Pseudo-Code Summary for TCP Congestion Control Algorithms (in segments)


TCP Tahoe                              TCP Reno
=========                              ========

Initialization:                        Initialization:
  cwnd = 1;                              cwnd = 1;

Slow Start:                            Slow Start:
  for each new ACK received              for each new ACK received
      cwnd++;                                  cwnd++;

Congestion Avoidance:                  Congestion Avoidance:
  for each new ACK received              for each new ACK received
      cwnd += 1/cwnd;                          cwnd += 1/cwnd;

Packet Loss (3 dupACKs):               Packet Loss (3 dupACKs):
  ssthresh = cwnd/2;                     ssthresh = cwnd/2;
  cwnd = 1;                              cwnd = ssthresh;

Packet Loss (timeout):                 Packet Loss (timeout):
  ssthresh = cwnd/2;                     ssthresh = cwnd/2;
  cwnd = 1;                              cwnd = 1;


Notes:
  1 segment = MSS bytes (Maximum Segment Size) (e.g., 1460 bytes)
  W = min(W_s, W_r, cwnd)