_fjid, password=None,
-    comment=None, is_continued=False):
-
-        self.room_jid = room_jid
+    def __init__(self, account, event):
         self.account = account
-        self.password = password
-        self.is_continued = is_continued
-        self.contact_fjid = contact_fjid
+        self.room_jid = str(event.muc)
+        self.from_ = str(event.from_)
+        self.password = event.password
+        self.is_continued = event.continued
 
-        jid = app.get_jid_without_resource(contact_fjid)
+        if event.from_.bareMatch(event.muc):
+            contact_text = event.from_.getResource()
+        else:
+            contact = app.contacts.get_first_contact_from_jid(
+                account, event.from_.getBare())
+            if contact is None:
+                contact_text = str(event.from_)
+            else:
+                contact_text = contact.get_shown_name()
 
         pritext = _('''You are invited to a groupchat''')
         #Don't translate $Contact
-        if is_continued:
+        if self.is_continued:
             sectext = _('$Contact has invited you to join a discussion')
         else:
             sectext = _('$Contact has invited you to group chat %(room_jid)s')\
-                % {'room_jid': room_jid}
-        contact = app.contacts.get_first_contact_from_jid(account, jid)
-        contact_text = contact and contact.name or jid
-        sectext = i18n.direction_mark + sectext.replace('$Contact',
-            contact_text)
+                % {'room_jid': self.room_jid}
 
-        if comment: # only if not None and not ''
-            comment = GLib.markup_escape_text(comment)
+        sectext = sectext.replace('$Contact', contact_text)
+
+        if event.reason:
+            comment = GLib.markup_escape_text(event.reason)
             comment = _('Comment: %s') % comment
             sectext += '\n\n%s' % comment
         sectext += '\n\n' + _('Do you want to accept the invitation?')
 
-        def on_yes(checked, text):
+        def on_yes(_checked, _text):
             if self.is_continued:
-                app.interface.join_gc_room(self.account, self.room_jid,
-                    app.nicks[self.account], self.password,
-                    is_continued=True)
+                app.interface.join_gc_room(self.account,
+                                           self.room_jid,
+                                           app.nicks[self.account],
+                                           self.password,
+                                           is_continued=True)
             else:
-                app.interface.join_gc_minimal(
-                    self.account, self.room_jid, password=self.password)
+                app.interface.join_gc_minimal(self.account,
+                                              self.room_jid,
+                                              password=self.password)
 
         def on_no(text):
             app.connections[account].get_module('MUC').decline(
-                self.room_jid, self.contact_fjid, text)
+                self.room_jid, self.from_, text)
 
-        dlg = YesNoDialog(pritext, sectext,
-            text_label=_('Reason (if you decline):'), on_response_yes=on_yes,
-            on_response_no=on_no)
+        dlg = YesNoDialog(pritext,
+                          sectext,
+                          text_label=_('Reason (if you decline):'),
+                          on_response_yes=on_yes,
+                          on_response_no=on_no)
         dlg.set_title(_('Groupchat Invitation'))
 
 class ProgressDialog:
diff --git a/gajim/groupchat_control.py b/gajim/groupchat_control.py
index bb15bcdd7..5f01c1bc9 100644
--- a/gajim/groupchat_control.py
+++ b/gajim/groupchat_control.py
@@ -33,6 +33,7 @@ import logging
 from enum import IntEnum, unique
 
 import nbxmpp
+from nbxmpp.const import StatusCode
 
 from gi.repository import Gtk
 from gi.repository import Gdk
@@ -1080,7 +1081,7 @@ class GroupchatControl(ChatControlBase):
     def _on_voice_approval(self, event):
         if event.account != self.account:
             return
-        if event.room_jid != self.room_jid:
+        if event.jid != self.room_jid:
             return
         SingleMessageWindow(self.account,
                             self.room_jid,
@@ -1091,7 +1092,7 @@ class GroupchatControl(ChatControlBase):
     def _on_captcha_challenge(self, event):
         if event.account != self.account:
             return
-        if event.room_jid != self.room_jid:
+        if event.jid != self.room_jid:
             return
 
         if self.form_widget:
@@ -1419,11 +1420,11 @@ class GroupchatControl(ChatControlBase):
             return
         self.set_subject(event.subject)
         text = _('%(nick)s has set the subject to %(subject)s') % {
-            'nick': event.resource, 'subject': event.subject}
+            'nick': event.nickname, 'subject': event.subject}
 
-        if event.delayed:
+        if event.user_timestamp:
             date = time.strftime('%d-%m-%Y %H:%M:%S',
-                                 time.localtime(event.timestamp))
+                                 time.localtime(event.user_timestamp))
             text = '%s - %s' % (text, date)
 
         just_joined = self.join_time > time.time() - 10
@@ -1440,35 +1441,31 @@ class GroupchatControl(ChatControlBase):
         if event.account != self.account:
             return
 
-        if event.room_jid != self.room_jid:
+        if event.jid != self.room_jid:
             return
 
         changes = []
-        if '100' in event.status_codes:
-            # Can be a presence (see chg_contact_status in groupchat_control.py)
-            changes.append(_('Any occupant is allowed to see your full JID'))
-            self.is_anonymous = False
-        if '102' in event.status_codes:
+        if StatusCode.SHOWING_UNAVAILABLE in event.status_codes:
             changes.append(_('Room now shows unavailable members'))
-        if '103' in event.status_codes:
+        if StatusCode.NOT_SHOWING_UNAVAILABLE in event.status_codes:
             changes.append(_('Room now does not show unavailable members'))
-        if '104' in event.status_codes:
+        if StatusCode.CONFIG_NON_PRIVACY_RELATED in event.status_codes:
             changes.append(_('A setting not related to privacy has been '
                              'changed'))
             app.connections[self.account].get_module('Discovery').disco_muc(
                 self.room_jid, self.update_actions, update=True)
-        if '170' in event.status_codes:
+        if StatusCode.CONFIG_ROOM_LOGGING in event.status_codes:
             # Can be a presence (see chg_contact_status in groupchat_control.py)
             changes.append(_('Room logging is now enabled'))
-        if '171' in event.status_codes:
+        if StatusCode.CONFIG_NO_ROOM_LOGGING in event.status_codes:
             changes.append(_('Room logging is now disabled'))
-        if '172' in event.status_codes:
+        if StatusCode.CONFIG_NON_ANONYMOUS in event.status_codes:
             changes.append(_('Room is now non-anonymous'))
             self.is_anonymous = False
-        if '173' in event.status_codes:
+        if StatusCode.CONFIG_SEMI_ANONYMOUS in event.status_codes:
             changes.append(_('Room is now semi-anonymous'))
             self.is_anonymous = True
-        if '174' in event.status_codes:
+        if StatusCode.CONFIG_FULL_ANONYMOUS in event.status_codes:
             changes.append(_('Room is now fully anonymous'))
             self.is_anonymous = True
 
diff --git a/gajim/gtk/groupchat_config.py b/gajim/gtk/groupchat_config.py
index e73780efa..91ce0fb8f 100644
--- a/gajim/gtk/groupchat_config.py
+++ b/gajim/gtk/groupchat_config.py
@@ -62,8 +62,7 @@ class GroupchatConfig(Gtk.ApplicationWindow):
             con.get_module('MUC').get_affiliation(
                 self.jid,
                 affiliation,
-                self._on_affiliations_received,
-                self._on_affiliations_error)
+                callback=self._on_affiliations_received)
 
         if form is not None:
             self._ui.stack.set_visible_child_name('config')
@@ -340,29 +339,28 @@ class GroupchatConfig(Gtk.ApplicationWindow):
         con = app.connections[self.account]
         con.get_module('MUC').set_affiliation(self.jid, diff_dict)
 
-    def _on_affiliations_error(self, affiliation, error):
-        log.info('Error while requesting %s affiliations: %s',
-                 affiliation, error)
+    def _on_affiliations_received(self, result):
+        if result.is_error:
+            log.info('Error while requesting %s affiliations: %s',
+                     result.affiliation, result.error)
+            return
 
-    def _on_affiliations_received(self, _account, _room_jid,
-                                  affiliation, users):
-
-        if affiliation == 'outcast':
+        if result.affiliation == 'outcast':
             self._ui.stack.get_child_by_name('outcast').show()
 
-        for jid, attrs in users.items():
-            affiliation_edit, jid_edit = self._allowed_to_edit(affiliation)
-            if affiliation == 'outcast':
+        for jid, attrs in result.users.items():
+            affiliation_edit, jid_edit = self._allowed_to_edit(result.affiliation)
+            if result.affiliation == 'outcast':
                 reason = attrs.get('reason')
                 self._ui.outcast_store.append(
                     [jid,
                      reason,
                      None,
-                     affiliation,
+                     result.affiliation,
                      None,
                      affiliation_edit,
                      jid_edit])
-                self._affiliations[jid] = {'affiliation': affiliation,
+                self._affiliations[jid] = {'affiliation': result.affiliation,
                                            'reason': reason}
             else:
                 nick = attrs.get('nick')
@@ -371,11 +369,11 @@ class GroupchatConfig(Gtk.ApplicationWindow):
                     [jid,
                      nick,
                      role,
-                     affiliation,
-                     _(affiliation.capitalize()),
+                     result.affiliation,
+                     _(result.affiliation.capitalize()),
                      affiliation_edit,
                      jid_edit])
-                self._affiliations[jid] = {'affiliation': affiliation,
+                self._affiliations[jid] = {'affiliation': result.affiliation,
                                            'nick': nick}
                 if role is not None:
                     self._ui.role_column.set_visible(True)
diff --git a/gajim/gtk/notification.py b/gajim/gtk/notification.py
index 59e67d53c..9ea10213a 100644
--- a/gajim/gtk/notification.py
+++ b/gajim/gtk/notification.py
@@ -109,7 +109,7 @@ class Notification:
     def _on_event_removed(self, event_list):
         for event in event_list:
             if event.type_ == 'gc-invitation':
-                self._withdraw('gc-invitation', event.account, event.room_jid)
+                self._withdraw('gc-invitation', event.account, event.muc)
             if event.type_ in ('normal', 'printed_chat', 'chat',
                                'printed_pm', 'pm', 'printed_marked_gc_msg',
                                'printed_gc_msg'):
diff --git a/gajim/gui_interface.py b/gajim/gui_interface.py
index aa441f09e..f43def857 100644
--- a/gajim/gui_interface.py
+++ b/gajim/gui_interface.py
@@ -609,39 +609,43 @@ class Interface:
             else:
                 GroupchatConfig(account, obj.jid, 'owner', obj.dataform)
 
-    def handle_event_gc_decline(self, obj):
-        gc_control = self.msg_win_mgr.get_gc_control(obj.room_jid, obj.account)
+    def handle_event_gc_decline(self, event):
+        gc_control = self.msg_win_mgr.get_gc_control(str(event.muc),
+                                                     event.account)
         if gc_control:
-            if obj.reason:
+            if event.reason:
                 gc_control.print_conversation(
                     _('%(jid)s declined the invitation: %(reason)s') % {
-                        'jid': obj.from_, 'reason': obj.reason},
+                        'jid': event.from_, 'reason': event.reason},
                     graphics=False)
             else:
                 gc_control.print_conversation(
                     _('%(jid)s declined the invitation') % {
-                        'jid': obj.from_}, graphics=False)
+                        'jid': event.from_}, graphics=False)
 
-    def handle_event_gc_invitation(self, obj):
-        if helpers.allow_popup_window(obj.account) or not self.systray_enabled:
-            dialogs.InvitationReceivedDialog(
-                obj.account, obj.room_jid,
-                str(obj.from_), obj.password, obj.reason,
-                is_continued=obj.is_continued)
+    def handle_event_gc_invitation(self, event):
+        if helpers.allow_popup_window(event.account) or not self.systray_enabled:
+            dialogs.InvitationReceivedDialog(event.account, event)
             return
 
-        event = events.GcInvitationtEvent(
-            obj.room_jid, obj.reason,
-            obj.password, obj.is_continued, str(obj.from_))
-        self.add_event(obj.account, str(obj.from_), event)
+        from_ = str(event.from_)
+        muc = str(event.muc)
 
-        if helpers.allow_showing_notification(obj.account):
+        event_ = events.GcInvitationtEvent(event)
+        self.add_event(event.account, from_, event_)
+
+        if helpers.allow_showing_notification(event.account):
             event_type = _('Groupchat Invitation')
-            text = _('You are invited to {room} by {user}').format(
-                room=obj.room_jid, user=str(obj.from_))
-            app.notification.popup(
-                event_type, str(obj.from_), obj.account, 'gc-invitation',
-                'gajim-gc_invitation', event_type, text, room_jid=obj.room_jid)
+            text = _('You are invited to {room} by {user}').format(room=muc,
+                                                                   user=from_)
+            app.notification.popup(event_type,
+                                   from_,
+                                   event.account,
+                                   'gc-invitation',
+                                   'gajim-gc_invitation',
+                                   event_type,
+                                   text,
+                                   room_jid=muc)
 
     def forget_gpg_passphrase(self, keyid):
         if keyid in self.gpg_passphrase:
@@ -1523,7 +1527,9 @@ class Interface:
             if app.contacts.get_contact_with_highest_priority(account, jid):
                 self.roster.draw_contact(jid, account)
             else:
-                self.roster.add_to_not_in_the_roster(account, jid)
+                groupchat = event.type_ == 'gc-invitation'
+                self.roster.add_to_not_in_the_roster(
+                    account, jid, groupchat=groupchat)
 
         # Select the big brother contact in roster, it's visible because it has
         # events.
@@ -1621,8 +1627,7 @@ class Interface:
             event = app.events.get_first_event(account, jid, type_)
             if event is None:
                 return
-            dialogs.InvitationReceivedDialog(account, event.room_jid, jid,
-                event.password, event.reason, event.is_continued)
+            dialogs.InvitationReceivedDialog(account, event)
             app.events.remove_events(account, jid, event)
             self.roster.draw_contact(jid, account)
         elif type_ == 'subscription_request':
diff --git a/gajim/roster_window.py b/gajim/roster_window.py
index 77120cd5d..eb8d6c284 100644
--- a/gajim/roster_window.py
+++ b/gajim/roster_window.py
@@ -1032,14 +1032,16 @@ class RosterWindow:
                 self.draw_group(group, account)
 
     # FIXME: integrate into add_contact()
-    def add_to_not_in_the_roster(self, account, jid, nick='', resource=''):
+    def add_to_not_in_the_roster(self, account, jid, nick='', resource='',
+                                 groupchat=False):
         keyID = ''
         attached_keys = app.config.get_per('accounts', account,
                 'attached_gpg_keys').split()
         if jid in attached_keys:
             keyID = attached_keys[attached_keys.index(jid) + 1]
-        contact = app.contacts.create_not_in_roster_contact(jid=jid,
-                account=account, resource=resource, name=nick, keyID=keyID)
+        contact = app.contacts.create_not_in_roster_contact(
+            jid=jid, account=account, resource=resource, name=nick,
+            keyID=keyID, groupchat=groupchat)
         app.contacts.add_contact(account, contact)
         self.add_contact(contact.jid, account)
         return contact
@@ -2002,9 +2004,7 @@ class RosterWindow:
             return True
 
         if event.type_ == 'gc-invitation':
-            dialogs.InvitationReceivedDialog(account, event.room_jid,
-                event.jid_from, event.password, event.reason,
-                is_continued=event.is_continued)
+            dialogs.InvitationReceivedDialog(account, event)
             app.events.remove_events(account, jid, event)
             return True
 
@@ -2692,12 +2692,8 @@ class RosterWindow:
         app.log('avatar').debug('Draw roster avatar: %s', obj.jid)
         self.draw_avatar(obj.jid, obj.account)
 
-    def _nec_gc_subject_received(self, obj):
-        contact = app.contacts.get_contact_with_highest_priority(
-            obj.account, obj.jid)
-        if contact:
-            contact.status = obj.subject
-            self.draw_contact(obj.jid, obj.account)
+    def _nec_gc_subject_received(self, event):
+        self.draw_contact(event.jid, event.account)
 
     def _nec_metacontacts_received(self, obj):
         self.redraw_metacontacts(obj.conn.name)