diff --git a/model/sync-app-data-publish.cc b/model/sync-app-data-publish.cc
index 17d52ee..faaf482 100644
--- a/model/sync-app-data-publish.cc
+++ b/model/sync-app-data-publish.cc
@@ -21,6 +21,9 @@
  */
 
 #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;
@@ -28,6 +31,7 @@
 namespace Sync
 {
 
+
 string
 AppDataPublish::getRecentData (const string &prefix, uint32_t session)
 {
@@ -38,7 +42,7 @@
 }
 
 uint32_t
-AppDataPublish::getHighestSeq (const string &prefix, uint32_t session)
+AppDataPublish::getNextSeq (const string &prefix, uint32_t session)
 {
   unordered_map<string, Seq>::iterator i = m_sequenceLog.find(prefix);
 
@@ -48,30 +52,32 @@
       if (s.session == session)
         return s.seq;
     }
-
-  return 0;
+	else
+    BOOST_THROW_EXCEPTION(GetSeqException() << errmsg_info_str("No corresponding seq"));
 }
 
 bool
 AppDataPublish::publishData (const string &name, uint32_t session, const string &dataBuffer, int freshness)
 {
-  uint32_t seq = getHighestSeq(name, session);
-  if (seq == 0)
+  uint32_t seq = 0;
+	try
+		{
+			seq =  getNextSeq(name, session);
+		}
+	catch (GetSeqException &e){
     m_sequenceLog.erase(name);
-
-  seq++;
-  if (seq == 0)
-    seq = 1;
-  Seq s;
-  s.session = session;
-  s.seq = seq;
-  m_sequenceLog[name] = s;
+	}
 
   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);
diff --git a/model/sync-app-data-publish.h b/model/sync-app-data-publish.h
index d072189..85bb9ae 100644
--- a/model/sync-app-data-publish.h
+++ b/model/sync-app-data-publish.h
@@ -36,6 +36,8 @@
   uint32_t seq;
 };
 
+struct GetSeqException : virtual boost::exception, virtual std::exception { };
+
 /**
  * \ingroup sync
  * @brief publishes application data using incrementing sequence number (for
@@ -66,7 +68,7 @@
    * @param session session
    */
   uint32_t
-  getHighestSeq (const std::string &prefix, uint32_t session);
+  getNextSeq (const std::string &prefix, uint32_t session);
 
   /**
    * @brief publish data for a name prefix, updates the corresponding
diff --git a/model/sync-app-socket.cc b/model/sync-app-socket.cc
index 3dca250..2f1d174 100644
--- a/model/sync-app-socket.cc
+++ b/model/sync-app-socket.cc
@@ -29,13 +29,12 @@
 {
 
 SyncAppSocket::SyncAppSocket (const string &syncPrefix, CcnxWrapper::DataCallback dataCallback)
-  : m_ccnxHandle (new CcnxWrapper())
-  , m_fetcher (m_ccnxHandle, dataCallback)
-  , m_publisher (m_ccnxHandle)
+	: m_appHandle (new CcnxWrapper())
+  , m_fetcher (m_appHandle, dataCallback)
+  , m_publisher (m_appHandle)
   , m_syncLogic (syncPrefix,
                  bind (&AppDataFetch::onUpdate, m_fetcher, _1, _2, _3),
-                 bind (&AppDataFetch::onRemove, m_fetcher, _1),
-                 m_ccnxHandle)
+                 bind (&AppDataFetch::onRemove, m_fetcher, _1))
 {
 }
 
@@ -46,7 +45,7 @@
 bool SyncAppSocket::publish (const string &prefix, uint32_t session, const string &dataBuffer, int freshness)
 {
   m_publisher.publishData (prefix, session, dataBuffer, freshness);
-  m_syncLogic.addLocalNames (prefix, session, m_publisher.getHighestSeq (prefix, session));
+  m_syncLogic.addLocalNames (prefix, session, m_publisher.getNextSeq (prefix, session));
 }
 
 }
diff --git a/model/sync-app-socket.h b/model/sync-app-socket.h
index dfa29db..7c01cf2 100644
--- a/model/sync-app-socket.h
+++ b/model/sync-app-socket.h
@@ -70,8 +70,13 @@
    */
   void remove (const std::string &prefix) {m_syncLogic.remove(prefix);}
 
+  /**
+   * @brief start sync process
+   */
+	void start() {m_syncLogic.start();}
+
 private:
-  CcnxWrapperPtr m_ccnxHandle;
+	CcnxWrapperPtr m_appHandle;
 
   AppDataFetch   m_fetcher;
   AppDataPublish m_publisher;
diff --git a/model/sync-logic.cc b/model/sync-logic.cc
index 4a243a4..c8452dc 100644
--- a/model/sync-logic.cc
+++ b/model/sync-logic.cc
@@ -37,12 +37,11 @@
 
 SyncLogic::SyncLogic (const std::string &syncPrefix,
                       LogicUpdateCallback onUpdate,
-                      LogicRemoveCallback onRemove,
-                      CcnxWrapperPtr ccnxHandle)
+                      LogicRemoveCallback onRemove)
   : m_syncPrefix (syncPrefix)
   , m_onUpdate (onUpdate)
   , m_onRemove (onRemove)
-  , m_ccnxHandle (ccnxHandle)
+  , m_ccnxHandle(new CcnxWrapper())
   , m_randomGenerator (static_cast<unsigned int> (std::time (0)))
   , m_rangeUniformRandom (m_randomGenerator, uniform_int<> (20,100))
 {
@@ -63,6 +62,7 @@
 void
 SyncLogic::respondSyncInterest (const string &interest)
 {
+  // cout << "Respond Sync Interest" << endl;
   string hash = interest.substr(interest.find_last_of("/") + 1);
   DigestPtr digest = make_shared<Digest> ();
   try
@@ -82,7 +82,7 @@
 void
 SyncLogic::processSyncInterest (DigestConstPtr digest, const std::string &interestName, bool timedProcessing/*=false*/)
 {
-  // cout << "SyncLogic::processSyncInterest " << timedProcessing << endl;
+  //cout << "SyncLogic::processSyncInterest " << timedProcessing << endl;
   recursive_mutex::scoped_lock lock (m_stateMutex);
     
   if (*m_state.getDigest() == *digest)
@@ -119,6 +119,7 @@
 void
 SyncLogic::processSyncData (const string &name, const string &dataBuffer)
 {
+  // cout << "Process Sync Data" <<endl;
   DiffStatePtr diffLog = make_shared<DiffState> ();
   
   try
@@ -211,6 +212,7 @@
 void
 SyncLogic::processPendingSyncInterests (DiffStatePtr &diffLog) 
 {
+  //cout << "Process Pending Interests" <<endl;
   recursive_mutex::scoped_lock lock (m_stateMutex);
 
   diffLog->setDigest(m_state.getDigest());
@@ -223,18 +225,19 @@
   vector<string> pis = m_syncInterestTable.fetchAll ();
   if (pis.size () > 0)
     {
-      stringstream ss;
+  stringstream ss;
       ss << *diffLog;
-      for (vector<string>::iterator ii = pis.begin(); ii != pis.end(); ++ii)
-        {
-          m_ccnxHandle->publishData (*ii, ss.str(), m_syncResponseFreshness);
-        }
-    }
+  for (vector<string>::iterator ii = pis.begin(); ii != pis.end(); ++ii)
+  {
+    m_ccnxHandle->publishData (*ii, ss.str(), m_syncResponseFreshness);
+  }
+}
 }
 
 void
 SyncLogic::addLocalNames (const string &prefix, uint32_t session, uint32_t seq)
 {
+  //cout << "Add local names" <<endl;
   recursive_mutex::scoped_lock lock (m_stateMutex);
   NameInfoConstPtr info = StdNameInfo::FindOrCreate(prefix);
   SeqNo seqN(session, seq);
@@ -262,6 +265,7 @@
 void
 SyncLogic::sendSyncInterest ()
 {
+  // cout << "Sending Sync Interest" << endl;
   recursive_mutex::scoped_lock lock (m_stateMutex);
 
   ostringstream os;
diff --git a/model/sync-logic.h b/model/sync-logic.h
index 03c129a..da0a7fa 100644
--- a/model/sync-logic.h
+++ b/model/sync-logic.h
@@ -26,6 +26,7 @@
 #include <boost/shared_ptr.hpp>
 #include <boost/thread/recursive_mutex.hpp>
 #include <boost/random.hpp>
+#include <memory>
 
 #include "sync-ccnx-wrapper.h"
 #include "sync-interest-table.h"
@@ -59,8 +60,7 @@
    */
   SyncLogic (const std::string &syncPrefix,
              LogicUpdateCallback onUpdate,
-             LogicRemoveCallback onRemove,
-             CcnxWrapperPtr ccnxHandle);
+             LogicRemoveCallback onRemove);
 
   ~SyncLogic ();
 
@@ -88,6 +88,11 @@
    */
   void remove (const std::string &prefix);
 
+  /**
+   * @brief start the sync process
+   */
+	 void start();
+
 #ifdef _DEBUG
   Scheduler &
   getScheduler () { return m_scheduler; }
@@ -116,7 +121,7 @@
   std::string m_syncPrefix;
   LogicUpdateCallback m_onUpdate;
   LogicRemoveCallback m_onRemove;
-  CcnxWrapperPtr m_ccnxHandle;
+  std::auto_ptr<CcnxWrapper> m_ccnxHandle;
 
   Scheduler m_scheduler;
 
diff --git a/test/test_app_socket.cc b/test/test_app_socket.cc
new file mode 100644
index 0000000..016ef54
--- /dev/null
+++ b/test/test_app_socket.cc
@@ -0,0 +1,137 @@
+/* -*- 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>
+ *         卞超轶 Chaoyi Bian <bcy@pku.edu.cn>
+ *	   Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+
+#include <boost/test/unit_test.hpp>
+#include <boost/test/output_test_stream.hpp> 
+using boost::test_tools::output_test_stream;
+
+#include <boost/make_shared.hpp>
+
+#include "../model/sync-app-socket.h"
+extern "C" {
+#include <unistd.h>
+}
+
+using namespace Sync;
+using namespace std;
+using namespace boost;
+
+class TestSocketApp {
+public:
+  map<string, string> data;
+  void set(string str1, string str2) {
+    data.insert(make_pair(str1, str2));
+  }
+
+  string toString(){
+    map<string, string>::iterator it = data.begin(); 
+    string str = "\n";
+    for (; it != data.end(); ++it){
+      str += "<";
+      str += it->first;
+      str += "|";
+      str += it->second;
+      str += ">";
+			str += "\n";
+    }
+    return str;
+  }
+
+};
+
+BOOST_AUTO_TEST_CASE (AppSocketTest)
+{
+
+	TestSocketApp a1, a2, a3;
+	boost::function<void(string, string)> f1 = bind(&TestSocketApp::set, &a1, _1,
+	_2);
+	boost::function<void(string, string)> f2 = bind(&TestSocketApp::set, &a2, _1,
+	_2);
+	boost::function<void(string, string)> f3 = bind(&TestSocketApp::set, &a3, _1,
+	_2);
+	
+	string syncPrefix("/let/us/sync");
+	string p1("/irl.cs.ucla.edu"), p2("/yakshi.org"), p3("/google.com");
+
+	SyncAppSocket s1(syncPrefix, f1), s2(syncPrefix, f2), s3(syncPrefix, f3);
+
+	s1.start();
+	s2.start();
+	s3.start();
+
+	// single source
+	string data0 = "Very funny Scotty, now beam down my clothes";
+	s1.publish(p1, 0, data0 , 10); 
+	usleep(10000);
+
+	// from code logic, we won't be fetching our own data
+	a1.set(p1 + "/0/0", data0);
+	BOOST_CHECK_EQUAL(a1.toString(), a2.toString());
+	BOOST_CHECK_EQUAL(a2.toString(), a3.toString());
+
+	// single source, multiple data at once
+	string data1 = "Yes, give me that ketchup";
+	string data2 = "Don't look conspicuous, it draws fire";
+	s1.publish(p1, 0, data1, 10); 
+	s1.publish(p1, 0, data2, 10); 
+	usleep(10000);
+
+	// from code logic, we won't be fetching our own data
+	a1.set(p1 + "/0/1", data1);
+	a1.set(p1 + "/0/2", data2);
+	BOOST_CHECK_EQUAL(a1.toString(), a2.toString());
+	BOOST_CHECK_EQUAL(a2.toString(), a3.toString());
+
+	// another single source
+	string data3 = "You surf the Internet, I surf the real world";
+	string data4 = "I got a fortune cookie once that said 'You like Chinese food'";
+	string data5 = "Real men wear pink. Why? Because their wives make them";
+	s3.publish(p3, 0, data3, 10); 
+	usleep(10000);
+	// another single source, multiple data at once
+	s2.publish(p2, 0, data4, 10); 
+	s2.publish(p2, 0, data5, 10);
+	usleep(10000);
+
+	// from code logic, we won't be fetching our own data
+	a3.set(p3 + "/0/0", data3);
+	a2.set(p2 + "/0/0", data4);
+	a2.set(p2 + "/0/1", data5);
+	BOOST_CHECK_EQUAL(a1.toString(), a2.toString());
+	BOOST_CHECK_EQUAL(a2.toString(), a3.toString());
+
+	// not sure weither this is simultanous data generation from multiple sources
+	string data6 = "Shakespeare says: 'Prose before hos.'";
+	string data7 = "Pick good people, talent never wears out";
+	s1.publish(p1, 0, data6, 10); 
+	s2.publish(p2, 0, data7, 10); 
+	usleep(10000);
+
+	// from code logic, we won't be fetching our own data
+	a1.set(p1 + "/0/3", data6);
+	a2.set(p2 + "/0/2", data7);
+	BOOST_CHECK_EQUAL(a1.toString(), a2.toString());
+	BOOST_CHECK_EQUAL(a2.toString(), a3.toString());
+
+}
+
+
diff --git a/test/test_data_fetch_and_publish.cc b/test/test_data_fetch_and_publish.cc
index a442830..b1e7647 100644
--- a/test/test_data_fetch_and_publish.cc
+++ b/test/test_data_fetch_and_publish.cc
@@ -67,7 +67,7 @@
   TestStructApp bar;
 	
   string interest = "/april/fool";
-  string seq[5] = {"1", "2", "3", "4", "5"};
+  string seq[5] = {"0", "1", "2", "3", "4" };
   string str[5] = {"panda", "express", "tastes", "so", "good"};
 
   for (int i = 0; i < 5; i++) {
@@ -86,10 +86,10 @@
     publisher.publishData(interest, 0, str[i - 1], 5);
   }
 
-  BOOST_CHECK_EQUAL(publisher.getHighestSeq(interest, 0), 5);
+  BOOST_CHECK_EQUAL(publisher.getNextSeq(interest, 0), 5);
   BOOST_CHECK_EQUAL(publisher.getRecentData(interest, 0), str[4]);
 
-  fetcher.onUpdate (interest, SeqNo (0,5), SeqNo (0,0));
+  fetcher.onUpdate (interest, SeqNo (0,4), SeqNo (0,-1));
   // give time for ccnd to react
   sleep(1);
   BOOST_CHECK_EQUAL(foo.toString(), bar.toString());
@@ -99,7 +99,7 @@
     bind(&TestStructApp::erase, &bar, _1, _2);
   fetcher.setDataCallback(eraseFunc);
 
-  fetcher.onUpdate (interest, SeqNo (0,5), SeqNo (0,0));
+  fetcher.onUpdate (interest, SeqNo (0,4), SeqNo (0,-1));
   // give time for ccnd to react
   sleep(1);
   TestStructApp poo;
diff --git a/test/test_scheduler.cc b/test/test_scheduler.cc
index 1dce279..821155c 100644
--- a/test/test_scheduler.cc
+++ b/test/test_scheduler.cc
@@ -144,7 +144,7 @@
 BOOST_AUTO_TEST_CASE (SyncLogicSchedulerTest)
 {  
   SyncLogic *logic = 0;
-  BOOST_CHECK_NO_THROW (logic = new SyncLogic ("/prefix", funcUpdate, funcRemove, make_shared<CcnxWrapper> ()));
+  BOOST_CHECK_NO_THROW (logic = new SyncLogic ("/prefix", funcUpdate, funcRemove));
 
   Scheduler &scheduler = logic->getScheduler ();
   BOOST_CHECK_EQUAL (scheduler.getEventsSize (), 0);