diff --git a/telephony/java/android/telephony/CarrierConfigManager.java b/telephony/java/android/telephony/CarrierConfigManager.java
index a171d9d4c40d0..b0d4acdd206f3 100644
--- a/telephony/java/android/telephony/CarrierConfigManager.java
+++ b/telephony/java/android/telephony/CarrierConfigManager.java
@@ -245,6 +245,14 @@ public class CarrierConfigManager {
      */
     public static final String KEY_CARRIER_VT_AVAILABLE_BOOL = "carrier_vt_available_bool";
 
+    /**
+     * Flag specifying whether the carrier supports downgrading a video call (tx, rx or tx/rx)
+     * directly to an audio call.
+     * @hide
+     */
+    public static final String KEY_SUPPORT_DOWNGRADE_VT_TO_AUDIO_BOOL =
+            "support_downgrade_vt_to_audio_bool";
+
     /**
      * Flag specifying whether WFC over IMS should be available for carrier: independent of
      * carrier provisioning. If false: hard disabled. If true: then depends on carrier
@@ -927,6 +935,7 @@ public class CarrierConfigManager {
         sDefaults.putBoolean(KEY_CARRIER_SETTINGS_ENABLE_BOOL, false);
         sDefaults.putBoolean(KEY_CARRIER_VOLTE_AVAILABLE_BOOL, false);
         sDefaults.putBoolean(KEY_CARRIER_VT_AVAILABLE_BOOL, false);
+        sDefaults.putBoolean(KEY_SUPPORT_DOWNGRADE_VT_TO_AUDIO_BOOL, true);
         sDefaults.putBoolean(KEY_CARRIER_WFC_IMS_AVAILABLE_BOOL, false);
         sDefaults.putBoolean(KEY_CARRIER_WFC_SUPPORTS_WIFI_ONLY_BOOL, false);
         sDefaults.putBoolean(KEY_CARRIER_DEFAULT_WFC_IMS_ENABLED_BOOL, false);
diff --git a/telephony/java/android/telephony/TelephonyManager.java b/telephony/java/android/telephony/TelephonyManager.java
index 759ea1d2b8acb..013efe7fb21b4 100644
--- a/telephony/java/android/telephony/TelephonyManager.java
+++ b/telephony/java/android/telephony/TelephonyManager.java
@@ -715,6 +715,28 @@ public class TelephonyManager {
     public static final String EVENT_HANDOVER_TO_WIFI_FAILED =
             "android.telephony.event.EVENT_HANDOVER_TO_WIFI_FAILED";
 
+    /**
+     * {@link android.telecom.Connection} event used to indicate that a video call was downgraded to
+     * audio because the data limit was reached.
+     * <p>
+     * Sent via {@link android.telecom.Connection#sendConnectionEvent(String, Bundle)}.
+     * The {@link Bundle} parameter is expected to be null when this connection event is used.
+     * @hide
+     */
+    public static final String EVENT_DOWNGRADE_DATA_LIMIT_REACHED =
+            "android.telephony.event.EVENT_DOWNGRADE_DATA_LIMIT_REACHED";
+
+    /**
+     * {@link android.telecom.Connection} event used to indicate that a video call was downgraded to
+     * audio because the data was disabled.
+     * <p>
+     * Sent via {@link android.telecom.Connection#sendConnectionEvent(String, Bundle)}.
+     * The {@link Bundle} parameter is expected to be null when this connection event is used.
+     * @hide
+     */
+    public static final String EVENT_DOWNGRADE_DATA_DISABLED =
+            "android.telephony.event.EVENT_DOWNGRADE_DATA_DISABLED";
+
     /**
      * Response codes for sim activation. Activation completed successfully.
      * @hide