diff --git a/core/res/res/values/config.xml b/core/res/res/values/config.xml
index 05d9a28333b76..f909695610119 100644
--- a/core/res/res/values/config.xml
+++ b/core/res/res/values/config.xml
@@ -2212,6 +2212,21 @@
     <!-- Sprint need a 70 ms delay for 3way call -->
     <integer name="config_cdma_3waycall_flash_delay">0</integer>
 
+    <!-- If there is no preload VM number in the sim card, carriers such as
+         Verizon require to load a default vm number from the configurantion.
+         Define config_default_vm_number for this purpose. And there are two
+         optional formats for this configuration as below:
+         (1)<item>voicemail number</item>
+         (2)<item>voicemail number;gid</item>
+         The logic to pick up the correct voicemail number:
+         (1) If the config_default_vm_number array has no gid special item, the last one will be
+         picked
+         (2) If the config_default_vm_number array has gid special item and  it matches the current
+         sim's gid, it will be picked.
+         (3) If the config_default_vm_number array has gid special item but it doesn't match the
+         current sim's gid, the last one without gid will be picked -->
+    <string-array translatable="false" name="config_default_vm_number" />
+
     <!--SIM does not save, but the voice mail number to be changed. -->
     <bool name="editable_voicemailnumber">false</bool>
 
diff --git a/core/res/res/values/symbols.xml b/core/res/res/values/symbols.xml
index 5018e2fb63c05..9a394373059a8 100644
--- a/core/res/res/values/symbols.xml
+++ b/core/res/res/values/symbols.xml
@@ -2237,6 +2237,7 @@
   <java-symbol type="layout" name="resolver_different_item_header" />
   <java-symbol type="array" name="config_default_vm_number" />
   <java-symbol type="integer" name="config_cdma_3waycall_flash_delay"/>
+  <java-symbol type="array" name="config_default_vm_number" />
   <java-symbol type="attr" name="windowBackgroundFallback" />
   <java-symbol type="id" name="textSpacerNoButtons" />
   <java-symbol type="array" name="dial_string_replace" />
diff --git a/telephony/java/android/telephony/CarrierConfigManager.java b/telephony/java/android/telephony/CarrierConfigManager.java
index ff7ca6201b55e..3b6b696019d7e 100644
--- a/telephony/java/android/telephony/CarrierConfigManager.java
+++ b/telephony/java/android/telephony/CarrierConfigManager.java
@@ -700,6 +700,15 @@ public class CarrierConfigManager {
     public static final String KEY_DURATION_BLOCKING_DISABLED_AFTER_EMERGENCY_INT =
             "duration_blocking_disabled_after_emergency_int";
 
+    /**
+     * For carriers which require an empty flash to be sent before sending the normal 3-way calling
+     * flash, the duration in milliseconds of the empty flash to send.  When {@code 0}, no empty
+     * flash is sent.
+     * @hide
+     */
+    public static final String KEY_CDMA_3WAYCALL_FLASH_DELAY_INT = "cdma_3waycall_flash_delay_int";
+
+
     /**
      * @hide
      * The default value for preferred CDMA roaming mode (aka CDMA system select.)
@@ -807,6 +816,7 @@ public class CarrierConfigManager {
         sDefaults.putInt(KEY_GSM_DTMF_TONE_DELAY_INT, 0);
         sDefaults.putInt(KEY_IMS_DTMF_TONE_DELAY_INT, 0);
         sDefaults.putInt(KEY_CDMA_DTMF_TONE_DELAY_INT, 100);
+        sDefaults.putInt(KEY_CDMA_3WAYCALL_FLASH_DELAY_INT , 0);
         sDefaults.putBoolean(KEY_SUPPORT_CONFERENCE_CALL_BOOL, true);
         sDefaults.putBoolean(KEY_EDITABLE_ENHANCED_4G_LTE_BOOL, true);
         sDefaults.putBoolean(KEY_HIDE_IMS_APN_BOOL, false);