diff --git a/src/com/android/phone/CallFeaturesSetting.java b/src/com/android/phone/CallFeaturesSetting.java
index 111e263..a6d54ef 100644
--- a/src/com/android/phone/CallFeaturesSetting.java
+++ b/src/com/android/phone/CallFeaturesSetting.java
@@ -284,7 +284,9 @@
 
         if (ImsManager.isVtEnabledByPlatform(mPhone.getContext()) &&
                 ImsManager.isVtProvisionedOnDevice(mPhone.getContext()) &&
-                mPhone.mDcTracker.isDataEnabled(true)) {
+                (carrierConfig.getBoolean(
+                        CarrierConfigManager.KEY_IGNORE_DATA_ENABLED_CHANGED_FOR_VIDEO_CALLS)
+                        || mPhone.mDcTracker.isDataEnabled(true))) {
             boolean currentValue =
                     ImsManager.isEnhanced4gLteModeSettingEnabledByUser(mPhone.getContext())
                     ? PhoneGlobals.getInstance().phoneMgr.isVideoCallingEnabled(
@@ -328,7 +330,8 @@
         } else {
             int resId = com.android.internal.R.string.wifi_calling_off_summary;
             if (ImsManager.isWfcEnabledByUser(mPhone.getContext())) {
-                int wfcMode = ImsManager.getWfcMode(mPhone.getContext());
+                boolean isRoaming = telephonyManager.isNetworkRoaming();
+                int wfcMode = ImsManager.getWfcMode(mPhone.getContext(), isRoaming);
                 switch (wfcMode) {
                     case ImsConfig.WfcModeFeatureValueConstants.WIFI_ONLY:
                         resId = com.android.internal.R.string.wfc_mode_wifi_only_summary;
diff --git a/src/com/android/phone/NetworkSetting.java b/src/com/android/phone/NetworkSetting.java
index a09c5c5..29608da 100644
--- a/src/com/android/phone/NetworkSetting.java
+++ b/src/com/android/phone/NetworkSetting.java
@@ -161,8 +161,6 @@
         public void onServiceConnected(ComponentName className, IBinder service) {
             if (DBG) log("connection created, binding local service.");
             mNetworkQueryService = ((NetworkQueryService.LocalBinder) service).getService();
-            // as soon as it is bound, run a query.
-            loadNetworksList();
         }
 
         /** Handle the task of cleaning up the local binding */
diff --git a/src/com/android/phone/settings/AccessibilitySettingsFragment.java b/src/com/android/phone/settings/AccessibilitySettingsFragment.java
index ea19f75..0c186a9 100644
--- a/src/com/android/phone/settings/AccessibilitySettingsFragment.java
+++ b/src/com/android/phone/settings/AccessibilitySettingsFragment.java
@@ -24,7 +24,6 @@
 import android.preference.PreferenceFragment;
 import android.preference.PreferenceScreen;
 import android.provider.Settings;
-import android.telecom.TelecomManager;
 import android.telephony.CarrierConfigManager;
 import android.telephony.PhoneStateListener;
 import android.telephony.TelephonyManager;
@@ -35,9 +34,6 @@
 import com.android.internal.telephony.PhoneFactory;
 import com.android.phone.PhoneGlobals;
 import com.android.phone.R;
-import com.android.phone.settings.TtyModeListPreference;
-
-import java.util.List;
 
 public class AccessibilitySettingsFragment extends PreferenceFragment {
     private static final String LOG_TAG = AccessibilitySettingsFragment.class.getSimpleName();
@@ -60,7 +56,7 @@
             if (pref != null) {
                 final boolean isVolteTtySupported = ImsManager.isVolteEnabledByPlatform(mContext)
                         && getVolteTtySupported();
-                pref.setEnabled((isVolteTtySupported && !isVideoCallInProgress()) ||
+                pref.setEnabled((isVolteTtySupported && !isVideoCallOrConferenceInProgress()) ||
                         (state == TelephonyManager.CALL_STATE_IDLE));
             }
         }
@@ -144,15 +140,15 @@
                 CarrierConfigManager.KEY_CARRIER_VOLTE_TTY_SUPPORTED_BOOL);
     }
 
-    private boolean isVideoCallInProgress() {
+    private boolean isVideoCallOrConferenceInProgress() {
         final Phone[] phones = PhoneFactory.getPhones();
         if (phones == null) {
-            if (DBG) Log.d(LOG_TAG, "isVideoCallInProgress: No phones found. Return false");
+            if (DBG) Log.d(LOG_TAG, "isVideoCallOrConferenceInProgress: No phones found.");
             return false;
         }
 
         for (Phone phone : phones) {
-            if (phone.isVideoCallPresent()) {
+            if (phone.isImsVideoCallOrConferencePresent()) {
                 return true;
             }
         }
diff --git a/src/com/android/phone/vvm/omtp/ActivationTask.java b/src/com/android/phone/vvm/omtp/ActivationTask.java
index 72f1f54..6fd42fd 100644
--- a/src/com/android/phone/vvm/omtp/ActivationTask.java
+++ b/src/com/android/phone/vvm/omtp/ActivationTask.java
@@ -27,7 +27,6 @@
 import android.telecom.PhoneAccountHandle;
 import android.telephony.ServiceState;
 import android.telephony.TelephonyManager;
-
 import com.android.phone.Assert;
 import com.android.phone.PhoneGlobals;
 import com.android.phone.VoicemailStatus;
@@ -40,7 +39,6 @@
 import com.android.phone.vvm.omtp.sync.OmtpVvmSyncService;
 import com.android.phone.vvm.omtp.sync.SyncTask;
 import com.android.phone.vvm.omtp.utils.PhoneAccountHandleConverter;
-
 import java.io.IOException;
 import java.util.HashSet;
 import java.util.Set;
@@ -135,7 +133,7 @@
         OmtpVvmCarrierConfigHelper helper = new OmtpVvmCarrierConfigHelper(getContext(), subId);
         if (!helper.isValid()) {
             VvmLog.i(TAG, "VVM not supported on subId " + subId);
-            VoicemailStatus.disable(getContext(), phoneAccountHandle);
+            OmtpVvmSourceManager.getInstance(getContext()).removeSource(phoneAccountHandle);
             return;
         }
 
diff --git a/src/com/android/phone/vvm/omtp/SimChangeReceiver.java b/src/com/android/phone/vvm/omtp/SimChangeReceiver.java
index 25c27db..a506a12 100644
--- a/src/com/android/phone/vvm/omtp/SimChangeReceiver.java
+++ b/src/com/android/phone/vvm/omtp/SimChangeReceiver.java
@@ -24,12 +24,13 @@
 import android.os.UserManager;
 import android.telecom.PhoneAccountHandle;
 import android.telephony.CarrierConfigManager;
+import android.telephony.ServiceState;
 import android.telephony.SubscriptionManager;
 import android.telephony.TelephonyManager;
+import android.text.TextUtils;
 import com.android.internal.telephony.IccCardConstants;
 import com.android.internal.telephony.PhoneConstants;
 import com.android.internal.telephony.TelephonyIntents;
-import com.android.phone.VoicemailStatus;
 import com.android.phone.settings.VisualVoicemailSettingsUtil;
 import com.android.phone.vvm.omtp.sync.OmtpVvmSourceManager;
 import com.android.phone.vvm.omtp.utils.PhoneAccountHandleConverter;
@@ -70,6 +71,25 @@
                     VvmLog.i(TAG, "Received SIM change for invalid subscription id.");
                     return;
                 }
+
+                TelephonyManager telephonyManager = context
+                        .getSystemService(TelephonyManager.class);
+                if(TextUtils.isEmpty(telephonyManager.getSimOperator())){
+                    VvmLog.e(TAG,
+                            "Empty MCCMNC, possible modem crash."
+                                    + " Ignoring carrier config changed event");
+                    return;
+                }
+
+                PhoneAccountHandle phoneAccountHandle = PhoneAccountHandleConverter
+                        .fromSubId(subId);
+                if("null".equals(phoneAccountHandle.getId())){
+                    VvmLog.e(TAG,
+                            "null phone account handle ID, possible modem crash."
+                                    + " Ignoring carrier config changed event");
+                    return;
+                }
+
                 VvmLog.d(TAG, "Carrier config changed");
                 if (UserManager.get(context).isUserUnlocked() && !isCryptKeeperMode()) {
                     processSubId(context, subId);
@@ -99,6 +119,12 @@
                 // can be recorded.
                 OmtpVvmSourceManager.getInstance(context).addPhoneStateListener(
                         phoneAccount);
+                if (context.getSystemService(TelephonyManager.class)
+                        .getServiceStateForSubscriber(subId).getState()
+                        != ServiceState.STATE_IN_SERVICE) {
+                    VvmLog.i(TAG, "Cellular signal not available, not activating");
+                    return;
+                }
                 carrierConfigHelper.startActivation();
             } else {
                 if (carrierConfigHelper.isLegacyModeEnabled()) {
@@ -115,7 +141,7 @@
             String mccMnc = context.getSystemService(TelephonyManager.class).getSimOperator(subId);
             VvmLog.d(TAG,
                     "visual voicemail not supported for carrier " + mccMnc + " on subId " + subId);
-            VoicemailStatus.disable(context, phoneAccount);
+            OmtpVvmSourceManager.getInstance(context).removeSource(phoneAccount);
         }
     }
 
diff --git a/src/com/android/phone/vvm/omtp/protocol/OmtpProtocol.java b/src/com/android/phone/vvm/omtp/protocol/OmtpProtocol.java
index d002652..7ec3dba 100644
--- a/src/com/android/phone/vvm/omtp/protocol/OmtpProtocol.java
+++ b/src/com/android/phone/vvm/omtp/protocol/OmtpProtocol.java
@@ -28,6 +28,7 @@
     public OmtpMessageSender createMessageSender(SmsManager smsManager, short applicationPort,
             String destinationNumber) {
         return new OmtpStandardMessageSender(smsManager, applicationPort, destinationNumber,
-                null, OmtpConstants.PROTOCOL_VERSION1_1, null);
+                OmtpConstants.CLIENT_TYPE_GOOGLE_10, OmtpConstants.PROTOCOL_VERSION1_1,
+                null /*clientPrefix*/);
     }
 }
diff --git a/src/com/android/phone/vvm/omtp/protocol/Vvm3EventHandler.java b/src/com/android/phone/vvm/omtp/protocol/Vvm3EventHandler.java
index d95879f..524c96d 100644
--- a/src/com/android/phone/vvm/omtp/protocol/Vvm3EventHandler.java
+++ b/src/com/android/phone/vvm/omtp/protocol/Vvm3EventHandler.java
@@ -18,13 +18,17 @@
 
 import android.annotation.IntDef;
 import android.content.Context;
+import android.provider.VoicemailContract.Status;
+import android.telecom.PhoneAccountHandle;
 import android.util.Log;
+
 import com.android.phone.VoicemailStatus;
 import com.android.phone.settings.VoicemailChangePinActivity;
 import com.android.phone.vvm.omtp.DefaultOmtpEventHandler;
 import com.android.phone.vvm.omtp.OmtpEvents;
 import com.android.phone.vvm.omtp.OmtpEvents.Type;
 import com.android.phone.vvm.omtp.OmtpVvmCarrierConfigHelper;
+
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 
@@ -113,19 +117,22 @@
         OmtpEvents event) {
         switch (event) {
             case CONFIG_REQUEST_STATUS_SUCCESS:
-                if (status.getPhoneAccountHandle() == null) {
-                    // This should never happen.
-                    Log.e(TAG, "status editor has null phone account handle");
-                    return true;
-                }
-
-                if (!VoicemailChangePinActivity
-                    .isDefaultOldPinSet(context, status.getPhoneAccountHandle())) {
+                if (!isPinRandomized(context, status.getPhoneAccountHandle())) {
                     return false;
                 } else {
                     postError(status, PIN_NOT_SET);
                 }
                 break;
+            case CONFIG_ACTIVATING_SUBSEQUENT:
+                if (isPinRandomized(context, status.getPhoneAccountHandle())) {
+                    status.setConfigurationState(PIN_NOT_SET);
+                } else {
+                    status.setConfigurationState(Status.CONFIGURATION_STATE_OK);
+                }
+                status
+                        .setNotificationChannelState(Status.NOTIFICATION_CHANNEL_STATE_OK)
+                        .setDataChannelState(Status.DATA_CHANNEL_STATE_OK).apply();
+                break;
             case CONFIG_DEFAULT_PIN_REPLACED:
                 postError(status, PIN_NOT_SET);
                 break;
@@ -269,4 +276,13 @@
         }
         editor.apply();
     }
+
+    private static boolean isPinRandomized(Context context, PhoneAccountHandle phoneAccountHandle) {
+        if (phoneAccountHandle == null) {
+            // This should never happen.
+            Log.e(TAG, "status editor has null phone account handle");
+            return false;
+        }
+        return VoicemailChangePinActivity.isDefaultOldPinSet(context, phoneAccountHandle);
+    }
 }
diff --git a/src/com/android/phone/vvm/omtp/sms/OmtpCvvmMessageSender.java b/src/com/android/phone/vvm/omtp/sms/OmtpCvvmMessageSender.java
index 7f45254..98d8594 100644
--- a/src/com/android/phone/vvm/omtp/sms/OmtpCvvmMessageSender.java
+++ b/src/com/android/phone/vvm/omtp/sms/OmtpCvvmMessageSender.java
@@ -48,7 +48,7 @@
     private void sendCvvmMessage(String request, PendingIntent sentIntent) {
         StringBuilder sb = new StringBuilder().append(request);
         sb.append(OmtpConstants.SMS_PREFIX_SEPARATOR);
-        appendField(sb, "dt", "15");
+        appendField(sb, "dt" /* device type */, "6" /* no VTT (transcription) support*/);
         sendSms(sb.toString(), sentIntent);
     }
 }
diff --git a/src/com/android/services/telephony/CdmaConferenceController.java b/src/com/android/services/telephony/CdmaConferenceController.java
index 0a7c18b..846df61 100644
--- a/src/com/android/services/telephony/CdmaConferenceController.java
+++ b/src/com/android/services/telephony/CdmaConferenceController.java
@@ -122,8 +122,18 @@
                 }
             }, ADD_OUTGOING_CONNECTION_DELAY_MILLIS);
         } else {
-            // This is the first connection, or it is incoming, so let it flow through.
-            addInternal(connection);
+            // Post the call to addInternal to the handler with no delay.
+            // Why you ask?  In TelephonyConnectionService#
+            // onCreateIncomingConnection(PhoneAccountHandle, ConnectionRequest) or
+            // TelephonyConnectionService#onCreateOutgoingConnection(PhoneAccountHandle,
+            // ConnectionRequest) we can create a new connection it will trigger a call to
+            // TelephonyConnectionService#addConnectionToConferenceController, which will cause us
+            // to get here.  HOWEVER, at this point ConnectionService#addConnection has not yet run,
+            // so if we end up calling ConnectionService#addConference, the connection service will
+            // not yet know about the new connection, so it won't get added to the conference.
+            // Posting to the handler ensures addConnection has a chance to happen before we add the
+            // conference.
+            mHandler.post(() -> addInternal(connection));
         }
     }
 
diff --git a/src/com/android/services/telephony/DisconnectCauseUtil.java b/src/com/android/services/telephony/DisconnectCauseUtil.java
index c356899..fcc37f4 100644
--- a/src/com/android/services/telephony/DisconnectCauseUtil.java
+++ b/src/com/android/services/telephony/DisconnectCauseUtil.java
@@ -27,11 +27,10 @@
 public class DisconnectCauseUtil {
 
    /**
-    * Converts from a disconnect code in {@link android.telephony.DisconnectCause} into a more generic
-    * {@link android.telecom.DisconnectCause}.object, possibly populated with a localized message
-    * and tone.
+    * Converts from a disconnect code in {@link android.telephony.DisconnectCause} into a more
+    * generic {@link android.telecom.DisconnectCause} object, possibly populated with a localized
+    * message and tone.
     *
-    * @param context The context.
     * @param telephonyDisconnectCause The code for the reason for the disconnect.
     */
     public static DisconnectCause toTelecomDisconnectCause(int telephonyDisconnectCause) {
@@ -39,11 +38,10 @@
     }
 
    /**
-    * Converts from a disconnect code in {@link android.telephony.DisconnectCause} into a more generic
-    * {@link android.telecom.DisconnectCause}.object, possibly populated with a localized message
-    * and tone.
+    * Converts from a disconnect code in {@link android.telephony.DisconnectCause} into a more
+    * generic {@link android.telecom.DisconnectCause}.object, possibly populated with a localized
+    * message and tone.
     *
-    * @param context The context.
     * @param telephonyDisconnectCause The code for the reason for the disconnect.
     * @param reason Description of the reason for the disconnect, not intended for the user to see..
     */
@@ -54,7 +52,7 @@
                 toTelecomDisconnectCauseCode(telephonyDisconnectCause),
                 toTelecomDisconnectCauseLabel(context, telephonyDisconnectCause),
                 toTelecomDisconnectCauseDescription(context, telephonyDisconnectCause),
-                toTelecomDisconnectReason(telephonyDisconnectCause, reason),
+                toTelecomDisconnectReason(context,telephonyDisconnectCause, reason),
                 toTelecomDisconnectCauseTone(telephonyDisconnectCause));
     }
 
@@ -129,6 +127,7 @@
             case android.telephony.DisconnectCause.DATA_DISABLED:
             case android.telephony.DisconnectCause.DATA_LIMIT_REACHED:
             case android.telephony.DisconnectCause.DIALED_ON_WRONG_SLOT:
+            case android.telephony.DisconnectCause.DIALED_CALL_FORWARDING_WHILE_ROAMING:
             case android.telephony.DisconnectCause.IMEI_NOT_ACCEPTED:
             case android.telephony.DisconnectCause.WIFI_LOST:
                 return DisconnectCause.ERROR;
@@ -382,6 +381,9 @@
             case android.telephony.DisconnectCause.DATA_LIMIT_REACHED:
                 resourceId = R.string.callFailed_data_limit_reached_description;
                 break;
+            case android.telephony.DisconnectCause.DIALED_CALL_FORWARDING_WHILE_ROAMING:
+                resourceId = com.android.internal.R.string.mmiErrorWhileRoaming;
+                break;
 
             case android.telephony.DisconnectCause.IMEI_NOT_ACCEPTED:
                 resourceId = R.string.callFailed_imei_not_accepted;
@@ -397,7 +399,36 @@
         return resourceId == null ? "" : context.getResources().getString(resourceId);
     }
 
-    private static String toTelecomDisconnectReason(int telephonyDisconnectCause, String reason) {
+    /**
+     * Maps the telephony {@link android.telephony.DisconnectCause} into a reason string which is
+     * returned in the Telecom {@link DisconnectCause#getReason()}.
+     *
+     * @param context The current context.
+     * @param telephonyDisconnectCause The {@link android.telephony.DisconnectCause} code.
+     * @param reason A reason provided by the caller; only used if a more specific reason cannot
+     *               be determined here.
+     * @return The disconnect reason.
+     */
+    private static String toTelecomDisconnectReason(Context context, int telephonyDisconnectCause,
+            String reason) {
+
+        if (context == null) {
+            return "";
+        }
+
+        switch (telephonyDisconnectCause) {
+            case android.telephony.DisconnectCause.POWER_OFF:
+                // Airplane mode (radio off)
+                // intentional fall-through
+            case android.telephony.DisconnectCause.OUT_OF_SERVICE:
+                // No network connection.
+                if (ImsUtil.shouldPromoteWfc(context)) {
+                    return android.telecom.DisconnectCause.REASON_WIFI_ON_BUT_WFC_OFF;
+                }
+                break;
+        }
+
+        // If no specific code-mapping found, then fall back to using the reason.
         String causeAsString = android.telephony.DisconnectCause.toString(telephonyDisconnectCause);
         if (reason == null) {
             return causeAsString;
diff --git a/src/com/android/services/telephony/TelephonyConnectionService.java b/src/com/android/services/telephony/TelephonyConnectionService.java
index e165fa2..722183a 100644
--- a/src/com/android/services/telephony/TelephonyConnectionService.java
+++ b/src/com/android/services/telephony/TelephonyConnectionService.java
@@ -480,6 +480,15 @@
             return failedConnection;
         }
 
+        // Check roaming status to see if we should block custom call forwarding codes
+        if (blockCallForwardingNumberWhileRoaming(phone, number)) {
+            return Connection.createFailedConnection(
+                    DisconnectCauseUtil.toTelecomDisconnectCause(
+                            android.telephony.DisconnectCause.DIALED_CALL_FORWARDING_WHILE_ROAMING,
+                            "Call forwarding while roaming"));
+        }
+
+
         final TelephonyConnection connection =
                 createConnectionFor(phone, null, true /* isOutgoing */, request.getAccountHandle(),
                         request.getTelecomCallId(), request.getAddress(), request.getVideoState());
@@ -691,6 +700,28 @@
         }
     }
 
+    private boolean blockCallForwardingNumberWhileRoaming(Phone phone, String number) {
+        if (phone == null || TextUtils.isEmpty(number) || !phone.getServiceState().getRoaming()) {
+            return false;
+        }
+        String[] blockPrefixes = null;
+        CarrierConfigManager cfgManager = (CarrierConfigManager)
+                phone.getContext().getSystemService(Context.CARRIER_CONFIG_SERVICE);
+        if (cfgManager != null) {
+            blockPrefixes = cfgManager.getConfigForSubId(phone.getSubId()).getStringArray(
+                    CarrierConfigManager.KEY_CALL_FORWARDING_BLOCKS_WHILE_ROAMING_STRING_ARRAY);
+        }
+
+        if (blockPrefixes != null) {
+            for (String prefix : blockPrefixes) {
+                if (number.startsWith(prefix)) {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
     private boolean isRadioOn() {
         boolean result = false;
         for (Phone phone : PhoneFactory.getPhones()) {