diff --git a/proto/telecom.proto b/proto/telecom.proto
index 73eba87..411b8e2 100644
--- a/proto/telecom.proto
+++ b/proto/telecom.proto
@@ -177,6 +177,13 @@
 
   // The type of the in-call service
   optional InCallServiceType in_call_service_type = 2;
+
+  // The number of milliseconds that the in call service remained bound between binding and
+  // disconnection.
+  optional int64 bound_duration_millis = 3;
+
+  // True if the in call service has ever crashed during a call.
+  optional bool is_null_binding = 4;
 }
 
 // Information about each call.
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 93c5782..a0a518f 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -68,6 +68,15 @@
         background. This app may be accessing and playing audio over the call.
     </string>
 
+    <!-- Crashed in call service notification label, used when the in call service has cranshed and
+         the system fall back to use system dialer. [CHAR LIMIT=NONE] -->
+    <string name="notification_crashedInCallService_title">Crashed phone app</string>
+    <!-- Body of the notification presented when an in call service crashed. [CHAR LIMIT=NONE] -->
+    <string name="notification_crashedInCallService_body">
+        Your Phone app <xliff:g id="in_call_service_app_name">%s</xliff:g> has crashed.
+        You call was continued using the Phone app that came with your device.
+    </string>
+
     <!-- Content description of the call muted notification icon for
          accessibility (not shown on the screen). [CHAR LIMIT=NONE] -->
     <string name="accessibility_call_muted">Call muted.</string>
@@ -300,6 +309,8 @@
     <string name="notification_channel_background_calls">Background calls</string>
     <!-- Notification channel name for a channel containing disconnected call notifications. -->
     <string name="notification_channel_disconnected_calls">Disconnected calls</string>
+    <!-- Notification channel name for a channel containing crashed phone apps service notifications. -->
+    <string name="notification_channel_in_call_service_crash">Crashed phone apps</string>
 
     <!-- Alert dialog content used to inform the user that placing a new outgoing call will end the
          ongoing call in the app "other_app". -->
diff --git a/src/com/android/server/telecom/Analytics.java b/src/com/android/server/telecom/Analytics.java
index 2997454..410660e 100644
--- a/src/com/android/server/telecom/Analytics.java
+++ b/src/com/android/server/telecom/Analytics.java
@@ -201,7 +201,8 @@
         public void addVideoEvent(int eventId, int videoState) {
         }
 
-        public void addInCallService(String serviceName, int type) {
+        public void addInCallService(String serviceName, int type, long boundDuration,
+                boolean isNullBinding) {
         }
 
         public void addCallProperties(int properties) {
@@ -370,10 +371,13 @@
         }
 
         @Override
-        public void addInCallService(String serviceName, int type) {
+        public void addInCallService(String serviceName, int type, long boundDuration,
+                boolean isNullBinding) {
             inCallServiceInfos.add(new TelecomLogClass.InCallServiceInfo()
                     .setInCallServiceName(serviceName)
-                    .setInCallServiceType(type));
+                    .setInCallServiceType(type)
+                    .setBoundDurationMillis(boundDuration)
+                    .setIsNullBinding(isNullBinding));
         }
 
         @Override
@@ -533,6 +537,10 @@
                 s.append(service.getInCallServiceName());
                 s.append(" type: ");
                 s.append(service.getInCallServiceType());
+                s.append(" is crashed: ");
+                s.append(service.getIsNullBinding());
+                s.append(" service last time in ms: ");
+                s.append(service.getBoundDurationMillis());
                 s.append("\n");
             }
             s.append("]");
diff --git a/src/com/android/server/telecom/CallsManager.java b/src/com/android/server/telecom/CallsManager.java
index 0643d3a..64bbe99 100644
--- a/src/com/android/server/telecom/CallsManager.java
+++ b/src/com/android/server/telecom/CallsManager.java
@@ -2501,6 +2501,11 @@
         if (!mCalls.contains(call)) {
             Log.w(this, "Unknown call (%s) asked to be removed from hold", call);
         } else {
+            if (getOutgoingCall() != null) {
+                Log.w(this, "There is an outgoing call, so it is unable to unhold this call %s",
+                        call);
+                return;
+            }
             Call activeCall = (Call) mConnectionSvrFocusMgr.getCurrentFocusCall();
             String activeCallId = null;
             if (activeCall != null && !activeCall.isLocallyDisconnecting()) {
diff --git a/src/com/android/server/telecom/InCallController.java b/src/com/android/server/telecom/InCallController.java
index b18c6ff..797a442 100644
--- a/src/com/android/server/telecom/InCallController.java
+++ b/src/com/android/server/telecom/InCallController.java
@@ -18,6 +18,8 @@
 
 import android.Manifest;
 import android.annotation.NonNull;
+import android.app.Notification;
+import android.app.NotificationManager;
 import android.content.ComponentName;
 import android.content.Context;
 import android.content.Intent;
@@ -47,6 +49,7 @@
 import com.android.internal.telecom.IInCallService;
 import com.android.internal.util.IndentingPrintWriter;
 import com.android.server.telecom.SystemStateHelper.SystemStateListener;
+import com.android.server.telecom.ui.NotificationChannelManager;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -65,6 +68,8 @@
  * a binding to the {@link IInCallService} (implemented by the in-call app).
  */
 public class InCallController extends CallsManagerListenerBase {
+    public static final int IN_CALL_SERVICE_NOTIFICATION_ID = 3;
+    public static final String NOTIFICATION_TAG = InCallController.class.getSimpleName();
 
     public class InCallServiceConnection {
         /**
@@ -83,7 +88,7 @@
         public static final int CONNECTION_NOT_SUPPORTED = 3;
 
         public class Listener {
-            public void onDisconnect(InCallServiceConnection conn) {}
+            public void onDisconnect(InCallServiceConnection conn, Call call) {}
         }
 
         protected Listener mListener;
@@ -97,6 +102,7 @@
         }
         public InCallServiceInfo getInfo() { return null; }
         public void dump(IndentingPrintWriter pw) {}
+        public Call mCall;
     }
 
     private class InCallServiceInfo {
@@ -104,6 +110,8 @@
         private boolean mIsExternalCallsSupported;
         private boolean mIsSelfManagedCallsSupported;
         private final int mType;
+        private long mBindingStartTime;
+        private long mDisconnectTime;
 
         public InCallServiceInfo(ComponentName componentName,
                 boolean isExternalCallsSupported,
@@ -131,6 +139,22 @@
             return mType;
         }
 
+        public long getBindingStartTime() {
+            return mBindingStartTime;
+        }
+
+        public long getDisconnectTime() {
+            return mDisconnectTime;
+        }
+
+        public void setBindingStartTime(long bindingStartTime) {
+            mBindingStartTime = bindingStartTime;
+        }
+
+        public void setDisconnectTime(long disconnectTime) {
+            mDisconnectTime = disconnectTime;
+        }
+
         @Override
         public boolean equals(Object o) {
             if (this == o) {
@@ -198,14 +222,47 @@
                     }
                 }
             }
+
+            @Override
+            public void onNullBinding(ComponentName name) {
+                Log.startSession("ICSBC.oNB");
+                synchronized (mLock) {
+                    try {
+                        Log.d(this, "onNullBinding: %s", name);
+                        mIsNullBinding = true;
+                        mIsBound = false;
+                        onDisconnected();
+                    } finally {
+                        Log.endSession();
+                    }
+                }
+            }
+
+            @Override
+            public void onBindingDied(ComponentName name) {
+                Log.startSession("ICSBC.oBD");
+                synchronized (mLock) {
+                    try {
+                        Log.d(this, "onBindingDied: %s", name);
+                        mIsBound = false;
+                        onDisconnected();
+                    } finally {
+                        Log.endSession();
+                    }
+                }
+            }
         };
 
         private final InCallServiceInfo mInCallServiceInfo;
         private boolean mIsConnected = false;
         private boolean mIsBound = false;
+        private boolean mIsNullBinding = false;
+        private NotificationManager mNotificationManager;
 
         public InCallServiceBindingConnection(InCallServiceInfo info) {
             mInCallServiceInfo = info;
+            mNotificationManager =
+                    (NotificationManager) mContext.getSystemService(Context.NOTIFICATION_SERVICE);
         }
 
         @Override
@@ -234,6 +291,7 @@
 
             Log.i(this, "Attempting to bind to InCall %s, with %s", mInCallServiceInfo, intent);
             mIsConnected = true;
+            mInCallServiceInfo.setBindingStartTime(mClockProxy.elapsedRealtime());
             if (!mContext.bindServiceAsUser(intent, mServiceConnection,
                         Context.BIND_AUTO_CREATE | Context.BIND_FOREGROUND_SERVICE
                         | Context.BIND_ALLOW_BACKGROUND_ACTIVITY_STARTS,
@@ -242,11 +300,10 @@
                 mIsConnected = false;
             }
 
-            if (call != null && mIsConnected) {
-                call.getAnalytics().addInCallService(
-                        mInCallServiceInfo.getComponentName().flattenToShortString(),
-                        mInCallServiceInfo.getType());
+            if (mIsConnected && call != null) {
+                mCall = call;
             }
+            Log.i(this, "mCall: %s, mIsConnected: %s", mCall, mIsConnected);
 
             return mIsConnected ? CONNECTION_SUCCEEDED : CONNECTION_FAILED;
         }
@@ -259,10 +316,36 @@
         @Override
         public void disconnect() {
             if (mIsConnected) {
-                Log.i(InCallController.this, "ICSBC#disconnect: unbinding; %s",
-                        mInCallServiceInfo);
+                mInCallServiceInfo.setDisconnectTime(mClockProxy.elapsedRealtime());
+                Log.i(InCallController.this, "ICSBC#disconnect: unbinding after %s ms;"
+                                + "%s. isCrashed: %s", mInCallServiceInfo.mDisconnectTime
+                                - mInCallServiceInfo.mBindingStartTime,
+                        mInCallServiceInfo, mIsNullBinding);
+                String packageName = mInCallServiceInfo.getComponentName().getPackageName();
                 mContext.unbindService(mServiceConnection);
                 mIsConnected = false;
+                if (mIsNullBinding) {
+                    Notification.Builder builder = new Notification.Builder(mContext,
+                            NotificationChannelManager.CHANNEL_ID_IN_CALL_SERVICE_CRASH);
+                    builder.setSmallIcon(R.drawable.ic_phone)
+                            .setColor(mContext.getResources().getColor(R.color.theme_color))
+                            .setContentTitle(
+                                    mContext.getText(
+                                            R.string.notification_crashedInCallService_title))
+                            .setStyle(new Notification.BigTextStyle()
+                                    .bigText(mContext.getString(
+                                            R.string.notification_crashedInCallService_body,
+                                            packageName)));
+                    mNotificationManager.notify(NOTIFICATION_TAG, IN_CALL_SERVICE_NOTIFICATION_ID,
+                            builder.build());
+                }
+                if (mCall != null) {
+                    mCall.getAnalytics().addInCallService(
+                            mInCallServiceInfo.getComponentName().flattenToShortString(),
+                            mInCallServiceInfo.getType(),
+                            mInCallServiceInfo.getDisconnectTime()
+                                    - mInCallServiceInfo.getBindingStartTime(), mIsNullBinding);
+                }
             } else {
                 Log.i(InCallController.this, "ICSBC#disconnect: already disconnected; %s",
                         mInCallServiceInfo);
@@ -302,7 +385,7 @@
             InCallController.this.onDisconnected(mInCallServiceInfo);
             disconnect();  // Unbind explicitly if we get disconnected.
             if (mListener != null) {
-                mListener.onDisconnect(InCallServiceBindingConnection.this);
+                mListener.onDisconnect(InCallServiceBindingConnection.this, mCall);
             }
         }
     }
@@ -319,7 +402,7 @@
 
         private Listener mSubListener = new Listener() {
             @Override
-            public void onDisconnect(InCallServiceConnection subConnection) {
+            public void onDisconnect(InCallServiceConnection subConnection, Call call) {
                 if (subConnection == mSubConnection) {
                     if (mIsConnected && mIsProxying) {
                         // At this point we know that we need to be connected to the InCallService
@@ -327,7 +410,7 @@
                         // just died so we need to stop proxying and connect to the system in-call
                         // service instead.
                         mIsProxying = false;
-                        connect(null);
+                        connect(call);
                     }
                 }
             }
@@ -799,6 +882,7 @@
     private final Handler mHandler = new Handler(Looper.getMainLooper());
     private CarSwappingInCallServiceConnection mInCallServiceConnection;
     private NonUIInCallServiceConnectionCollection mNonUIInCallServiceConnections;
+    private final ClockProxy mClockProxy;
 
     // Future that's in a completed state unless we're in the middle of binding to a service.
     // The future will complete with true if binding succeeds, false if it timed out.
@@ -809,7 +893,8 @@
     public InCallController(Context context, TelecomSystem.SyncRoot lock, CallsManager callsManager,
             SystemStateHelper systemStateHelper,
             DefaultDialerCache defaultDialerCache, Timeouts.Adapter timeoutsAdapter,
-            EmergencyCallHelper emergencyCallHelper, CarModeTracker carModeTracker) {
+            EmergencyCallHelper emergencyCallHelper, CarModeTracker carModeTracker,
+            ClockProxy clockProxy) {
         mContext = context;
         mLock = lock;
         mCallsManager = callsManager;
@@ -819,6 +904,7 @@
         mEmergencyCallHelper = emergencyCallHelper;
         mCarModeTracker = carModeTracker;
         mSystemStateHelper.addListener(mSystemStateListener);
+        mClockProxy = clockProxy;
     }
 
     @Override
diff --git a/src/com/android/server/telecom/TelecomSystem.java b/src/com/android/server/telecom/TelecomSystem.java
index a8e16ae..4bc61e0 100644
--- a/src/com/android/server/telecom/TelecomSystem.java
+++ b/src/com/android/server/telecom/TelecomSystem.java
@@ -270,7 +270,7 @@
                     EmergencyCallHelper emergencyCallHelper) {
                 return new InCallController(context, lock, callsManager, systemStateProvider,
                         defaultDialerCache, timeoutsAdapter, emergencyCallHelper,
-                        new CarModeTracker());
+                        new CarModeTracker(), clockProxy);
             }
         };
 
diff --git a/src/com/android/server/telecom/ui/NotificationChannelManager.java b/src/com/android/server/telecom/ui/NotificationChannelManager.java
index 360239b..58794a6 100644
--- a/src/com/android/server/telecom/ui/NotificationChannelManager.java
+++ b/src/com/android/server/telecom/ui/NotificationChannelManager.java
@@ -39,6 +39,7 @@
     public static final String CHANNEL_ID_CALL_BLOCKING = "TelecomCallBlocking";
     public static final String CHANNEL_ID_AUDIO_PROCESSING = "TelecomBackgroundAudioProcessing";
     public static final String CHANNEL_ID_DISCONNECTED_CALLS = "TelecomDisconnectedCalls";
+    public static final String CHANNEL_ID_IN_CALL_SERVICE_CRASH = "TelecomInCallServiceCrash";
 
     private BroadcastReceiver mLocaleChangeReceiver = new BroadcastReceiver() {
         @Override
@@ -61,6 +62,7 @@
         createOrUpdateChannel(context, CHANNEL_ID_CALL_BLOCKING);
         createOrUpdateChannel(context, CHANNEL_ID_AUDIO_PROCESSING);
         createOrUpdateChannel(context, CHANNEL_ID_DISCONNECTED_CALLS);
+        createOrUpdateChannel(context, CHANNEL_ID_IN_CALL_SERVICE_CRASH);
     }
 
     private void createOrUpdateChannel(Context context, String channelId) {
@@ -118,6 +120,13 @@
                 vibration = true;
                 sound = silentRingtone;
                 break;
+            case CHANNEL_ID_IN_CALL_SERVICE_CRASH:
+                name = context.getText(R.string.notification_channel_in_call_service_crash);
+                importance = NotificationManager.IMPORTANCE_DEFAULT;
+                canShowBadge = true;
+                lights = true;
+                vibration = true;
+                sound = null;
         }
 
         NotificationChannel channel = new NotificationChannel(channelId, name, importance);
diff --git a/testapps/src/com/android/server/telecom/testapps/TestInCallServiceImpl.java b/testapps/src/com/android/server/telecom/testapps/TestInCallServiceImpl.java
index 78b8bcc..fb15e1d 100644
--- a/testapps/src/com/android/server/telecom/testapps/TestInCallServiceImpl.java
+++ b/testapps/src/com/android/server/telecom/testapps/TestInCallServiceImpl.java
@@ -16,7 +16,6 @@
 
 package com.android.server.telecom.testapps;
 
-import android.content.Context;
 import android.content.Intent;
 import android.telecom.Call;
 import android.telecom.CallAudioState;
diff --git a/tests/src/com/android/server/telecom/tests/InCallControllerTests.java b/tests/src/com/android/server/telecom/tests/InCallControllerTests.java
index 23d22e9..38a1798 100644
--- a/tests/src/com/android/server/telecom/tests/InCallControllerTests.java
+++ b/tests/src/com/android/server/telecom/tests/InCallControllerTests.java
@@ -16,8 +16,14 @@
 
 package com.android.server.telecom.tests;
 
+import static com.android.server.telecom.InCallController.IN_CALL_SERVICE_NOTIFICATION_ID;
+import static com.android.server.telecom.InCallController.NOTIFICATION_TAG;
+
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.ArgumentMatchers.anyLong;
 import static org.mockito.ArgumentMatchers.matches;
 import static org.mockito.ArgumentMatchers.nullable;
 import static org.mockito.Matchers.any;
@@ -33,6 +39,8 @@
 import static org.mockito.Mockito.when;
 
 import android.Manifest;
+import android.app.Notification;
+import android.app.NotificationManager;
 import android.app.UiModeManager;
 import android.content.ComponentName;
 import android.content.ContentResolver;
@@ -44,12 +52,14 @@
 import android.content.pm.ResolveInfo;
 import android.content.pm.ServiceInfo;
 import android.content.res.Resources;
+import android.os.Build;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.IBinder;
 import android.os.Looper;
 import android.os.UserHandle;
 import android.telecom.InCallService;
+import android.telecom.Log;
 import android.telecom.ParcelableCall;
 import android.telecom.PhoneAccountHandle;
 import android.telecom.TelecomManager;
@@ -64,6 +74,7 @@
 import com.android.server.telecom.Call;
 import com.android.server.telecom.CallsManager;
 import com.android.server.telecom.CarModeTracker;
+import com.android.server.telecom.ClockProxy;
 import com.android.server.telecom.DefaultDialerCache;
 import com.android.server.telecom.EmergencyCallHelper;
 import com.android.server.telecom.InCallController;
@@ -85,23 +96,10 @@
 import org.mockito.invocation.InvocationOnMock;
 import org.mockito.stubbing.Answer;
 
-import java.util.ArrayList;
 import java.util.Collections;
 import java.util.LinkedList;
-import java.util.List;
 import java.util.concurrent.CompletableFuture;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-import static org.mockito.ArgumentMatchers.matches;
-import static org.mockito.Matchers.any;
-import static org.mockito.Matchers.eq;
-import static org.mockito.Mockito.doReturn;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.verify;
-
 @RunWith(JUnit4.class)
 public class InCallControllerTests extends TelecomTestCase {
     @Mock CallsManager mMockCallsManager;
@@ -115,6 +113,9 @@
     @Mock Timeouts.Adapter mTimeoutsAdapter;
     @Mock DefaultDialerCache mDefaultDialerCache;
     @Mock RoleManagerAdapter mMockRoleManagerAdapter;
+    @Mock ClockProxy mClockProxy;
+    @Mock Analytics.CallInfoImpl mCallInfo;
+    @Mock NotificationManager mNotificationManager;
 
     private static final int CURRENT_USER_ID = 900973;
     private static final String DEF_PKG = "defpkg";
@@ -159,7 +160,9 @@
         when(mMockCallsManager.getRoleManagerAdapter()).thenReturn(mMockRoleManagerAdapter);
         mInCallController = new InCallController(mMockContext, mLock, mMockCallsManager,
                 mMockSystemStateHelper, mDefaultDialerCache, mTimeoutsAdapter,
-                mEmergencyCallHelper, new CarModeTracker());
+                mEmergencyCallHelper, new CarModeTracker(), mClockProxy);
+        when(mMockContext.getSystemService(eq(Context.NOTIFICATION_SERVICE)))
+                .thenReturn(mNotificationManager);
         // Companion Apps don't have CONTROL_INCALL_EXPERIENCE permission.
         doAnswer(invocation -> {
             int uid = invocation.getArgument(0);
@@ -472,6 +475,58 @@
         assertEquals(SYS_CLASS, bindIntent.getComponent().getClassName());
     }
 
+    @Test
+    public void testBindToService_NullBinding_FallBackToSystem() throws Exception {
+        ApplicationInfo applicationInfo = new ApplicationInfo();
+        applicationInfo.targetSdkVersion = Build.VERSION_CODES.R;
+        when(mMockCallsManager.isInEmergencyCall()).thenReturn(false);
+        when(mMockContext.getPackageManager()).thenReturn(mMockPackageManager);
+        when(mMockCall.isIncoming()).thenReturn(false);
+        when(mMockCall.isExternalCall()).thenReturn(false);
+        when(mMockCallsManager.getCurrentUserHandle()).thenReturn(mUserHandle);
+        when(mMockCall.getAnalytics()).thenReturn(mCallInfo);
+        when(mMockContext.bindServiceAsUser(
+                any(Intent.class), any(ServiceConnection.class), anyInt(), any(UserHandle.class)))
+                .thenReturn(true);
+        when(mMockContext.getApplicationInfo()).thenReturn(applicationInfo);
+
+        setupMockPackageManager(true /* default */, true /* system */, false /* external calls */);
+        mInCallController.bindToServices(mMockCall);
+
+        ArgumentCaptor<Intent> bindIntentCaptor = ArgumentCaptor.forClass(Intent.class);
+        ArgumentCaptor<ServiceConnection> serviceConnectionCaptor =
+                ArgumentCaptor.forClass(ServiceConnection.class);
+        verify(mMockContext, times(1)).bindServiceAsUser(
+                bindIntentCaptor.capture(),
+                serviceConnectionCaptor.capture(),
+                anyInt(),
+                any(UserHandle.class));
+        ServiceConnection serviceConnection = serviceConnectionCaptor.getValue();
+        ComponentName defDialerComponentName = new ComponentName(DEF_PKG, DEF_CLASS);
+        ComponentName sysDialerComponentName = new ComponentName(SYS_PKG, SYS_CLASS);
+
+        IBinder mockBinder = mock(IBinder.class);
+        IInCallService mockInCallService = mock(IInCallService.class);
+        when(mockBinder.queryLocalInterface(anyString())).thenReturn(mockInCallService);
+
+        serviceConnection.onServiceConnected(defDialerComponentName, mockBinder);
+        // verify(mockInCallService).setInCallAdapter(any(IInCallAdapter.class));
+        serviceConnection.onNullBinding(defDialerComponentName);
+
+        verify(mNotificationManager).notify(eq(NOTIFICATION_TAG),
+                eq(IN_CALL_SERVICE_NOTIFICATION_ID), any(Notification.class));
+        verify(mCallInfo).addInCallService(eq(sysDialerComponentName.flattenToShortString()),
+                anyInt(), anyLong(), eq(true));
+
+        ArgumentCaptor<Intent> bindIntentCaptor2 = ArgumentCaptor.forClass(Intent.class);
+        verify(mMockContext, times(2)).bindServiceAsUser(
+                bindIntentCaptor2.capture(),
+                any(ServiceConnection.class),
+                eq(Context.BIND_AUTO_CREATE | Context.BIND_FOREGROUND_SERVICE
+                        | Context.BIND_ALLOW_BACKGROUND_ACTIVITY_STARTS),
+                eq(UserHandle.CURRENT));
+    }
+
     /**
      * Ensures that the {@link InCallController} will bind to an {@link InCallService} which
      * supports external calls.