helper+utils:  Small extension of global routing helper and restoring several IP-based metric collectors, including Ipv4RateL3Tracer
diff --git a/utils/tracers/ipv4-l3-tracer.cc b/utils/tracers/ipv4-l3-tracer.cc
new file mode 100644
index 0000000..8e36d26
--- /dev/null
+++ b/utils/tracers/ipv4-l3-tracer.cc
@@ -0,0 +1,58 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2011 UCLA
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Author:  Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+
+#include "ipv4-l3-tracer.h"
+#include "ns3/node.h"
+#include "ns3/config.h"
+#include "ns3/names.h"
+#include "ns3/callback.h"
+
+#include <boost/lexical_cast.hpp>
+
+using namespace std;
+
+namespace ns3 {
+
+Ipv4L3Tracer::Ipv4L3Tracer (Ptr<Node> node)
+: m_nodePtr (node)
+{
+  m_node = boost::lexical_cast<string> (m_nodePtr->GetId ());
+
+  Connect ();
+
+  string name = Names::FindName (node);
+  if (!name.empty ())
+    {
+      m_node = name;
+    }
+}
+
+void
+Ipv4L3Tracer::Connect ()
+{
+  Config::Connect ("/NodeList/"+m_node+"/$ns3::Ipv4L3Protocol/Tx",
+                   MakeCallback (&Ipv4L3Tracer::Tx, this));
+  Config::Connect ("/NodeList/"+m_node+"/$ns3::Ipv4L3Protocol/Rx",
+                   MakeCallback (&Ipv4L3Tracer::Rx, this));
+  Config::Connect ("/NodeList/"+m_node+"/$ns3::Ipv4L3Protocol/Drop",
+                   MakeCallback (&Ipv4L3Tracer::Drop, this));
+}
+
+} // namespace ns3