diff --git a/ndn.cxx/ndn-api-face.h b/ndn.cxx/ndn-api-face.h
index 133f29c..8c589bb 100644
--- a/ndn.cxx/ndn-api-face.h
+++ b/ndn.cxx/ndn-api-face.h
@@ -23,144 +23,90 @@
 #ifndef NDN_API_FACE_H
 #define NDN_API_FACE_H
 
-#include <boost/exception/all.hpp>
-#include <boost/function.hpp>
-#include <string>
-
 #include <ns3/ptr.h>
 #include <ns3/node.h>
-#include <ns3/random-variable.h>
-#include <ns3/ndn-app.h>
+#include <ns3/callback.h>
+#include <ns3/ndn-face.h>
 #include <ns3/ndn-name.h>
 
-#include <ns3/ndnSIM/utils/trie/trie-with-policy.h>
-#include <ns3/ndnSIM/utils/trie/counting-policy.h>
-
 namespace ns3 {
 namespace ndn {
 
-template<class Callback>
-struct FilterEntry : public ns3::SimpleRefCount< FilterEntry<Callback> >
-{
-public:
-  FilterEntry (ns3::Ptr<const ns3::ndn::Name> prefix)
-    : m_prefix (prefix)
-  { }
-  
-  const ns3::ndn::Name &
-  GetPrefix () const
-  { return *m_prefix; }
+class ApiFacePriv;
 
-  void
-  AddCallback (Callback callback)
-  { 
-    m_callback = callback;
-  }
-
-  void
-  ClearCallback ()
-  {
-    m_callback = 0;
-  }
-  
-public:
-  ns3::Ptr<const ns3::ndn::Name> m_prefix; ///< \brief Prefix of the PIT entry
-  Callback m_callback;
-};
-
-
-template<class Callback>
-struct FilterEntryContainer :
-    public ns3::ndn::ndnSIM::trie_with_policy<ns3::ndn::Name,
-                                              ns3::ndn::ndnSIM::smart_pointer_payload_traits< FilterEntry<Callback> >,
-                                              ns3::ndn::ndnSIM::counting_policy_traits>
-{
-};
-
-
-struct OperationException : virtual boost::exception, virtual std::exception { };
 /**
  * \ingroup sync
  * @brief A handler for NDN; clients of this code do not need to deal
  * with NDN API directly
  */
 class ApiFace
-  // : private ns3::ndn::Face
+  : public ns3::ndn::Face
 {
 public:
-  // typedef boost::function<void (const ndn::Name &, Ptr<Packet>)> DataCallback;
-  // typedef boost::function<void (const ndn::Name &)> InterestCallback;
-  
-  // /**
-  //  * @brief initialize the handler; a lot of things needs to be done. 1) init
-  //  * keystore 2) init keylocator 3) start a thread to hold a loop of ccn_run
-  //  *
-  //  */
-  // ApiFace (Ptr<Node> node);
-  // ~ApiFace ();
-
-  // /**
-  //  * @brief send Interest; need to grab lock m_mutex first
-  //  *
-  //  * @param name the Interest name
-  //  * @param dataCallback the callback function to deal with the returned data
-  //  * @return the return code of ccn_express_interest
-  //  */
-  // // int
-  // // sendInterestForString (const std::string &strInterest, const StringDataCallback &strDataCallback/*, int retry = 0*/);
-
-  // int
-  // sendInterest (const ndn::Name &name, const DataCallback &rawDataCallback/*, int retry = 0*/);
-  
-  // /**
-  //  * @brief set Interest filter (specify what interest you want to receive)
-  //  *
-  //  * @param prefix the prefix of Interest
-  //  * @param interestCallback the callback function to deal with the returned data
-  //  * @return the return code of ccn_set_interest_filter
-  //  */
-  // int
-  // setInterestFilter (const ndn::Name &prefix, const InterestCallback &interestCallback);
-
-  // /**
-  //  * @brief clear Interest filter
-  //  * @param prefix the prefix of Interest
-  //  */
-  // void
-  // clearInterestFilter (const std::string &prefix);
+  typedef Callback<void, Ptr<const Name>,     Ptr<const Interest> > InterestCallback;
+  typedef Callback<void, Ptr<const Interest>, Ptr<const ContentObject> > DataCallback;
+  typedef Callback<void, Ptr<const Interest> > TimeoutCallback;
 
   /**
-   * @brief publish data and put it to local ccn content store; need to grab
-   * lock m_mutex first
+   * @brief initialize the handler; a lot of things needs to be done. 1) init
+   * keystore 2) init keylocator 3) start a thread to hold a loop of ccn_run
    *
-   * @param name the name for the data object
-   * @param dataBuffer the data to be published
-   * @param freshness the freshness time for the data object
-   * @return code generated by NDN library calls, >0 if success
    */
-  // int
-  // publishStringData (const std::string &name, const std::string &dataBuffer, int freshness)
-  // {
-  //   return publishRawData (name, dataBuffer.c_str(), dataBuffer.length(), freshness);
-  // }
+  ApiFace (Ptr<Node> node);
+  ~ApiFace ();
 
-  // int
-  // publishRawData (const std::string &name, const char *buf, size_t len, int freshness);
+  /**
+   * @brief Express Interest
+   *
+   * @param name the Interest name
+   * @param onData the callback function to deal with the returned data
+   * @param onTimeout the callback function to deal with timeouts
+   */
+  void
+  ExpressInterest (Ptr<Interest> interest,
+                   DataCallback onData,
+                   TimeoutCallback onTimeout); // = MakeNullCallback< void, Ptr<Interest> > ()
+
+  /**
+   * @brief set Interest filter (specify what interest you want to receive)
+   *
+   * @param prefix the prefix of Interest
+   * @param onInterest the callback function to deal with the returned data
+   */
+  void
+  SetInterestFilter (Ptr<const Name> prefix, InterestCallback onInterest);
+
+  /**
+   * @brief clear Interest filter
+   * @param prefix the prefix of Interest
+   */
+  void
+  ClearInterestFilter (Ptr<const Name> prefix);
+
+  /**
+   * @brief Publish data
+   * @param data Data packet to publish
+   */
+  void
+  Put (Ptr<ContentObject> data);
+
+public:
+  virtual bool
+  SendInterest (Ptr<const Interest> interest);
+
+  virtual bool
+  SendData (Ptr<const ContentObject> data);
+
+  virtual std::ostream&
+  Print (std::ostream &os) const;
 
 private:
-  // // from ndn::App
-  // virtual void
-  // OnInterest (const ns3::Ptr<const ns3::ndn::Interest> &interest, ns3::Ptr<ns3::Packet> packet);
- 
-  // virtual void
-  // OnContentObject (const ns3::Ptr<const ns3::ndn::ContentObject> &contentObject,
-  //                  ns3::Ptr<ns3::Packet> payload);
+  ApiFace () : Face (0) {}
+  ApiFace (const ApiFace &) : Face (0) {}
+  ApiFace& operator= (const ApiFace &) { return *this; }
 
 private:
-  ns3::UniformVariable m_rand; // nonce generator
-
-  FilterEntryContainer<RawDataCallback> m_dataCallbacks;
-  FilterEntryContainer<InterestCallback> m_interestCallbacks;
+  ApiFacePriv *m_this;
 };
 
 }