helper+utils:  Small extension of global routing helper and restoring several IP-based metric collectors, including Ipv4RateL3Tracer
diff --git a/utils/tracers/ipv4-rate-l3-tracer.h b/utils/tracers/ipv4-rate-l3-tracer.h
new file mode 100644
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+++ b/utils/tracers/ipv4-rate-l3-tracer.h
@@ -0,0 +1,100 @@
+/* -*- 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>
+ */
+
+#ifndef IPV4_RATE_L3_TRACER_H
+#define IPV4_RATE_L3_TRACER_H
+
+#include "ipv4-l3-tracer.h"
+
+#include "ns3/nstime.h"
+#include "ns3/event-id.h"
+
+#include <boost/tuple/tuple.hpp>
+#include <boost/shared_ptr.hpp>
+#include <map>
+
+namespace ns3 {
+
+/**
+ * @ingroup ccnx
+ * @brief CCNx network-layer rate tracer
+ */
+class Ipv4RateL3Tracer : public Ipv4L3Tracer
+{
+public:
+  /**
+   * @brief Network layer tracer constructor
+   */
+  Ipv4RateL3Tracer (boost::shared_ptr<std::ostream> os, Ptr<Node> node);
+  virtual ~Ipv4RateL3Tracer ();
+
+  /**
+   * @brief Helper method to install tracers on all simulation nodes
+   *
+   * @param file File to which traces will be written
+   * @param averagingPeriod Defines averaging period for the rate calculation,
+   *        as well as how often data will be written into the trace file (default, every half second)
+   *
+   * @returns a tuple of reference to output stream and list of tracers. !!! Attention !!! This tuple needs to be preserved
+   *          for the lifetime of simulation, otherwise SEGFAULTs are inevitable
+   *
+   */
+  static boost::tuple< boost::shared_ptr<std::ostream>, std::list<Ptr<Ipv4RateL3Tracer> > >
+  InstallAll (const std::string &file, Time averagingPeriod = Seconds (0.5));
+
+  void
+  SetAveragingPeriod (const Time &period);
+
+  virtual void
+  PrintHeader (std::ostream &os) const;
+
+  virtual void
+  Print (std::ostream &os) const;
+
+  virtual void
+  Rx  (std::string context,
+       Ptr<const Packet>, Ptr<Ipv4>,  uint32_t);
+
+  virtual void
+  Tx   (std::string context,
+        Ptr<const Packet>, Ptr<Ipv4>,  uint32_t);
+
+  virtual void
+  Drop (std::string context,
+        const Ipv4Header &, Ptr<const Packet>, Ipv4L3Protocol::DropReason, Ptr<Ipv4>, uint32_t);
+
+private:
+  void
+  PeriodicPrinter ();
+
+  void
+  Reset ();
+
+private:
+  boost::shared_ptr<std::ostream> m_os;
+  Time m_period;
+  EventId m_printEvent;
+
+  mutable std::map<uint32_t, boost::tuple<Stats, Stats, Stats, Stats> > m_stats;
+};
+
+} // namespace ns3
+
+#endif // IPV4_RATE_L3_TRACER_H