diff --git a/plugins/OStatus/OStatusPlugin.php b/plugins/OStatus/OStatusPlugin.php
index 62ecaf6310..4b9b4d2c32 100644
--- a/plugins/OStatus/OStatusPlugin.php
+++ b/plugins/OStatus/OStatusPlugin.php
@@ -114,10 +114,15 @@ class OStatusPlugin extends Plugin
         if ($action instanceof ApiTimelineUserAction || $action instanceof ApiTimelineGroupAction) {
             $id = $action->arg('id');
             if (strval(intval($id)) === strval($id)) {
-                // Canonical form of id in URL?
-                // Updates will be handled for our internal PuSH hub.
+                // Canonical form of id in URL? These are used for OStatus syndication.
+
+                $hub = common_config('ostatus', 'hub');
+                if (empty($hub)) {
+                    // Updates will be handled through our internal PuSH hub.
+                    $hub = common_local_url('pushhub');
+                }
                 $action->element('link', array('rel' => 'hub',
-                                               'href' => common_local_url('pushhub')));
+                                               'href' => $hub));
 
                 // Also, we'll add in the salmon link
                 $action->element('link', array('rel' => 'salmon',
diff --git a/plugins/OStatus/classes/Feedinfo.php b/plugins/OStatus/classes/Feedinfo.php
index b4e55c3643..2344a4a0ee 100644
--- a/plugins/OStatus/classes/Feedinfo.php
+++ b/plugins/OStatus/classes/Feedinfo.php
@@ -160,7 +160,7 @@ class Feedinfo extends Memcached_DataObject
 
     function keyTypes()
     {
-        return array('id' => 'K'); // @fixme we'll need a profile_id key at least
+        return array('id' => 'K', 'feeduri' => 'U'); // @fixme we'll need a profile_id key at least
     }
 
     function sequenceKey()
@@ -323,7 +323,7 @@ class Feedinfo extends Memcached_DataObject
         if ($this->secret) {
             if (preg_match('/^sha1=([0-9a-fA-F]{40})$/', $hmac, $matches)) {
                 $their_hmac = strtolower($matches[1]);
-                $our_hmac = sha1($xml . $this->secret);
+                $our_hmac = hash_hmac('sha1', $xml, $this->secret);
                 if ($their_hmac !== $our_hmac) {
                     common_log(LOG_ERR, __METHOD__ . ": ignoring PuSH with bad SHA-1 HMAC: got $their_hmac, expected $our_hmac");
                     return;
diff --git a/plugins/OStatus/classes/HubSub.php b/plugins/OStatus/classes/HubSub.php
index 1769f6c941..7071ee5b4f 100644
--- a/plugins/OStatus/classes/HubSub.php
+++ b/plugins/OStatus/classes/HubSub.php
@@ -242,7 +242,7 @@ class HubSub extends Memcached_DataObject
     {
         $headers = array('Content-Type: application/atom+xml');
         if ($this->secret) {
-            $hmac = sha1($atom . $this->secret);
+            $hmac = hash_hmac('sha1', $atom, $this->secret);
             $headers[] = "X-Hub-Signature: sha1=$hmac";
         } else {
             $hmac = '(none)';
diff --git a/plugins/OStatus/lib/hubdistribqueuehandler.php b/plugins/OStatus/lib/hubdistribqueuehandler.php
index a35b8874c5..245a57f720 100644
--- a/plugins/OStatus/lib/hubdistribqueuehandler.php
+++ b/plugins/OStatus/lib/hubdistribqueuehandler.php
@@ -49,15 +49,7 @@ class HubDistribQueueHandler extends QueueHandler
         $feed = common_local_url('ApiTimelineUser',
                                  array('id' => $notice->profile_id,
                                        'format' => 'atom'));
-        $sub = new HubSub();
-        $sub->topic = $feed;
-        if ($sub->find()) {
-            $atom = $this->userFeedForNotice($notice);
-            $this->pushFeeds($atom, $sub);
-        } else {
-            common_log(LOG_INFO, "No PuSH subscribers for $feed");
-        }
-        return true;
+        $this->pushFeed($feed, array($this, 'userFeedForNotice'), $notice);
     }
 
     function pushGroup($notice, $group_id)
@@ -65,19 +57,69 @@ class HubDistribQueueHandler extends QueueHandler
         $feed = common_local_url('ApiTimelineGroup',
                                  array('id' => $group_id,
                                        'format' => 'atom'));
+        $this->pushFeed($feed, array($this, 'groupFeedForNotice'), $group_id, $notice);
+    }
+
+    /**
+     * @param string $feed URI to the feed
+     * @param callable $callback function to generate Atom feed update if needed
+     *        any additional params are passed to the callback.
+     */
+    function pushFeed($feed, $callback)
+    {
+        $hub = common_config('ostatus', 'hub');
+        if ($hub) {
+            $this->pushFeedExternal($feed, $hub);
+        }
+
         $sub = new HubSub();
         $sub->topic = $feed;
         if ($sub->find()) {
-            common_log(LOG_INFO, "Building PuSH feed for $feed");
-            $atom = $this->groupFeedForNotice($group_id, $notice);
-            $this->pushFeeds($atom, $sub);
+            $args = array_slice(func_get_args(), 2);
+            $atom = call_user_func_array($callback, $args);
+            $this->pushFeedInternal($atom, $sub);
         } else {
             common_log(LOG_INFO, "No PuSH subscribers for $feed");
         }
+        return true;
     }
 
-    
-    function pushFeeds($atom, $sub)
+    /**
+     * Ping external hub about this update.
+     * The hub will pull the feed and check for new items later.
+     * Not guaranteed safe in an environment with database replication.
+     *
+     * @param string $feed feed topic URI
+     * @param string $hub PuSH hub URI
+     * @fixme can consolidate pings for user & group posts
+     */
+    function pushFeedExternal($feed, $hub)
+    {
+        $client = new HTTPClient();
+        try {
+            $data = array('hub.mode' => 'publish',
+                          'hub.url' => $feed);
+            $response = $client->post($hub, array(), $data);
+            if ($response->getStatus() == 204) {
+                common_log(LOG_INFO, "PuSH ping to hub $hub for $feed ok");
+                return true;
+            } else {
+                common_log(LOG_ERR, "PuSH ping to hub $hub for $feed failed with HTTP " .
+                                    $response->getStatus() . ': ' .
+                                    $response->getBody());
+            }
+        } catch (Exception $e) {
+            common_log(LOG_ERR, "PuSH ping to hub $hub for $feed failed: " . $e->getMessage());
+            return false;
+        }
+    }
+
+    /**
+     * Queue up direct feed update pushes to subscribers on our internal hub.
+     * @param string $atom update feed, containing only new/changed items
+     * @param HubSub $sub open query of subscribers
+     */
+    function pushFeedInternal($atom, $sub)
     {
         common_log(LOG_INFO, "Preparing $sub->N PuSH distribution(s) for $sub->topic");
         $qm = QueueManager::get();