The note describes the validation testsin test-suite-sack.tcl.SACK1 and SACK1Z:The test "sack1" shows Fast Recovery with SACK when a single packetis dropped.  Note the burst of packets when the ACK for packet 26is received at time 2.6.  Test "sack1z" shows the same test withmaxburst_ set to 4 packets.SACK1A and SACK1AA:Test "sack1a" shows Fast Recovery with SACK when three packets aredropped from a window of data.  Notice the burst of packets at time1.65.  Test ""sack1aa" shows the same test with maxburst_ set to4 packets.SACK1B and SACK1C:Test "sack1b" shows Fast Recovery with SACK when many packets aredropped from a window of data.  Test "sack1c" is a variant of test"sack1b" in that is shows correct behavior when the last packetsent before a Fast Retransmit is dropped.SACK3:Test "sack3" shows, for the bottom connection, a Fast Recovery withSACK when packets are dropped from a connection with a smallcongestion window.SACK5 and SACK5A: Test "sack5" shows the burst of packets from the bottom connectionsent at time 3.5.  Explain!!  For the top connection, this testshows the behavior when half the packets are dropped from a largewindow of data.  Test ""sack5a" shows the same test with maxburst_set to 4 packets.SACKB2:Both connections in this test show show a Fast Retransmit, followedby a retransmit timeout for a retransmitted packet that is itselfdropped.  Because the bottom connection's congestion window isrelatively large when the initial Fast Retransmit occurs, it beginsthe retransmit timeout with a reasonably large value for ssthresh,and recovers fairly quickly.  Because the top connection's congestionwindow is small when the initial Fast Retransmit occurs, it beginsthe retransmit timeout with a smaller value for ssthresh, andrecovers more slowly.SACKB4 and SACKB4A:Test "sackB4" shows the burstiness when SACK TCP recovers fromtwo packets dropped early in a large window of data.Test "sackB4a" shows the same test when "maxburst_" is set tofour packets.FALSEPIPE:Test "FalsePipe" shows that, during fast recovery, the pipe_ valueused by SACK can be over-estimated if partial ACKs are trigered by packet reordering instead of by packet loss.DELAYEDSACK:The "delayedSack" test from the v1 test suite should be included.TIMERSSACK:The test "timersSack" needs to be checked.PHASE:The phase tests were deleted as unnecessary to the validation test.