diff --git a/utils/ndn-limits-window.h b/utils/ndn-limits-window.h
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+++ b/utils/ndn-limits-window.h
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+/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2011 University of California, Los Angeles
+ *
+ * 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 _NDN_LIMITS_WINDOW_H_
+#define	_NDN_LIMITS_WINDOW_H_
+
+#include "ndn-limits.h"
+
+namespace ns3 {
+namespace ndn {
+
+/**
+ * \ingroup ndn
+ * \brief Structure to manage limits for outstanding interests
+ */
+class LimitsWindow :
+    public Limits
+{
+public:
+  typedef Limits super;
+  
+  static TypeId
+  GetTypeId ();
+  
+  /**
+   * \brief Constructor
+   * \param prefix smart pointer to the prefix for the FIB entry
+   */
+  LimitsWindow ()
+  : m_outstanding (0)
+  { }
+
+  virtual
+  ~LimitsWindow () { }
+
+
+  // from limits
+  virtual bool
+  IsBelowLimit ();
+
+  ////////////////////////////////////////////////////////////////////////////
+  ////////////////////////////////////////////////////////////////////////////
+  ////////////////////////////////////////////////////////////////////////////
+
+  // specific to window-based limits
+  
+  /**
+   * @brief Remove outstanding interests
+   */
+  void
+  RemoveOutstanding ();
+
+  double
+  GetOutstanding () const
+  {
+    return m_outstanding;
+  }
+  
+protected:
+  TracedValue< double > m_outstanding;
+};
+  
+
+} // namespace ndn
+} // namespace ns3
+
+#endif // _NDN_LIMITS_WINDOW_H_