diff --git a/linphone-desktop/src/Utils.hpp b/linphone-desktop/src/Utils.hpp
index ba5398150..d8ab74b37 100644
--- a/linphone-desktop/src/Utils.hpp
+++ b/linphone-desktop/src/Utils.hpp
@@ -33,23 +33,10 @@ namespace Utils {
     return QString::fromLocal8Bit(string.c_str(), static_cast<int>(string.size()));
   }
 
-  inline std::string qStringToLinphoneString (const QString &string) {
+  inline std::string appStringToCoreString (const QString &string) {
     return string.toLocal8Bit().constData();
   }
 
-  template<class T>
-  T *findParentType (const QObject *object) {
-    QObject *parent = object->parent();
-    if (!parent)
-      return nullptr;
-
-    T *found = qobject_cast<T *>(parent);
-    if (found)
-      return found;
-
-    return findParentType<T>(parent);
-  }
-
   // Reverse function of strstr.
   char *rstrstr (const char *a, const char *b);
 }
diff --git a/linphone-desktop/src/app/App.cpp b/linphone-desktop/src/app/App.cpp
index dbf819fba..ab4c200cc 100644
--- a/linphone-desktop/src/app/App.cpp
+++ b/linphone-desktop/src/app/App.cpp
@@ -444,7 +444,7 @@ QString App::getConfigLocale () const {
 
 void App::setConfigLocale (const QString &locale) {
   CoreManager::getInstance()->getCore()->getConfig()->setString(
-    SettingsModel::UI_SECTION, "locale", ::Utils::qStringToLinphoneString(locale)
+    SettingsModel::UI_SECTION, "locale", ::Utils::appStringToCoreString(locale)
   );
 
   emit configLocaleChanged(locale);
diff --git a/linphone-desktop/src/app/paths/Paths.cpp b/linphone-desktop/src/app/paths/Paths.cpp
index fdfb44001..5c0378587 100644
--- a/linphone-desktop/src/app/paths/Paths.cpp
+++ b/linphone-desktop/src/app/paths/Paths.cpp
@@ -80,7 +80,7 @@ inline void ensureFilePathExists (const QString &path) {
 }
 
 inline string getReadableDirPath (const QString &dirname) {
-  return Utils::qStringToLinphoneString(QDir::toNativeSeparators(dirname));
+  return Utils::appStringToCoreString(QDir::toNativeSeparators(dirname));
 }
 
 inline string getWritableDirPath (const QString &dirname) {
@@ -89,7 +89,7 @@ inline string getWritableDirPath (const QString &dirname) {
 }
 
 inline string getReadableFilePath (const QString &filename) {
-  return Utils::qStringToLinphoneString(QDir::toNativeSeparators(filename));
+  return Utils::appStringToCoreString(QDir::toNativeSeparators(filename));
 }
 
 inline string getWritableFilePath (const QString &filename) {
diff --git a/linphone-desktop/src/components/assistant/AssistantModel.cpp b/linphone-desktop/src/components/assistant/AssistantModel.cpp
index a0b22e862..acb82b3ed 100644
--- a/linphone-desktop/src/components/assistant/AssistantModel.cpp
+++ b/linphone-desktop/src/components/assistant/AssistantModel.cpp
@@ -198,7 +198,7 @@ void AssistantModel::setEmail (const QString &email) {
   shared_ptr<linphone::Config> config = CoreManager::getInstance()->getCore()->getConfig();
   QString error;
 
-  switch (mAccountCreator->setEmail(::Utils::qStringToLinphoneString(email))) {
+  switch (mAccountCreator->setEmail(::Utils::appStringToCoreString(email))) {
     case linphone::AccountCreatorEmailStatusOk:
       break;
     case linphone::AccountCreatorEmailStatusMalformed:
@@ -222,7 +222,7 @@ void AssistantModel::setPassword (const QString &password) {
   shared_ptr<linphone::Config> config = CoreManager::getInstance()->getCore()->getConfig();
   QString error;
 
-  switch (mAccountCreator->setPassword(::Utils::qStringToLinphoneString(password))) {
+  switch (mAccountCreator->setPassword(::Utils::appStringToCoreString(password))) {
     case linphone::AccountCreatorPasswordStatusOk:
       break;
     case linphone::AccountCreatorPasswordStatusTooShort:
@@ -269,7 +269,7 @@ void AssistantModel::setUsername (const QString &username) {
   emit usernameChanged(
     username,
     mapAccountCreatorUsernameStatusToString(
-      mAccountCreator->setUsername(::Utils::qStringToLinphoneString(username))
+      mAccountCreator->setUsername(::Utils::appStringToCoreString(username))
     )
   );
 }
@@ -284,7 +284,7 @@ void AssistantModel::setDisplayName (const QString &displayName) {
   emit displayNameChanged(
     displayName,
     mapAccountCreatorUsernameStatusToString(
-      mAccountCreator->setDisplayName(::Utils::qStringToLinphoneString(displayName))
+      mAccountCreator->setDisplayName(::Utils::appStringToCoreString(displayName))
     )
   );
 }
@@ -302,7 +302,7 @@ void AssistantModel::setConfigFilename (const QString &configFilename) {
   qInfo() << QStringLiteral("Set config on assistant: `%1`.").arg(configPath);
 
   CoreManager::getInstance()->getCore()->getConfig()->loadFromXmlFile(
-    ::Utils::qStringToLinphoneString(configPath)
+    ::Utils::appStringToCoreString(configPath)
   );
 
   emit configFilenameChanged(configFilename);
diff --git a/linphone-desktop/src/components/call/CallModel.cpp b/linphone-desktop/src/components/call/CallModel.cpp
index 74247fcd4..792bc67ec 100644
--- a/linphone-desktop/src/components/call/CallModel.cpp
+++ b/linphone-desktop/src/components/call/CallModel.cpp
@@ -78,7 +78,7 @@ QString CallModel::getSipAddress () const {
 
 void CallModel::setRecordFile (shared_ptr<linphone::CallParams> &callParams) {
   callParams->setRecordFile(
-    ::Utils::qStringToLinphoneString(
+    ::Utils::appStringToCoreString(
       QStringLiteral("%1%2.mkv")
       .arg(CoreManager::getInstance()->getSettingsModel()->getSavedVideosFolder())
       .arg(QDateTime::currentDateTime().toString("yyyy-MM-dd_hh:mm:ss"))
@@ -142,7 +142,7 @@ void CallModel::askForTransfer () {
 }
 
 bool CallModel::transferTo (const QString &sipAddress) {
-  bool status = !!mCall->transfer(::Utils::qStringToLinphoneString(sipAddress));
+  bool status = !!mCall->transfer(::Utils::appStringToCoreString(sipAddress));
   if (status)
     qWarning() << QStringLiteral("Unable to transfer: `%1`.").arg(sipAddress);
   return status;
@@ -176,7 +176,7 @@ void CallModel::takeSnapshot () {
   qInfo() << QStringLiteral("Take snapshot of call:") << this;
 
   mCall->takeVideoSnapshot(
-    ::Utils::qStringToLinphoneString(
+    ::Utils::appStringToCoreString(
       CoreManager::getInstance()->getSettingsModel()->getSavedScreenshotsFolder() + newName
     )
   );
diff --git a/linphone-desktop/src/components/calls/CallsListModel.cpp b/linphone-desktop/src/components/calls/CallsListModel.cpp
index c96f9a403..5fff3da5c 100644
--- a/linphone-desktop/src/components/calls/CallsListModel.cpp
+++ b/linphone-desktop/src/components/calls/CallsListModel.cpp
@@ -93,7 +93,7 @@ void CallsListModel::askForTransfer (CallModel *callModel) {
 
 void CallsListModel::launchAudioCall (const QString &sipUri) const {
   shared_ptr<linphone::Core> core = CoreManager::getInstance()->getCore();
-  shared_ptr<linphone::Address> address = core->interpretUrl(::Utils::qStringToLinphoneString(sipUri));
+  shared_ptr<linphone::Address> address = core->interpretUrl(::Utils::appStringToCoreString(sipUri));
 
   if (!address)
     return;
@@ -107,7 +107,7 @@ void CallsListModel::launchAudioCall (const QString &sipUri) const {
 
 void CallsListModel::launchVideoCall (const QString &sipUri) const {
   shared_ptr<linphone::Core> core = CoreManager::getInstance()->getCore();
-  shared_ptr<linphone::Address> address = core->interpretUrl(::Utils::qStringToLinphoneString(sipUri));
+  shared_ptr<linphone::Address> address = core->interpretUrl(::Utils::appStringToCoreString(sipUri));
 
   if (!address)
     return;
diff --git a/linphone-desktop/src/components/chat/ChatModel.cpp b/linphone-desktop/src/components/chat/ChatModel.cpp
index 3b6e1d737..4d830cc4d 100644
--- a/linphone-desktop/src/components/chat/ChatModel.cpp
+++ b/linphone-desktop/src/components/chat/ChatModel.cpp
@@ -78,7 +78,7 @@ inline void createThumbnail (const shared_ptr<linphone::ChatMessage> &message) {
     return;
   }
 
-  message->setAppdata(::Utils::qStringToLinphoneString(fileId));
+  message->setAppdata(::Utils::appStringToCoreString(fileId));
 }
 
 inline void removeFileMessageThumbnail (const shared_ptr<linphone::ChatMessage> &message) {
@@ -259,7 +259,7 @@ void ChatModel::setSipAddress (const QString &sipAddress) {
 
   shared_ptr<linphone::Core> core = CoreManager::getInstance()->getCore();
 
-  mChatRoom = core->getChatRoomFromUri(::Utils::qStringToLinphoneString(sipAddress));
+  mChatRoom = core->getChatRoomFromUri(::Utils::appStringToCoreString(sipAddress));
 
   if (mChatRoom->getUnreadMessagesCount() > 0)
     resetMessagesCount();
@@ -316,7 +316,7 @@ void ChatModel::sendMessage (const QString &message) {
   if (!mChatRoom)
     return;
 
-  shared_ptr<linphone::ChatMessage> _message = mChatRoom->createMessage(::Utils::qStringToLinphoneString(message));
+  shared_ptr<linphone::ChatMessage> _message = mChatRoom->createMessage(::Utils::appStringToCoreString(message));
   _message->setListener(mMessageHandlers);
 
   insertMessageAtEnd(_message);
@@ -376,10 +376,10 @@ void ChatModel::sendFileMessage (const QString &path) {
   content->setSubtype("octet-stream");
 
   content->setSize(static_cast<size_t>(fileSize));
-  content->setName(::Utils::qStringToLinphoneString(QFileInfo(file).fileName()));
+  content->setName(::Utils::appStringToCoreString(QFileInfo(file).fileName()));
 
   shared_ptr<linphone::ChatMessage> message = mChatRoom->createFileTransferMessage(content);
-  message->setFileTransferFilepath(::Utils::qStringToLinphoneString(path));
+  message->setFileTransferFilepath(::Utils::appStringToCoreString(path));
   message->setListener(mMessageHandlers);
 
   createThumbnail(message);
@@ -423,7 +423,7 @@ void ChatModel::downloadFile (int id, const QString &downloadPath) {
       return;
   }
 
-  message->setFileTransferFilepath(::Utils::qStringToLinphoneString(downloadPath));
+  message->setFileTransferFilepath(::Utils::appStringToCoreString(downloadPath));
   message->setListener(mMessageHandlers);
 
   if (message->downloadFile() < 0)
diff --git a/linphone-desktop/src/components/codecs/AbstractCodecsModel.cpp b/linphone-desktop/src/components/codecs/AbstractCodecsModel.cpp
index ec157b166..af4b1ad5f 100644
--- a/linphone-desktop/src/components/codecs/AbstractCodecsModel.cpp
+++ b/linphone-desktop/src/components/codecs/AbstractCodecsModel.cpp
@@ -95,7 +95,7 @@ void AbstractCodecsModel::setRecvFmtp (int id, const QString &recvFmtp) {
   QVariantMap &map = mCodecs[id];
   shared_ptr<linphone::PayloadType> codec = getCodecFromMap(map);
 
-  codec->setRecvFmtp(::Utils::qStringToLinphoneString(recvFmtp));
+  codec->setRecvFmtp(::Utils::appStringToCoreString(recvFmtp));
   map["recvFmtp"] = ::Utils::coreStringToAppString(codec->getRecvFmtp());
 
   emit dataChanged(index(id, 0), index(id, 0));
diff --git a/linphone-desktop/src/components/conference/ConferenceAddModel.cpp b/linphone-desktop/src/components/conference/ConferenceAddModel.cpp
index 2fdfa8285..d24c5b26b 100644
--- a/linphone-desktop/src/components/conference/ConferenceAddModel.cpp
+++ b/linphone-desktop/src/components/conference/ConferenceAddModel.cpp
@@ -96,7 +96,7 @@ bool ConferenceHelperModel::ConferenceAddModel::addToConference (const QString &
 
   qInfo() << QStringLiteral("Add sip address to conference: `%1`.").arg(sipAddress);
   shared_ptr<linphone::Address> linphoneAddress = CoreManager::getInstance()->getCore()->interpretUrl(
-      ::Utils::qStringToLinphoneString(sipAddress)
+      ::Utils::appStringToCoreString(sipAddress)
     );
   addToConferencePrivate(linphoneAddress);
 
diff --git a/linphone-desktop/src/components/conference/ConferenceModel.cpp b/linphone-desktop/src/components/conference/ConferenceModel.cpp
index 2727e2374..953412257 100644
--- a/linphone-desktop/src/components/conference/ConferenceModel.cpp
+++ b/linphone-desktop/src/components/conference/ConferenceModel.cpp
@@ -71,7 +71,7 @@ void ConferenceModel::startRecording () {
 
   CoreManager *coreManager = CoreManager::getInstance();
   coreManager->getCore()->startConferenceRecording(
-    ::Utils::qStringToLinphoneString(
+    ::Utils::appStringToCoreString(
       QStringLiteral("%1%2.mkv")
       .arg(coreManager->getSettingsModel()->getSavedVideosFolder())
       .arg(QDateTime::currentDateTime().toString("yyyy-MM-dd_hh:mm:ss"))
diff --git a/linphone-desktop/src/components/contact/VcardModel.cpp b/linphone-desktop/src/components/contact/VcardModel.cpp
index 128c583b9..5929e30b5 100644
--- a/linphone-desktop/src/components/contact/VcardModel.cpp
+++ b/linphone-desktop/src/components/contact/VcardModel.cpp
@@ -55,7 +55,7 @@ inline shared_ptr<T> findBelCardValue (const list<shared_ptr<T> > &list, const s
 
 template<class T>
 inline shared_ptr<T> findBelCardValue (const list<shared_ptr<T> > &list, const QString &value) {
-  return findBelCardValue(list, ::Utils::qStringToLinphoneString(value));
+  return findBelCardValue(list, ::Utils::appStringToCoreString(value));
 }
 
 inline bool isLinphoneDesktopPhoto (const shared_ptr<belcard::BelCardPhoto> &photo) {
@@ -100,7 +100,7 @@ static string interpretSipAddress (const QString &sipAddress) {
   string out;
 
   shared_ptr<linphone::Address> linphoneAddress = CoreManager::getInstance()->getCore()->interpretUrl(
-      ::Utils::qStringToLinphoneString(sipAddress)
+      ::Utils::appStringToCoreString(sipAddress)
     );
 
   if (!linphoneAddress) {
@@ -189,7 +189,7 @@ bool VcardModel::setAvatar (const QString &path) {
   // 3. Update new photo.
   if (!path.isEmpty()) {
     shared_ptr<belcard::BelCardPhoto> photo = belcard::BelCardGeneric::create<belcard::BelCardPhoto>();
-    photo->setValue(VCARD_SCHEME + ::Utils::qStringToLinphoneString(fileId));
+    photo->setValue(VCARD_SCHEME + ::Utils::appStringToCoreString(fileId));
 
     if (!belcard->addPhoto(photo)) {
       file.remove();
@@ -214,7 +214,7 @@ void VcardModel::setUsername (const QString &username) {
   if (username.length() == 0 || username == getUsername())
     return;
 
-  mVcard->setFullName(::Utils::qStringToLinphoneString(username));
+  mVcard->setFullName(::Utils::appStringToCoreString(username));
   emit vcardUpdated();
 }
 
@@ -254,7 +254,7 @@ void VcardModel::setStreet (const QString &street) {
   CHECK_VCARD_IS_WRITABLE(this);
 
   shared_ptr<belcard::BelCardAddress> address = getOrCreateBelCardAddress(mVcard->getVcard());
-  address->setStreet(::Utils::qStringToLinphoneString(street));
+  address->setStreet(::Utils::appStringToCoreString(street));
   emit vcardUpdated();
 }
 
@@ -262,7 +262,7 @@ void VcardModel::setLocality (const QString &locality) {
   CHECK_VCARD_IS_WRITABLE(this);
 
   shared_ptr<belcard::BelCardAddress> address = getOrCreateBelCardAddress(mVcard->getVcard());
-  address->setLocality(::Utils::qStringToLinphoneString(locality));
+  address->setLocality(::Utils::appStringToCoreString(locality));
   emit vcardUpdated();
 }
 
@@ -270,7 +270,7 @@ void VcardModel::setPostalCode (const QString &postalCode) {
   CHECK_VCARD_IS_WRITABLE(this);
 
   shared_ptr<belcard::BelCardAddress> address = getOrCreateBelCardAddress(mVcard->getVcard());
-  address->setPostalCode(::Utils::qStringToLinphoneString(postalCode));
+  address->setPostalCode(::Utils::appStringToCoreString(postalCode));
   emit vcardUpdated();
 }
 
@@ -278,7 +278,7 @@ void VcardModel::setCountry (const QString &country) {
   CHECK_VCARD_IS_WRITABLE(this);
 
   shared_ptr<belcard::BelCardAddress> address = getOrCreateBelCardAddress(mVcard->getVcard());
-  address->setCountry(::Utils::qStringToLinphoneString(country));
+  address->setCountry(::Utils::appStringToCoreString(country));
   emit vcardUpdated();
 }
 
@@ -379,7 +379,7 @@ bool VcardModel::addCompany (const QString &company) {
     return false;
 
   shared_ptr<belcard::BelCardRole> value = belcard::BelCardGeneric::create<belcard::BelCardRole>();
-  value->setValue(::Utils::qStringToLinphoneString(company));
+  value->setValue(::Utils::appStringToCoreString(company));
 
   if (!belcard->addRole(value)) {
     qWarning() << QStringLiteral("Unable to add company on vcard: `%1`.").arg(company);
@@ -433,7 +433,7 @@ bool VcardModel::addEmail (const QString &email) {
     return false;
 
   shared_ptr<belcard::BelCardEmail> value = belcard::BelCardGeneric::create<belcard::BelCardEmail>();
-  value->setValue(::Utils::qStringToLinphoneString(email));
+  value->setValue(::Utils::appStringToCoreString(email));
 
   if (!belcard->addEmail(value)) {
     qWarning() << QStringLiteral("Unable to add email on vcard: `%1`.").arg(email);
@@ -488,7 +488,7 @@ bool VcardModel::addUrl (const QString &url) {
     return false;
 
   shared_ptr<belcard::BelCardURL> value = belcard::BelCardGeneric::create<belcard::BelCardURL>();
-  value->setValue(::Utils::qStringToLinphoneString(url));
+  value->setValue(::Utils::appStringToCoreString(url));
 
   if (!belcard->addURL(value)) {
     qWarning() << QStringLiteral("Unable to add url on vcard: `%1`.").arg(url);
diff --git a/linphone-desktop/src/components/settings/AccountSettingsModel.cpp b/linphone-desktop/src/components/settings/AccountSettingsModel.cpp
index 093cdb984..2f0ed1a46 100644
--- a/linphone-desktop/src/components/settings/AccountSettingsModel.cpp
+++ b/linphone-desktop/src/components/settings/AccountSettingsModel.cpp
@@ -131,7 +131,7 @@ bool AccountSettingsModel::addOrUpdateProxyConfig (
   // Sip address.
   {
     shared_ptr<linphone::Address> address = linphone::Factory::get()->createAddress(
-        ::Utils::qStringToLinphoneString(literal)
+        ::Utils::appStringToCoreString(literal)
       );
     if (!address) {
       qWarning() << QStringLiteral("Unable to create sip address object from: `%1`.").arg(literal);
@@ -145,15 +145,15 @@ bool AccountSettingsModel::addOrUpdateProxyConfig (
   {
     QString serverAddress = data["serverAddress"].toString();
 
-    if (proxyConfig->setServerAddr(::Utils::qStringToLinphoneString(serverAddress))) {
+    if (proxyConfig->setServerAddr(::Utils::appStringToCoreString(serverAddress))) {
       qWarning() << QStringLiteral("Unable to add server address: `%1`.").arg(serverAddress);
       return false;
     }
   }
 
   proxyConfig->setPublishExpires(data["registrationDuration"].toInt());
-  proxyConfig->setRoute(::Utils::qStringToLinphoneString(data["route"].toString()));
-  proxyConfig->setContactParameters(::Utils::qStringToLinphoneString(data["contactParams"].toString()));
+  proxyConfig->setRoute(::Utils::appStringToCoreString(data["route"].toString()));
+  proxyConfig->setContactParameters(::Utils::appStringToCoreString(data["contactParams"].toString()));
   proxyConfig->setAvpfRrInterval(static_cast<uint8_t>(data["avpfInterval"].toInt()));
   proxyConfig->enableRegister(data["registerEnabled"].toBool());
   proxyConfig->enablePublish(data["publishEnabled"].toBool());
@@ -174,8 +174,8 @@ void AccountSettingsModel::addAuthInfo (
   const QString &password,
   const QString &userId
 ) {
-  authInfo->setPasswd(::Utils::qStringToLinphoneString(password));
-  authInfo->setUserid(::Utils::qStringToLinphoneString(userId));
+  authInfo->setPasswd(::Utils::appStringToCoreString(password));
+  authInfo->setUserid(::Utils::appStringToCoreString(userId));
 
   CoreManager::getInstance()->getCore()->addAuthInfo(authInfo);
 }
@@ -199,7 +199,7 @@ void AccountSettingsModel::setUsername (const QString &username) {
   shared_ptr<const linphone::Address> address = getUsedSipAddress();
   shared_ptr<linphone::Address> newAddress = address->clone();
 
-  if (newAddress->setDisplayName(::Utils::qStringToLinphoneString(username))) {
+  if (newAddress->setDisplayName(::Utils::appStringToCoreString(username))) {
     qWarning() << QStringLiteral("Unable to set displayName on sip address: `%1`.")
       .arg(::Utils::coreStringToAppString(newAddress->asStringUriOnly()));
   } else {
@@ -231,7 +231,7 @@ void AccountSettingsModel::setPrimaryUsername (const QString &username) {
   shared_ptr<linphone::Address> primary = core->getPrimaryContactParsed();
 
   primary->setUsername(
-    username.isEmpty() ? "linphone" : ::Utils::qStringToLinphoneString(username)
+    username.isEmpty() ? "linphone" : ::Utils::appStringToCoreString(username)
   );
   core->setPrimaryContact(primary->asString());
 
@@ -248,7 +248,7 @@ void AccountSettingsModel::setPrimaryDisplayName (const QString &displayName) {
   shared_ptr<linphone::Core> core = CoreManager::getInstance()->getCore();
   shared_ptr<linphone::Address> primary = core->getPrimaryContactParsed();
 
-  primary->setDisplayName(::Utils::qStringToLinphoneString(displayName));
+  primary->setDisplayName(::Utils::appStringToCoreString(displayName));
   core->setPrimaryContact(primary->asString());
 
   emit accountSettingsUpdated();
diff --git a/linphone-desktop/src/components/settings/SettingsModel.cpp b/linphone-desktop/src/components/settings/SettingsModel.cpp
index 730fb18ca..fc3b4ff0f 100644
--- a/linphone-desktop/src/components/settings/SettingsModel.cpp
+++ b/linphone-desktop/src/components/settings/SettingsModel.cpp
@@ -61,7 +61,7 @@ QString SettingsModel::getCaptureDevice () const {
 
 void SettingsModel::setCaptureDevice (const QString &device) {
   CoreManager::getInstance()->getCore()->setCaptureDevice(
-    ::Utils::qStringToLinphoneString(device)
+    ::Utils::appStringToCoreString(device)
   );
   emit captureDeviceChanged(device);
 }
@@ -76,7 +76,7 @@ QString SettingsModel::getPlaybackDevice () const {
 
 void SettingsModel::setPlaybackDevice (const QString &device) {
   CoreManager::getInstance()->getCore()->setPlaybackDevice(
-    ::Utils::qStringToLinphoneString(device)
+    ::Utils::appStringToCoreString(device)
   );
   emit playbackDeviceChanged(device);
 }
@@ -91,7 +91,7 @@ QString SettingsModel::getRingerDevice () const {
 
 void SettingsModel::setRingerDevice (const QString &device) {
   CoreManager::getInstance()->getCore()->setRingerDevice(
-    ::Utils::qStringToLinphoneString(device)
+    ::Utils::appStringToCoreString(device)
   );
   emit ringerDeviceChanged(device);
 }
@@ -106,7 +106,7 @@ void SettingsModel::setRingPath (const QString &path) {
   QString cleanedPath = QDir::cleanPath(path);
 
   CoreManager::getInstance()->getCore()->setRing(
-    ::Utils::qStringToLinphoneString(cleanedPath)
+    ::Utils::appStringToCoreString(cleanedPath)
   );
 
   emit ringPathChanged(cleanedPath);
@@ -146,7 +146,7 @@ QString SettingsModel::getVideoDevice () const {
 
 void SettingsModel::setVideoDevice (const QString &device) {
   CoreManager::getInstance()->getCore()->setVideoDevice(
-    ::Utils::qStringToLinphoneString(device)
+    ::Utils::appStringToCoreString(device)
   );
   emit videoDeviceChanged(device);
 }
@@ -161,7 +161,7 @@ QString SettingsModel::getVideoPreset () const {
 
 void SettingsModel::setVideoPreset (const QString &preset) {
   CoreManager::getInstance()->getCore()->setVideoPreset(
-    ::Utils::qStringToLinphoneString(preset)
+    ::Utils::appStringToCoreString(preset)
   );
   emit videoPresetChanged(preset);
 }
@@ -243,7 +243,7 @@ QString SettingsModel::getFileTransferUrl () const {
 
 void SettingsModel::setFileTransferUrl (const QString &url) {
   CoreManager::getInstance()->getCore()->setFileTransferServer(
-    ::Utils::qStringToLinphoneString(url)
+    ::Utils::appStringToCoreString(url)
   );
   emit fileTransferUrlChanged(url);
 }
@@ -530,7 +530,7 @@ QString SettingsModel::getStunServer () const {
 
 void SettingsModel::setStunServer (const QString &stunServer) {
   CoreManager::getInstance()->getCore()->getNatPolicy()->setStunServer(
-    ::Utils::qStringToLinphoneString(stunServer)
+    ::Utils::appStringToCoreString(stunServer)
   );
 }
 
@@ -544,7 +544,7 @@ QString SettingsModel::getTurnUser () const {
 
 void SettingsModel::setTurnUser (const QString &user) {
   CoreManager::getInstance()->getCore()->getNatPolicy()->setStunServerUsername(
-    ::Utils::qStringToLinphoneString(user)
+    ::Utils::appStringToCoreString(user)
   );
 
   emit turnUserChanged(user);
@@ -569,12 +569,12 @@ void SettingsModel::setTurnPassword (const QString &password) {
 
   if (authInfo) {
     shared_ptr<linphone::AuthInfo> clonedAuthInfo = authInfo->clone();
-    clonedAuthInfo->setPasswd(::Utils::qStringToLinphoneString(password));
+    clonedAuthInfo->setPasswd(::Utils::appStringToCoreString(password));
 
     core->removeAuthInfo(authInfo);
     core->addAuthInfo(clonedAuthInfo);
   } else {
-    authInfo = linphone::Factory::get()->createAuthInfo(username, username, ::Utils::qStringToLinphoneString(password), "", "", "");
+    authInfo = linphone::Factory::get()->createAuthInfo(username, username, ::Utils::appStringToCoreString(password), "", "", "");
     core->addAuthInfo(authInfo);
   }
 
@@ -625,7 +625,7 @@ QString SettingsModel::getSavedScreenshotsFolder () const {
 void SettingsModel::setSavedScreenshotsFolder (const QString &folder) {
   QString cleanedFolder = QDir::cleanPath(folder) + QDir::separator();
 
-  mConfig->setString(UI_SECTION, "saved_screenshots_folder", ::Utils::qStringToLinphoneString(cleanedFolder));
+  mConfig->setString(UI_SECTION, "saved_screenshots_folder", ::Utils::appStringToCoreString(cleanedFolder));
   emit savedScreenshotsFolderChanged(cleanedFolder);
 }
 
@@ -642,7 +642,7 @@ QString SettingsModel::getSavedVideosFolder () const {
 void SettingsModel::setSavedVideosFolder (const QString &folder) {
   QString _folder = QDir::cleanPath(folder) + QDir::separator();
 
-  mConfig->setString(UI_SECTION, "saved_videos_folder", ::Utils::qStringToLinphoneString(_folder));
+  mConfig->setString(UI_SECTION, "saved_videos_folder", ::Utils::appStringToCoreString(_folder));
   emit savedVideosFolderChanged(_folder);
 }
 
@@ -653,7 +653,7 @@ QString SettingsModel::getRemoteProvisioning () const {
 }
 
 void SettingsModel::setRemoteProvisioning (const QString &remoteProvisioning) {
-  if (!CoreManager::getInstance()->getCore()->setProvisioningUri(::Utils::qStringToLinphoneString(remoteProvisioning)))
+  if (!CoreManager::getInstance()->getCore()->setProvisioningUri(::Utils::appStringToCoreString(remoteProvisioning)))
     emit remoteProvisioningChanged(remoteProvisioning);
   else
     emit remoteProvisioningNotChanged(remoteProvisioning);
diff --git a/linphone-desktop/src/components/sip-addresses/SipAddressesModel.cpp b/linphone-desktop/src/components/sip-addresses/SipAddressesModel.cpp
index f872d6123..bed28bad9 100644
--- a/linphone-desktop/src/components/sip-addresses/SipAddressesModel.cpp
+++ b/linphone-desktop/src/components/sip-addresses/SipAddressesModel.cpp
@@ -142,7 +142,7 @@ SipAddressObserver *SipAddressesModel::getSipAddressObserver (const QString &sip
 
 QString SipAddressesModel::interpretUrl (const QString &sipAddress) const {
   shared_ptr<linphone::Address> lAddress = CoreManager::getInstance()->getCore()->interpretUrl(
-      ::Utils::qStringToLinphoneString(sipAddress)
+      ::Utils::appStringToCoreString(sipAddress)
     );
 
   return lAddress ? ::Utils::coreStringToAppString(lAddress->asStringUriOnly()) : "";
@@ -150,7 +150,7 @@ QString SipAddressesModel::interpretUrl (const QString &sipAddress) const {
 
 QString SipAddressesModel::getTransportFromSipAddress (const QString &sipAddress) const {
   const shared_ptr<const linphone::Address> address = linphone::Factory::get()->createAddress(
-      ::Utils::qStringToLinphoneString(sipAddress)
+      ::Utils::appStringToCoreString(sipAddress)
     );
 
   if (!address)
@@ -172,7 +172,7 @@ QString SipAddressesModel::getTransportFromSipAddress (const QString &sipAddress
 
 QString SipAddressesModel::addTransportToSipAddress (const QString &sipAddress, const QString &transport) const {
   shared_ptr<linphone::Address> address = linphone::Factory::get()->createAddress(
-      ::Utils::qStringToLinphoneString(sipAddress)
+      ::Utils::appStringToCoreString(sipAddress)
     );
 
   if (!address)
@@ -193,7 +193,7 @@ QString SipAddressesModel::addTransportToSipAddress (const QString &sipAddress,
 
 bool SipAddressesModel::sipAddressIsValid (const QString &sipAddress) {
   return !!linphone::Factory::get()->createAddress(
-    ::Utils::qStringToLinphoneString(sipAddress)
+    ::Utils::appStringToCoreString(sipAddress)
   );
 }
 
diff --git a/linphone-desktop/src/components/sound-player/SoundPlayer.cpp b/linphone-desktop/src/components/sound-player/SoundPlayer.cpp
index 26cf1b8e9..a93e6e589 100644
--- a/linphone-desktop/src/components/sound-player/SoundPlayer.cpp
+++ b/linphone-desktop/src/components/sound-player/SoundPlayer.cpp
@@ -97,7 +97,7 @@ void SoundPlayer::play () {
 
   if (
     (mPlaybackState == SoundPlayer::StoppedState || mPlaybackState == SoundPlayer::ErrorState) &&
-    mInternalPlayer->open(::Utils::qStringToLinphoneString(mSource))
+    mInternalPlayer->open(::Utils::appStringToCoreString(mSource))
   ) {
     qWarning() << QStringLiteral("Unable to open: `%1`").arg(mSource);
     return;