diff --git a/src/chatdlg.cpp b/src/chatdlg.cpp
index a6d88cef..2982916c 100755
--- a/src/chatdlg.cpp
+++ b/src/chatdlg.cpp
@@ -31,7 +31,8 @@ CChatDlg::CChatDlg ( QWidget* parent, Qt::WindowFlags f ) :
 {
     setupUi ( this );
 
-    // add help text to controls -----------------------------------------------
+
+    // Add help text to controls -----------------------------------------------
     lineEditLocalInputText->setAccessibleName ( "New chat text edit box" );
     TextViewChatWindow->setAccessibleName ( "Chat history" );
 
diff --git a/src/clientsettingsdlg.cpp b/src/clientsettingsdlg.cpp
index e475942d..dee65ddf 100755
--- a/src/clientsettingsdlg.cpp
+++ b/src/clientsettingsdlg.cpp
@@ -31,6 +31,7 @@ CClientSettingsDlg::CClientSettingsDlg ( CClient* pNCliP, QWidget* parent,
 {
     setupUi ( this );
 
+
     // Add help text to controls -----------------------------------------------
     // jitter buffer
     QString strJitterBufferSize = tr ( "<b>Jitter Buffer Size:</b> The jitter "
diff --git a/src/global.h b/src/global.h
index 2240449b..6d820ca2 100755
--- a/src/global.h
+++ b/src/global.h
@@ -60,7 +60,7 @@
 #define LLCON_DOWNLOAD_URL              "http://sourceforge.net/projects/llcon/files"
 
 // defined port number for client and server
-#define LLCON_DEFAULT_PORT_NUMBER       22124
+#define LLCON_DEFAULT_PORT_NUMBER       22122
 
 // system sample rate (the sound card and audio coder works on this sample rate)
 #define SYSTEM_SAMPLE_RATE_HZ           48000 // Hz
diff --git a/src/llconclientdlg.cpp b/src/llconclientdlg.cpp
index ea001e29..04eeec05 100755
--- a/src/llconclientdlg.cpp
+++ b/src/llconclientdlg.cpp
@@ -55,6 +55,7 @@ CLlconClientDlg::CLlconClientDlg ( CClient*        pNCliP,
 {
     setupUi ( this );
 
+
     // Add help text to controls -----------------------------------------------
     // input level meter
     QString strInpLevH = tr ( "<b>Input Level Meter:</b> The input level "
diff --git a/src/llconserverdlg.cpp b/src/llconserverdlg.cpp
index 025991ec..840bcea3 100755
--- a/src/llconserverdlg.cpp
+++ b/src/llconserverdlg.cpp
@@ -31,6 +31,75 @@ CLlconServerDlg::CLlconServerDlg ( CServer* pNServP, QWidget* parent )
 {
     setupUi ( this );
 
+
+    // Add help text to controls -----------------------------------------------
+    // client list
+    ListViewClients->setWhatsThis ( tr ( "<b>Client List:</b> The client list "
+        "shows all clients which are currently connected to this server. Some "
+        "informations about the clients like the IP address, name, buffer "
+        "state are given for each connected client." ) );
+
+    ListViewClients->setAccessibleName ( tr ( "Connected clients list view" ) );
+
+    // register server flag
+    cbRegisterServer->setWhatsThis ( tr ( "<b>Register Server Status:</b> If "
+        "the register server check box is checked, this server registers "
+        "itself at the central server so that all " ) + APP_NAME +
+        tr ( " users can see the server in the connect dialog server list and "
+        "connect to it. The registering of the server is renewed periodically "
+        "to make sure that all servers in the connect dialog server list are "
+        "actually available." ) );
+
+    // central server address
+    QString strCentrServAddr = tr ( "<b>Central Server Address:</b> The "
+        "Central server address is the IP address or URL of the central server "
+        "at which this server is registered. If the Default check box is "
+        "checked, the default central server address is shown read-only." );
+
+    LabelCentralServerAddress->setWhatsThis    ( strCentrServAddr );
+    cbDefaultCentralServer->setWhatsThis       ( strCentrServAddr );
+    LineEditCentralServerAddress->setWhatsThis ( strCentrServAddr );
+
+    cbDefaultCentralServer->setAccessibleName (
+        tr ( "Default central server check box" ) );
+
+    LineEditCentralServerAddress->setAccessibleName (
+        tr ( "Central server address line edit" ) );
+
+    // server name
+    QString strServName = tr ( "<b>Server Name:</b> The server name identifies "
+        "your server in the connect dialog server list at the clients. If no "
+        "name is given, the IP address is shown instead." );
+
+    LabelServerName->setWhatsThis    ( strServName );
+    LineEditServerName->setWhatsThis ( strServName );
+
+    LineEditServerName->setAccessibleName ( tr ( "Server name line edit" ) );
+
+    // location city
+    QString strLocCity = tr ( "<b>Location City:</b> The city in which this "
+        "server is located can be set here. If a city name is entered, it "
+        "will be shown in the connect dialog server list at the clients." );
+
+    LabelLocationCity->setWhatsThis    ( strLocCity );
+    LineEditLocationCity->setWhatsThis ( strLocCity );
+
+    LineEditLocationCity->setAccessibleName ( tr (
+        "City where the server is located line edit" ) );
+
+    // location country
+    QString strLocCountry = tr ( "<b>Location country:</b> The country in "
+        "which this server is located can be set here. If a country is "
+        "entered, it will be shown in the connect dialog server list at the "
+        "clients." );
+
+    LabelLocationCountry->setWhatsThis    ( strLocCountry );
+    ComboBoxLocationCountry->setWhatsThis ( strLocCountry );
+
+    ComboBoxLocationCountry->setAccessibleName ( tr (
+        "Country where the server is located combo box" ) );
+
+
     // set text for version and application name
     TextLabelNameVersion->setText ( QString ( APP_NAME ) +
         tr ( " server " ) + QString ( VERSION ) );
@@ -54,6 +123,16 @@ CLlconServerDlg::CLlconServerDlg ( CServer* pNServP, QWidget* parent )
     LineEditCentralServerAddress->setText (
         pServer->GetServerListCentralServerAddress() );
 
+    // update default central server address check box
+    if ( pServer->GetUseDefaultCentralServerAddress() )
+    {
+        cbDefaultCentralServer->setCheckState ( Qt::Checked );
+    }
+    else
+    {
+        cbDefaultCentralServer->setCheckState ( Qt::Unchecked );
+    }
+
     // update server name line edit
     LineEditServerName->setText ( pServer->GetServerName() );
 
@@ -86,9 +165,7 @@ CLlconServerDlg::CLlconServerDlg ( CServer* pNServP, QWidget* parent )
         static_cast<int> ( pServer->GetServerCountry() ) ) );
 
     // update register server check box
-    const bool bCurSerListEnabled = pServer->GetServerListEnabled();
-
-    if ( bCurSerListEnabled )
+    if ( pServer->GetServerListEnabled() )
     {
         cbRegisterServer->setCheckState ( Qt::Checked );
     }
@@ -97,8 +174,8 @@ CLlconServerDlg::CLlconServerDlg ( CServer* pNServP, QWidget* parent )
         cbRegisterServer->setCheckState ( Qt::Unchecked );
     }
 
-    // update GUI dependency
-    UpdateServerInfosDependency ( bCurSerListEnabled );
+    // update GUI dependencies
+    UpdateGUIDependencies();
 
 
     // Main menu bar -----------------------------------------------------------
@@ -114,10 +191,13 @@ CLlconServerDlg::CLlconServerDlg ( CServer* pNServP, QWidget* parent )
     QObject::connect ( cbRegisterServer, SIGNAL ( stateChanged ( int ) ),
         this, SLOT ( OnRegisterServerStateChanged ( int ) ) );
 
+    QObject::connect ( cbDefaultCentralServer, SIGNAL ( stateChanged ( int ) ),
+        this, SLOT ( OnDefaultCentralServerStateChanged ( int ) ) );
+
     // line edits
     QObject::connect ( LineEditCentralServerAddress,
-        SIGNAL ( textChanged ( const QString& ) ),
-        this, SLOT ( OnLineEditCentralServerAddressTextChanged ( const QString& ) ) );
+        SIGNAL ( editingFinished() ),
+        this, SLOT ( OnLineEditCentralServerAddressEditingFinished() ) );
 
     QObject::connect ( LineEditServerName, SIGNAL ( textChanged ( const QString& ) ),
         this, SLOT ( OnLineEditServerNameTextChanged ( const QString& ) ) );
@@ -138,58 +218,64 @@ CLlconServerDlg::CLlconServerDlg ( CServer* pNServP, QWidget* parent )
     Timer.start ( GUI_CONTRL_UPDATE_TIME );
 }
 
-void CLlconServerDlg::OnRegisterServerStateChanged ( int value )
+void CLlconServerDlg::OnDefaultCentralServerStateChanged ( int value )
 {
-    const bool bEnabled = ( value == Qt::Checked );
-
-    // update GUI dependency
-    UpdateServerInfosDependency ( bEnabled );
-
     // apply new setting to the server and update it
-    pServer->SetServerListEnabled ( bEnabled );
+    pServer->SetUseDefaultCentralServerAddress ( value == Qt::Checked );
     pServer->UpdateServerList();
+
+    // update GUI dependencies
+    UpdateGUIDependencies();
 }
 
-void CLlconServerDlg::OnLineEditCentralServerAddressTextChanged ( const QString& strNewAddr )
+void CLlconServerDlg::OnRegisterServerStateChanged ( int value )
 {
     // apply new setting to the server and update it
-    pServer->SetServerListCentralServerAddress ( strNewAddr );
+    pServer->SetServerListEnabled ( value == Qt::Checked );
+    pServer->UpdateServerList();
 
-// TODO
-// only apply this in case the focus is lost and the name has actually changed!
-pServer->UpdateServerList();
+    // update GUI dependencies
+    UpdateGUIDependencies();
+}
 
+void CLlconServerDlg::OnLineEditCentralServerAddressEditingFinished()
+{
+    // apply new setting to the server and update it
+    pServer->SetServerListCentralServerAddress (
+        LineEditCentralServerAddress->text() );
+
+    pServer->UpdateServerList();
 }
 
 void CLlconServerDlg::OnLineEditServerNameTextChanged ( const QString& strNewName )
 {
-    // check length
-    if ( strNewName.length() <= MAX_LEN_SERVER_NAME )
-    {
+    // check length
+    if ( strNewName.length() <= MAX_LEN_SERVER_NAME )
+    {
         // apply new setting to the server and update it
         pServer->SetServerName ( strNewName );
         pServer->UpdateServerList();
-    }
-    else
-    {
-        // text is too long, update control with shortend text
-        LineEditServerName->setText ( strNewName.left ( MAX_LEN_SERVER_NAME ) );
+    }
+    else
+    {
+        // text is too long, update control with shortend text
+        LineEditServerName->setText ( strNewName.left ( MAX_LEN_SERVER_NAME ) );
     }
 }
 
 void CLlconServerDlg::OnLineEditLocationCityTextChanged ( const QString& strNewCity )
 {
-    // check length
-    if ( strNewCity.length() <= MAX_LEN_SERVER_CITY )
-    {
+    // check length
+    if ( strNewCity.length() <= MAX_LEN_SERVER_CITY )
+    {
         // apply new setting to the server and update it
         pServer->SetServerCity ( strNewCity );
         pServer->UpdateServerList();
-    }
-    else
-    {
-        // text is too long, update control with shortend text
-        LineEditLocationCity->setText ( strNewCity.left ( MAX_LEN_SERVER_CITY ) );
+    }
+    else
+    {
+        // text is too long, update control with shortend text
+        LineEditLocationCity->setText ( strNewCity.left ( MAX_LEN_SERVER_CITY ) );
     }
 }
 
@@ -250,14 +336,41 @@ void CLlconServerDlg::OnTimer()
     ListViewMutex.unlock();
 }
 
-void CLlconServerDlg::UpdateServerInfosDependency ( const bool bState )
+void CLlconServerDlg::UpdateGUIDependencies()
 {
+    // get the states which define the GUI dependencies from the server
+    const bool bCurSerListEnabled = pServer->GetServerListEnabled();
+
+    const bool bCurUseDefCentServAddr =
+        pServer->GetUseDefaultCentralServerAddress();
+
     // if register server is not enabled, we disable all the configuration
     // controls for the server list
-    LabelCentralServerAddress->setEnabled    ( bState );
-    cbDefaultCentralServer->setEnabled       ( bState );
-    LineEditCentralServerAddress->setEnabled ( bState );
-    GroupBoxServerInfo->setEnabled           ( bState );
+    cbDefaultCentralServer->setEnabled       ( bCurSerListEnabled );
+    LineEditCentralServerAddress->setEnabled ( bCurSerListEnabled );
+    GroupBoxServerInfo->setEnabled           ( bCurSerListEnabled );
+
+    // If the default central server address is enabled, the line edit shows
+    // the default server and is not editable. Make sure the line edit does not
+    // fire signals when we update the text.
+    LineEditCentralServerAddress->blockSignals ( true );
+    {
+        if ( bCurUseDefCentServAddr )
+        {
+            LineEditCentralServerAddress->setText ( DEFAULT_SERVER_ADDRESS );
+        }
+        else
+        {
+            LineEditCentralServerAddress->setText (
+                pServer->GetServerListCentralServerAddress() );
+        }
+    }
+    LineEditCentralServerAddress->blockSignals ( false );
+
+    // the line edit of the central server address is only enabled, if the
+    // server list is enabled and not the default address is used
+    LineEditCentralServerAddress->setEnabled (
+        !bCurUseDefCentServAddr && bCurSerListEnabled );
 }
 
 void CLlconServerDlg::customEvent ( QEvent* Event )
diff --git a/src/llconserverdlg.h b/src/llconserverdlg.h
index 55113b13..36aba428 100755
--- a/src/llconserverdlg.h
+++ b/src/llconserverdlg.h
@@ -67,12 +67,12 @@ protected:
     QMenuBar*                     pMenu;
 
     virtual void customEvent ( QEvent* Event );
-    void         UpdateServerInfosDependency ( const bool bState );
-
+    void         UpdateGUIDependencies();
 
 public slots:
     void OnRegisterServerStateChanged ( int value );
-    void OnLineEditCentralServerAddressTextChanged ( const QString& strNewAddr );
+    void OnDefaultCentralServerStateChanged ( int value );
+    void OnLineEditCentralServerAddressEditingFinished();
     void OnLineEditServerNameTextChanged ( const QString& strNewName );
     void OnLineEditLocationCityTextChanged ( const QString& strNewCity );
     void OnComboBoxLocationCountryActivated ( int iCntryListItem );
diff --git a/src/llconserverdlgbase.ui b/src/llconserverdlgbase.ui
index 8b0cbc45..93cdf385 100755
--- a/src/llconserverdlgbase.ui
+++ b/src/llconserverdlgbase.ui
@@ -6,7 +6,7 @@
     <x>0</x>
     <y>0</y>
     <width>588</width>
-    <height>438</height>
+    <height>378</height>
    </rect>
   </property>
   <property name="windowTitle" >
@@ -67,6 +67,9 @@
        </property>
       </widget>
      </item>
+     <item>
+      <widget class="QLineEdit" name="LineEditCentralServerAddress" />
+     </item>
      <item>
       <widget class="QCheckBox" name="cbDefaultCentralServer" >
        <property name="text" >
@@ -74,9 +77,6 @@
        </property>
       </widget>
      </item>
-     <item>
-      <widget class="QLineEdit" name="LineEditCentralServerAddress" />
-     </item>
     </layout>
    </item>
    <item>
diff --git a/src/main.cpp b/src/main.cpp
index e5e6daaf..b1ded77d 100755
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -349,6 +349,11 @@ int main ( int argc, char** argv )
 
             if ( bUseGUI )
             {
+                // special case for the GUI mode: as the default we want to use
+                // the default central server address (if not given in the
+                // settings file)
+                Server.SetUseDefaultCentralServerAddress ( true );
+
                 // load settings from init-file
                 CSettings Settings ( &Server );
                 Settings.Load ( strIniFileName );
diff --git a/src/server.h b/src/server.h
index 67681671..ac333d87 100755
--- a/src/server.h
+++ b/src/server.h
@@ -141,6 +141,12 @@ public:
     QString GetServerListCentralServerAddress()
         { return ServerListManager.GetCentralServerAddress(); }
 
+    void SetUseDefaultCentralServerAddress ( const bool bNUDCSeAddr )
+        { ServerListManager.SetUseDefaultCentralServerAddress ( bNUDCSeAddr ); }
+
+    bool GetUseDefaultCentralServerAddress()
+        { return ServerListManager.GetUseDefaultCentralServerAddress(); }
+
     void SetServerName ( const QString& strNewName )
         { ServerListManager.SetServerName ( strNewName ); }
 
diff --git a/src/serverlist.cpp b/src/serverlist.cpp
index 4c4d1a91..a72e1ad1 100755
--- a/src/serverlist.cpp
+++ b/src/serverlist.cpp
@@ -29,7 +29,8 @@
 CServerListManager::CServerListManager ( const QString& sNCentServAddr,
                                          const QString& strServerInfo,
                                          CProtocol*     pNConLProt )
-    : pConnLessProtocol ( pNConLProt )
+    : bUseDefaultCentralServerAddress ( false ),
+      pConnLessProtocol               ( pNConLProt )
 {
     // set the central server address
     SetCentralServerAddress ( sNCentServAddr );
@@ -294,6 +295,17 @@ void CServerListManager::OnTimerRegistering()
 
     if ( !bIsCentralServer && bEnabled )
     {
+        // get the correct central server address
+        QString strCurCentrServAddr;
+        if ( bUseDefaultCentralServerAddress )
+        {
+            strCurCentrServAddr = DEFAULT_SERVER_ADDRESS;
+        }
+        else
+        {
+            strCurCentrServAddr = strCentralServerAddress;
+        }
+
         // For the slave server, the slave server properties are store in the
         // very first item in the server list (which is actually no server list
         // but just one item long for the slave server).
@@ -301,7 +313,7 @@ void CServerListManager::OnTimerRegistering()
         // it is an URL of a dynamic IP address, the IP address might have
         // changed in the meanwhile.
         CHostAddress HostAddress;
-        if ( LlconNetwUtil().ParseNetworkAddress ( strCentralServerAddress,
+        if ( LlconNetwUtil().ParseNetworkAddress ( strCurCentrServAddr,
                                                    HostAddress ) )
         {
             pConnLessProtocol->CreateCLRegisterServerMes ( HostAddress,
diff --git a/src/serverlist.h b/src/serverlist.h
index 6c12afea..7a9e5923 100755
--- a/src/serverlist.h
+++ b/src/serverlist.h
@@ -135,6 +135,12 @@ public:
     void SetCentralServerAddress ( const QString sNCentServAddr );
     QString GetCentralServerAddress() { return strCentralServerAddress; }
 
+    void SetUseDefaultCentralServerAddress ( const bool bNUDCSeAddr )
+        { bUseDefaultCentralServerAddress = bNUDCSeAddr; }
+
+    bool GetUseDefaultCentralServerAddress()
+        { return bUseDefaultCentralServerAddress; }
+
     bool GetIsCentralServer() const { return bIsCentralServer; }
 
     void RegisterServer ( const CHostAddress&    InetAddr,
@@ -169,6 +175,7 @@ protected:
     QString                 strCentralServerAddress;
     bool                    bEnabled;
     bool                    bIsCentralServer;
+    bool                    bUseDefaultCentralServerAddress;
 
     CProtocol*              pConnLessProtocol;
 
diff --git a/src/settings.cpp b/src/settings.cpp
index cff2fb08..6f0fdaef 100755
--- a/src/settings.cpp
+++ b/src/settings.cpp
@@ -197,6 +197,12 @@ void CSettings::ReadIniFile ( const QString& sFileName )
         pServer->SetServerListCentralServerAddress (
             GetIniSetting ( IniXMLDocument, "server", "centralservaddr" ) );
 
+        // use default central server address flag
+        if ( GetFlagIniSet ( IniXMLDocument, "server", "defcentservaddr", bValue ) )
+        {
+            pServer->SetUseDefaultCentralServerAddress ( bValue );
+        }
+
         // server list enabled flag
         if ( GetFlagIniSet ( IniXMLDocument, "server", "servlistenabled", bValue ) )
         {
@@ -309,6 +315,10 @@ void CSettings::WriteIniFile ( const QString& sFileName )
         PutIniSetting ( IniXMLDocument, "server", "centralservaddr",
             pServer->GetServerListCentralServerAddress() );
 
+        // use default central server address flag
+        SetFlagIniSet ( IniXMLDocument, "server", "defcentservaddr",
+            pServer->GetUseDefaultCentralServerAddress() );
+
         // server list enabled flag
         SetFlagIniSet ( IniXMLDocument, "server", "servlistenabled",
             pServer->GetServerListEnabled() );