diff --git a/model/pit/ccnx-pit-impl.cc b/model/pit/ccnx-pit-impl.cc
new file mode 100644
index 0000000..c1867f0
--- /dev/null
+++ b/model/pit/ccnx-pit-impl.cc
@@ -0,0 +1,281 @@
+/* -*- 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>
+ */
+
+#include "ccnx-pit-impl.h"
+
+#include "ns3/ccnx-interest-header.h"
+#include "ns3/ccnx-content-object-header.h"
+
+#include "ns3/log.h"
+#include "ns3/string.h"
+#include "ns3/uinteger.h"
+#include "ns3/simulator.h"
+
+#include <boost/lambda/bind.hpp>
+#include <boost/lambda/lambda.hpp>
+
+NS_LOG_COMPONENT_DEFINE ("CcnxPitImpl");
+
+using namespace boost::tuples;
+using namespace boost;
+namespace ll = boost::lambda;
+
+namespace ns3 {
+
+NS_OBJECT_ENSURE_REGISTERED (CcnxPitImpl);
+
+
+// CcnxPitEntryImpl::CcnxPitEntryImpl (CcnxPit &pit,
+//                                     Ptr<const CcnxInterestHeader> header,
+//                                     Ptr<CcnxFibEntry> fibEntry)
+//   : CcnxPitEntry (pit, header, fibEntry)
+//   , item_ (0)
+// {
+//   static_cast<CcnxPitImpl&> (m_container).i_time.insert (*this);
+// }
+
+// CcnxPitEntryImpl::~CcnxPitEntryImpl ()
+// {
+//   static_cast<CcnxPitImpl&> (m_container).i_time.erase (*this);
+// }
+
+TypeId
+CcnxPitImpl::GetTypeId ()
+{
+  static TypeId tid = TypeId ("ns3::CcnxPit")
+    .SetGroupName ("Ccnx")
+    .SetParent<CcnxPit> ()
+    .AddConstructor<CcnxPitImpl> ()
+    .AddAttribute ("MaxSize",
+                   "Set maximum number of entries in PIT. If 0, limit is not enforced",
+                   StringValue ("0"),
+                   MakeUintegerAccessor (&CcnxPitImpl::GetMaxSize, &CcnxPitImpl::SetMaxSize),
+                   MakeUintegerChecker<uint32_t> ())
+    ;
+
+  return tid;
+}
+
+CcnxPitImpl::CcnxPitImpl ()
+{
+}
+
+CcnxPitImpl::~CcnxPitImpl ()
+{
+}
+
+uint32_t
+CcnxPitImpl::GetMaxSize () const
+{
+  return getPolicy ().get_max_size ();
+}
+
+void
+CcnxPitImpl::SetMaxSize (uint32_t maxSize)
+{
+  getPolicy ().set_max_size (maxSize);
+}
+
+void 
+CcnxPitImpl::NotifyNewAggregate ()
+{
+  if (m_fib == 0)
+    {
+      m_fib = GetObject<CcnxFib> ();
+    }
+}
+
+void 
+CcnxPitImpl::DoDispose ()
+{
+  super::clear ();
+}
+
+void CcnxPitImpl::RescheduleCleaning ()
+{
+  m_cleanEvent.Cancel ();
+  if (i_time.empty ())
+    {
+      NS_LOG_DEBUG ("No items in PIT");
+      return;
+    }
+
+  Time nextEvent = i_time.begin ()->GetExpireTime () - Simulator::Now ();
+  if (nextEvent < 0) nextEvent = Seconds (0);
+  
+  NS_LOG_DEBUG ("Schedule next cleaning in " <<
+                nextEvent.ToDouble (Time::S) << "s (at " <<
+                i_time.begin ()->GetExpireTime () << "s abs time");
+  m_cleanEvent = Simulator::Schedule (nextEvent,
+                                      &CcnxPitImpl::CleanExpired, this);
+}
+
+void
+CcnxPitImpl::CleanExpired ()
+{
+  NS_LOG_LOGIC ("Cleaning PIT. Total: " << i_time.size ());
+  Time now = Simulator::Now ();
+
+  // uint32_t count = 0;
+  while (!i_time.empty ())
+    {
+      time_index::iterator entry = i_time.begin ();
+      if (entry->GetExpireTime () <= now) // is the record stale?
+        {
+          super::erase (entry->to_iterator ());
+      //     // count ++;
+        }
+      else
+        break; // nothing else to do. All later records will not be stale
+    }
+
+  RescheduleCleaning ();
+}
+
+Ptr<CcnxPitEntry>
+CcnxPitImpl::Lookup (const CcnxContentObjectHeader &header)
+{
+  /// @todo use predicate to search with exclude filters  
+  super::iterator item = super::longest_prefix_match (header.GetName ());
+
+  if (item == super::end ())
+    return 0;
+  else
+    return item->payload (); // which could also be 0
+}
+
+Ptr<CcnxPitEntry>
+CcnxPitImpl::Lookup (const CcnxInterestHeader &header)
+{
+  NS_LOG_FUNCTION (header.GetName ());
+  NS_ASSERT_MSG (m_fib != 0, "FIB should be set");
+
+  super::iterator foundItem, lastItem;
+  bool reachLast;
+  boost::tie (foundItem, reachLast, lastItem) = super::getTrie ().find (header.GetName ());
+
+  if (!reachLast || lastItem == super::end ())
+    return 0;
+  else
+    return lastItem->payload (); // which could also be 0
+}
+
+Ptr<CcnxPitEntry>
+CcnxPitImpl::Create (Ptr<const CcnxInterestHeader> header)
+{
+  Ptr<CcnxFibEntry> fibEntry = m_fib->LongestPrefixMatch (*header);
+  NS_ASSERT_MSG (fibEntry != 0,
+                 "There should be at least default route set" <<
+                 " Prefix = "<< header->GetName() << "NodeID == " << m_fib->GetObject<Node>()->GetId() << "\n" << *m_fib);
+
+
+  Ptr< entry > newEntry = ns3::Create< entry > (boost::ref (*this), header, fibEntry);
+  std::pair< super::iterator, bool > result = super::insert (header->GetName (), newEntry);
+  if (result.first != super::end ())
+    {
+      if (result.second)
+        {
+          newEntry->SetTrie (result.first);
+          return newEntry;
+        }
+      else
+        {
+          // should we do anything?
+          // update payload? add new payload?
+          return result.first->payload ();
+        }
+    }
+  else
+    return 0;
+}
+
+
+void
+CcnxPitImpl::MarkErased (Ptr<CcnxPitEntry> item)
+{
+  // entry->SetExpireTime (Simulator::Now () + m_PitEntryPruningTimout);
+  super::erase (StaticCast< entry > (item)->to_iterator ());
+}
+
+
+void
+CcnxPitImpl::Print (std::ostream& os) const
+{
+  // !!! unordered_set imposes "random" order of item in the same level !!!
+  super::parent_trie::const_recursive_iterator item (super::getTrie ()), end (0);
+  for (; item != end; item++)
+    {
+      if (item->payload () == 0) continue;
+
+      os << item->payload ()->GetPrefix () << "\t" << *item->payload () << "\n";
+    }
+}
+
+uint32_t
+CcnxPitImpl::GetSize () const
+{
+  return super::getPolicy ().size ();
+}
+
+Ptr<CcnxPitEntry>
+CcnxPitImpl::Begin ()
+{
+  super::parent_trie::recursive_iterator item (super::getTrie ()), end (0);
+  for (; item != end; item++)
+    {
+      if (item->payload () == 0) continue;
+      break;
+    }
+
+  if (item == end)
+    return End ();
+  else
+    return item->payload ();
+}
+
+Ptr<CcnxPitEntry>
+CcnxPitImpl::End ()
+{
+  return 0;
+}
+
+Ptr<CcnxPitEntry>
+CcnxPitImpl::Next (Ptr<CcnxPitEntry> from)
+{
+  if (from == 0) return 0;
+  
+  super::parent_trie::recursive_iterator
+    item (*StaticCast< entry > (from)->to_iterator ()),
+    end (0);
+  
+  for (item++; item != end; item++)
+    {
+      if (item->payload () == 0) continue;
+      break;
+    }
+
+  if (item == end)
+    return End ();
+  else
+    return item->payload ();
+}
+
+
+} // namespace ns3