--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/internet/test/tcp-hybla-test.cc	Wed Oct 28 11:28:28 2015 +0100
@@ -0,0 +1,149 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2015 Natale Patriciello, <natale.patriciello@gmail.com>
+ *
+ * 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/test.h"
+#include "ns3/log.h"
+#include "ns3/tcp-congestion-ops.h"
+#include "ns3/tcp-socket-base.h"
+#include "ns3/tcp-hybla.h"
+
+namespace ns3 {
+
+NS_LOG_COMPONENT_DEFINE ("TcpHyblaTestSuite");
+
+/**
+ * \brief Testing the congestion avoidance increment on TcpHybla
+ */
+class TcpHyblaIncrementTest : public TestCase
+{
+public:
+  TcpHyblaIncrementTest (uint32_t cWnd, uint32_t ssThresh,
+                         uint32_t segmentSize, const Time& rtt,
+                         const std::string &name);
+
+private:
+  virtual void DoRun (void);
+  void RhoUpdated (double oldVal, double newVal);
+
+  uint32_t m_cWnd;
+  uint32_t m_ssThresh;
+  uint32_t m_segmentSize;
+  Time m_rtt;
+  double m_rho;
+  Ptr<TcpSocketState> m_state;
+};
+
+TcpHyblaIncrementTest::TcpHyblaIncrementTest (uint32_t cWnd, uint32_t ssThresh,
+                                              uint32_t segmentSize, const Time &rtt,
+                                              const std::string &name)
+  : TestCase (name),
+  m_cWnd (cWnd),
+  m_ssThresh (ssThresh),
+  m_segmentSize (segmentSize),
+  m_rtt (rtt),
+  m_rho (0)
+{
+}
+
+void
+TcpHyblaIncrementTest::RhoUpdated (double oldVal, double newVal)
+{
+  m_rho = newVal;
+}
+
+void
+TcpHyblaIncrementTest::DoRun ()
+{
+  m_state = CreateObject<TcpSocketState> ();
+
+  m_state->m_cWnd = m_cWnd;
+  m_state->m_ssThresh = m_ssThresh;
+  m_state->m_segmentSize = m_segmentSize;
+
+  Ptr<TcpHybla> cong = CreateObject <TcpHybla> ();
+
+  cong->TraceConnectWithoutContext ("Rho",
+                                    MakeCallback (&TcpHyblaIncrementTest::RhoUpdated, this));
+
+  // Each received ACK weight is "coeffA". To see an increase of 1 MSS, we need
+  // to ACK at least segCwnd/coeffA ACK.
+
+  TimeValue rRtt;
+  cong->GetAttribute ("RRTT", rRtt);
+  cong->PktsAcked (m_state, 1, m_rtt);
+
+  double calcRho = std::max (m_rtt.GetSeconds () / rRtt.Get ().GetSeconds (), 1.0);
+
+  NS_TEST_ASSERT_MSG_NE (m_rho, 0,
+                         "Rho never updated by implementation");
+  NS_TEST_ASSERT_MSG_EQ_TOL (calcRho, m_rho, MilliSeconds (10),
+                         "Different rho values between implementation and test");
+
+  cong->IncreaseWindow (m_state, 1);
+
+  if (m_cWnd <= m_ssThresh)
+    {
+      // We expect an increment of 2^rho - 1, which does not go beyond ssThresh
+      double inc = std::pow (2, calcRho) - 1.0;
+      uint32_t cWndExpected = m_cWnd + (inc * m_segmentSize);
+      NS_TEST_ASSERT_MSG_LT_OR_EQ (m_state->m_cWnd.Get (), m_state->m_ssThresh.Get (),
+                                   "Congestion window has gone too far");
+      NS_TEST_ASSERT_MSG_EQ (m_state->m_cWnd.Get (), cWndExpected,
+                             "Congestion window different than expected");
+    }
+  else
+    {
+      // We expect an increment of rho^2 / cWnd
+      uint32_t segCwnd = m_cWnd / m_segmentSize;
+      double inc = std::pow (m_rho, 2) / ((double) segCwnd);
+      uint32_t cWndExpected = m_cWnd + (inc * m_segmentSize);
+
+      if (inc >= 1.0)
+        {
+          // LT because implementation does not add value less than MSS.
+          NS_TEST_ASSERT_MSG_LT_OR_EQ (m_state->m_cWnd.Get (), cWndExpected,
+                                       "Congestion window different than expected");
+        }
+    }
+
+}
+
+// -------------------------------------------------------------------
+
+static class TcpHyblaTestSuite : public TestSuite
+{
+public:
+  TcpHyblaTestSuite () : TestSuite ("tcp-hybla-test", UNIT)
+  {
+    AddTestCase (new TcpHyblaIncrementTest (1000, 0xFFFFFFFF, 500, MilliSeconds (55), "Rho=1.1, slow start"),
+                 TestCase::QUICK);
+    AddTestCase (new TcpHyblaIncrementTest (1000, 0xFFFFFFFF, 500, MilliSeconds (100), "Rho=2, slow start"),
+                 TestCase::QUICK);
+    AddTestCase (new TcpHyblaIncrementTest (1000, 0xFFFFFFFF, 500, MilliSeconds (750), "Rho=30, slow start"),
+                 TestCase::QUICK);
+    AddTestCase (new TcpHyblaIncrementTest (1000, 500, 500, Seconds (0.55), "Rho=1.1, cong avoid"),
+                 TestCase::QUICK);
+    AddTestCase (new TcpHyblaIncrementTest (1000, 500, 500, Seconds (0.1), "Rho=2, cong avoid"),
+                 TestCase::QUICK);
+    AddTestCase (new TcpHyblaIncrementTest (1000, 500, 500, Seconds (0.75), "Rho=30, cong avoid"),
+                 TestCase::QUICK);
+  }
+} g_tcpHyblaTest;
+
+} // namespace ns3

--- a/src/internet/wscript	Wed Oct 28 11:28:25 2015 +0100
+++ b/src/internet/wscript	Wed Oct 28 11:28:28 2015 +0100
@@ -240,6 +240,7 @@
         'test/tcp-fast-retr-test.cc',
         'test/tcp-rto-test.cc',
         'test/tcp-highspeed-test.cc',
+        'test/tcp-hybla-test.cc',
         'test/udp-test.cc',
         'test/ipv6-address-generator-test-suite.cc',
         'test/ipv6-dual-stack-test-suite.cc',