diff --git a/telecomm/java/android/telecom/Connection.java b/telecomm/java/android/telecom/Connection.java
index 300caa8..30fd528 100644
--- a/telecomm/java/android/telecom/Connection.java
+++ b/telecomm/java/android/telecom/Connection.java
@@ -775,6 +775,21 @@
             "android.telecom.extra.REMOTE_PHONE_ACCOUNT_HANDLE";
 
     /**
+     * The Telecom call ID of the conference an existing connection should be added to.  This is
+     * required when {@link com.android.services.telephony.TelephonyConnectionService} adds a
+     * {@link Conference} to Telecom using the
+     * {@link ConnectionService#addExistingConnection(PhoneAccountHandle, Connection, Conference)}
+     * API.  That API specifies a parent conference associated with the new existing connection
+     * being added, and there is no equivalent as part of the {@link RemoteConnectionService} API.
+     * This extra key is used to stack the ID of the conference to which the existing connection
+     * will be added so that Telecom can link it up correctly when the {@link RemoteConference}
+     * is added to Telecom by the connection manager.
+     * @hide
+     */
+    public static final String EXTRA_ADD_TO_CONFERENCE_ID =
+            "android.telecom.extra.ADD_TO_CONFERENCE_ID";
+
+    /**
      * Extra key set from a {@link ConnectionService} when using the remote connection APIs
      * (e.g. {@link RemoteConnectionService#createRemoteConnection(PhoneAccountHandle,
      * ConnectionRequest, boolean)}) to create a remote connection.  Provides the receiving
diff --git a/telecomm/java/android/telecom/RemoteConnectionService.java b/telecomm/java/android/telecom/RemoteConnectionService.java
index bf6a6ef7..efe35d2 100644
--- a/telecomm/java/android/telecom/RemoteConnectionService.java
+++ b/telecomm/java/android/telecom/RemoteConnectionService.java
@@ -239,13 +239,9 @@
                     conference.addConnection(c);
                 }
             }
-            if (conference.getConnections().size() == 0) {
-                // A conference was created, but none of its connections are ones that have been
-                // created by, and therefore being tracked by, this remote connection service. It
-                // is of no interest to us.
-                Log.d(this, "addConferenceCall - skipping");
-                return;
-            }
+            // We used to skip adding empty conferences; however in the world of IMS conference
+            // calls we need to add them to the remote connection service because they will always
+            // start with no participants.
 
             conference.setState(parcel.getState());
             conference.setConnectionCapabilities(parcel.getConnectionCapabilities());
@@ -379,6 +375,8 @@
         @Override
         public void addExistingConnection(String callId, ParcelableConnection connection,
                 Session.Info sessionInfo) {
+            Log.i(RemoteConnectionService.this, "addExistingConnection: callId=%s, conn=%s", callId,
+                    connection);
             String callingPackage = mOurConnectionServiceImpl.getApplicationContext().
                     getOpPackageName();
             int callingTargetSdkVersion = mOurConnectionServiceImpl.getApplicationInfo()
@@ -390,6 +388,20 @@
             Bundle newExtras = new Bundle();
             newExtras.putParcelable(Connection.EXTRA_REMOTE_PHONE_ACCOUNT_HANDLE,
                     connection.getPhoneAccount());
+            if (connection.getParentCallId() != null) {
+                RemoteConference parentConf = mConferenceById.get(connection.getParentCallId());
+                // If there is a parent being set, we need to stash the conference ID here.
+                // Telephony can add an existing connection while specifying a parent conference.
+                // There is no equivalent version of that operation as part of the remote connection
+                // API, so we will stash the pre-defined parent's ID in the extras.  When the
+                // connectionmanager copies over the extras from the remote connection to the
+                // actual one, it'll get passed to Telecom so that it can make the association.
+                if (parentConf != null) {
+                    newExtras.putString(Connection.EXTRA_ADD_TO_CONFERENCE_ID, parentConf.getId());
+                    Log.i(this, "addExistingConnection: stash parent of %s as %s",
+                            connection.getParentCallId(), parentConf.getId());
+                }
+            }
             remoteConnection.putExtras(newExtras);
             mConnectionById.put(callId, remoteConnection);
             remoteConnection.registerCallback(new RemoteConnection.Callback() {