These tests show the basic behavior of TCP: Slow Start and Congestion avoidance.

• When congestion window is less than slow start threshold, cwnd =< sstthresh, one packet increment is added to congestion window for each new ACK.
• When congestion window is greater than slow start threshold, congestion avoidance is performed. Congestion window will increase by one packet roughly per one round-trip time. However, the usable window is min(cwnd, rwnd), and in this demo the usable window becomes rwnd-limited before the Congestion Avoidance is entered.

Test Topology

  Client..................................Server

                   800kbs 100ms
   0(0)-----------------------------------1(0)
                                            |
                                          tcpdump

SSF Configuration Test File: basic1.dml

send window = receive window = 14 packets

SSF Tcpdump File: basic1.tcpdump