-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Matthew Toseland wrote: > "Every time a group of packets equivalent to the congestion window has > been successfully acknowledged one packet is added to the congestion > window (picture 1)."
This is only true in congestion avoidance mode - the behaviour in slow start mode is more aggressive and matches what you described for Dijjer. When the congestion window is less than the slow start threshold (slow start mode), the congestion window is increased by one each time a segment is acknowledged. This produces exponential growth as long as all segments are acknowledged, because in the first RTT one segment is sent and acked, in the next RTT two segments are sent and acked, etc. When the congestion window is greater than the slow start threshold (congestion avoidance mode), the congestion window is increased by one over its current size each time a segment is acknowledged. This produces linear growth as long as all segments are acknowledged: the congestion window increases by one each round trip time. The slow start threshold is calculated dynamically using the amount of data in flight and the sender's maximum segment size; RFC 2581 has the details. Cheers, Michael -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2.2 (GNU/Linux) iD8DBQFEPR11yua14OQlJ3sRAhHEAJ9nOoe7bkTQcqllpRb3z8phy4IWMACg13CJ JdVNMBA40QBX2qJaQZtZkLs= =zgG6 -----END PGP SIGNATURE-----
