TCP Congestion Control Mechanisms | a detailed overview!

  • Routers are capable of reordering or dropping data packets when received rates reach critical levels
  • Flow control mechanisms that respond appropriately when data flow rates reach critical levels

Because TCP uses acknowledgments to trigger (or clock) its increase in congestion window size, TCP is said to be self-clocking.

  • A lost segment implies congestion, and hence, the TCP sender’s rate should be decreased when a segment is lost.
  • An acknowledged segment indicates that the network is delivering the sender’s segments to the receiver, and hence, the sender’s rate can be increased when an ACK arrives for a previously unacknowledged segment.
Slow start Mechanisms (figure 1)
AIMD mechanism (figure 2)



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