diff --git a/helper/tracers/ccnx-consumer-window-tracer.cc b/helper/tracers/ccnx-consumer-window-tracer.cc
new file mode 100644
index 0000000..e2bf877
--- /dev/null
+++ b/helper/tracers/ccnx-consumer-window-tracer.cc
@@ -0,0 +1,86 @@
+/* -*- 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 "ccnx-consumer-window-tracer.h"
+#include "ns3/node.h"
+#include "ns3/packet.h"
+#include "ns3/config.h"
+#include "ns3/callback.h"
+#include "ns3/names.h"
+#include "ns3/simulator.h"
+
+#include <boost/lexical_cast.hpp>
+
+using namespace std;
+using namespace boost;
+
+namespace ns3 {
+    
+CcnxConsumerWindowTracer::CcnxConsumerWindowTracer (std::ostream &os, Ptr<Node> node, const std::string &appId)
+  : m_appId (appId)
+  , m_nodePtr (node)
+  , m_os (os)
+{
+  m_node = boost::lexical_cast<string> (m_nodePtr->GetId ());
+
+  Connect ();
+
+  string name = Names::FindName (node);
+  if (!name.empty ())
+    {
+      m_node = name;
+    }
+}
+
+void
+CcnxConsumerWindowTracer::Connect ()
+{
+  Config::Connect ("/NodeList/"+m_node+"/ApplicationList/"+m_appId+"/$ns3::CcnxConsumerWindow/WindowTrace",
+                   MakeCallback (&CcnxConsumerWindowTracer::OnWindowChange, this));
+}
+
+
+void
+CcnxConsumerWindowTracer::PrintHeader (std::ostream &os) const
+{
+  os << "Time\t"
+     << "Node\t"
+     << "AppId\t"
+     << "Window";
+}
+  
+void
+CcnxConsumerWindowTracer::Print (std::ostream &os) const
+{
+  // do nothing
+}
+
+void
+CcnxConsumerWindowTracer::OnWindowChange (std::string context,
+                                          uint32_t oldValue, uint32_t newValue)
+{
+  m_os                                                             
+    << Simulator::Now ().ToDouble (Time::S) << "\t"                   
+    << m_node << "\t"                                                 
+    << m_appId << "\t"
+    << newValue << endl;
+}
+
+} // namespace ns3
diff --git a/helper/tracers/ccnx-consumer-window-tracer.h b/helper/tracers/ccnx-consumer-window-tracer.h
new file mode 100644
index 0000000..b178ee1
--- /dev/null
+++ b/helper/tracers/ccnx-consumer-window-tracer.h
@@ -0,0 +1,69 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2012 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 CCNX_CONSUMER_WINDOW_TRACER_H
+#define CCNX_CONSUMER_WINDOW_TRACER_H
+
+#include "ns3/ptr.h"
+#include "ns3/simple-ref-count.h"
+
+namespace ns3 {
+
+class Node;
+
+class CcnxConsumerWindowTracer : public SimpleRefCount<CcnxConsumerWindowTracer>
+{
+public:
+  CcnxConsumerWindowTracer (std::ostream &os, Ptr<Node> node, const std::string &appId = "*");
+  virtual ~CcnxConsumerWindowTracer ()  { };
+
+  void
+  Connect ();
+
+  virtual void
+  PrintHeader (std::ostream &os) const;
+  
+  virtual void
+  Print (std::ostream &os) const;
+
+  virtual void
+  OnWindowChange (std::string context,
+                  uint32_t oldValue, uint32_t newValue);
+
+protected:
+  std::string m_appId;
+  std::string m_node;
+  Ptr<Node> m_nodePtr;
+  std::ostream& m_os;
+};
+
+inline std::ostream&
+operator << (std::ostream &os, const CcnxConsumerWindowTracer &tracer)
+{
+  os << "# ";
+  tracer.PrintHeader (os);
+  os << "\n";
+  tracer.Print (os);
+  return os;
+}
+
+} // namespace ns3
+
+#endif // CCNX_CONSUMER_WINDOW_TRACER_H