diff --git a/js/ndnProtocol/modules/NdnProtocolInfo.jsm b/js/ndnProtocol/modules/NdnProtocolInfo.jsm
new file mode 100644
index 0000000..553e1ba
--- /dev/null
+++ b/js/ndnProtocol/modules/NdnProtocolInfo.jsm
@@ -0,0 +1,44 @@
+/*
+ * @author: Jeff Thompson
+ * See COPYING for copyright and distribution information.
+ */
+
+var EXPORTED_SYMBOLS = ["addNdnHubChangedListener", "setConnectedNdnHub"];
+
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+const Cr = Components.results;
+
+Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
+
+var ndnHubHost = null;
+var ndnHubPort = null;
+var ndnHubChangedListenerList = [];
+
+/*
+ * When the NDN hub host or port is changed, the system calls listener(host, port).
+ */
+function addNdnHubChangedListener(listener) {
+    ndnHubChangedListenerList.push(listener);
+}
+
+/*
+ * If host and port are different than ndnHubHost or ndnHubPort, set them and call each
+ * listener in ndnHubChangedListenerList.
+ */
+function setConnectedNdnHub(host, port) {
+    if (host == ndnHubHost && port == ndnHubPort)
+        // No change.
+        return;
+    
+    ndnHubHost = host;
+    ndnHubPort = port;
+    for (var i = 0; i < ndnHubChangedListenerList.length; ++i) {
+        try {
+            ndnHubChangedListenerList[i](host, port);
+        }
+        catch (ex) {
+            // Ignore error from the listener.
+        }
+    }
+}
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