--- a/src/internet/model/tcp-socket-base.cc	Tue Nov 10 09:42:46 2015 -0800
+++ a/src/internet/model/tcp-socket-base.cc	Wed Nov 11 20:34:14 2015 -0800
@@ -783,8 +783,7 @@ 
         { // Try to send the data out
           if (!m_sendPendingDataEvent.IsRunning ())
             {
-              m_sendPendingDataEvent = Simulator::Schedule (TimeStep (1),
-                                                            &TcpSocketBase::SendPendingData,
+              m_sendPendingDataEvent = Simulator::ScheduleNow (&TcpSocketBase::SendPendingData,
                                                             this, m_connected);
             }
         }
@@ -1243,8 +1242,7 @@ 
       // Try to send more data, since window has been updated
       if (!m_sendPendingDataEvent.IsRunning ())
         {
-          m_sendPendingDataEvent = Simulator::Schedule (TimeStep (1),
-                                                        &TcpSocketBase::SendPendingData,
+          m_sendPendingDataEvent = Simulator::ScheduleNow (&TcpSocketBase::SendPendingData,
                                                         this, m_connected);
         }
     }
@@ -1553,8 +1551,7 @@ 
       // Try to send more data
       if (!m_sendPendingDataEvent.IsRunning ())
         {
-          m_sendPendingDataEvent = Simulator::Schedule (TimeStep (1),
-                                                        &TcpSocketBase::SendPendingData,
+          m_sendPendingDataEvent = Simulator::ScheduleNow (&TcpSocketBase::SendPendingData,
                                                         this, m_connected);
         }
     }