Adding new trace into CcnxFace
diff --git a/model/ccnx-face.h b/model/ccnx-face.h
index 16a31fd..ad8ca80 100644
--- a/model/ccnx-face.h
+++ b/model/ccnx-face.h
@@ -232,7 +232,11 @@
   Time m_lastLeakTime;
   uint32_t m_metric; ///< \brief metric of the face
 
-  bool m_enableMetricTagging; 
+  // bool m_enableMetricTagging;
+
+  TracedCallback<Ptr<const Packet> > m_ccnxTxTrace;
+  TracedCallback<Ptr<const Packet> > m_ccnxRxTrace;
+  TracedCallback<Ptr<const Packet> > m_ccnxDropTrace;
 };
 
 std::ostream& operator<< (std::ostream& os, const CcnxFace &face);