diff --git a/src/internet/model/tcp-newreno.cc b/src/internet/model/tcp-newreno.cc
--- a/src/internet/model/tcp-newreno.cc
+++ b/src/internet/model/tcp-newreno.cc
@@ -128,8 +128,13 @@
       m_cWnd -= seq - m_txBuffer.HeadSequence ();
       m_cWnd += m_segmentSize;  // increase cwnd
       NS_LOG_INFO ("Partial ACK in fast recovery: cwnd set to " << m_cWnd);
+      /*
+       * Patch by Morteza Kheirkhah (m.kheirkhah@sussex.ac.uk), University of Sussex, United Kingdom.
+       * Personal webpage: http://www.uclmail.net/users/m.kheirkhah/
+       */
+      m_txBuffer.DiscardUpTo(seq); // Discard data up to but not including this sequence number.
+      DoRetransmit (); // Assume the next seq is lost. Retransmit lost packet
       TcpSocketBase::NewAck (seq); // update m_nextTxSequence and send new data if allowed by window
-      DoRetransmit (); // Assume the next seq is lost. Retransmit lost packet
       return;
     }
   else if (m_inFastRec && seq >= m_recover)