Event  TCP DATA SENDER                            TCP DATA RECEIVER
 _____  ____________________________________________________________
   1.   Send P0, P1, P2, P3          -->
	[P1, P2, P3 dropped by network]

   2.                                <--          Receive P0, ACK P0

   3a.  2RTTs after (2), TLP timer fires
   3b.  TLP: retransmits P3          -->

   4.                                <--         Receive P3, SACK P3

   5a.  Receive SACK for P3
   5b.  RACK: marks P1, P2 lost
   5c.  Retransmit P1, P2            -->
	[P1 retransmission dropped by network]

   6.                                <--    Receive P2, SACK P2 & P3

   7a.  RACK: marks P1 retransmission lost
   7b.  Retransmit P1                -->

   8.                                <--          Receive P1, ACK P3