diff --git a/ccnx/sync-app-data-fetch.cc b/ccnx/sync-app-data-fetch.cc
deleted file mode 100644
index 5cfabce..0000000
--- a/ccnx/sync-app-data-fetch.cc
+++ /dev/null
@@ -1,67 +0,0 @@
-/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil -*- */
-/*
- * Copyright (c) 2012 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: Zhenkai Zhu <zhenkai@cs.ucla.edu>
- *         Chaoyi Bian <bcy@pku.edu.cn>
- *	   Alexander Afanasyev <alexander.afanasyev@ucla.edu>
- */
-
-#include "sync-app-data-fetch.h"
-#include "sync-log.h"
-
-using namespace std;
-using namespace boost;
-
-namespace Sync
-{
-
-INIT_LOGGER ("AppDataFetch");
-
-void
-AppDataFetch::onUpdate (const std::string &prefix, const SeqNo &newSeq, const SeqNo &oldSeq)
-{
-  _LOG_FUNCTION (this << ", " << prefix << ", " << newSeq << ", " << oldSeq);
-  
-  // sequence number logic here
-  uint32_t start = 0;
-  if (oldSeq.isValid () && oldSeq.getSession() == newSeq.getSession())
-    {
-      start = oldSeq.getSeq () + 1;
-    }
-  uint32_t end = newSeq.getSeq ();
-
-  //
-  // add logic for wrap around
-  //
-
-  for (uint32_t i = start; i <= end; i++)
-    {
-      ostringstream interestName;
-      interestName << prefix << "/" << newSeq.getSession () << "/" << i;
-      m_ccnxHandle->sendInterest (interestName.str (), m_dataCallback);
-    }
-}
-
-void
-AppDataFetch::onRemove (const std::string &prefix)
-{
-  _LOG_FUNCTION (this << ", " << prefix);
-  
-  // I guess this should be somewhere in app
-}
-
-}
diff --git a/ccnx/sync-app-data-fetch.h b/ccnx/sync-app-data-fetch.h
deleted file mode 100644
index 1e42860..0000000
--- a/ccnx/sync-app-data-fetch.h
+++ /dev/null
@@ -1,86 +0,0 @@
-/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil -*- */
-/*
- * Copyright (c) 2012 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: Zhenkai Zhu <zhenkai@cs.ucla.edu>
- *         Chaoyi Bian <bcy@pku.edu.cn>
- *	   Alexander Afanasyev <alexander.afanasyev@ucla.edu>
- */
-
-#ifndef SYNC_APP_DATA_FETCH_H
-#define SYNC_APP_DATA_FETCH_H
-
-#include "sync-ccnx-wrapper.h"
-#include "sync-seq-no.h"
-
-namespace Sync {
-
-/**
- * \ingroup sync
- * @brief fetch application data, by default it will try to fetch every piece
- * of data
- */
-class AppDataFetch
-{
-public:
-  /**
-   * @brief Constructor
-   * @param ccnxHandle handle for CCNx
-   * @param dataCallback the callback function to process data
-   */
-  AppDataFetch (CcnxWrapperPtr ccnxHandle,
-                CcnxWrapper::DataCallback dataCallback)
-    : m_ccnxHandle (ccnxHandle)
-    , m_dataCallback (dataCallback)
-  { }
-
-  /**
-   * @brief Set data callback
-   * @param dataCallback the callback function to process data
-   */
-  void
-  setDataCallback(CcnxWrapper::DataCallback dataCallback)
-  {
-    m_dataCallback = dataCallback;
-  }
-
-  /**
-   * @brief Fired from SyncLogic when new data is available
-   *
-   * @param prefix the prefix for the data
-   * @param newSeq old session ID/sequence number
-   * @param oldSeq new session ID/sequence number
-   */
-  void
-  onUpdate (const std::string &prefix, const SeqNo &newSeq, const SeqNo &oldSeq);
-
-  /**
-   * @brief Fired from SyncLogic when data is removed
-   *
-   * @param prefix the prefix for the data
-   */
-  void
-  onRemove (const std::string &prefix);
-  
-private:
-  CcnxWrapperPtr m_ccnxHandle;
-  CcnxWrapper::DataCallback m_dataCallback;
-};
-
-
-} // Sync
-
-#endif // SYNC_APP_DATA_FETCH_H
diff --git a/ccnx/sync-app-data-publish.cc b/ccnx/sync-app-data-publish.cc
deleted file mode 100644
index e7bee97..0000000
--- a/ccnx/sync-app-data-publish.cc
+++ /dev/null
@@ -1,81 +0,0 @@
-/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil -*- */
-/*
- * Copyright (c) 2012 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: Zhenkai Zhu <zhenkai@cs.ucla.edu>
- *         Chaoyi Bian <bcy@pku.edu.cn>
- *	   Alexander Afanasyev <alexander.afanasyev@ucla.edu>
- */
-
-#include "sync-app-data-publish.h"
-#include <boost/throw_exception.hpp>
-typedef boost::error_info<struct tag_errmsg, std::string> errmsg_info_str;
-typedef boost::error_info<struct tag_errmsg, int> errmsg_info_int;
-
-using namespace std;
-using namespace boost;
-
-namespace Sync
-{
-
-
-string
-AppDataPublish::getRecentData (const string &prefix, uint32_t session)
-{
-  if (m_recentData.find(make_pair(prefix, session)) != m_recentData.end())
-    return m_recentData[make_pair(prefix, session)];
-  else
-    return "";
-}
-
-uint32_t
-AppDataPublish::getNextSeq (const string &prefix, uint32_t session)
-{
-  SequenceLog::iterator i = m_sequenceLog.find (prefix);
-
-  if (i != m_sequenceLog.end ())
-    {
-      Seq s = i->second;
-      if (s.session == session)
-        return s.seq;
-    }
-  return 0;
-}
-
-uint32_t
-AppDataPublish::publishData (const string &name, uint32_t session, const string &dataBuffer, int freshness)
-{
-  uint32_t seq = getNextSeq (name, session);
-
-  ostringstream contentNameWithSeqno;
-  contentNameWithSeqno << name << "/" << session << "/" << seq;
-
-  m_ccnxHandle->publishData (contentNameWithSeqno.str (), dataBuffer, freshness);
-
-  Seq s;
-  s.session = session;
-  s.seq = seq + 1;
-  m_sequenceLog[name] = s;
-
-  unordered_map<pair<string, uint32_t>, string>::iterator it = m_recentData.find(make_pair(name, session));
-   if (it != m_recentData.end()) 
-     m_recentData.erase(it);
-   m_recentData.insert(make_pair(make_pair(name, session), dataBuffer));
-
-  return seq;
-}
-
-} // Sync
diff --git a/ccnx/sync-app-data-publish.h b/ccnx/sync-app-data-publish.h
deleted file mode 100644
index ec95a60..0000000
--- a/ccnx/sync-app-data-publish.h
+++ /dev/null
@@ -1,97 +0,0 @@
-/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil -*- */
-/*
- * Copyright (c) 2012 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: Zhenkai Zhu <zhenkai@cs.ucla.edu>
- *         Chaoyi Bian <bcy@pku.edu.cn>
- *	   Alexander Afanasyev <alexander.afanasyev@ucla.edu>
- */
-
-#ifndef SYNC_APP_DATA_PUBLISH_H
-#define SYNC_APP_DATA_PUBLISH_H
-
-#include <boost/unordered_map.hpp>
-#include "sync-seq-no.h"
-#include "sync-ccnx-wrapper.h"
-#include <utility>
-#include <map>
-
-namespace Sync {
-
-struct Seq
-{
-  uint32_t session;
-  uint32_t seq;
-};
-
-struct GetSeqException : virtual boost::exception, virtual std::exception { };
-
-/**
- * \ingroup sync
- * @brief publishes application data using incrementing sequence number (for
- * each sequence namber and keeps track of most recently published data for
- * each name prefix
- */
-class AppDataPublish
-{
-public:
-  AppDataPublish (CcnxWrapperPtr ccnxHandle)
-  : m_ccnxHandle (ccnxHandle)
-  { }
-
-  /**
-   * @brief get the name (including sequence number) and the content
-   * (unencoded, just XML stanza) of the most recent published data
-   *
-   * @param prefix the name prefix to look for
-   * @param session session
-   * @return the pair of name and content
-   */
-  std::string
-  getRecentData (const std::string &prefix, uint32_t session);
-
-  /**
-   * @brief get the most recent sequence number for a name prefix
-   * @param prefix the name prefix to look for
-   * @param session session
-   */
-  uint32_t
-  getNextSeq (const std::string &prefix, uint32_t session);
-
-  /**
-   * @brief publish data for a name prefix, updates the corresponding
-   * sequence number and recent data
-   *
-   * @param name data prefix
-   * @param session session to which data is published
-   * @param dataBuffer the data itself
-   * @param freshness the freshness for the data object
-   * @return published sequence number, will throw an exception if something wrong happened
-   */
-  uint32_t publishData (const std::string &name, uint32_t session, const std::string &dataBuffer, int freshness);
-
-private:
-  typedef boost::unordered_map<std::string, Seq> SequenceLog;
-  typedef boost::unordered_map<std::pair<std::string, uint32_t>, std::string> RecentData;
-  
-  CcnxWrapperPtr m_ccnxHandle;
-  SequenceLog m_sequenceLog;
-  RecentData m_recentData;
-};
-
-} // Sync
-
-#endif // SYNC_APP_DATA_PUBLISH_H
diff --git a/ccnx/sync-app-socket.cc b/ccnx/sync-app-socket.cc
index 848a6d0..ce65674 100644
--- a/ccnx/sync-app-socket.cc
+++ b/ccnx/sync-app-socket.cc
@@ -28,13 +28,12 @@
 namespace Sync
 {
 
-SyncAppSocket::SyncAppSocket (const string &syncPrefix, CcnxWrapper::DataCallback dataCallback)
-	: m_appHandle (new CcnxWrapper())
-  , m_fetcher (m_appHandle, dataCallback)
-  , m_publisher (m_appHandle)
+SyncAppSocket::SyncAppSocket (const string &syncPrefix, NewDataCallback dataCallback, RemoveCallback rmCallback )
+	: m_ccnxHandle (new CcnxWrapper())
+  , m_newDataCallback(dataCallback)
   , m_syncLogic (syncPrefix,
-                 bind (&AppDataFetch::onUpdate, m_fetcher, _1, _2, _3),
-                 bind (&AppDataFetch::onRemove, m_fetcher, _1))
+                 bind(&SyncAppSocket::passCallback, this, _1),
+                 rmCallback)
 {
 }
 
@@ -42,10 +41,62 @@
 {
 }
 
-bool SyncAppSocket::publish (const string &prefix, uint32_t session, const string &dataBuffer, int freshness)
+bool 
+SyncAppSocket::publishString (const string &prefix, uint32_t session, const string &dataBuffer, int freshness)
 {
-  uint32_t sequence = m_publisher.publishData (prefix, session, dataBuffer, freshness);
+  uint32_t sequence = getNextSeq(prefix, session);
+  ostringstream contentNameWithSeqno;
+  contentNameWithSeqno << prefix << "/" << session << "/" << sequence;
+  m_ccnxHandle->publishStringData (contentNameWithSeqno.str (), dataBuffer, freshness);
+
+  SeqNo s(session, sequence + 1);
+  m_sequenceLog[prefix] = s;
+
   m_syncLogic.addLocalNames (prefix, session, sequence);
 }
 
+bool 
+SyncAppSocket::publishRaw(const std::string &prefix, uint32_t session, const char *buf, size_t len, int freshness)
+{
+  uint32_t sequence = getNextSeq(prefix, session);
+  ostringstream contentNameWithSeqno;
+  contentNameWithSeqno << prefix << "/" << session << "/" << sequence;
+  m_ccnxHandle->publishRawData (contentNameWithSeqno.str (), buf, len, freshness);
+
+  SeqNo s(session, sequence + 1);
+  m_sequenceLog[prefix] = s;
+  m_syncLogic.addLocalNames (prefix, session, sequence);
+}
+
+
+void 
+SyncAppSocket::fetchString(const std::string &prefix, const SeqNo &seq, CcnxWrapper::StringDataCallback callback, int retry)
+{
+  ostringstream interestName;
+  interestName << prefix << "/" << seq.getSession() << "/" << seq.getSeq();
+  m_ccnxHandle->sendInterestForString(interestName.str(), callback, retry);
+}
+
+void 
+SyncAppSocket::fetchRaw(const std::string &prefix, const SeqNo &seq, CcnxWrapper::RawDataCallback callback, int retry)
+{
+  ostringstream interestName;
+  interestName << prefix << "/" << seq.getSession() << "/" << seq.getSeq();
+  m_ccnxHandle->sendInterest(interestName.str(), callback, retry);
+}
+
+uint32_t
+SyncAppSocket::getNextSeq (const string &prefix, uint32_t session)
+{
+  SequenceLog::iterator i = m_sequenceLog.find (prefix);
+
+  if (i != m_sequenceLog.end ())
+    {
+      SeqNo s = i->second;
+      if (s.getSession() == session)
+        return s.getSeq();
+    }
+  return 0;
+}
+
 }
diff --git a/ccnx/sync-app-socket.h b/ccnx/sync-app-socket.h
index f5e5e0f..07c0aa0 100644
--- a/ccnx/sync-app-socket.h
+++ b/ccnx/sync-app-socket.h
@@ -24,9 +24,14 @@
 #define SYNC_APP_SOCKET_H
 
 #include "sync-logic.h"
-#include "sync-app-data-fetch.h"
-#include "sync-app-data-publish.h"
 #include <boost/function.hpp>
+#include <boost/unordered_map.hpp>
+#include "sync-seq-no.h"
+#include "sync-ccnx-wrapper.h"
+#include <utility>
+#include <map>
+#include <vector>
+#include <sstream>
 
 namespace Sync {
 
@@ -37,6 +42,8 @@
 class SyncAppSocket
 {
 public:
+  typedef boost::function< void (const std::vector<MissingDataInfo> &, SyncAppSocket * ) > NewDataCallback;
+  typedef boost::function< void ( const std::string &/*prefix*/ ) > RemoveCallback;
   /**
    * @brief the constructor for SyncAppSocket; the parameter syncPrefix
    * should be passed to the constructor of m_syncAppWrapper; the other
@@ -48,7 +55,7 @@
    * @param syncPrefix the name prefix for Sync Interest
    * @param dataCallback the callback to process data
    */
-  SyncAppSocket (const std::string &syncPrefix, CcnxWrapper::DataCallback dataCallback);
+  SyncAppSocket (const std::string &syncPrefix, NewDataCallback dataCallback, RemoveCallback rmCallback);
   ~SyncAppSocket ();
 
   /**
@@ -60,7 +67,9 @@
    * @param dataBuffer the data itself
    * @param freshness the freshness time for the data (in seconds)
    */
-  bool publish (const std::string &prefix, uint32_t session, const std::string &dataBuffer, int freshness);
+  bool publishString (const std::string &prefix, uint32_t session, const std::string &dataBuffer, int freshness);
+
+  bool publishRaw(const std::string &prefix, uint32_t session, const char *buf, size_t len, int freshness);
 
   /**
    * @brief delete a participant's subtree from the sync tree; SyncLogic will do the work
@@ -70,13 +79,20 @@
    */
   void remove (const std::string &prefix) {m_syncLogic.remove(prefix);}
 
-  int getSeq();
+  void fetchString(const std::string &prefix, const SeqNo &seq, CcnxWrapper::StringDataCallback callback, int retry = 0);
+  void fetchRaw(const std::string &prefix, const SeqNo &seq, CcnxWrapper::RawDataCallback callback, int retry = 0);
+
+  void passCallback(std::vector<MissingDataInfo> &v) {m_newDataCallback(v, this);}
 
 private:
-  CcnxWrapperPtr m_appHandle;
+  uint32_t
+  getNextSeq (const std::string &prefix, uint32_t session);
 
-  AppDataFetch   m_fetcher;
-  AppDataPublish m_publisher;
+private:
+  typedef boost::unordered_map<std::string, SeqNo> SequenceLog;
+  NewDataCallback m_newDataCallback;
+  SequenceLog m_sequenceLog;
+  CcnxWrapperPtr m_ccnxHandle;
   SyncLogic      m_syncLogic;
 };
 
diff --git a/ccnx/sync-ccnx-wrapper.cc b/ccnx/sync-ccnx-wrapper.cc
index 85ffbd6..559cfad 100644
--- a/ccnx/sync-ccnx-wrapper.cc
+++ b/ccnx/sync-ccnx-wrapper.cc
@@ -158,9 +158,13 @@
 }
 
 /// @endcond
+int
+CcnxWrapper::publishStringData (const string &name, const string &dataBuffer, int freshness) {
+  publishRawData(name, dataBuffer.c_str(), dataBuffer.length(), freshness);
+}
 
 int
-CcnxWrapper::publishData (const string &name, const string &dataBuffer, int freshness)
+CcnxWrapper::publishRawData (const string &name, const char *buf, size_t len, int freshness)
 {
   recursive_mutex::scoped_lock lock(m_mutex);
   if (!m_running)
@@ -181,7 +185,7 @@
 			 NULL,
 			 m_keyLoactor);
   if(ccn_encode_ContentObject(content, pname, signed_info,
-			   dataBuffer.c_str(), dataBuffer.length (),
+			   (const unsigned char *)buf, len,
 			   NULL, getPrivateKey()) < 0)
     BOOST_THROW_EXCEPTION(CcnxOperationException() << errmsg_info_str("encode content failed"));
 
@@ -235,7 +239,6 @@
              ccn_upcall_kind kind,
              ccn_upcall_info *info)
 {
-  //CcnxWrapper::DataCallback *f = static_cast<CcnxWrapper::DataCallback*> (selfp->data);
   ClosurePass *cp = static_cast<ClosurePass *> (selfp->data);
 
   switch (kind)
@@ -282,13 +285,13 @@
   return CCN_UPCALL_RESULT_OK;
 }
 
-int CcnxWrapper::sendInterest (const string &strInterest, const DataCallback &dataCallback, int retry)
+int CcnxWrapper::sendInterestForString (const string &strInterest, const StringDataCallback &strDataCallback, int retry)
 {
-  DataClosurePass * pass = new DataClosurePass(STRING_FORM, retry, dataCallback);
+  DataClosurePass * pass = new DataClosurePass(STRING_FORM, retry, strDataCallback);
   sendInterest(strInterest, pass);
 }
 
-int CcnxWrapper::sendInterestForRawData (const string &strInterest, const RawDataCallback &rawDataCallback, int retry)
+int CcnxWrapper::sendInterest (const string &strInterest, const RawDataCallback &rawDataCallback, int retry)
 {
   RawDataClosurePass * pass = new RawDataClosurePass(RAW_DATA, retry, rawDataCallback);
   sendInterest(strInterest, pass);
@@ -356,9 +359,9 @@
   ccn_charbuf_destroy(&pname);
 }
 
-DataClosurePass::DataClosurePass (CallbackType type, int retry, const CcnxWrapper::DataCallback &dataCallback): ClosurePass(type, retry), m_callback(NULL)
+DataClosurePass::DataClosurePass (CallbackType type, int retry, const CcnxWrapper::StringDataCallback &strDataCallback): ClosurePass(type, retry), m_callback(NULL)
 {
-   m_callback = new CcnxWrapper::DataCallback (dataCallback); 
+   m_callback = new CcnxWrapper::StringDataCallback (strDataCallback); 
 }
 
 DataClosurePass::~DataClosurePass () 
diff --git a/ccnx/sync-ccnx-wrapper.h b/ccnx/sync-ccnx-wrapper.h
index b8c3c93..b51c629 100644
--- a/ccnx/sync-ccnx-wrapper.h
+++ b/ccnx/sync-ccnx-wrapper.h
@@ -37,6 +37,7 @@
 #include <boost/thread/thread.hpp>
 #include <boost/function.hpp>
 #include <string>
+#include <sstream>
 
 /**
  * \defgroup sync SYNC protocol
@@ -53,7 +54,7 @@
  */
 class CcnxWrapper {
 public:
-  typedef boost::function<void (std::string, std::string)> DataCallback;
+  typedef boost::function<void (std::string, std::string)> StringDataCallback;
   typedef boost::function<void (std::string, const char *buf, size_t len)> RawDataCallback;
   typedef boost::function<void (std::string)> InterestCallback;
   
@@ -78,10 +79,10 @@
    * @return the return code of ccn_express_interest
    */
   int
-  sendInterest (const std::string &strInterest, const DataCallback &dataCallback, int retry = 0);
+  sendInterestForString (const std::string &strInterest, const StringDataCallback &strDataCallback, int retry = 0);
 
   int 
-  sendInterestForRawData (const std::string &strInterest, const RawDataCallback &rawDataCallback, int retry = 0);
+  sendInterest (const std::string &strInterest, const RawDataCallback &rawDataCallback, int retry = 0);
 
   /**
    * @brief set Interest filter (specify what interest you want to receive)
@@ -110,7 +111,10 @@
    * @return code generated by ccnx library calls, >0 if success
    */
   int
-  publishData (const std::string &name, const std::string &dataBuffer, int freshness);
+  publishStringData (const std::string &name, const std::string &dataBuffer, int freshness);
+
+  int 
+  publishRawData (const std::string &name, const char *buf, size_t len, int freshness);
 
 private:
   /// @cond include_hidden 
@@ -165,11 +169,11 @@
 
 class DataClosurePass: public ClosurePass {
 public:
-  DataClosurePass(CallbackType type, int retry, const CcnxWrapper::DataCallback &dataCallback);
+  DataClosurePass(CallbackType type, int retry, const CcnxWrapper::StringDataCallback &strDataCallback);
   virtual ~DataClosurePass();
   virtual void runCallback(std::string name, const char *, size_t len);
 private:
-  CcnxWrapper::DataCallback * m_callback;  
+  CcnxWrapper::StringDataCallback * m_callback;  
 };
 
 class RawDataClosurePass: public ClosurePass {