diff --git a/CHANGELOG.md b/CHANGELOG.md
index 009e193ed..a363926b2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+### Version 2.8.6
+
+* Offer to record voice message when callee is busy
+
 ### Version 2.8.5
 
 * Reduce echo during calls on some devices
diff --git a/README.md b/README.md
index e43c9fe4b..da7166cb5 100644
--- a/README.md
+++ b/README.md
@@ -43,7 +43,7 @@
 
 * End-to-end encryption with [OMEMO](http://conversations.im/omemo/) or [OpenPGP](http://openpgp.org/about/)
 * Send and receive images as well as other kind of files
-* Encrypted audio and video calls (DLTS-SRTP)
+* Encrypted audio and video calls (DTLS-SRTP)
 * Share your location
 * Send voice messages
 * Indication when your contact has read your message
diff --git a/build.gradle b/build.gradle
index 2bdfc67c3..40ba513ae 100644
--- a/build.gradle
+++ b/build.gradle
@@ -96,8 +96,8 @@ android {
     defaultConfig {
         minSdkVersion 16
         targetSdkVersion 25
-        versionCode 388
-        versionName "2.8.5"
+        versionCode 390
+        versionName "2.8.6"
         archivesBaseName += "-$versionName"
         applicationId "eu.sum7.conversations"
         resValue "string", "applicationId", applicationId
diff --git a/metadata/en-US/changelogs/390.txt b/metadata/en-US/changelogs/390.txt
new file mode 100644
index 000000000..f22ea34cd
--- /dev/null
+++ b/metadata/en-US/changelogs/390.txt
@@ -0,0 +1 @@
+• Offer to record voice message when callee is busy
diff --git a/screenshots.xcf b/screenshots.xcf
index 7e3aebc68..45f79ca5a 100644
Binary files a/screenshots.xcf and b/screenshots.xcf differ
diff --git a/src/main/java/eu/siacs/conversations/crypto/sasl/ScramMechanism.java b/src/main/java/eu/siacs/conversations/crypto/sasl/ScramMechanism.java
index 6949daec4..4d40d2b74 100644
--- a/src/main/java/eu/siacs/conversations/crypto/sasl/ScramMechanism.java
+++ b/src/main/java/eu/siacs/conversations/crypto/sasl/ScramMechanism.java
@@ -195,6 +195,10 @@ abstract class ScramMechanism extends SaslMechanism {
 
                 final byte[] clientProof = new byte[keys.clientKey.length];
 
+                if (clientSignature.length < keys.clientKey.length) {
+                    throw new AuthenticationException("client signature was shorter than clientKey");
+                }
+
                 for (int i = 0; i < clientProof.length; i++) {
                     clientProof[i] = (byte) (keys.clientKey[i] ^ clientSignature[i]);
                 }
diff --git a/src/main/java/eu/siacs/conversations/entities/Account.java b/src/main/java/eu/siacs/conversations/entities/Account.java
index d2d25e321..4b7e424a3 100644
--- a/src/main/java/eu/siacs/conversations/entities/Account.java
+++ b/src/main/java/eu/siacs/conversations/entities/Account.java
@@ -432,7 +432,7 @@ public class Account extends AbstractEntity implements AvatarService.Avatarable
 
     public int activeDevicesWithRtpCapability() {
         int i = 0;
-        for(Presence presence : getSelfContact().getPresences().getPresences().values()) {
+        for(Presence presence : getSelfContact().getPresences().getPresences()) {
             if (RtpCapability.check(presence) != RtpCapability.Capability.NONE) {
                 i++;
             }
diff --git a/src/main/java/eu/siacs/conversations/entities/Presences.java b/src/main/java/eu/siacs/conversations/entities/Presences.java
index c8301123b..feca98839 100644
--- a/src/main/java/eu/siacs/conversations/entities/Presences.java
+++ b/src/main/java/eu/siacs/conversations/entities/Presences.java
@@ -9,138 +9,164 @@ import java.util.List;
 import java.util.Map;
 
 public class Presences {
-	private final Hashtable<String, Presence> presences = new Hashtable<>();
+    private final Hashtable<String, Presence> presences = new Hashtable<>();
 
-	public Hashtable<String, Presence> getPresences() {
-		return this.presences;
-	}
+    private static String nameWithoutVersion(String name) {
+        String[] parts = name.split(" ");
+        if (parts.length > 1 && Character.isDigit(parts[parts.length - 1].charAt(0))) {
+            StringBuilder output = new StringBuilder();
+            for (int i = 0; i < parts.length - 1; ++i) {
+                if (output.length() != 0) {
+                    output.append(' ');
+                }
+                output.append(parts[i]);
+            }
+            return output.toString();
+        } else {
+            return name;
+        }
+    }
 
-	public void updatePresence(String resource, Presence presence) {
-		synchronized (this.presences) {
-			this.presences.put(resource, presence);
-		}
-	}
+    public List<Presence> getPresences() {
+        synchronized (this.presences) {
+            return new ArrayList<>(this.presences.values());
+        }
+    }
 
-	public void removePresence(String resource) {
-		synchronized (this.presences) {
-			this.presences.remove(resource);
-		}
-	}
+    public Map<String, Presence> getPresencesMap() {
+        synchronized (this.presences) {
+            return new HashMap<>(this.presences);
+        }
+    }
 
-	public void clearPresences() {
-		synchronized (this.presences) {
-			this.presences.clear();
-		}
-	}
+    public Presence get(String resource) {
+        synchronized (this.presences) {
+            return this.presences.get(resource);
+        }
+    }
 
-	public Presence.Status getShownStatus() {
-		Presence.Status status = Presence.Status.OFFLINE;
-		synchronized (this.presences) {
-			for(Presence p : presences.values()) {
-				if (p.getStatus() == Presence.Status.DND) {
-					return p.getStatus();
-				} else if (p.getStatus().compareTo(status) < 0){
-					status = p.getStatus();
-				}
-			}
-		}
-		return status;
-	}
+    public void updatePresence(String resource, Presence presence) {
+        synchronized (this.presences) {
+            this.presences.put(resource, presence);
+        }
+    }
 
-	public int size() {
-		synchronized (this.presences) {
-			return presences.size();
-		}
-	}
+    public void removePresence(String resource) {
+        synchronized (this.presences) {
+            this.presences.remove(resource);
+        }
+    }
 
-	public String[] toResourceArray() {
-		synchronized (this.presences) {
-			final String[] presencesArray = new String[presences.size()];
-			presences.keySet().toArray(presencesArray);
-			return presencesArray;
-		}
-	}
+    public void clearPresences() {
+        synchronized (this.presences) {
+            this.presences.clear();
+        }
+    }
 
-	public List<PresenceTemplate> asTemplates() {
-		synchronized (this.presences) {
-			ArrayList<PresenceTemplate> templates = new ArrayList<>(presences.size());
-			for(Presence p : presences.values()) {
-				if (p.getMessage() != null && !p.getMessage().trim().isEmpty()) {
-					templates.add(new PresenceTemplate(p.getStatus(), p.getMessage()));
-				}
-			}
-			return templates;
-		}
-	}
+    public Presence.Status getShownStatus() {
+        Presence.Status status = Presence.Status.OFFLINE;
+        synchronized (this.presences) {
+            for (Presence p : presences.values()) {
+                if (p.getStatus() == Presence.Status.DND) {
+                    return p.getStatus();
+                } else if (p.getStatus().compareTo(status) < 0) {
+                    status = p.getStatus();
+                }
+            }
+        }
+        return status;
+    }
 
-	public boolean has(String presence) {
-		synchronized (this.presences) {
-			return presences.containsKey(presence);
-		}
-	}
+    public int size() {
+        synchronized (this.presences) {
+            return presences.size();
+        }
+    }
 
-	public List<String> getStatusMessages() {
-		ArrayList<String> messages = new ArrayList<>();
-		synchronized (this.presences) {
-			for(Presence presence : this.presences.values()) {
-				String message = presence.getMessage() == null ? null : presence.getMessage().trim();
-				if (message != null && !message.isEmpty() && !messages.contains(message)) {
-					messages.add(message);
-				}
-			}
-		}
-		return messages;
-	}
+    public String[] toResourceArray() {
+        synchronized (this.presences) {
+            final String[] presencesArray = new String[presences.size()];
+            presences.keySet().toArray(presencesArray);
+            return presencesArray;
+        }
+    }
 
-	public boolean allOrNonSupport(String namespace) {
-		synchronized (this.presences) {
-			for(Presence presence : this.presences.values()) {
-				ServiceDiscoveryResult disco = presence.getServiceDiscoveryResult();
-				if (disco == null || !disco.getFeatures().contains(namespace)) {
-					return false;
-				}
-			}
-		}
-		return true;
-	}
+    public List<PresenceTemplate> asTemplates() {
+        synchronized (this.presences) {
+            ArrayList<PresenceTemplate> templates = new ArrayList<>(presences.size());
+            for (Presence p : presences.values()) {
+                if (p.getMessage() != null && !p.getMessage().trim().isEmpty()) {
+                    templates.add(new PresenceTemplate(p.getStatus(), p.getMessage()));
+                }
+            }
+            return templates;
+        }
+    }
 
-	public Pair<Map<String, String>,Map<String,String>> toTypeAndNameMap() {
-		Map<String,String> typeMap = new HashMap<>();
-		Map<String,String> nameMap = new HashMap<>();
-		synchronized (this.presences) {
-			for(Map.Entry<String,Presence> presenceEntry : this.presences.entrySet()) {
-				String resource = presenceEntry.getKey();
-				Presence presence = presenceEntry.getValue();
-				ServiceDiscoveryResult serviceDiscoveryResult = presence == null ? null : presence.getServiceDiscoveryResult();
-				if (serviceDiscoveryResult != null && serviceDiscoveryResult.getIdentities().size() > 0) {
-					ServiceDiscoveryResult.Identity identity = serviceDiscoveryResult.getIdentities().get(0);
-					String type = identity.getType();
-					String name = identity.getName();
-					if (type != null) {
-						typeMap.put(resource,type);
-					}
-					if (name != null) {
-						nameMap.put(resource, nameWithoutVersion(name));
-					}
-				}
-			}
-		}
-		return new Pair<>(typeMap,nameMap);
-	}
+    public boolean has(String presence) {
+        synchronized (this.presences) {
+            return presences.containsKey(presence);
+        }
+    }
 
-	private static String nameWithoutVersion(String name) {
-		String[] parts = name.split(" ");
-		if (parts.length > 1 && Character.isDigit(parts[parts.length -1].charAt(0))) {
-			StringBuilder output = new StringBuilder();
-			for(int i = 0; i < parts.length -1; ++i) {
-				if (output.length() != 0) {
-					output.append(' ');
-				}
-				output.append(parts[i]);
-			}
-			return output.toString();
-		} else {
-			return name;
-		}
-	}
+    public List<String> getStatusMessages() {
+        ArrayList<String> messages = new ArrayList<>();
+        synchronized (this.presences) {
+            for (Presence presence : this.presences.values()) {
+                String message = presence.getMessage() == null ? null : presence.getMessage().trim();
+                if (message != null && !message.isEmpty() && !messages.contains(message)) {
+                    messages.add(message);
+                }
+            }
+        }
+        return messages;
+    }
+
+    public boolean allOrNonSupport(String namespace) {
+        synchronized (this.presences) {
+            for (Presence presence : this.presences.values()) {
+                ServiceDiscoveryResult disco = presence.getServiceDiscoveryResult();
+                if (disco == null || !disco.getFeatures().contains(namespace)) {
+                    return false;
+                }
+            }
+        }
+        return true;
+    }
+
+    public boolean anySupport(final String namespace) {
+        synchronized (this.presences) {
+            for (Presence presence : this.presences.values()) {
+                ServiceDiscoveryResult disco = presence.getServiceDiscoveryResult();
+                if (disco != null && disco.getFeatures().contains(namespace)) {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
+    public Pair<Map<String, String>, Map<String, String>> toTypeAndNameMap() {
+        Map<String, String> typeMap = new HashMap<>();
+        Map<String, String> nameMap = new HashMap<>();
+        synchronized (this.presences) {
+            for (Map.Entry<String, Presence> presenceEntry : this.presences.entrySet()) {
+                String resource = presenceEntry.getKey();
+                Presence presence = presenceEntry.getValue();
+                ServiceDiscoveryResult serviceDiscoveryResult = presence == null ? null : presence.getServiceDiscoveryResult();
+                if (serviceDiscoveryResult != null && serviceDiscoveryResult.getIdentities().size() > 0) {
+                    ServiceDiscoveryResult.Identity identity = serviceDiscoveryResult.getIdentities().get(0);
+                    String type = identity.getType();
+                    String name = identity.getName();
+                    if (type != null) {
+                        typeMap.put(resource, type);
+                    }
+                    if (name != null) {
+                        nameMap.put(resource, nameWithoutVersion(name));
+                    }
+                }
+            }
+        }
+        return new Pair<>(typeMap, nameMap);
+    }
 }
diff --git a/src/main/java/eu/siacs/conversations/services/ExportBackupService.java b/src/main/java/eu/siacs/conversations/services/ExportBackupService.java
index 7b034a255..7c98db35d 100644
--- a/src/main/java/eu/siacs/conversations/services/ExportBackupService.java
+++ b/src/main/java/eu/siacs/conversations/services/ExportBackupService.java
@@ -14,6 +14,8 @@ import android.os.IBinder;
 import android.support.v4.app.NotificationCompat;
 import android.util.Log;
 
+import com.google.common.base.Strings;
+
 import java.io.DataOutputStream;
 import java.io.File;
 import java.io.FileOutputStream;
@@ -70,7 +72,7 @@ public class ExportBackupService extends Service {
         if (Compatibility.runsAndTargetsTwentyFour(context)) {
             openIntent.setType("resource/folder");
         } else {
-            openIntent.setDataAndType(Uri.parse("file://"+path),"resource/folder");
+            openIntent.setDataAndType(Uri.parse("file://" + path), "resource/folder");
         }
         openIntent.putExtra("org.openintents.extra.ABSOLUTE_PATH", path);
 
@@ -87,7 +89,7 @@ public class ExportBackupService extends Service {
 
     }
 
-    private static void accountExport(SQLiteDatabase db, String uuid, PrintWriter writer) {
+    private static void accountExport(final SQLiteDatabase db, final String uuid, final PrintWriter writer) {
         final StringBuilder builder = new StringBuilder();
         final Cursor accountCursor = db.query(Account.TABLENAME, null, Account.UUID + "=?", new String[]{uuid}, null, null, null);
         while (accountCursor != null && accountCursor.moveToNext()) {
@@ -136,27 +138,28 @@ public class ExportBackupService extends Service {
         }
     }
 
-    public static byte[] getKey(String password, byte[] salt) {
+    public static byte[] getKey(final String password, final byte[] salt) throws InvalidKeySpecException {
+        final SecretKeyFactory factory;
         try {
-            SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
-            return factory.generateSecret(new PBEKeySpec(password.toCharArray(), salt, 1024, 128)).getEncoded();
-        } catch (NoSuchAlgorithmException | InvalidKeySpecException e) {
-            throw new AssertionError(e);
+            factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
+        } catch (NoSuchAlgorithmException e) {
+            throw new IllegalStateException(e);
         }
+        return factory.generateSecret(new PBEKeySpec(password.toCharArray(), salt, 1024, 128)).getEncoded();
     }
 
-    private static String cursorToString(String tablename, Cursor cursor, int max) {
-        return cursorToString(tablename, cursor, max, false);
+    private static String cursorToString(final String table, final Cursor cursor, final int max) {
+        return cursorToString(table, cursor, max, false);
     }
 
-    private static String cursorToString(final String tablename, final Cursor cursor, int max, boolean ignore) {
-        final boolean identities = SQLiteAxolotlStore.IDENTITIES_TABLENAME.equals(tablename);
+    private static String cursorToString(final String table, final Cursor cursor, int max, boolean ignore) {
+        final boolean identities = SQLiteAxolotlStore.IDENTITIES_TABLENAME.equals(table);
         StringBuilder builder = new StringBuilder();
         builder.append("INSERT ");
         if (ignore) {
             builder.append("OR IGNORE ");
         }
-        builder.append("INTO ").append(tablename).append("(");
+        builder.append("INTO ").append(table).append("(");
         int skipColumn = -1;
         for (int i = 0; i < cursor.getColumnCount(); ++i) {
             final String name = cursor.getColumnName(i);
@@ -222,7 +225,8 @@ public class ExportBackupService extends Service {
                 try {
                     files = export();
                     success = true;
-                } catch (Exception e) {
+                } catch (final Exception e) {
+                    Log.d(Config.LOGTAG, "unable to create backup", e);
                     success = false;
                     files = Collections.emptyList();
                 }
@@ -234,6 +238,8 @@ public class ExportBackupService extends Service {
                 stopSelf();
             }).start();
             return START_STICKY;
+        } else {
+            Log.d(Config.LOGTAG, "ExportBackupService. ignoring start command because already running");
         }
         return START_NOT_STICKY;
     }
@@ -241,7 +247,7 @@ public class ExportBackupService extends Service {
     private void messageExport(SQLiteDatabase db, String uuid, PrintWriter writer, Progress progress) {
         Cursor cursor = db.rawQuery("select messages.* from messages join conversations on conversations.uuid=messages.conversationUuid where conversations.accountUuid=?", new String[]{uuid});
         int size = cursor != null ? cursor.getCount() : 0;
-        Log.d(Config.LOGTAG, "exporting " + size + " messages");
+        Log.d(Config.LOGTAG, "exporting " + size + " messages for account " + uuid);
         int i = 0;
         int p = 0;
         while (cursor != null && cursor.moveToNext()) {
@@ -272,7 +278,14 @@ public class ExportBackupService extends Service {
         final int max = this.mAccounts.size();
         final SecureRandom secureRandom = new SecureRandom();
         final List<File> files = new ArrayList<>();
-        for (Account account : this.mAccounts) {
+        Log.d(Config.LOGTAG, "starting backup for " + max + " accounts");
+        for (final Account account : this.mAccounts) {
+            final String password = account.getPassword();
+            if (Strings.nullToEmpty(password).trim().isEmpty()) {
+                Log.d(Config.LOGTAG, String.format("skipping backup for %s because password is empty. unable to encrypt", account.getJid().asBareJid()));
+                continue;
+            }
+            Log.d(Config.LOGTAG, String.format("exporting data for account %s (%s)", account.getJid().asBareJid(), account.getUuid()));
             final byte[] IV = new byte[12];
             final byte[] salt = new byte[16];
             secureRandom.nextBytes(IV);
@@ -281,8 +294,9 @@ public class ExportBackupService extends Service {
             final Progress progress = new Progress(mBuilder, max, count);
             final File file = new File(FileBackend.getBackupDirectory(this) + account.getJid().asBareJid().toEscapedString() + ".ceb");
             files.add(file);
-            if (file.getParentFile().mkdirs()) {
-                Log.d(Config.LOGTAG, "created backup directory " + file.getParentFile().getAbsolutePath());
+            final File directory = file.getParentFile();
+            if (directory != null && directory.mkdirs()) {
+                Log.d(Config.LOGTAG, "created backup directory " + directory.getAbsolutePath());
             }
             final FileOutputStream fileOutputStream = new FileOutputStream(file);
             final DataOutputStream dataOutputStream = new DataOutputStream(fileOutputStream);
@@ -290,8 +304,7 @@ public class ExportBackupService extends Service {
             dataOutputStream.flush();
 
             final Cipher cipher = Compatibility.twentyEight() ? Cipher.getInstance(CIPHERMODE) : Cipher.getInstance(CIPHERMODE, PROVIDER);
-            byte[] key = getKey(account.getPassword(), salt);
-            Log.d(Config.LOGTAG, backupFileHeader.toString());
+            final byte[] key = getKey(password, salt);
             SecretKeySpec keySpec = new SecretKeySpec(key, KEYTYPE);
             IvParameterSpec ivSpec = new IvParameterSpec(IV);
             cipher.init(Cipher.ENCRYPT_MODE, keySpec, ivSpec);
@@ -315,7 +328,7 @@ public class ExportBackupService extends Service {
         return files;
     }
 
-    private void notifySuccess(List<File> files) {
+    private void notifySuccess(final List<File> files) {
         final String path = FileBackend.getBackupDirectory(this);
 
         PendingIntent openFolderIntent = null;
@@ -331,14 +344,14 @@ public class ExportBackupService extends Service {
         if (files.size() > 0) {
             final Intent intent = new Intent(Intent.ACTION_SEND_MULTIPLE);
             ArrayList<Uri> uris = new ArrayList<>();
-            for(File file : files) {
+            for (File file : files) {
                 uris.add(FileBackend.getUriForFile(this, file));
             }
             intent.putParcelableArrayListExtra(Intent.EXTRA_STREAM, uris);
             intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
             intent.setType(MIME_TYPE);
             final Intent chooser = Intent.createChooser(intent, getString(R.string.share_backup_files));
-            shareFilesIntent = PendingIntent.getActivity(this,190, chooser, PendingIntent.FLAG_UPDATE_CURRENT);
+            shareFilesIntent = PendingIntent.getActivity(this, 190, chooser, PendingIntent.FLAG_UPDATE_CURRENT);
         }
 
         NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(getBaseContext(), "backup");
@@ -361,7 +374,7 @@ public class ExportBackupService extends Service {
         return null;
     }
 
-    private class Progress {
+    private static class Progress {
         private final NotificationCompat.Builder builder;
         private final int max;
         private final int count;
diff --git a/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java b/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java
index 8ea3ed2ea..6f1ff65cc 100644
--- a/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java
+++ b/src/main/java/eu/siacs/conversations/services/XmppConnectionService.java
@@ -4468,8 +4468,8 @@ public class XmppConnectionService extends Service {
     }
 
     private void injectServiceDiscoveryResult(Roster roster, String hash, String ver, ServiceDiscoveryResult disco) {
-        for (Contact contact : roster.getContacts()) {
-            for (Presence presence : contact.getPresences().getPresences().values()) {
+        for (final Contact contact : roster.getContacts()) {
+            for (final Presence presence : contact.getPresences().getPresences()) {
                 if (hash.equals(presence.getHash()) && ver.equals(presence.getVer())) {
                     presence.setServiceDiscoveryResult(disco);
                 }
diff --git a/src/main/java/eu/siacs/conversations/ui/ConversationFragment.java b/src/main/java/eu/siacs/conversations/ui/ConversationFragment.java
index 6308d74eb..6ff2135aa 100644
--- a/src/main/java/eu/siacs/conversations/ui/ConversationFragment.java
+++ b/src/main/java/eu/siacs/conversations/ui/ConversationFragment.java
@@ -116,6 +116,7 @@ import eu.siacs.conversations.utils.QuickLoader;
 import eu.siacs.conversations.utils.StylingHelper;
 import eu.siacs.conversations.utils.TimeFrameUtils;
 import eu.siacs.conversations.utils.UIHelper;
+import eu.siacs.conversations.xml.Namespace;
 import eu.siacs.conversations.xmpp.XmppConnection;
 import eu.siacs.conversations.xmpp.chatstate.ChatState;
 import eu.siacs.conversations.xmpp.jingle.AbstractJingleConnection;
@@ -1342,11 +1343,28 @@ public class ConversationFragment extends XmppFragment implements EditMessage.Ke
             Toast.makeText(getActivity(), R.string.only_one_call_at_a_time, Toast.LENGTH_LONG).show();
             return;
         }
+
         final Contact contact = conversation.getContact();
+        if (contact.getPresences().anySupport(Namespace.JINGLE_MESSAGE)) {
+            triggerRtpSession(contact.getAccount(),contact.getJid().asBareJid(),action);
+        } else {
+            final RtpCapability.Capability capability;
+            if (action.equals(RtpSessionActivity.ACTION_MAKE_VIDEO_CALL)) {
+                capability = RtpCapability.Capability.VIDEO;
+            } else {
+                capability = RtpCapability.Capability.AUDIO;
+            }
+            PresenceSelector.selectFullJidForDirectRtpConnection(activity, contact, capability, fullJid -> {
+                triggerRtpSession(contact.getAccount(), fullJid, action);
+            });
+        }
+    }
+
+    private void triggerRtpSession(final Account account, final Jid with, final String action) {
         final Intent intent = new Intent(activity, RtpSessionActivity.class);
         intent.setAction(action);
-        intent.putExtra(RtpSessionActivity.EXTRA_ACCOUNT, contact.getAccount().getJid().toEscapedString());
-        intent.putExtra(RtpSessionActivity.EXTRA_WITH, contact.getJid().asBareJid().toEscapedString());
+        intent.putExtra(RtpSessionActivity.EXTRA_ACCOUNT, account.getJid().toEscapedString());
+        intent.putExtra(RtpSessionActivity.EXTRA_WITH, with.toEscapedString());
         intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
         intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
         startActivity(intent);
@@ -2120,6 +2138,7 @@ public class ConversationFragment extends XmppFragment implements EditMessage.Ke
         final String downloadUuid = extras.getString(ConversationsActivity.EXTRA_DOWNLOAD_UUID);
         final String text = extras.getString(Intent.EXTRA_TEXT);
         final String nick = extras.getString(ConversationsActivity.EXTRA_NICK);
+        final String postInitAction = extras.getString(ConversationsActivity.EXTRA_POST_INIT_ACTION);
         final boolean asQuote = extras.getBoolean(ConversationsActivity.EXTRA_AS_QUOTE);
         final boolean pm = extras.getBoolean(ConversationsActivity.EXTRA_IS_PRIVATE_MESSAGE, false);
         final boolean doNotAppend = extras.getBoolean(ConversationsActivity.EXTRA_DO_NOT_APPEND, false);
@@ -2160,6 +2179,10 @@ public class ConversationFragment extends XmppFragment implements EditMessage.Ke
                 appendText(text, doNotAppend);
             }
         }
+        if (ConversationsActivity.POST_ACTION_RECORD_VOICE.equals(postInitAction)) {
+            attachFile(ATTACHMENT_CHOICE_RECORD_VOICE);
+            return;
+        }
         final Message message = downloadUuid == null ? null : conversation.findMessageWithFileAndUuid(downloadUuid);
         if (message != null) {
             startDownloadable(message);
diff --git a/src/main/java/eu/siacs/conversations/ui/ConversationsActivity.java b/src/main/java/eu/siacs/conversations/ui/ConversationsActivity.java
index 43addb299..24e167e85 100644
--- a/src/main/java/eu/siacs/conversations/ui/ConversationsActivity.java
+++ b/src/main/java/eu/siacs/conversations/ui/ConversationsActivity.java
@@ -94,6 +94,8 @@ public class ConversationsActivity extends XmppActivity implements OnConversatio
     public static final String EXTRA_NICK = "nick";
     public static final String EXTRA_IS_PRIVATE_MESSAGE = "pm";
     public static final String EXTRA_DO_NOT_APPEND = "do_not_append";
+    public static final String EXTRA_POST_INIT_ACTION = "post_init_action";
+    public static final String POST_ACTION_RECORD_VOICE = "record_voice";
 
     private static List<String> VIEW_AND_SHARE_ACTIONS = Arrays.asList(
             ACTION_VIEW_CONVERSATION,
diff --git a/src/main/java/eu/siacs/conversations/ui/RtpSessionActivity.java b/src/main/java/eu/siacs/conversations/ui/RtpSessionActivity.java
index a6ac2ba1b..b7e018abf 100644
--- a/src/main/java/eu/siacs/conversations/ui/RtpSessionActivity.java
+++ b/src/main/java/eu/siacs/conversations/ui/RtpSessionActivity.java
@@ -44,12 +44,14 @@ import eu.siacs.conversations.R;
 import eu.siacs.conversations.databinding.ActivityRtpSessionBinding;
 import eu.siacs.conversations.entities.Account;
 import eu.siacs.conversations.entities.Contact;
+import eu.siacs.conversations.entities.Conversation;
 import eu.siacs.conversations.services.AppRTCAudioManager;
 import eu.siacs.conversations.services.XmppConnectionService;
 import eu.siacs.conversations.ui.util.AvatarWorkerTask;
 import eu.siacs.conversations.ui.util.MainThreadExecutor;
 import eu.siacs.conversations.utils.PermissionUtils;
 import eu.siacs.conversations.utils.TimeFrameUtils;
+import eu.siacs.conversations.xml.Namespace;
 import eu.siacs.conversations.xmpp.jingle.AbstractJingleConnection;
 import eu.siacs.conversations.xmpp.jingle.JingleRtpConnection;
 import eu.siacs.conversations.xmpp.jingle.Media;
@@ -101,6 +103,14 @@ public class RtpSessionActivity extends XmppActivity implements XmppConnectionSe
         }
     }
 
+    private static void addSink(final VideoTrack videoTrack, final SurfaceViewRenderer surfaceViewRenderer) {
+        try {
+            videoTrack.addSink(surfaceViewRenderer);
+        } catch (final IllegalStateException e) {
+            Log.e(Config.LOGTAG, "possible race condition on trying to display video track. ignoring", e);
+        }
+    }
+
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -297,7 +307,13 @@ public class RtpSessionActivity extends XmppActivity implements XmppConnectionSe
 
     private void proposeJingleRtpSession(final Account account, final Jid with, final Set<Media> media) {
         checkMicrophoneAvailability();
-        xmppConnectionService.getJingleConnectionManager().proposeJingleRtpSession(account, with, media);
+        if (with.isBareJid()) {
+            xmppConnectionService.getJingleConnectionManager().proposeJingleRtpSession(account, with, media);
+        } else {
+            final String sessionId = xmppConnectionService.getJingleConnectionManager().initializeRtpSession(account, with, media);
+            initializeActivityWithRunningRtpSession(account, with, sessionId);
+            resetIntent(account, with, sessionId);
+        }
         putScreenInCallMode(media);
     }
 
@@ -372,7 +388,6 @@ public class RtpSessionActivity extends XmppActivity implements XmppConnectionSe
         }
     }
 
-
     @RequiresApi(api = Build.VERSION_CODES.O)
     private void startPictureInPicture() {
         try {
@@ -412,12 +427,12 @@ public class RtpSessionActivity extends XmppActivity implements XmppConnectionSe
         final WeakReference<JingleRtpConnection> reference = xmppConnectionService.getJingleConnectionManager()
                 .findJingleRtpConnection(account, with, sessionId);
         if (reference == null || reference.get() == null) {
-            finish();
-            return true;
+            throw new IllegalStateException("failed to initialize activity with running rtp session. session not found");
         }
         this.rtpConnectionReference = reference;
         final RtpEndUserState currentState = requireRtpConnection().getEndUserState();
         if (currentState == RtpEndUserState.ENDED) {
+            reference.get().throwStateTransitionException();
             finish();
             return true;
         }
@@ -436,8 +451,12 @@ public class RtpSessionActivity extends XmppActivity implements XmppConnectionSe
         return false;
     }
 
-    private void reInitializeActivityWithRunningRapSession(final Account account, Jid with, String sessionId) {
+    private void reInitializeActivityWithRunningRtpSession(final Account account, Jid with, String sessionId) {
         runOnUiThread(() -> initializeActivityWithRunningRtpSession(account, with, sessionId));
+        resetIntent(account, with, sessionId);
+    }
+
+    private void resetIntent(final Account account, final Jid with, final String sessionId) {
         final Intent intent = new Intent(Intent.ACTION_VIEW);
         intent.putExtra(EXTRA_ACCOUNT, account.getJid().toEscapedString());
         intent.putExtra(EXTRA_WITH, with.toEscapedString());
@@ -551,11 +570,13 @@ public class RtpSessionActivity extends XmppActivity implements XmppConnectionSe
             this.binding.acceptCall.setImageResource(R.drawable.ic_call_white_48dp);
             this.binding.acceptCall.setVisibility(View.VISIBLE);
         } else if (state == RtpEndUserState.DECLINED_OR_BUSY) {
-            this.binding.rejectCall.setVisibility(View.INVISIBLE);
-            this.binding.endCall.setOnClickListener(this::exit);
-            this.binding.endCall.setImageResource(R.drawable.ic_clear_white_48dp);
-            this.binding.endCall.setVisibility(View.VISIBLE);
-            this.binding.acceptCall.setVisibility(View.INVISIBLE);
+            this.binding.rejectCall.setOnClickListener(this::exit);
+            this.binding.rejectCall.setImageResource(R.drawable.ic_clear_white_48dp);
+            this.binding.rejectCall.setVisibility(View.VISIBLE);
+            this.binding.endCall.setVisibility(View.INVISIBLE);
+            this.binding.acceptCall.setOnClickListener(this::recordVoiceMail);
+            this.binding.acceptCall.setImageResource(R.drawable.ic_voicemail_white_24dp);
+            this.binding.acceptCall.setVisibility(View.VISIBLE);
         } else if (asList(RtpEndUserState.CONNECTIVITY_ERROR, RtpEndUserState.APPLICATION_ERROR, RtpEndUserState.RETRACTED).contains(state)) {
             this.binding.rejectCall.setOnClickListener(this::exit);
             this.binding.rejectCall.setImageResource(R.drawable.ic_clear_white_48dp);
@@ -762,14 +783,14 @@ public class RtpSessionActivity extends XmppActivity implements XmppConnectionSe
             //paint local view over remote view
             binding.localVideo.setZOrderMediaOverlay(true);
             binding.localVideo.setMirror(requireRtpConnection().isFrontCamera());
-            localVideoTrack.get().addSink(binding.localVideo);
+            addSink(localVideoTrack.get(), binding.localVideo);
         } else {
             binding.localVideo.setVisibility(View.GONE);
         }
         final Optional<VideoTrack> remoteVideoTrack = getRemoteVideoTrack();
         if (remoteVideoTrack.isPresent()) {
             ensureSurfaceViewRendererIsSetup(binding.remoteVideo);
-            remoteVideoTrack.get().addSink(binding.remoteVideo);
+            addSink(remoteVideoTrack.get(), binding.remoteVideo);
             if (state == RtpEndUserState.CONNECTED) {
                 binding.appBarLayout.setVisibility(View.GONE);
                 getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
@@ -828,7 +849,6 @@ public class RtpSessionActivity extends XmppActivity implements XmppConnectionSe
     }
 
     private void retry(View view) {
-        Log.d(Config.LOGTAG, "attempting retry");
         final Intent intent = getIntent();
         final Account account = extractAccount(intent);
         final Jid with = Jid.ofEscaped(intent.getStringExtra(EXTRA_WITH));
@@ -836,10 +856,25 @@ public class RtpSessionActivity extends XmppActivity implements XmppConnectionSe
         final String action = intent.getAction();
         final Set<Media> media = actionToMedia(lastAction == null ? action : lastAction);
         this.rtpConnectionReference = null;
+        Log.d(Config.LOGTAG, "attempting retry with " + with.toEscapedString());
         proposeJingleRtpSession(account, with, media);
     }
 
-    private void exit(View view) {
+    private void exit(final View view) {
+        finish();
+    }
+
+    private void recordVoiceMail(final View view) {
+        final Intent intent = getIntent();
+        final Account account = extractAccount(intent);
+        final Jid with = Jid.ofEscaped(intent.getStringExtra(EXTRA_WITH));
+        final Conversation conversation = xmppConnectionService.findOrCreateConversation(account, with, false, true);
+        final Intent launchIntent = new Intent(this, ConversationsActivity.class);
+        launchIntent.setAction(ConversationsActivity.ACTION_VIEW_CONVERSATION);
+        launchIntent.putExtra(ConversationsActivity.EXTRA_CONVERSATION, conversation.getUuid());
+        launchIntent.setFlags(intent.getFlags() | Intent.FLAG_ACTIVITY_CLEAR_TOP);
+        launchIntent.putExtra(ConversationsActivity.EXTRA_POST_INIT_ACTION, ConversationsActivity.POST_ACTION_RECORD_VOICE);
+        startActivity(launchIntent);
         finish();
     }
 
@@ -875,7 +910,7 @@ public class RtpSessionActivity extends XmppActivity implements XmppConnectionSe
                 return;
             }
             //this happens when going from proposed session to actual session
-            reInitializeActivityWithRunningRapSession(account, with, sessionId);
+            reInitializeActivityWithRunningRtpSession(account, with, sessionId);
             return;
         }
         final AbstractJingleConnection.Id id = requireRtpConnection().getId();
@@ -952,8 +987,12 @@ public class RtpSessionActivity extends XmppActivity implements XmppConnectionSe
 
     private void resetIntent(final Account account, Jid with, final RtpEndUserState state, final Set<Media> media) {
         final Intent intent = new Intent(Intent.ACTION_VIEW);
-        intent.putExtra(EXTRA_WITH, with.asBareJid().toEscapedString());
         intent.putExtra(EXTRA_ACCOUNT, account.getJid().toEscapedString());
+        if (account.getRoster().getContact(with).getPresences().anySupport(Namespace.JINGLE_MESSAGE)) {
+            intent.putExtra(EXTRA_WITH, with.asBareJid().toEscapedString());
+        } else {
+            intent.putExtra(EXTRA_WITH, with.toEscapedString());
+        }
         intent.putExtra(EXTRA_LAST_REPORTED_STATE, state.toString());
         intent.putExtra(EXTRA_LAST_ACTION, media.contains(Media.VIDEO) ? ACTION_MAKE_VIDEO_CALL : ACTION_MAKE_VOICE_CALL);
         setIntent(intent);
diff --git a/src/main/java/eu/siacs/conversations/ui/util/PresenceSelector.java b/src/main/java/eu/siacs/conversations/ui/util/PresenceSelector.java
index defabcb4a..14e82b406 100644
--- a/src/main/java/eu/siacs/conversations/ui/util/PresenceSelector.java
+++ b/src/main/java/eu/siacs/conversations/ui/util/PresenceSelector.java
@@ -44,92 +44,110 @@ import eu.siacs.conversations.entities.Conversation;
 import eu.siacs.conversations.entities.Presences;
 import eu.siacs.conversations.utils.CryptoHelper;
 import eu.siacs.conversations.xmpp.Jid;
+import eu.siacs.conversations.xmpp.jingle.RtpCapability;
 
 public class PresenceSelector {
 
-	public static void showPresenceSelectionDialog(Activity activity, final Conversation conversation, final OnPresenceSelected listener) {
-		final Contact contact = conversation.getContact();
-		final Presences presences = contact.getPresences();
-		AlertDialog.Builder builder = new AlertDialog.Builder(activity);
-		builder.setTitle(activity.getString(R.string.choose_presence));
-		final String[] resourceArray = presences.toResourceArray();
-		Pair<Map<String, String>, Map<String, String>> typeAndName = presences.toTypeAndNameMap();
-		final Map<String, String> resourceTypeMap = typeAndName.first;
-		final Map<String, String> resourceNameMap = typeAndName.second;
-		final String[] readableIdentities = new String[resourceArray.length];
-		final AtomicInteger selectedResource = new AtomicInteger(0);
-		for (int i = 0; i < resourceArray.length; ++i) {
-			String resource = resourceArray[i];
-			if (resource.equals(contact.getLastResource())) {
-				selectedResource.set(i);
-			}
-			String type = resourceTypeMap.get(resource);
-			String name = resourceNameMap.get(resource);
-			if (type != null) {
-				if (Collections.frequency(resourceTypeMap.values(), type) == 1) {
-					readableIdentities[i] = translateType(activity, type);
-				} else if (name != null) {
-					if (Collections.frequency(resourceNameMap.values(), name) == 1
-							|| CryptoHelper.UUID_PATTERN.matcher(resource).matches()) {
-						readableIdentities[i] = translateType(activity, type) + "  (" + name + ")";
-					} else {
-						readableIdentities[i] = translateType(activity, type) + " (" + name + " / " + resource + ")";
-					}
-				} else {
-					readableIdentities[i] = translateType(activity, type) + " (" + resource + ")";
-				}
-			} else {
-				readableIdentities[i] = resource;
-			}
-		}
-		builder.setSingleChoiceItems(readableIdentities,
-				selectedResource.get(),
-				(dialog, which) -> selectedResource.set(which));
-		builder.setNegativeButton(R.string.cancel, null);
-		builder.setPositiveButton(R.string.ok, (dialog, which) -> {
-			try {
-				Jid next = Jid.of(contact.getJid().getLocal(), contact.getJid().getDomain(), resourceArray[selectedResource.get()]);
-				conversation.setNextCounterpart(next);
-			} catch (IllegalArgumentException e) {
-				conversation.setNextCounterpart(null);
-			}
-			listener.onPresenceSelected();
-		});
-		builder.create().show();
-	}
+    public static void showPresenceSelectionDialog(Activity activity, final Conversation conversation, final OnPresenceSelected listener) {
+        final Contact contact = conversation.getContact();
+        final String[] resourceArray = contact.getPresences().toResourceArray();
+        showPresenceSelectionDialog(activity, contact, resourceArray, fullJid -> {
+            conversation.setNextCounterpart(fullJid);
+            listener.onPresenceSelected();
+        });
+    }
 
-	public static void warnMutualPresenceSubscription(Activity activity, final Conversation conversation, final OnPresenceSelected listener) {
-		AlertDialog.Builder builder = new AlertDialog.Builder(activity);
-		builder.setTitle(conversation.getContact().getJid().toString());
-		builder.setMessage(R.string.without_mutual_presence_updates);
-		builder.setNegativeButton(R.string.cancel, null);
-		builder.setPositiveButton(R.string.ignore, (dialog, which) -> {
-			conversation.setNextCounterpart(null);
-			if (listener != null) {
-				listener.onPresenceSelected();
-			}
-		});
-		builder.create().show();
-	}
+    public static void selectFullJidForDirectRtpConnection(final Activity activity, final Contact contact, final RtpCapability.Capability required, final OnFullJidSelected onFullJidSelected) {
+        final String[] resources = RtpCapability.filterPresences(contact, required);
+        if (resources.length == 1) {
+            onFullJidSelected.onFullJidSelected(contact.getJid().withResource(resources[0]));
+        } else {
+            showPresenceSelectionDialog(activity, contact, resources, onFullJidSelected);
+        }
+    }
 
-	private static String translateType(Context context, String type) {
-		switch (type.toLowerCase()) {
-			case "pc":
-				return context.getString(R.string.type_pc);
-			case "phone":
-				return context.getString(R.string.type_phone);
-			case "tablet":
-				return context.getString(R.string.type_tablet);
-			case "web":
-				return context.getString(R.string.type_web);
-			case "console":
-				return context.getString(R.string.type_console);
-			default:
-				return type;
-		}
-	}
+    private static void showPresenceSelectionDialog(final Activity activity, final Contact contact, final String[] resourceArray, final OnFullJidSelected onFullJidSelected) {
+        final Presences presences = contact.getPresences();
+        AlertDialog.Builder builder = new AlertDialog.Builder(activity);
+        builder.setTitle(activity.getString(R.string.choose_presence));
+        Pair<Map<String, String>, Map<String, String>> typeAndName = presences.toTypeAndNameMap();
+        final Map<String, String> resourceTypeMap = typeAndName.first;
+        final Map<String, String> resourceNameMap = typeAndName.second;
+        final String[] readableIdentities = new String[resourceArray.length];
+        final AtomicInteger selectedResource = new AtomicInteger(0);
+        for (int i = 0; i < resourceArray.length; ++i) {
+            String resource = resourceArray[i];
+            if (resource.equals(contact.getLastResource())) {
+                selectedResource.set(i);
+            }
+            String type = resourceTypeMap.get(resource);
+            String name = resourceNameMap.get(resource);
+            if (type != null) {
+                if (Collections.frequency(resourceTypeMap.values(), type) == 1) {
+                    readableIdentities[i] = translateType(activity, type);
+                } else if (name != null) {
+                    if (Collections.frequency(resourceNameMap.values(), name) == 1
+                            || CryptoHelper.UUID_PATTERN.matcher(resource).matches()) {
+                        readableIdentities[i] = translateType(activity, type) + "  (" + name + ")";
+                    } else {
+                        readableIdentities[i] = translateType(activity, type) + " (" + name + " / " + resource + ")";
+                    }
+                } else {
+                    readableIdentities[i] = translateType(activity, type) + " (" + resource + ")";
+                }
+            } else {
+                readableIdentities[i] = resource;
+            }
+        }
+        builder.setSingleChoiceItems(readableIdentities,
+                selectedResource.get(),
+                (dialog, which) -> selectedResource.set(which));
+        builder.setNegativeButton(R.string.cancel, null);
+        builder.setPositiveButton(
+                R.string.ok,
+                (dialog, which) -> onFullJidSelected.onFullJidSelected(
+                        Jid.of(contact.getJid().getLocal(), contact.getJid().getDomain(), resourceArray[selectedResource.get()])
+                )
+        );
+        builder.create().show();
+    }
 
-	public interface OnPresenceSelected {
-		void onPresenceSelected();
-	}
+    public static void warnMutualPresenceSubscription(Activity activity, final Conversation conversation, final OnPresenceSelected listener) {
+        AlertDialog.Builder builder = new AlertDialog.Builder(activity);
+        builder.setTitle(conversation.getContact().getJid().toString());
+        builder.setMessage(R.string.without_mutual_presence_updates);
+        builder.setNegativeButton(R.string.cancel, null);
+        builder.setPositiveButton(R.string.ignore, (dialog, which) -> {
+            conversation.setNextCounterpart(null);
+            if (listener != null) {
+                listener.onPresenceSelected();
+            }
+        });
+        builder.create().show();
+    }
+
+    private static String translateType(Context context, String type) {
+        switch (type.toLowerCase()) {
+            case "pc":
+                return context.getString(R.string.type_pc);
+            case "phone":
+                return context.getString(R.string.type_phone);
+            case "tablet":
+                return context.getString(R.string.type_tablet);
+            case "web":
+                return context.getString(R.string.type_web);
+            case "console":
+                return context.getString(R.string.type_console);
+            default:
+                return type;
+        }
+    }
+
+    public interface OnPresenceSelected {
+        void onPresenceSelected();
+    }
+
+    public interface OnFullJidSelected {
+        void onFullJidSelected(Jid jid);
+    }
 }
diff --git a/src/main/java/eu/siacs/conversations/xmpp/jingle/AbstractJingleConnection.java b/src/main/java/eu/siacs/conversations/xmpp/jingle/AbstractJingleConnection.java
index ef28a2eb3..679a30abe 100644
--- a/src/main/java/eu/siacs/conversations/xmpp/jingle/AbstractJingleConnection.java
+++ b/src/main/java/eu/siacs/conversations/xmpp/jingle/AbstractJingleConnection.java
@@ -1,5 +1,6 @@
 package eu.siacs.conversations.xmpp.jingle;
 
+import com.google.common.base.MoreObjects;
 import com.google.common.base.Objects;
 import com.google.common.base.Preconditions;
 
@@ -61,6 +62,10 @@ public abstract class AbstractJingleConnection {
             return new Id(account, with, sessionId);
         }
 
+        public static Id of(Account account, Jid with) {
+            return new Id(account, with, JingleConnectionManager.nextRandomId());
+        }
+
         public static Id of(Message message) {
             return new Id(
                     message.getConversation().getAccount(),
@@ -78,14 +83,14 @@ public abstract class AbstractJingleConnection {
             if (this == o) return true;
             if (o == null || getClass() != o.getClass()) return false;
             Id id = (Id) o;
-            return Objects.equal(account.getJid(), id.account.getJid()) &&
+            return Objects.equal(account.getUuid(), id.account.getUuid()) &&
                     Objects.equal(with, id.with) &&
                     Objects.equal(sessionId, id.sessionId);
         }
 
         @Override
         public int hashCode() {
-            return Objects.hashCode(account.getJid(), with, sessionId);
+            return Objects.hashCode(account.getUuid(), with, sessionId);
         }
 
         @Override
@@ -102,6 +107,15 @@ public abstract class AbstractJingleConnection {
         public String getSessionId() {
             return sessionId;
         }
+
+        @Override
+        public String toString() {
+            return MoreObjects.toStringHelper(this)
+                    .add("account", account.getJid())
+                    .add("with", with)
+                    .add("sessionId", sessionId)
+                    .toString();
+        }
     }
 
 
diff --git a/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleConnectionManager.java b/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleConnectionManager.java
index d8be779ef..4a1f7148f 100644
--- a/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleConnectionManager.java
+++ b/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleConnectionManager.java
@@ -11,6 +11,7 @@ import com.google.common.cache.CacheBuilder;
 import com.google.common.collect.Collections2;
 import com.google.common.collect.ComparisonChain;
 import com.google.common.collect.ImmutableSet;
+import com.google.j2objc.annotations.Weak;
 
 import java.lang.ref.WeakReference;
 import java.security.SecureRandom;
@@ -134,7 +135,7 @@ public class JingleConnectionManager extends AbstractConnectionManager {
         }
     }
 
-    public Optional<RtpSessionProposal> findMatchingSessionProposal(final Account account, final Jid with, final Set<Media> media) {
+    private Optional<RtpSessionProposal> findMatchingSessionProposal(final Account account, final Jid with, final Set<Media> media) {
         synchronized (this.rtpSessionProposals) {
             for (Map.Entry<RtpSessionProposal, DeviceDiscoveryState> entry : this.rtpSessionProposals.entrySet()) {
                 final RtpSessionProposal proposal = entry.getKey();
@@ -446,7 +447,10 @@ public class JingleConnectionManager extends AbstractConnectionManager {
     }
 
     void finishConnection(final AbstractJingleConnection connection) {
-        this.connections.remove(connection.getId());
+        final AbstractJingleConnection.Id id = connection.getId();
+        if (this.connections.remove(id) == null) {
+            throw new IllegalStateException(String.format("Unable to finish connection with id=%s", id.toString()));
+        }
     }
 
     void getPrimaryCandidate(final Account account, final boolean initiator, final OnPrimaryCandidateFound listener) {
@@ -520,6 +524,15 @@ public class JingleConnectionManager extends AbstractConnectionManager {
         mXmppConnectionService.sendMessagePacket(account, messagePacket);
     }
 
+    public String initializeRtpSession(final Account account, final Jid with, final Set<Media> media) {
+        final AbstractJingleConnection.Id id = AbstractJingleConnection.Id.of(account, with);
+        final JingleRtpConnection rtpConnection = new JingleRtpConnection(this, id, account.getJid());
+        rtpConnection.setProposedMedia(media);
+        this.connections.put(id, rtpConnection);
+        rtpConnection.sendSessionInitiate();
+        return id.sessionId;
+    }
+
     public void proposeJingleRtpSession(final Account account, final Jid with, final Set<Media> media) {
         synchronized (this.rtpSessionProposals) {
             for (Map.Entry<RtpSessionProposal, DeviceDiscoveryState> entry : this.rtpSessionProposals.entrySet()) {
@@ -667,7 +680,7 @@ public class JingleConnectionManager extends AbstractConnectionManager {
         throw e;
     }
 
-    public void endSession(AbstractJingleConnection.Id id, final AbstractJingleConnection.State state) {
+    void endSession(AbstractJingleConnection.Id id, final AbstractJingleConnection.State state) {
         this.endedSessions.put(PersistableSessionId.of(id), state);
     }
 
diff --git a/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleFileTransferConnection.java b/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleFileTransferConnection.java
index 5d25cb3b0..2f84f7c45 100644
--- a/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleFileTransferConnection.java
+++ b/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleFileTransferConnection.java
@@ -417,7 +417,7 @@ public class JingleFileTransferConnection extends AbstractJingleConnection imple
         final Jid jid = this.id.with;
         String resource = jid != null ? jid.getResource() : null;
         if (resource != null) {
-            Presence presence = this.id.account.getRoster().getContact(jid).getPresences().getPresences().get(resource);
+            Presence presence = this.id.account.getRoster().getContact(jid).getPresences().get(resource);
             ServiceDiscoveryResult result = presence != null ? presence.getServiceDiscoveryResult() : null;
             return result == null ? Collections.emptyList() : result.getFeatures();
         } else {
diff --git a/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleRtpConnection.java b/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleRtpConnection.java
index 0af69ca28..8ff496835 100644
--- a/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleRtpConnection.java
+++ b/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleRtpConnection.java
@@ -123,6 +123,7 @@ public class JingleRtpConnection extends AbstractJingleConnection implements Web
     private final ArrayDeque<IceCandidate> pendingIceCandidates = new ArrayDeque<>();
     private final Message message;
     private State state = State.NULL;
+    private StateTransitionException stateTransitionException;
     private Set<Media> proposedMedia;
     private RtpContentMap initiatorRtpContentMap;
     private RtpContentMap responderRtpContentMap;
@@ -639,6 +640,10 @@ public class JingleRtpConnection extends AbstractJingleConnection implements Web
         }
     }
 
+    public void sendSessionInitiate() {
+        sendSessionInitiate(this.proposedMedia, State.SESSION_INITIALIZED);
+    }
+
     private void sendSessionInitiate(final Set<Media> media, final State targetState) {
         Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": prepare session-initiate");
         discoverIceServers(iceServers -> sendSessionInitiate(media, targetState, iceServers));
@@ -771,8 +776,16 @@ public class JingleRtpConnection extends AbstractJingleConnection implements Web
         xmppConnectionService.sendIqPacket(id.account, jinglePacket.generateResponse(IqPacket.TYPE.RESULT), null);
     }
 
+    public void throwStateTransitionException() {
+        final StateTransitionException exception = this.stateTransitionException;
+        if (exception != null) {
+            throw new IllegalStateException(String.format("Transition to %s did not call finish", exception.state), exception);
+        }
+    }
+
     public RtpEndUserState getEndUserState() {
         switch (this.state) {
+            case NULL:
             case PROPOSED:
             case SESSION_INITIALIZED:
                 if (isInitiator()) {
@@ -828,10 +841,19 @@ public class JingleRtpConnection extends AbstractJingleConnection implements Web
     public Set<Media> getMedia() {
         final State current = getState();
         if (current == State.NULL) {
+            if (isInitiator()) {
+                return Preconditions.checkNotNull(
+                        this.proposedMedia,
+                        "RTP connection has not been initialized properly"
+                );
+            }
             throw new IllegalStateException("RTP connection has not been initialized yet");
         }
         if (Arrays.asList(State.PROPOSED, State.PROCEED).contains(current)) {
-            return Preconditions.checkNotNull(this.proposedMedia, "RTP connection has not been initialized properly");
+            return Preconditions.checkNotNull(
+                    this.proposedMedia,
+                    "RTP connection has not been initialized properly"
+            );
         }
         final RtpContentMap initiatorContentMap = initiatorRtpContentMap;
         if (initiatorContentMap != null) {
@@ -983,6 +1005,7 @@ public class JingleRtpConnection extends AbstractJingleConnection implements Web
         final Collection<State> validTransitions = VALID_TRANSITIONS.get(this.state);
         if (validTransitions != null && validTransitions.contains(target)) {
             this.state = target;
+            this.stateTransitionException = new StateTransitionException(target);
             if (runnable != null) {
                 runnable.run();
             }
@@ -1231,4 +1254,12 @@ public class JingleRtpConnection extends AbstractJingleConnection implements Web
     private interface OnIceServersDiscovered {
         void onIceServersDiscovered(List<PeerConnection.IceServer> iceServers);
     }
+
+    private static class StateTransitionException extends Exception {
+        private final State state;
+
+        private StateTransitionException(final State state) {
+            this.state = state;
+        }
+    }
 }
diff --git a/src/main/java/eu/siacs/conversations/xmpp/jingle/RtpCapability.java b/src/main/java/eu/siacs/conversations/xmpp/jingle/RtpCapability.java
index 646137495..7fad0459a 100644
--- a/src/main/java/eu/siacs/conversations/xmpp/jingle/RtpCapability.java
+++ b/src/main/java/eu/siacs/conversations/xmpp/jingle/RtpCapability.java
@@ -1,8 +1,10 @@
 package eu.siacs.conversations.xmpp.jingle;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.Map;
 
 import eu.siacs.conversations.entities.Contact;
 import eu.siacs.conversations.entities.Presence;
@@ -37,10 +39,25 @@ public class RtpCapability {
         return Capability.NONE;
     }
 
+    public static String[] filterPresences(final Contact contact, Capability required) {
+        final Presences presences = contact.getPresences();
+        final ArrayList<String> resources = new ArrayList<>();
+        for(final Map.Entry<String,Presence> presence : presences.getPresencesMap().entrySet()) {
+            final Capability capability = check(presence.getValue());
+            if (capability == Capability.NONE) {
+                continue;
+            }
+            if (required == Capability.AUDIO || capability == required) {
+                resources.add(presence.getKey());
+            }
+        }
+        return resources.toArray(new String[0]);
+    }
+
     public static Capability check(final Contact contact) {
         final Presences presences = contact.getPresences();
         Capability result = Capability.NONE;
-        for(Presence presence : presences.getPresences().values()) {
+        for(Presence presence : presences.getPresences()) {
             Capability capability = check(presence);
             if (capability == Capability.VIDEO) {
                 result = capability;
diff --git a/src/main/res/drawable-hdpi/ic_voicemail_white_24dp.png b/src/main/res/drawable-hdpi/ic_voicemail_white_24dp.png
new file mode 100644
index 000000000..03a62e15f
Binary files /dev/null and b/src/main/res/drawable-hdpi/ic_voicemail_white_24dp.png differ
diff --git a/src/main/res/drawable-mdpi/ic_voicemail_white_24dp.png b/src/main/res/drawable-mdpi/ic_voicemail_white_24dp.png
new file mode 100644
index 000000000..e5aa7db05
Binary files /dev/null and b/src/main/res/drawable-mdpi/ic_voicemail_white_24dp.png differ
diff --git a/src/main/res/drawable-xhdpi/ic_voicemail_white_24dp.png b/src/main/res/drawable-xhdpi/ic_voicemail_white_24dp.png
new file mode 100644
index 000000000..59126d706
Binary files /dev/null and b/src/main/res/drawable-xhdpi/ic_voicemail_white_24dp.png differ
diff --git a/src/main/res/drawable-xxhdpi/ic_voicemail_white_24dp.png b/src/main/res/drawable-xxhdpi/ic_voicemail_white_24dp.png
new file mode 100644
index 000000000..28b8e936a
Binary files /dev/null and b/src/main/res/drawable-xxhdpi/ic_voicemail_white_24dp.png differ
diff --git a/src/main/res/drawable-xxxhdpi/ic_voicemail_white_24dp.png b/src/main/res/drawable-xxxhdpi/ic_voicemail_white_24dp.png
new file mode 100644
index 000000000..820ff5066
Binary files /dev/null and b/src/main/res/drawable-xxxhdpi/ic_voicemail_white_24dp.png differ
diff --git a/src/main/res/values-fr/strings.xml b/src/main/res/values-fr/strings.xml
index 8a5dfb6b6..58f1ac344 100644
--- a/src/main/res/values-fr/strings.xml
+++ b/src/main/res/values-fr/strings.xml
@@ -246,7 +246,7 @@
   <string name="contact_added_you">Votre correspondant vous a ajouté dans sa liste de contacts</string>
   <string name="add_back">Ajouter en retour</string>
   <string name="contact_has_read_up_to_this_point">%s a tout lu jusqu\'ici</string>
-  <string name="contacts_have_read_up_to_this_point">%s a tout lu jusqu\'ici</string>
+  <string name="contacts_have_read_up_to_this_point">%s ont tout lu jusqu\'ici</string>
   <string name="contacts_and_n_more_have_read_up_to_this_point">%1$s+%2$d autres ont tout lu jusqu\'ici</string>
   <string name="everyone_has_read_up_to_this_point">Tout le monde a lu jusqu\'ici</string>
   <string name="publish">Publier</string>
@@ -398,7 +398,7 @@
   <string name="until_further_notice">Jusqu\'à nouvel ordre</string>
   <string name="snooze">Répéter les notifications</string>
   <string name="reply">Répondre</string>
-  <string name="mark_as_read">Marqué comme lu</string>
+  <string name="mark_as_read">Marquer comme lu</string>
   <string name="pref_input_options">Saisie</string>
   <string name="pref_enter_is_send">Touche Entrée pour envoyer</string>
   <string name="pref_enter_is_send_summary">Utiliser la touche Entrée pour envoyer un message.</string>
@@ -918,6 +918,8 @@
   <string name="only_one_call_at_a_time">Vous ne pouvez prendre qu\'un appel à la fois.</string>
   <string name="return_to_ongoing_call">Reprendre l\'appel en cours</string>
   <string name="could_not_switch_camera">Impossible de changer de caméra</string>
+  <string name="add_to_favorites">Ajouter aux favoris</string>
+  <string name="remove_from_favorites">Enlever des favoris</string>
   <plurals name="view_users">
     <item quantity="one">Voir %1$d participant</item>
     <item quantity="other">Voir %1$d participants</item>
diff --git a/src/main/res/values-hu/strings.xml b/src/main/res/values-hu/strings.xml
index 82327c0d5..dd1f62576 100644
--- a/src/main/res/values-hu/strings.xml
+++ b/src/main/res/values-hu/strings.xml
@@ -272,6 +272,8 @@
   <string name="pref_quiet_hours_summary">Az értesítések el lesznek némítva a csendes órák alatt</string>
   <string name="pref_expert_options_other">Egyéb</string>
   <string name="pref_autojoin">Szinkronizálás a könyvjelzőkkel</string>
+  <string name="pref_autojoin_summary">Automatikusan csatlakozzon a csoportos csevegésekhez, ha ez szerepel a könyvjelzőben</string>
+  <string name="toast_message_omemo_fingerprint">OMEMO ujjlenyomat a vágólapra lett másolva</string>
   <string name="conference_banned">Ki van tiltva ebből a csoportos csevegésből</string>
   <string name="conference_members_only">Ez a csoportos csevegés csak tagoknak szól</string>
   <string name="conference_resource_constraint">Erőforráskényszer</string>
@@ -886,6 +888,8 @@
   <string name="only_one_call_at_a_time">Egyszerre csak egy hívásban vehet részt.</string>
   <string name="return_to_ongoing_call">Visszatérés a kimenő híváshoz</string>
   <string name="could_not_switch_camera">Nem sikerült átváltani a kamerát</string>
+  <string name="add_to_favorites">Hozzáadás a kedvencekhez</string>
+  <string name="remove_from_favorites">Eltávolítás a kedvencekből</string>
   <plurals name="view_users">
     <item quantity="one">%1$d résztvevő megtekintése</item>
     <item quantity="other">%1$d résztvevő megtekintése</item>
diff --git a/src/main/res/values-ru/strings.xml b/src/main/res/values-ru/strings.xml
index effaf0ef9..111a65c43 100644
--- a/src/main/res/values-ru/strings.xml
+++ b/src/main/res/values-ru/strings.xml
@@ -207,25 +207,32 @@
   <string name="add_back">Добавить в ответ</string>
   <string name="contact_has_read_up_to_this_point">%s прочит. сообщ. до этого момента</string>
   <string name="contacts_have_read_up_to_this_point">%s прочитали сообщения до этого момента</string>
+  <string name="contacts_and_n_more_have_read_up_to_this_point">%1$s + ещё %2$d прочитали до этого места</string>
   <string name="everyone_has_read_up_to_this_point">Все прочитали сообщения до этого момента</string>
   <string name="publish">Опубликовать</string>
+  <string name="touch_to_choose_picture">Нажмите на аватар, чтобы выбрать новую фотографию из галереи</string>
   <string name="publishing">Установка…</string>
   <string name="error_publish_avatar_server_reject">Сервер отклонил размещение аватара</string>
+  <string name="error_publish_avatar_converting">Не удалось преобразовать вашу фотографию</string>
   <string name="error_saving_avatar">Не удалось сохранить аватар</string>
   <string name="or_long_press_for_default">(Или долгое прикосновение, чтобы вернуть значения по умолчанию)</string>
+  <string name="error_publish_avatar_no_server_support">Ваш сервер не поддерживает публикацию аватаров</string>
   <string name="private_message">шёпот</string>
   <string name="private_message_to">отправить %s</string>
   <string name="send_private_message_to">Приватное сообщение %s</string>
   <string name="connect">Подключиться</string>
   <string name="account_already_exists">Аккаунт уже существует</string>
   <string name="next">Далее</string>
+  <string name="server_info_session_established">Сеанс установлен</string>
   <string name="skip">Пропустить</string>
   <string name="disable_notifications">Отключить уведомления</string>
   <string name="enable">Включить</string>
   <string name="conference_requires_password">Конференция требует авторизации</string>
   <string name="enter_password">Введите пароль</string>
+  <string name="request_presence_updates">Пожалуйста, сначала запросите обновления присутствия у вашего собеседника.\n\n<small>Эта информация будет использоваться для определения того, каким клиентом пользуется ваш собеседник</small>.</string>
   <string name="request_now">Запросить сейчас</string>
   <string name="ignore">Игнорировать</string>
+  <string name="without_mutual_presence_updates"><b>Внимание:</b> Если обновления присутствия не включены на обеих сторонах, это может привести к возникновению неожиданных проблем.\n\n<small>Просмотрите сведения о контакте для проверки настроек обновлений присутствия.</small></string>
   <string name="pref_security_settings">Безопасность</string>
   <string name="pref_allow_message_correction">Разрешить исправление сообщений</string>
   <string name="pref_allow_message_correction_summary">Позволить контактам редактировать сообщения</string>
@@ -248,6 +255,7 @@
   <string name="conference_shutdown">Конференция была остановлена</string>
   <string name="conference_unknown_error">Вы больше не состоите в этой конференции</string>
   <string name="using_account">используется аккаунт %s</string>
+  <string name="hosted_on">размещено на %s</string>
   <string name="checking_x">Проверка %s на сервере HTTP</string>
   <string name="not_connected_try_again">Вы неподключены. Попробуйте позже</string>
   <string name="check_x_filesize">Проверить размер %s</string>
@@ -778,6 +786,7 @@
   <string name="enter_your_name_instructions">Пожалуйста, введите ваше имя, чтобы другие люди, у которых нет вас в списке контактов, знали кто вы.</string>
   <string name="your_name">Ваше имя</string>
   <string name="enter_your_name">Введите ваше имя</string>
+  <string name="no_name_set_instructions">Используйте кнопку редактирования, чтобы задать ваше имя.</string>
   <string name="reject_request">Отклонить запрос</string>
   <string name="install_orbot">Установите Orbot</string>
   <string name="start_orbot">Запустите Orbot</string>
diff --git a/src/main/res/values-tr-rTR/strings.xml b/src/main/res/values-tr-rTR/strings.xml
index 747fa315b..06db19906 100644
--- a/src/main/res/values-tr-rTR/strings.xml
+++ b/src/main/res/values-tr-rTR/strings.xml
@@ -3,7 +3,11 @@
   <string name="action_settings">Ayarlar</string>
   <string name="action_add">Yeni konuşma</string>
   <string name="action_accounts">Hesapları yönet</string>
+  <string name="action_account">Hesabı yönet</string>
+  <string name="action_end_conversation">Bu konuşmayı kapat</string>
   <string name="action_contact_details">Kişi bilgileri</string>
+  <string name="action_muc_details">Küme konuşması ayrıntıları</string>
+  <string name="channel_details">Kanal ayrıntıları</string>
   <string name="action_secure">Güvenli konuşma</string>
   <string name="action_add_account">Hesap ekle</string>
   <string name="action_edit_contact">İsmi düzenle</string>
@@ -13,14 +17,20 @@
   <string name="action_unblock_contact">Kişiyi engellemekten vazgeç</string>
   <string name="action_block_domain">Alan adını engelle</string>
   <string name="action_unblock_domain">Alan adını engellemekten vazgeç</string>
+  <string name="action_block_participant">Katılımcıyı engelle</string>
+  <string name="action_unblock_participant">Katılımcının engelini kaldır</string>
   <string name="title_activity_manage_accounts">Hesapları yönet</string>
   <string name="title_activity_settings">Ayarlar</string>
   <string name="title_activity_sharewith">Konuşmayla paylaş</string>
   <string name="title_activity_start_conversation">Konuşma Başlat</string>
+  <string name="title_activity_choose_contact">Kişi Seç</string>
+  <string name="title_activity_choose_contacts">Kişi Seç</string>
+  <string name="title_activity_share_via_account">Hesap aracılığıyla paylaş</string>
   <string name="title_activity_block_list">Listeyi blokla</string>
   <string name="just_now">şimdi</string>
   <string name="minute_ago">1 dakika önce</string>
   <string name="minutes_ago">%d dakika önc</string>
+  <string name="x_unread_conversations">%d okunmamış konuşma</string>
   <string name="sending">gönderiyor…</string>
   <string name="message_decrypting">İleti deşifre ediliyor. Lütfen bekleyin…</string>
   <string name="pgp_message">OpenPGP şifreli ileti</string>
@@ -35,10 +45,14 @@
   <string name="block_domain_text">%s üzerinden gelen tüm kişileri engellemek istiyor musunuz? </string>
   <string name="unblock_domain_text">%s üzerinden gelen kişilerdeki engellemeyi kaldırmak istiyor musunuz?</string>
   <string name="contact_blocked">Kişi engellendi</string>
+  <string name="blocked">Engellendi</string>
   <string name="register_account">Sunucuda yeni bir hesap oluştur</string>
   <string name="change_password_on_server">Sunucudaki şifreni değiştir</string>
   <string name="share_with">Paylaş...</string>
+  <string name="start_conversation">Konuşma başlat</string>
+  <string name="invite_contact">Kişi davet et</string>
   <string name="contacts">Kişiler</string>
+  <string name="contact">Kişi</string>
   <string name="cancel">İptal et</string>
   <string name="set">Ayarla</string>
   <string name="add">Ekle</string>
diff --git a/src/main/res/values-uk/strings.xml b/src/main/res/values-uk/strings.xml
index 7eb79819b..2de77dbfe 100644
--- a/src/main/res/values-uk/strings.xml
+++ b/src/main/res/values-uk/strings.xml
@@ -924,9 +924,9 @@
   <string name="ongoing_video_call">Активний відеовиклик</string>
   <string name="disable_tor_to_make_call">Вимкнути ToR для здійснення викликів</string>
   <string name="incoming_call">Вхідний виклик</string>
-  <string name="incoming_call_duration">%s · Вхідний виклик · %s</string>
+  <string name="incoming_call_duration">Вхідний виклик · %s</string>
   <string name="outgoing_call">Вихідний виклик</string>
-  <string name="outgoing_call_duration">%s · Вихідний виклик · %s</string>
+  <string name="outgoing_call_duration">Вихідний виклик · %s</string>
   <string name="missed_call">Пропущені виклики</string>
   <string name="audio_call">Голосовий виклик</string>
   <string name="video_call">Відеовиклик</string>
diff --git a/src/main/res/values-zh-rCN/strings.xml b/src/main/res/values-zh-rCN/strings.xml
index bb08debaf..07324fe66 100644
--- a/src/main/res/values-zh-rCN/strings.xml
+++ b/src/main/res/values-zh-rCN/strings.xml
@@ -9,7 +9,7 @@
   <string name="action_muc_details">群聊详情</string>
   <string name="channel_details">频道详情</string>
   <string name="action_secure">加密聊天</string>
-  <string name="action_add_account">添加账号</string>
+  <string name="action_add_account">添加账户</string>
   <string name="action_edit_contact">编辑名称</string>
   <string name="action_add_phone_book">添加到通讯录</string>
   <string name="action_delete_contact">从畅聊通讯录中删除</string>
@@ -167,7 +167,7 @@
   <string name="encryption_choice_otr">OTR</string>
   <string name="encryption_choice_pgp">OpenPGP</string>
   <string name="encryption_choice_omemo">OMEMO</string>
-  <string name="mgmt_account_delete">删除账号</string>
+  <string name="mgmt_account_delete">删除账户</string>
   <string name="mgmt_account_disable">暂时不可用</string>
   <string name="mgmt_account_publish_avatar">发布头像</string>
   <string name="mgmt_account_publish_pgp">发布OpenPGP公钥</string>
@@ -261,7 +261,7 @@
   <string name="private_message_to">至%s</string>
   <string name="send_private_message_to">与%s私聊</string>
   <string name="connect">连接</string>
-  <string name="account_already_exists">该账号已存在</string>
+  <string name="account_already_exists">该账户已存在</string>
   <string name="next">下一步</string>
   <string name="server_info_session_established">会话已建立</string>
   <string name="skip">跳过</string>