diff --git a/apps/ccnx-consumer-window.cc b/apps/ccnx-consumer-window.cc
index 57ca8f5..d244061 100644
--- a/apps/ccnx-consumer-window.cc
+++ b/apps/ccnx-consumer-window.cc
@@ -46,6 +46,10 @@
                    StringValue ("1000"),
                    MakeUintegerAccessor (&CcnxConsumerWindow::GetWindow, &CcnxConsumerWindow::SetWindow),
                    MakeUintegerChecker<uint32_t> ())
+
+    .AddTraceSource ("WindowTrace",
+                     "Window that controls how many outstanding interests are allowed",
+                     MakeTraceSourceAccessor (&CcnxConsumerWindow::m_window))
     ;
 
   return tid;
@@ -71,7 +75,7 @@
 void
 CcnxConsumerWindow::ScheduleNextPacket ()
 {
-  if (m_window == 0 || m_inFlight >= m_window)
+  if (m_window == static_cast<uint32_t> (0) || m_inFlight >= m_window)
     {
       if (!m_sendEvent.IsRunning ())
         m_sendEvent = Simulator::Schedule (Seconds (m_rtt->RetransmitTimeout ().ToDouble (Time::S) * 0.1), &CcnxConsumer::SendPacket, this);
@@ -106,7 +110,7 @@
   CcnxConsumer::OnNack (interest);
   if (m_inFlight > 0) m_inFlight--;
 
-  if (m_window > 0)
+  if (m_window > static_cast<uint32_t> (0))
     {
       // m_window = 0.5 * m_window;//m_window - 1;
       m_window = m_window - 1;
diff --git a/apps/ccnx-consumer-window.h b/apps/ccnx-consumer-window.h
index 47099f6..716608d 100644
--- a/apps/ccnx-consumer-window.h
+++ b/apps/ccnx-consumer-window.h
@@ -23,6 +23,7 @@
 #define CCNX_CONSUMER_WINDOW_H
 
 #include "ccnx-consumer.h"
+#include "ns3/traced-value.h"
 
 namespace ns3 
 {
@@ -70,7 +71,7 @@
   GetWindow () const;
   
 protected:
-  uint32_t m_window;
+  TracedValue<uint32_t> m_window;
   uint32_t m_inFlight;
 };
 
diff --git a/examples/congestion-pop.cc b/examples/congestion-pop.cc
index 0c65860..0a512cb 100644
--- a/examples/congestion-pop.cc
+++ b/examples/congestion-pop.cc
@@ -28,6 +28,7 @@
 #include "ns3/random-variable.h"
 #include "ns3/internet-module.h"
 #include "ns3/applications-module.h"
+#include "ns3/config-store.h"
 
 #include <iostream>
 #include <sstream>
@@ -256,6 +257,10 @@
   
   Config::SetDefault ("ns3::BulkSendApplication::SendSize", StringValue ("1040"));
 
+  Config::SetDefault ("ns3::ConfigStore::Filename", StringValue ("attributes.xml"));
+  Config::SetDefault ("ns3::ConfigStore::Mode", StringValue ("Save"));
+  Config::SetDefault ("ns3::ConfigStore::FileFormat", StringValue ("Xml"));
+  
   uint32_t maxRuns = 1;
   uint32_t startRun = 0;
   CommandLine cmd;
@@ -263,6 +268,9 @@
   cmd.AddValue ("runs", "Number of runs", maxRuns);
   cmd.Parse (argc, argv);
 
+  // ConfigStore config;
+  // config.ConfigureDefaults ();
+  
   for (uint32_t run = startRun; run < startRun + maxRuns; run++)
     {
       Config::SetGlobal ("RngRun", IntegerValue (run));
@@ -299,7 +307,9 @@
         // traceHelper.EnableRateL3All (prefix + "rate-trace.log");
         // traceHelper.EnableSeqsAppAll ("ns3::CcnxConsumerCbr", prefix + "consumers-seqs.log");
         traceHelper.EnableSeqsAppAll ("ns3::CcnxConsumerWindow", prefix + "consumers-seqs.log");
+        traceHelper.EnableWindowsAll (prefix + "windows.log");
 
+        // config.ConfigureAttributes ();
         experiment.Run (Seconds (200.0));
       }
 
diff --git a/helper/ccnx-trace-helper.cc b/helper/ccnx-trace-helper.cc
index 1742462..92c20f7 100644
--- a/helper/ccnx-trace-helper.cc
+++ b/helper/ccnx-trace-helper.cc
@@ -40,6 +40,7 @@
 #include "tracers/ccnx-rate-l3-tracer.h"
 #include "tracers/ccnx-seqs-app-tracer.h"
 #include "tracers/ipv4-seqs-app-tracer.h"
+#include "tracers/ccnx-consumer-window-tracer.h"
 
 #include "ns3/ccnx-interest-header.h"
 #include "ns3/ccnx-content-object-header.h"
@@ -57,6 +58,7 @@
   : m_l3RateTrace (0)
   , m_appSeqsTrace (0)
   , m_ipv4AppSeqsTrace (0)
+  , m_windowsTrace (0)
 {
 }
 
@@ -66,6 +68,7 @@
   if (m_l3RateTrace != 0) delete m_l3RateTrace;
   if (m_appSeqsTrace != 0) delete m_appSeqsTrace;
   if (m_ipv4AppSeqsTrace != 0) delete m_ipv4AppSeqsTrace;
+  if (m_windowsTrace != 0) delete m_windowsTrace;
   
   if (m_apps.size () > 0)
     {
@@ -286,5 +289,43 @@
     }
 }
 
+void
+CcnxTraceHelper::EnableWindowsAll (const std::string &windowTrace)
+{
+  NS_LOG_FUNCTION (this);
+  m_windowsTrace = new ofstream (windowTrace.c_str (), ios::trunc);
+
+  for (NodeList::Iterator node = NodeList::Begin ();
+       node != NodeList::End ();
+       node++)
+    {
+      ObjectVectorValue apps;
+      (*node)->GetAttribute ("ApplicationList", apps);
+
+      NS_LOG_DEBUG ("Node: " << lexical_cast<string> ((*node)->GetId ()));
+      
+      uint32_t appId = 0;
+      for (ObjectVectorValue::Iterator app = apps.Begin ();
+           app != apps.End ();
+           app++, appId++)
+        {
+          if ((*app)->GetInstanceTypeId ().GetName () == "ns3::CcnxConsumerWindow")
+            {
+              Ptr<CcnxConsumerWindowTracer> trace = Create<CcnxConsumerWindowTracer> (boost::ref(*m_windowsTrace),
+                                                                                      *node,
+                                                                                      lexical_cast<string> (appId));
+              m_windows.push_back (trace);
+            }
+        }
+      
+    }
+
+  if (m_windows.size () > 0)
+    {
+      m_windows.front ()->PrintHeader (*m_windowsTrace);
+      *m_windowsTrace << "\n";
+    }
+}
+
 
 } // namespace ns3
diff --git a/helper/ccnx-trace-helper.h b/helper/ccnx-trace-helper.h
index 4079f9c..544c887 100644
--- a/helper/ccnx-trace-helper.h
+++ b/helper/ccnx-trace-helper.h
@@ -31,6 +31,7 @@
 class CcnxAppTracer;
 class CcnxL3Tracer;
 class Ipv4AppTracer;
+class CcnxConsumerWindowTracer;
 
 class CcnxTraceHelper
 {
@@ -93,6 +94,12 @@
    */
   void
   EnableIpv4SeqsAppAll (const std::string &appSeqsTrace = "app-seqs.log");
+
+  /**
+   * @brief Enable tracing of window changes in CcnxConsumerWindow
+   */
+  void
+  EnableWindowsAll (const std::string &windowTrace = "windows.log");
   
 private:
   std::string m_appTrace;
@@ -109,6 +116,9 @@
 
   std::list<Ptr<Ipv4AppTracer> > m_ipv4AppSeqs;
   std::ostream *m_ipv4AppSeqsTrace;
+
+  std::list<Ptr<CcnxConsumerWindowTracer> > m_windows;
+  std::ostream *m_windowsTrace;
 };
 
 
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
diff --git a/wscript b/wscript
index b3470df..bbdda36 100644
--- a/wscript
+++ b/wscript
@@ -61,6 +61,7 @@
         "helper/tracers/ipv4-app-tracer.h",
         "helper/tracers/ccnx-app-tracer.h",
         "helper/tracers/ccnx-l3-tracer.h",
+        "helper/tracers/ccnx-consumer-window-tracer.h",
         "helper/ccnx-face-container.h",
 
         "apps/ccnx-app.h",