diff --git a/src/test/ns3tcp/ns3tcp-socket-test-suite.cc b/src/test/ns3tcp/ns3tcp-socket-test-suite.cc
index d42e039d0..b9e2d514a 100644
--- a/src/test/ns3tcp/ns3tcp-socket-test-suite.cc
+++ b/src/test/ns3tcp/ns3tcp-socket-test-suite.cc
@@ -34,6 +34,7 @@
 #include "ns3/tcp-socket-factory.h"
 #include "ns3/node-container.h"
 #include "ns3/simulator.h"
+#include "ns3tcp-socket-writer.h"
 
 using namespace ns3;
 
@@ -44,85 +45,6 @@ NS_LOG_COMPONENT_DEFINE ("Ns3SocketTest");
 // ===========================================================================
 //
 //
-//  Simple class to write data to sockets
-class SocketWriter : public Application
-{
-public:
-  SocketWriter ();
-  virtual ~SocketWriter ();
-  void Setup (Ptr<Node> node, Address peer);
-  void Connect ();
-  void Write (uint32_t numBytes);
-  void Close ();
-
-private:
-  virtual void StartApplication (void);
-  virtual void StopApplication (void);
-  Address m_peer;
-  Ptr<Node> m_node;
-  Ptr<Socket> m_socket;
-  bool m_isSetup;
-  bool m_isConnected;
-};
-
-SocketWriter::SocketWriter () : m_node (0), m_socket (0), m_isSetup (false), m_isConnected (false)
-{
-}
-
-SocketWriter::~SocketWriter ()
-{
-  m_socket = 0;
-  m_node = 0;
-}
-
-void
-SocketWriter::StartApplication ()
-{
-  m_socket = Socket::CreateSocket (m_node, TcpSocketFactory::GetTypeId ());
-  m_socket->Bind ();
-}
-
-void
-SocketWriter::StopApplication ()
-{
-}
-
-void
-SocketWriter::Setup (Ptr<Node> node, Address peer)
-{
-  m_peer = peer;
-  m_node = node;
-  m_isSetup = true;
-}
-
-void
-SocketWriter::Connect ()
-{
-  if (!m_isSetup)
-    {
-      NS_FATAL_ERROR ("Forgot to call Setup() first");
-    }
-  m_socket->Connect (m_peer);
-  m_isConnected = true;
-}
-
-void
-SocketWriter::Write (uint32_t numBytes)
-{
-  if (!m_isConnected)
-    {
-      Connect ();
-    }
-  Ptr<Packet> packet = Create<Packet> (numBytes);
-  m_socket->Send (packet);
-}
-
-void
-SocketWriter::Close ()
-{
-  m_socket->Close ();
-}
-
 class Ns3TcpSocketTestCase1 : public TestCase
 {
 public:
diff --git a/src/test/ns3tcp/ns3tcp-socket-writer.cc b/src/test/ns3tcp/ns3tcp-socket-writer.cc
new file mode 100644
index 000000000..b835a467b
--- /dev/null
+++ b/src/test/ns3tcp/ns3tcp-socket-writer.cc
@@ -0,0 +1,83 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2010 University of Washington
+ *
+ * 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
+ */
+
+#include "ns3tcp-socket-writer.h"
+#include "ns3/tcp-socket-factory.h"
+#include "ns3/packet.h"
+
+namespace ns3
+{
+
+SocketWriter::SocketWriter () : m_node (0), m_socket (0), m_isSetup (false), m_isConnected (false)
+{
+}
+
+SocketWriter::~SocketWriter ()
+{
+  m_socket = 0;
+  m_node = 0;
+}
+
+void
+SocketWriter::StartApplication ()
+{
+  m_socket = Socket::CreateSocket (m_node, TcpSocketFactory::GetTypeId ());
+  m_socket->Bind ();
+}
+
+void
+SocketWriter::StopApplication ()
+{
+}
+
+void
+SocketWriter::Setup (Ptr<Node> node, Address peer)
+{
+  m_peer = peer;
+  m_node = node;
+  m_isSetup = true;
+}
+
+void
+SocketWriter::Connect ()
+{
+  if (!m_isSetup)
+    {
+      NS_FATAL_ERROR ("Forgot to call Setup() first");
+    }
+  m_socket->Connect (m_peer);
+  m_isConnected = true;
+}
+
+void
+SocketWriter::Write (uint32_t numBytes)
+{
+  if (!m_isConnected)
+    {
+      Connect ();
+    }
+  Ptr<Packet> packet = Create<Packet> (numBytes);
+  m_socket->Send (packet);
+}
+
+void
+SocketWriter::Close ()
+{
+  m_socket->Close ();
+}
+}
diff --git a/src/test/ns3tcp/ns3tcp-socket-writer.h b/src/test/ns3tcp/ns3tcp-socket-writer.h
new file mode 100644
index 000000000..9c3083461
--- /dev/null
+++ b/src/test/ns3tcp/ns3tcp-socket-writer.h
@@ -0,0 +1,47 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2010 University of Washington
+ *
+ * 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
+ */
+
+#include "ns3/application.h"
+#include "ns3/node.h"
+#include "ns3/ptr.h"
+#include "ns3/socket.h"
+#include "ns3/address.h"
+
+namespace ns3
+{
+//  Simple class to write data to sockets
+class SocketWriter : public Application
+{
+public:
+  SocketWriter ();
+  virtual ~SocketWriter ();
+  void Setup (Ptr<Node> node, Address peer);
+  void Connect ();
+  void Write (uint32_t numBytes);
+  void Close ();
+
+private:
+  virtual void StartApplication (void);
+  virtual void StopApplication (void);
+  Address m_peer;
+  Ptr<Node> m_node;
+  Ptr<Socket> m_socket;
+  bool m_isSetup;
+  bool m_isConnected;
+};
+}
diff --git a/src/test/ns3tcp/ns3tcp.h b/src/test/ns3tcp/ns3tcp.h
index 30189c605..effaef699 100644
--- a/src/test/ns3tcp/ns3tcp.h
+++ b/src/test/ns3tcp/ns3tcp.h
@@ -4,5 +4,6 @@
  *
  * \section Ns3TcpTestsOverview ns-3 Tcp Implementation Tests Overview
  *
- * ns-3 has a TCP implemtation and we test it a litte.
+ * Includes tests of ns-3 TCP as well as tests involving the mix
+ * of ns-3 and Network Simulation Cradle (nsc) TCP models.
  */
diff --git a/src/test/ns3tcp/wscript b/src/test/ns3tcp/wscript
index 661cb3233..6f5eea428 100644
--- a/src/test/ns3tcp/wscript
+++ b/src/test/ns3tcp/wscript
@@ -10,9 +10,10 @@ def build(bld):
     headers.source = [
         'ns3tcp.h',
         ]
+    ns3tcp.source = [
+        'ns3tcp-socket-writer.cc',
+        ]
     if bld.env['NSC_ENABLED']:
-        ns3tcp.source = [
-            'ns3tcp-interop-test-suite.cc',
-            'ns3tcp-cwnd-test-suite.cc',
-            'ns3tcp-socket-test-suite.cc'
-            ]
+        ns3tcp.source.append ('ns3tcp-interop-test-suite.cc')
+        ns3tcp.source.append ('ns3tcp-cwnd-test-suite.cc')
+        ns3tcp.source.append ('ns3tcp-socket-test-suite.cc')